Darkroom Tour

While testing my recently acquired Hasselblad 501CM, I shot some pictures of my darkroom using the 40mm lens. The shots were hand held on TMax 100, so the depth of field was not great due to wide aperture, but it was as good a subject as any for test shots. This article simply puts those shots to use by explaining my darkroom setup. I like looking at pictures of other people’s darkrooms and I suspect I’m probably not alone. Darkrooms used to be so common that they were simply taken for granted. Now, being so rare, they seem to be more interesting. People who own classic cars like looking at pictures of other people’s classic cars, right? For me, my darkroom is like a time machine taking me back to the 1960s and 70s.

Below are the three pictures to which I have added numbers. Below the pictures I describe what the arrows are pointing to. Everyone with a darkroom arranges it to suit their preferences, so I am not presenting this as any kind of recommendation. The image files are about 3.5MB. If you click on them, they should open in your browser to full size, so you can zoom in. Note that many of the same items are identified in both pictures 2 and 3. The room measures 10′ x 12′ with the countertops running along the longer dimension. I should also note that the countertops are 30″ deep instead of the typical 25″ depth found in most kitchens. Since they are low cost and fabricated to order, you can specify the depth. The 30″ depth is needed for larger developing trays. The downside is that selenium toner stains laminate tops, but I’ve recently discovered a remedy for that!

My Darkroom, Picture 1: The “wet” side.

Picture 1 Legend

  1. Paper developing working solutions. Stored in 1 gallon large mouth bottles so I can pour chemicals back into the bottles from the trays without the need for a funnel. No funnel, means you can pour very fast, especially useful for single tray developing which I do for 16″x20″ and 20″x24″ size prints. Items 2 – 6 below all refer to these print developing chemicals.
  2. D-72 developer. I track developer usage with hash marks on the label. I mix my own D-72 by the gallon in a 1+1 dilution ever since Kodak transferred its photo chemical product line to a UK company and the Dektol that I had used for decades mixed up looking like frothy coffee. I now mostly steer clear of Kodak branded chemicals and use any product labeled “New Formula” for target practice at the local shooting range.
  3. Indicator Stop Bath. I use it until it starts to turn color.
  4. Rapid Fixer. I use two rapid mixing baths (no hardener). I track the usage with hash marks on the label. I think this method is described on the data sheets for both Kodak and Ilford rapid fixers.
  5. Hypo Clearing Agent. I use it only when printing on FB paper and mix it up fresh before a session. I use the first HCA after fixing and the second HCA after toning. Since I’ve only been printing 8×10 FB prints lately, I only mix up a liter for each.
  6. Selenium Toner. I use it at a nominal dilution of 1:20. Aside from when I first mix it up, I never know exactly what the dilution is because I replenish it as I use it based on its effect and smell. I find that adding 2 ml per 8×10 is a good baseline. I used to only tone FB prints as part of my standard archival processing routine but now I tone all RC and FB prints because the deeper blacks make the prints look better.
  7. Two 1 gallon jugs of tap water. I keep tap water handy at room temperature for rinsing film between developer and fixer. It’s just easier (I am one lazy mofo) than checking the temp of the water coming from the tap which can be too cold in winter and too warm in summer. The temperature of my darkroom is 71F year round, so all the chemicals are also 71F.
  8. Paper developer timer. I like this timer, but I also modified it with automotive glass tinting film to reduce the brightness and orange filter material just to make it more darkroom friendly than it already was. I only use it with the safelights on, so it doesn’t have to be very bright.
  9. 12″x16″ Paterson trays. I would prefer 11×14 trays for 8×10 prints, but Paterson doesn’t make that size and I like these trays because of the well designed pour spout in the corner which allows me to pour the chemicals back into their respective large-mouth bottles very quickly without making a mess. For larger prints, I also have the 16×20 and 20×24 version of these trays, also because of the pour spout. On some trays (Yankee comes to mind), the pour spout is terrible. I’m guessing the designer has never poured any liquid out of the tray he designed, just like the guy who made the design improvements to the Yankee bullet-shaped safelights never had to actually use them.
  10. Metal Tongs. These are good tongs. They stay springy and don’t damage prints. Like everything that I worry will someday go out of production, I have extras.
  11. Film chemicals. These are almost all film developers that have been decanted into smaller containers. I have some Ilfotec HC from 2013 which still works like new. I don’t really use it for anything, but I test it every now and then just because I’m curious which of us will outlive the other.
  12. Raw chemicals. I don’t use them very often, but when I find something I might want to try, I’ll often buy the chemicals so I’ll have them in case I ever do. I have experimented with several film and paper developing formulas as well as bleaches and toners.
  13. Liquid measuring devices. Graduated cylinders, measuring cups, funnels, spoons, eye droppers, syringes, etc. Measuring containers suffer from the same design flaws as trays in that the pour spout often allows the liquid to run down the outside of the cup. I’m fully aware that I may be the only darkroom owner on the planet who obsesses over little shit lie this.
  14. Print bleaching board. This panel swings down to an incline over the sink for bleaching prints. It has a laminate surface and aluminum edging. It also has a little sign that reads, “CAUTION! This board is heavy! It will hurt a lot if it falls on your head!”
  15. Premier 8″x10″ amber “OC” safelight. This is from back in the days when you could still buy high quality OC safelights brandy spankin’ new. I use OC safelight when I am printing pictures.
  16. Premier 5″x7″ red safelight. Red safelights are still available new. I use red safelights for developing otho litho sheet film for contrast masks. Why would they stop making OC safelights and keep making red safelights? I suspect it was yet another decision made by someone who’s never seen the inside of a darkroom.
  17. Articulated desk lamp. This was originally intended for use with the bleaching board, but it’s become the light I use now whenever I’m too lazy to walk all the way over to the wall switch to turn on the overhead lights.
  18. Room thermometer. This tells me whether the darkroom is 71F or 72F which seems to be the total temperature variance of the room. Kudos to whoever designed central heating and cooling. We have three heat pumps in my house. No one is allowed to change the setting on the one that controls the darkroom. NO ONE!
  19. Cordless telephone. I added little black flaps to this phone that cover the buttons and display screen so it doesn’t emit any light if someone calls unless I flip up the flap to see what robocaller is bothering me this time.
  20. Fixer timer. This timer is also modified using automotive window tinting film to make it dimmer. The time is set to either 30 or 60 seconds depending on whether I’m printing on RC or FB paper. It has a power switch but the display turns off by itself after a few minutes, so I leave it powered on all the time. That way it remembers the time so I don’t have to set it. I have lazy down to a science. Fixer gets its own timer because, with the two bath method, I have to use it twice for each print. Haha! Just kidding. I’d still have a dedicated fixer timer even if I used only one fixing bath.
My Darkroom, Picture 2: The “dry” side from the north.

Picture 2 Legend

  1. Omega 4″x 5″ Chromega enlarger. This has the tall column which, like the table it is mounted to, is bolted to the wall for stability. This part of the house has a slab foundation, so it’s pretty rigid. I’ve had this enlarger since the 1990s and have done B&W and Cibachrome printing with it.
  2. Dodging wands. I often make custom dodging and burning tools on the fly for a specific image. I label them with the negative number and print size and store them in a draw where I never use them again because who wants to look through a draw with hundreds of poster board shapes when it’s easier to just make a new one?
  3. RH Designs Stop Clock Timer. For Chromega enlarger. Maybe the most thoughtfully designed darkroom timer ever made. When I first bought it, I thought it was expensive. Now I think, considering how well designed it is, I consider it a bargain.
  4. RH Designs Zonemaster II. For Chromega enlarger. I could say the same for the Zoenmaster as I did for the Stop Clock. Both devices reduce trial and error attempts to get a perfect print. They will make your prints better because they will get you to a nicely exposed print before you get frustrated and settle for something less than perfect. Side benefits are that they will also make you easier to live with and reduce your use of profanity.
  5. Dahle 552 20″ paper trimmer. This comes in handy for cutting large photo paper down into smaller sizes from which test strips can be cut. I bought a smaller 12″ guillotine-style cutter on ebay strictly for cutting 2″ x 5″ test strips which are usually fine for printing 8x10s. For larger prints, I may do test strips in multiple places in the image space to sample all the important tones.
  6. Enlarger selection switch. Since I have two enlargers (diffusion and condenser), I also have two timers, each of which automatically shuts off the safelights during focusing or exposure. This switch simply connects the safelights to whichever timer I’m using.
  7. Stop Clock Timer. For Condenser enlarger. See item 3 above for description.
  8. Refridgerator. I use this mostly for film, but I also refrigerate Xtol type developer in 16 oz glass bottles. I’ve found that the developer has a longer shelf life if kept cold. Since this fridge has no freezer, I never have to defrost it. Defrosting is an objectionable task for people with stage 4 laziness such as myself.
  9. Enlarger bases. These are removable table tops associated with the Condenser enlarger. Since the ceiling limits the height to which I can raise the enlarger head, I can effectively lower the base by removing upper level tabletop(s) and placing the easel on a lower level. Generally, the only time I do this for extreme cropping. I can project all the way down to the floor.
  10. 16″x20″ Saunders 4-blade easel. This is their conventional (not the V-Track) easel. For the occasional 20″x24″ print, I have a home built easel without adjustable blades.
  11. Zonemaster Meter. For Condenser enlarger. See item 4 above for description.
  12. Door mounted exhaust fans. You can only see one in this picture, but I have two 8″ fans mounted on Doran light tight vents on the door. They just blow air out of the darkroom into the adjoining “frame shop”. Yeah, I probably wouldn’t be the first person anyone would hire to design a safe biochemical research facility, but aren’t toxic fumes part of the charm of chemical based hobbies?
  13. Omega 4″x 5″ DV condenser enlarger. This enlarger has the short column. The base is mounted in a slightly elevated position on a wall mounted shelf/bracket with a wall mounted top brace. When raised to the top, the lamp house just touches the ceiling and I have to stand on a step ladder to swap out the 6×6 contrast filters. One of the main reasons I have been using this enlarger for recent work is because I like having contrast filters above the negative.
  14. Yankee Bullet-shaped safelight. This safelight, as purchased new, is unusable for anyone able to recognize that a translucent white plastic enclosure for a safelight is a bad idea. But, it can be modified to work.
  15. Pre-flashing lamp. This is just a coffee can with an incandescent nightlight bulb mounted inside and a small filter frame on the open end facing down. The filter frame holds a #00 Ilford contrast filter and a UV filter from a Cibachrome color filter set. Pre-flashing a sheet of phot paper simply raises the sensitivity of the paper so that less additional light light is needed to create a very light gray tone. This tends to alter the foot of the paper sensitivity curve such that highlights can be more easily printed without washing out to pure white. I do this quite often when I want to maintain contrast in the mid tones while still having some detail in bright highlights. The secret is to always keep the pre-flash exposure time short enough so that it doesn’t, by itself, fog the paper. I control the exposure with the timer described in item 22 below.
  16. Premier 5″x 7″ amber OC safelight. I added this safelight when I started using the condenser enlarge became my primary printing station. That corner was quite dark and it’s difficult to shade a test strip for multiple exposures when you can’t see it. Later I added another safelight (item 14 above) to make it even easier to see. Despite having two safelights pointing down at the easel, it is still not very bright. I tend to err on the dim side for darkroom lighting.
  17. Speakers (only one is visible). I have speakers for the sound system (item 20 below) mounted above the door at each corner of the door frame. I have an identical pair of speakers mounted above the door in the same place except facing out into the frame shop. They are wired so the left and right stereo channels don’t change sides when I walk out into the frame shop from the darkroom.
  18. Premier 5″x7″ red safelight. Red safelights are still available new. I use red safelights when exposing and developing otho litho sheet film to make contrast masks. They are not controlled by teh enlarger timer and, therefore, not turned off contrast mask exposures. The red safelights are off when I’m doing normal printing.
  19. Premier 8″x10″ amber “OC” safelight. Last time I tried to by one of these, I couldn’t find them available new. I use OC safelight when I am printing pictures.
  20. Sounds system. This is an old 5.1 home theater sound system that I use to play music or podcasts from my little mp3 player or from my tablet. I use it in stereo mod, with the left and right channel each having two speakers wired in parallel. One pair of speakers is in the darkroom and the other pair are in the adjacent frame shop. You can see that the subwoofer is also in the darkroom. For podcasts I tend to use a bluetooth headset since my hearing isn’t that great anymore.
  21. Safelight power strip. All the orange safelights in the darkroom are controlled by whichever Stop Clock timer is in use. To be accurate, the enlarging meter (item 4 above) require that all the safelights be turned off when making exposure measurements. Power to these outlets is supplied from the enlarger selection switch (item 6 above).
  22. Pre-fash exposure timer. This is a GraLab model 300 timer. I keep the face of it covered with black poster board when I’m not using it because the green glow-in-the-dark dial seems very bright when it’s “charged up” by the white room lights. It controls the pre-flash lamp (item 15 above). I do pre-flashing often, so a dedicated lamp and timer are warranted.
My Darkroom, Picture 3: The “dry” side from the south.

Picture 3 Legend

  1. Large liquid measuring devices. These include taller items like graduated cylinders and measuring cups up to 5 liters. I also have a water spray bottle up there for wetting the paper take that I use to tape wet FB prints to glass to dry.
  2. Glass chemical storage bottles. These are new unused glass bottles that are used to decant developer concentrates and working solutions so that most of my chemicals are in full tightly capped bottles to ensure a long shelf life. I also use plastic (PET and LDPE) bottles, but in my experience, glass is a much better oxygen barrier.
  3. Black foamcore. I put this up to reduce white light from the easel being reflected back down from the ceiling. I did it on a whim without any reason to believe it was actually even a real problem. Since I started using Zonemaster meter, I am confident that that light scatter is not a significant issue in my darkroom.
  4. Yankee Bullet-shaped safelight. This safelight, as purchased new, is unusable for anyone able to recognize that a translucent white plastic enclosure for a safelight is a bad idea. But, it can be modified to work.
  5. Room thermometer. This tells me whether the darkroom is 71F or 72F which seems to be the total temperature variance of the room. Kudos to whoever designed central heating and cooling. We have three heat pumps in my house. No one is allowed to change the setting on the one that controls the darkroom. NO ONE!
  6. Cordless telephone. I added little black flaps to this phone that cover the buttons and display screen so it doesn’t emit any light if someone calls unless I flip up the flap to see what robocaller is bothering me this time.
  7. Grabber/Reacher and fly swatter. The grabber is to reach items on high shelves. The shelves go up to the ceiling in the darkroom and I’m only 5’8″ tall. The fly swatter is because I live in Alabama and apparently a lot of flies also live here. Flies are not welcome in my darkroom (or anywhere else in my house).
  8. Omega 4″x 5″ Chromega enlarger. This has the tall column which, like the table it is mounted to, is bolted to the wall for stability. This part of the house has a slab foundation, so it’s pretty rigid. I’ve had this enlarger since the 1990s and have done B&W and Cibachrome printing with it.
  9. Metal rulers. These are various lengths (12″, 18″, 24″, 48″) and are used as general purpose straight edges. One of them is a thick aluminum straight edge for cutting glass.
  10. My old paper safe. This is just a wood box with shelves inside. The inside is black. I’ve used this as a paper safe for decades and can honestly say that it is a really crappy paper safe. I have since built a new paper safe.
  11. Borderless easels and plexiglas sheets. I can’t remember the last time I used a borderless easel. I used the plexiglas sheets to cover stop bath and fixer trays when I take a break from printing that I expect to last for more than a half hour or so. I cover the developer tray by floating an identical tray on top of the developer surface like a floating lid, which prevents oxidation. I also cover my fixer tray when I tone prints which I do immediate after I print each picture. It eliminates the possibility of toner splashing into the fixer which is something I try to avoid for reasons I can no longer remember. I never leave chemicals in the trays over night.
  12. My new paper safe. This consists of two drawers, one above the other. Best paper safe I’ve ever had.
  13. RH Designs Stop Clock Timer. For Chromega enlarger. Maybe the most thoughtfully designed darkroom timer ever made. When I first bought it, I thought it was expensive. Now I think, considering how well designed it is, I consider it a bargain.
  14. Dahle 552 20″ paper trimmer. This comes in handy for cutting large photo paper down into smaller sizes from which test strips can be cut. I bought a smaller 12″ guillotine-style cutter on ebay strictly for cutting 2″ x 5″ test strips which are usually fine for printing 8x10s. For larger prints, I may do test strips in multiple places in the image space to sample all the important tones.
  15. Enlarger base. The upper table top for the Chromega (diffusion) enlarger is removable. By removing the table top and placing the easel on a lower level I can do more extreme cropping when it’s called for.
  16. Step stool and kneepad. The 6″ step stool is handy for reaching high shelves while the kneepad is for when I’m using the lower tables (or the floor) for printing. To look through a grain focuser when the printing easel is only a few inches off the floor I have to be kneeling on a very hard floor.
  17. Dish drying rack (barely visible). It where I place bottles, tanks, reels, and measuring cups to dry after they’re washed.
  18. Refridgerator. I use this mostly for film, but I also refrigerate Xtol type developer in 16 oz glass bottles. I’ve found that the developer has a longer shelf life if kept cold. Since this fridge has no freezer, I never have to defrost it. Defrosting is an objectionable task for people with stage 4 laziness such as myself.
  19. RH Designs Zonemaster II. For Chromega enlarger. I could say the same for the Zoenmaster as I did for the Stop Clock. Both devices reduce trial and error attempts to get a perfect print. They will make your prints better because they will get you to a nicely exposed print before you get frustrated and settle for something less than perfect. Side benefits are that they will also make you easier to live with and reduce your use of profanity.
  20. Enlarger selection switch. Since I have two enlargers (diffusion and condenser), I also have two timers, each of which automatically shuts off the safelights during focusing or exposure. This switch simply connects the safelights to whichever timer I’m using.
  21. Pre-fash exposure timer. This is a GraLab model 300 timer. I keep the face of it covered with black poster board when I’m not using it because the green glow-in-the-dark dial seems very bright when it’s “charged up” by the white room lights. It controls the pre-flash lamp (item 15 above). I do pre-flashing often, so a dedicated lamp and timer are warranted.
  22. Various small scales. These are used for weighing small amounts of dry chemicals for mixing various photo chemicals (developers, toners, bleaches, etc.). Some have a resolution of 0.01 g and others read in increments of 0.1 g. On the very top shelf there is a larger scale for weighing up to 50 lbs.
  23. Enlarger alignment thingamabob. This is a little 3D printed device to which a standard rail-mounted laser sight is attached. By placing on the easel under your enlarger, you can adjust the lens and negative carriers to perfectly parallel to the plane of the easel. The laser beam is precisely perpendicular to the easel and you can tell when the lens board and negative carrier are parallel when the laser beam is reflected back down into the laser projector.

Never Ending Enlarger Re-Alignment

Most articles that talk about enlarger alignment tell you how to do it, but don’t explain how it can be a never ending battle.  For me and my two Omega D5s, the mechanisms that throw my enlarger out of alignment are drop-away baseboard tabletops and different negative carriers.

Baseboard Alignment Error

My enlarger is bolted to the wall and the table is mounted below it.  To make larger prints or for more extreme cropping, I can remove the upper tabletop and project down to a lower table top.  I can also remove the lower tabletop and project all the way to the floor.

Removable Tabletops (projection surfaces)

Both of my enlargers are configured similarly.  The tabletops are 3/4″ plywood supported on three or four sides and they are not perfectly parallel, although they are close.  For most routine printing, they don’t introduce enough error to worry about, but when I am being very critical and exposing at wide apertures to avoid diffraction issues, I will align the enlarger for the specific configuration in use.

Negative Carrier Alignment Error

Omega has two main types of negative carrier.  First is the two-piece sandwich and second is the spring loaded Raid Shift carrier.

Rapid Shift (top row) and sandwich style (bottom row)

Each of these carriers can be further divided into glass and glassless.  I use glass carriers exclusively.  In theory, when the Omega lamp house is lowered onto these carriers, they are compressed perfectly flat eliminating any chance of injecting alignment error.  The reality is different. I align my enlargers using a laser alignment tool.  Once I have the enlarger aligned for one carrier, I would expect all my other carriers to behave the same.  They do not.  The rivets in these carriers warp the metal slightly.  The spring tabs at the rear of the Rapid Shift carriers are also cable of preventing the two haves from lying perfectly flat.

Finally, the glass thickness may not be precisely correct for the film thickness, causing a slight bowing of the carrier when the lamphouse is lowered onto it.  My carriers have a mix of original equipment clear and anti-Newton glass from Omega, Focal Point, and some that came installed in carriers purchased from ebay.

What I have found is that my laser alignment tool shows that aligning with one carrier, does not always mean all carriers will be in alignment.  Furthermore, lowering the lamphouse onto the carrier may also also alter the alignment.  Granted, the shift is not great, but it is enough to shake my confidence that I will get corner-to-corner sharpness in a large print at wide apertures.  Large, for me, is 16″ x 20″ or 20″ x 24″.

While there is no easy fix to this dilemma, anyone who uses a view camera knows that lens adjustments (swings and tilts) can be used to match a plane of focus to a non-parallel film plane using the Scheimpflug Principle.  Stated another way, the lens plane can be adjusted to accommodate any errors in alignment between the enlarger film plane and the easel.  Besseler did exactly that when they offered a lens board called a Bes-Align.  It has three adjustment screws to allow an enlarger lens position to be adjusted in a way that can be used to accommodate a misalignment between film and easel.

Bes-Align

The adjustable lens board can be used in conjunction with a Micromega or Peak grain focuser to tweak the lens plane as required to ensure the corners the image projected onto the easel are in focus.  It provides a quick way to fine tune enlarger alignment to compensate for errors introduced by different negative holders or baseboard (table top) configurations.

I made a version of the Bes-Align to fit an Omega D5 years ago.  I simply attached a lens mounting plate to an Omega lens board using three machine screws with an 3/16 inch layer of black foam between the plate and the lens board.  The foam serves as a light seal and as a spring to act against the three adjustment screws.

My copy of the Besseler Bes-Align adjustable lens board to fit an Omega D5 enlarger.

My copy of the Be-Align was functional, but I wanted something deeper that would accommodate the rear extension of my El-Nikkor lenses, so I decided to add a spacer and make it more rigid with actual springs rather than relying on the resilience of the foam rubber spacer.

Improvements included springs and a 1/4″ spacer.

I drilled out the threaded holes in the original design lens board in favor of threading new holes in the much thicker spacer.

The adjustment range of the new design will permit perspective control on architectural pictures.

I found cheap springs at the local home improvement store and cut them to length with a Dremel tool.

The springs are fairly stiff and the adjustment screws go most of the way through the 1/4″ space making the assembly quite rigid.

 

The hole in the stock Omega lens board is considerably larger than the lens mounting hole.

The rear of the lens extends up into the gap between the lens mounting plate and the Omega lens board.

I used soft black foam shelf liner material to seal against leaks. I cut the strips, roughed up the glue surfaces with sand paper, and then epoxied them to the edges of the 1/4″ spacer.

Fitting the light seal strips before actually gluing them.

I sanded, primed, and painted the pieces to further reduce light leakage and reflections. I did not paint the surfaces that were to be glued.

Spring placement and final assembly of the pieces.

As you can see, I ultimately settled on using Phillips head adjustment screws. I tested the 40 mm lens first to make sure the lens wasn’t too far away from the film plane to focus.

This shows how far back the lens extends toward the rear, but I will easily be able to slide the lens board out of the enlarger without having to unscrew the lens.

The 150 mm lens is the heaviest of my lenses, but will be held securely enough to keep it from moving when I change aperture settings.

The final product installed on the enlarger with my under-lens filter holder positioned under it.

DIY Omega D5 Focus Extension Lever

Have you ever made a big enlargement where the enlarger head was so far above the base board it was impossible or too awkward to reach the enlarger focusing knob while looking through the grain focuser?  I have and decided to find a way to make it easier.

Can’t reach focus knob while looking through grain focuser

There are a few solutions to this problem.  Omega made a flexible focusing shaft (P/N 464-055) which can still be found on line.  Saunders/LPL made a generic flexible focus extension that is apparently no longer available.  KHB Photografix sells a version deigned for use with the Omega Micromega Fine Focus Control and another version that works with the main focus control.

Being a penny pincher, I wondered if there might be a cheaper way that didn’t challenge my lazy lifestyle too much.  What I came up with was a simple lever that extends down from the focusing shaft.  The procedure is to set up the enlarger as I normally would to make a large (or heavily cropped) print, focus as I normally do, but then simply replace the focusing knob for the long lever to do the critical focusing with the grain focuser.

The materials to build the lever are below.  Dimensions should be adjusted to meet your own requirements.

  1. Pine wood strip 3/16″ thick x 1-1/4″ wide x 27″ long.
  2. Aluminum rod 3/8″ in diameter x 7″ long.
  3. #10-24 machine screw and washer.
  4. 3/8″ shaft coupler (available on Amazon)

The wood strip needs to be light, but rigid.  The length of the aluminum rod should be long enough to keep the lever out of the image area.  The shaft is attached to the end of the wood by drilling the appropriate hole in the end of the shaft and tapping the hole to accommodate the machine screw.  I had a #10-24 tap handy, so I drilled a 5/32″ hole and threaded the hole to accommodate the length of the screw.

The ruler is just for scale. Note the small piece of sandpaper at the hole on the left end of the wood.

Painted black and assembled.

Small piece of sandpaper glued to wood ensures the rod won’t rotate.

Allen wrench sizes are 5/64″ for the knob and 3/32″ for the coupling.

I couldn’t reach the focusing knob, but can easily reach the lever for critical focus.

The lever extends down where I can easily reach it.  “Easily” is a relative term. Since I will be on my knees to look through the grain focuser, it is not as comfortable as when I’m standing up.  I don’t think the flexible shaft focuser would be much better.

The secret is to hang the lever on the focusing shaft so it is vertical before tightening the set screw.  The lever is then moved to effect a small rotation of the focusing knob, making it easy to fine tune the focusing.  If you did a reasonable job eye-balling the focus during setup, the fine adjustment is very small.The light weight of the lever is not enough to turn the focusing knob by its own weight, so once you adjust it, it stays put.  I also found it to be a simple matter to remove the coupling from the shaft without corrupting the focus.

The lever is light, so it will not rotate the focusing shift by its own weight.

I did not tighten the friction tension on the focusing shaft for this project, nor do I consider the focus particularly stiff on my two D5s, but even if you have your focus set to be more loose, the lever will likely never be at much of an angle from its initial vertical position, so the torque will be very tiny.

Adding fans to Omega DV Condenser Lamp House

Bcakground

In my last article, I conducted some temperature tests using the 250W PH213 lamp in the Omega DV Condenser lamphouse.  Omega offered a blower for the DV lamphouse that permitted use of 250W bulb. The Omega part number is 412-020.  I’ve never seen one, but it is listed on the KBH Photografix website.

As expected, with no blower, the 250W bulb generated considerably more heat than the 150W bulb, exceeding 200 F between the bulb and heat absorbing glass.  This article describes my adventures in adding a pair of small fans to the lamphouse to try and reduce the heat buildup from the higher wattage bulb.

Construction

The first step was to remove the plastic covers on each side of the lamphouse.  These covers permit air to flow into the sides of the lamphouse and exit through an opening in the top, cooling by convection.  The bulb is completely enclosed within an inner chamber preventing any light leakage through these ventilation openings.  For this project I decided to attach a 12 VDC 60mm low speed computer fan (Noctua NF-A6x25 FLX) available from Amazon to each side of the lamphouse, both blowing air inwards.   The low speed will minimize noise and vibration and the speed can be controlled by simply reducing supply voltage (or adding resistance in series with the power).  The down side is that a small fan running at low speed doesn’t move a lot of air.

Noctua NF-A6x25 FLX 60mm Fan

To attach the fans, I designed a mounting plate that can be attached to the lamphouse using the existing threaded holes previously used to attach the plastic covers.  Since the #6-32 threading in those holes does not extend very deep into the holes, I used the original self-threading screws to deepen the threads.  I simply worked the screws in and out, each time going slightly deeper.  My #6-32 tap has a pretty long taper and I was afraid it would bottom out sooner than the screws.

Fan Mounting Plate (dimensions approximate)

I cut the plates out of some 0.092″ thick scrap aluminum I had lying around and started marking and drilling.  As you can tell, I am much more inclined toward functionality than prettiness.  Also, I’m kind of lazy and have a short attention span, so I needed to keep the project within the limited range of my mechanical skills.

Cut scrap aluminum to size and started drilling.

To cut the fan hole, I screwed the plate to a piece of wood so I could rotate it around as I cut it with my jig saw (aka sabre saw).

Jig to cut the main hole in the plate. (the 2 holes at the bottom do not need to be countersunk).

As you can see, the hole placement does not lend itself to easy assembly.  I wanted to mount the fan to the plate and then mount the plate to the lamphouse.  Unfortunately, two of the screws that mount the plate to the lamphouse are under the fan.  The problem solved itself, however, because the upper two screw holes were bisected by the fan cutout.  I installed those two screws into the lamphouse and simply slid the fan plate (with the fan installed) down under them.  Then I simply installed the two lower screws.  Note that I countersunk all four holes, but the countersinking is only needed for the top two screws which are trapped under the fan.

Hook the plate under the upper two screws (already installed) and then install the lower two.

Fan plate with fan attached (this is actually the second fan plate).

I got a variable 3- 12 VDC fan power supply from Amazon to power the fans, but left the task of dressing up the wires until after doing the testing.  Ultimately, the fans were wired together and the wire routed along side the main lamphouse power cord so as to be out of the way.

Results

Test setup.  Thermocouple placement was identical before and after fans.

The “Before Fan tests” were conducted with the original plastic covers still in place before work started on the fans.  The thermocouple was then left undisturbed as I added the fans so as to ensure no other variables were introduced in the test results.  I have heat absorbing glass installed in the top slot of the variable condenser housing.  The thermocouple was centered in the middle of the heat glass and suspended 0.500″ above the surface and 0.700″ below the bulb.  I measured this before the fans were added and after the fans were added to make sure nothing changed.  Experiments are worthless if the conditions of the test are inadvertently altered during the test.  The variable speed controller was set to maximum output (12 VDC) for all of the tests with the fans.

The results are tabulated below.  The results with no fans are the same measurement collected for my previous article.  I started each test with the temperature stabilized at room temperature.  I had the lamp turned on for 120 seconds and then turned off for 120 seconds.  Temperature readings were made at 30 second intervals on the ramp up and on the cool down.

Temperature comparison with fans and without fans.

While the fans certainly do reduce the temperatures, I was hoping for better than this.  My goal was to keep the temperature range for the fan cooled 250W bulb more in line with the temperatures generated by the convection cooled 150W bulb.  That was overly optimistic given the fact that the airflow never actually touches the bulb which is enclosed in its own chamber.  On the bright side, the cool down time is definitely accelerated by the fans.  After the 250W lamp has been off for the 2 minute cool-down, the temperature (111.2 F) is very close to that of the 150W bulb with no fans (109.4 F).

For those who are wondering, I did run one test to see if the cooling performance was different if one fan was flipped to blow out instead of inwards.  The performance was measurably worse, so I reverted to having both fans blowing inwards.

Noise

I measured the acoustic noise of the modified condenser lamphouse against the noise generated by the fan in my Chromega with the noise meter 10″ in front of the respective enlarger heads.  As you have probably guessed, the reason for the noise test is to get an idea of whether the fans could induce vibration that diminishes print sharpness.  The heads on these enlargers are massive compared to the mass of the spinning fan blades, so the risk is presumably quite small.

  • Modified Omega DV Condenser Lamphouse:  43.5 – 44.5 dBA
  • Standard Chromega Lamphouse:  46.5 – 47.5 dBA
  • Ambient Noise Floor:  38 – 40 dBA

For the hell of it, I listened to each of them using a stethoscope and the Chromega was noticeably louder.

But What About Temperatures at Negative Plane

Measuring the temperature at the negative plane with the 250W bulb and starting at 23 C (73.4 F) ambient, I got a thermocouple reading of 27 C (80.6 F) after the lamp had been on for 120 seconds.  With the 150W bulb, the reading was 25 C (77 F) after 120 seconds.  While not hot enough to damage the negative, this may be enough to cause the negative to “pop” out of focus.  This is of little concern to me since I use glass carriers.

I use heat absorbing glass (Omega p/n 473-103) in my condenser enlarger and I don’t have any test results without having the glass installed in the uppermost shelf in the variable condenser housing.  Since I never use a 135 mm lens, I never have to install the movable condenser lens in that slot.  For 4x5s, I use 150 mm which eliminates the movable lens completely.

Finally, and this applies to this article as well as the previous one, thermocouples do not react instantly to temperature changes and we are dealing with a short time line for these tests, so the actual temperatures are likely to have been somewhat higher than the numbers recorded during these tests.  Nonetheless, I think the tests do provide useful information for comparison purposes between the three different wattage bulbs tested.  It also satisfied my curiosity about how practical it is to use a 250W bulb in the Omega DV condenser lamphouse.

Having now added the fans, I believe I will be quite comfortable using the 250W lamp when necessary for large magnifications or to shorten exposure times for dense negatives.

Using 250W PH213 Bulb in Omega DV Condenser Lamphouse

Background

If you have an Omega 4×5 variable condenser enlarger, you probably know it is common to use 75W and 150W bulbs in them.  These enlarger bulbs are designated #211 and #212, respectively.  Often they are referred to as the PH211 and PH212.  You may also know there is a brighter alternative that will physically fit.  The #213 is a 250W version of the above and is available online from Freestyle, B&H, and 3rd party sellers on Amazon.  I measured the new bulb at about 1.3 stops brighter than my 150W bulb which already has quite a few miles on it.

Left to right: 250W #213, 150W #212, and 75W #211

In its stock configuration, the Omega variable condenser lamp house is not rated for the 250W bulb.  My particular enlarger is rated at 75W and specifies the #211 bulb.

Lamp enclosure for Omega D variable condenser lamphouse.

Newer versions of the lamphouse are apparently rated at 150W, although I don’t know of any design differences.  I have been using the 150W bulb in my enlarger for years with no problems.  The power cord can certainly handle the load and there are no signs of any heat damage.  But, even with the 150W bulb, my condenser enlarger is not as bright as my Chromega with its 250W reflector bulb. This is a problem when I intentionally enlarge big and crop small to accentuate grain.  I’m not a fan of long exposure times measured in minutes.

Omega made a blower for the condenser lamphouse to specifically allow the use of the 250W bulb.  The Omega part number is 412-020.  I’ve never seen one, but it is listed on the KBH Photografix website.

There have been discussions on web forums on this topic.  Some suggest using an LED head to get more brightness.  In one discussion on the Large Format Photography forum, the highly regarded Bob Carnie of Toronto, posted that he has been using 250W bulbs in his Omega condenser heads for years with the only downside being a shorter lifespan for the bulb.

Anyway, on a recent project, I really wanted to shorten my exposure times, so I ordered one of the 250W #213 bulbs and started experimenting to assess the effects of using such a hot bulb.

Experimentation

I decided to test each of the three bulbs, 75W, 150W, and 250W, under identical conditions and collect some temperature data.  I do not have an IR temperature gun and I was mainly interested in reading internal temps, so I used the thermocouple that came with my multimeter.  I suspect the readings lag actual temps, but it should be sufficient for comparison purposes.

I use heat absorbing glass (Omega P/N 473-103) placed installed in the highest slot  in my condenser head.  I had the variable condenser in the lowest spot (for lenses up to 80mm).  I placed the thermocouple 0.425 inches above the heat absorbing glass which positions it about 0.700 inches below the bulb.  The temperature readings very greatly if the thermocouple is closer or further away from the bulb even by small amounts, so I repeatedly verified that the thermocouple never moved throughout the testing.

Test configuration: Thermocouple just above heat glass

I turned on the lamp and measured the temperature every 30 seconds up to 2 minutes and then turned the lamp off and measured the cool down for another 2 minutes.

Results

Rather than try to learn how to do a table in WordPress, I just used an image file.  The lamp is on for the first 120 seconds and then turned off for the next 120 seconds for a total measurement period of 240 seconds.

Conclusion

It’s pretty easy to see that the 250W bulb creates a lot more heat stress than the lower wattage bulbs.  Temperature build-up really depends on how long your exposures are and how much of the time the lamp is off and cooling down.  Cool down is slow, so I allowed a considerable interval between tests.  I know from my own past experience that the negative stage stays relatively cool regardless of the bulb wattage because there is so much glass separating the bulb from the negative.  But, since I practically never make more than a few exposures from the same negative, the average off time of the enlarger far exceeds the on time.

I have decided to remove the plastic covers and add a small cooling fan to each side of the lamphouse.  I will have pictures and test results from that project in a future article.

Relining the Chromega light mixer

I’ve had my Super Chromega D Dichroic II for over twenty years and have never paid much attention to the light mixing chamber that sits above the negative carrier.  I don’t print color, so the change in light color from long term yellowing has never caused me much grief.  Lately, though, I’ve noticed that I am not getting even light distribution across the entire negative area when I print 35mm and it could be even worse with larger negative sizes.

I noticed that the central area of the diffusion screen on the bottom of the mixing chamber has become quite glossy in the center and tests have shown that it reflects the negative.  Well, actually, it reflects the white negative carrier which results in a band of brighter light around the outside edges of he 35mm frame.  I was able to remedy the problem by covering the diffuser with dull finish diffusion material (like the diffusion material used on studio lights) or by covering the top of the negative carrier with black paper.

Nonetheless, the diffuser and lining of the mixing chamber had become yellowed and the shiny spot in the center made me think it needed to be replaced.  Luckily, Omega sells a relining kit that can be purchased through B&H for $98.50.  I ordered it and it came this week.

The mixer is accessible by removing the front door of the Chromega lamp house.

The lining kit includes the foam pieces, diffuser, and instructions.

First, remove the six screws that hold the top on.

You may need to pry the top off using a small screwdriver at the corner.

Save the springy plastic “pressure loop”. It will be reused.

Remove the long pins that hold the top foam piece on.

Next remove the tight fitting front and back pieces.

The output diffuser can be removed by pushing up from the bottom.

The old liner is on the left and the new kit is on the right.

I used a razor blade to bevel the upper edge of the top foam piece.

The bevelling of the upper edge eliminates interference with the cover.

Install the long pins to hold the top foam in place.

Replace the pressure loop.

Finally, install the cover and secure it with the six screws. Be careful not to over tighten the screws.

I noticed the new output diffuser has a glossy surface on the bottom and a matt finish on the top, opposite from the old one.  This is problematic because the glossy surface reflects the white edges of the negative carrier resulting in uneven lighting of the negative.  As noted above, the reflection can be eliminated by covering the diffuser with a piece of dull diffusion material or by covering the negative carrier with black paper.  I intend to use the latter option, except I will paint the negative carrier black.  I sometimes use Ilford Variable Contrast filters under the mixing chamber and, since they are glossy, they would present the same issue as the glossy diffuser.  Making the 35mm negative carrier black will reduce the light output, but  that suits me fine since I often find myself having to use neutral density filtration to get long enough exposure times with faster papers such as Adorama RC.

Unfortunately, I neglected to make a color temp reading of the light output before relining the chamber, but the light looks whiter.  I wouldn’t be surprised if my prints showed slightly higher contrast for the same filtration due to the replacement of the old yellowed liner.

If you want to test the light distribution of your enlarger, just make a high contrast print (max magenta filtering or a #5 VC filter) without a negative in the carrier.  Ideally, the print should be a uniform gray tone from corner to corner.  If you see light fall-off toward the corners, you might try using a lens made for a larger format.  For example, I get more even light distribution using my Nikkor 80mm lens than I do with my Nikkor 50mm lens.

Nothing is Ever Simple

In the process of adding older pictures to my website galleries, there was one I wanted to add but apparently lost the print.  So, today, I reprinted it.  The first print I made was of the wrong negative.  Duh.

The second print I made was great except for one tiny dust speck.  Rather than spot it, I decided to hunt down and destroy the dust particle.  It turned out to be stuck on the negative and would only come off after I used a moist Q-Tip on it.  I made another print and the speck was gone.  Success!  But, wait.  It didn’t look right.  Slightly crooked or something.  I straightened it up and made yet another print.  Still not right.  WTF?

I finally realized that I put the near perfectly symmetrical negative back in the carrier emulsion side up.  I don’t remember ever having done that before, but the emulsion side of TMax 100 film is quite shiny, so I didn’t notice it.

The five prints are pictured below with the first print (from the wrong negative) on the far right and the last (final) on the far left.  Look closely and you’ll see that two of the five are reversed.

Lynnette_Prints

Picture details:
TMax 100, 6×7 cm, RB-67 with 127mm lens, Developed in TMax RS, scan from 8×10 print on Ultrafine  VC Elite RC pearl Paper.  Shot in my very cramped unheated garage in December, 1998, long before I had a dedicated studio.

Lynnette, 1998

Lynnette, 1998