Monthly Archives: September 2011

Efke IR820: Red vs “Opaque” filters

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I’ve been experimenting with infrared films and have just run a test on a batch of Efke 35mm IR820 Aura.  I always test a few frames of Efke IR films because I have had a lot of problems with what I believe are emulsion defects.   The rolls I recently received had a new emulsion number, so I decided to test it before taking it on my upcoming San Francisco photo expedition.

I always use an IR720 filter with Efke IR820, but I decided to try a few shots with a plain old Nikon red #60 (equivalent to the standard #25A).  As expected, the IR effect (usually referred to as the “Wood effect“) essentially disappeared.  The sky came out about as dark as it would with ordinary panchromatic film using a standard red filter.  Since the emulsion of Efke IR film is created from an ordinary panchromatic formula to which IR sensitivity is added, exposing it to light in the visible spectrum easily overwhelms the IR sensitivity.

Efke IR820 Aura with IR720 "opaque" filter

Efke IR820 Aura using ordinary red filter

Shadows are commonly very dark when using red filtration, especially with IR film because the blue part of the sky does very little to fill shadows.  Most shadow fill must come from light reflected from other surfaces (such as the driveway).

Interestingly, the CFL lamp between the garage doors is visible in the second picture, but is dark in the one using the IR filter.  Fluorescent lamps radiate very little IR energy.

Given my recent discussion of cheap no-name filters, I should mention that the 77mm screw-in IR720 filter I use is, in fact, a no-name brand purchased off ebay for $18.  Name brand IR filters can easily cost $100-300.  The no-name brand works great from what I’ve been able to tell, although I admittedly don’t have a name-brand filter to compare it to.  I don’t do enough IR photography to justify the more costly filters.

So how about those cheap ebay filters?

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I’m an occasional user of filters to accentuate the sky on my pictures.  Mostly I use red with or without a polarizer, but being the cheapskate that I am, I use square series P Cokin plastic (optical resin) filters with adapters so I can put them on any lens I own.  The problem with Cokin is that they are fragile and a little awkward to use compared with screw-in filters, which are far more secure when you’re hiking through town with your camera dangling on a neck strap.

So, I decided to give those cheap no-name screw-in filters available on ebay from Hong Kong a try, beginning with orange and yellow.  I first ordered from a seller known as Fotocola and not being too happy with what I received, I then ordered from a seller named Citiwide, also disappointing.

Fotocola and Citiwide filters

I paid $7.99 for each of the Fotocola filters and $5.25 for each of the Citiwide filters.  Both were uncoated, but then so are my Cokin filters.  Mechanically, they seemed acceptable, although I didn’t experiment with whether they were easier or harder to get on and off than other name brand screw-in  filters.

One instantly noticeable peculiarity about the Fotocola filters is that they are apparently laminated (two pieces of glass with filter media in between).  You can see multiple reflections on these filters whereas this is not something I’ve seen with any other filter (although Tiffen is reputed to use laminated construction).  The reflection looks the same when viewed from either side.

Fotocola orange on left (note double reflection), Citiwide orange on right

I don’t know how much of an impairment that would be, but it might actually make the filter more scratch resistant.

The next noticeable aspect of these filters is the color.  While the Fotocola filters appeared to be almost what you’d expect for a medium yellow (K2) filter and an orange (G) filter, the Citiwide filters were more pale.  This was confirmed by measuring light transmission through the filters with a light meter.  The Citiwide filters passed less saturated.

Citiwide filters are more pale than Fotocola.

I don’t have an Orange (G or O56) filter from a top name company, but The Cokin yellow (001) filter (equivalent to K2) is a noticeably deeper yellow than the Citiwide filter (even if it’s not obvious from the picture below).  Even the Fotocola looked a little more pale than the Cokin and, indeed, measured slightly less dense with a light meter than the Cokin.

Fotocola (left), Citiwide (right), Cokin (bottom)

Finally, the color of orange Fotocola filter was not uniform over the entire filter.  The following two pictures should illustrate this.

Fotocola orange (on left): left side of filter is slightly lighter

Same picture but with Fotocola filter (on left) rotated so light side is on the right.

To summarize, the cheap filters definitely have a couple problems:

  1. The colors are not really coordinated or cross-referenced with the standard color values we’re familiar with  (K2, 25A, G, O56, X1, etc).  Of course, absolute precision in the color is not as important with black and white filters as it is with color, but the standard filter factors will be slightly inaccurate when used with these filters.
  2. Uniformity can be a problem and, of course, they are not coated (much less multicoated) as are filters from the more respected manufacturers.

Of these four filters, I will probably only use the Fotocola yellow filter because it seems comparable to the Cokin in color.  If you don’t use filters very often, paying upwards of $50 for one might not be too appealing.  I wanted to get 77mm filter which I could then adapt to all my lenses.  Oddly, I was able to find new Nikon #60 (red) filters readily available for $10, while their yellow (Y48) filter is $75 and their orange (O56) is $30.  I believe all are now out of production, which might be a factor.

In an upcoming post I will talk about low-priced UV filters from a company called JYC which look just like Hoya’s well regarded Pro1-D filters right down to the “Pro1-D” label.