Efke 820IR/ Lee 87c gel

[robertojoven]

I have read a small (but substantially confusing) amount of information regarding infrared photography as it relates to filters and was hoping that someone might be able to offer some clarification.

I purchased a 25 sheet box of Efke 820IR film the other day, as well as a Lee 87c gel. I am still unclear as to a few things:

1. What exposure compensation is needed for this filter? (I have heard/seen numbers ranging from an effective ISO of 1/2 all the way to 6 or 8)
2. What wavelength does the 87c cutoff at?
3. (regarding question #2) Will this give a dramatic IR look, moderate IR effect, or is the filter too opaque?
4. Shooting in southern california deserts in spring on bright sunny days, will there be enough IR light?
5. What sort of development (D76) is preferable?
6. Should I purchase a different filter (I also have a 25a, although I don't think this is deep enough)?

I was planning on doing a test run and bracketing 4 or 5 shots, but I read that the 87c cuts out too much light so I don't want to spend a day shooting only to receive completely black images.

Thanks

[Robert Skeoch]

I'm sure someone will give a better answer but this might get you started. I have some, but rather limited experience with the IR films.

It seems the opaque filters do the best job and give the greatest IR effect.

It would not surprise me if your effective ISO was 1 or 2.

I tried a number of different ways to meter and the most successful by far was to use the through the lens meter of another camera. I'm sure a spot meter would work as well. Place the filter in front of the lens for the reading and then use this information to set the lens of the LF camera.

The most successful and consistent exposures I ever had were using the 092 (b+w deep red) filter on a rangefinder camera and setting the camera to "A" Aperture mode for the metering.

Each time I used a hand-held meter (instead of metering through the filter) and tried to figure out exposure compensation my film was way to thin and produced nothing printable. When the 8x10 sheets were $8 each this was rather disappointing.

Your mileage may vary.

-Rob Skeoch

[vinny]

check flickr.com for examples from people shooting the stuff- search efke 820ir and you'll be overwhelmed with pics and stats.
775nm is the cutoff but that doesn't matter since you've already got the filter.
do a bellows test for a couple minutes with the darkslide half-way out. many bellows aren't ir proof.
you can bracket without shooting multiple sheets, just pull the darkslide out an inch at a time and calculate the cumulative exposure.
I shoot it at 1.5 asa, i think, usually 4 seconds at f22 with a b+w 89b. I have a lee 87 and it was too heavy for me too get a usable exposure time with my test roll. your 87c is even heavier.

[drew.saunders]

Unlike Lee, Freestyle has actual useful information on the two Lee IR filters, the regular 87 and the 87C. See http://www.freestylephoto.biz/5331006-Lee-4x4-Filter-for-Gel-Snap-Infrared-87-100x100mm-Opaque and http://www.freestylephoto.biz/5331007-Lee-4x4-Filter-for-Gel-Snap-Infrared-87C-100x100mm-Opaque?sc=24100

The 87 cuts off below 730nm, the 87C below 775.

Using the Hoya R72 (starts letting light in at about 600nm, 50% at 720 thus the 72 designation), I got an ISO of 1. With the 87 I expect an ISO of 0.5 or so. The 87C probably would be around 0.25. If you want to use the 87C, you may want to get some 35mm or 120 and do some testing.

I just got the 87, but can't use it until I get a mount for it, as it's a plain sheet of polyester. Here are the mounts: http://www.leefiltersusa.com/camera/products/show/ref:C47BE96B4E501C/

I have a hood with 2 slots for mounted polyester or plain glass filters, and all the other filters I bought were mounted. Since the two slots probably let light in, I'll get the 10-pack of mounts and make 2 of them up as empty and use them to fill the empty filter slots when I'm using the hood "plain."

Drew

[polyglot]

I get about ISO1 in full Australian sun from IR820 and an R72 filter. Don't think in terms of filter factor here, it implies that the filter takes a constant fraction of the light. The relationship between IR and visible components varies a lot, meaning your effective filter factor varies with time of day.

Get a roll of 35mm or something and test on that - you can take a few bracketed sequences, develop the whole lot on the cheap and choose the EI you like. Much quicker and cheaper than burning sheet film just to do very basic testing. I don't know what the reciprocity characteristics are like though, so you might want to test at similarly small apertures/times.

And you do need to test and not take our word for it - the ratio of visible light to IR varies with your geography (proximity to cities/smog), season, time of day, etc. So what works well for one is not guaranteed to work well for another and as you can see, there is much disagreement about what to do. And it gets more complicated because some meters are a bit sensitive to IR and some are not, which means people's results are all over the place.

Suck it and see is the only answer, sorry.

[Ron Marshall]

I found an EI of 3 works well for me with a Hoya R72 (similar to 87c) and Efke 820. But you should test.

[Diane Maher]

The Hoya R72 is similar to a Wratten 89B. An 87c has a cutoff that is really high when compared to the sensitivity of this film. An 87 filter may be used with this film. It has the highest cutoff wavelength of the range of filters (89B, 88A, 87), with the 89B having the lowest cutoff wavelength.

Keep the 87c for use with digital. :D

[robertojoven]

Unlike Lee, Freestyle has actual useful information on the two Lee IR filters, the regular 87 and the 87C. See http://www.freestylephoto.biz/5331006-Lee-4x4-Filter-for-Gel-Snap-Infrared-87-100x100mm-Opaque and http://www.freestylephoto.biz/5331007-Lee-4x4-Filter-for-Gel-Snap-Infrared-87C-100x100mm-Opaque?sc=24100

The 87 cuts off below 730nm, the 87C below 775.

Using the Hoya R72 (starts letting light in at about 600nm, 50% at 720 thus the 72 designation), I got an ISO of 1. With the 87 I expect an ISO of 0.5 or so. The 87C probably would be around 0.25. If you want to use the 87C, you may want to get some 35mm or 120 and do some testing.

I just got the 87, but can't use it until I get a mount for it, as it's a plain sheet of polyester. Here are the mounts: http://www.leefiltersusa.com/camera/products/show/ref:C47BE96B4E501C/

I have a hood with 2 slots for mounted polyester or plain glass filters, and all the other filters I bought were mounted. Since the two slots probably let light in, I'll get the 10-pack of mounts and make 2 of them up as empty and use them to fill the empty filter slots when I'm using the hood "plain."

Drew

I have the Lee "gel snap filter holder" but no mounts. What would be a good way to affix the filter to the camera? I would assume that light can 'leak' if the filter is not tight enough on the lens. The cheap holder doesn't seem like it would be sufficient. Should I try putting it inside the bellows (after composition, focusing, etc)? I've heard that few pieces of tape folded over on itself can work for these gels when putting them on the lens.

Also, I forgot to ask, but how should I go about focusing/compensating for differences in focus between IR and normal light?

Thanks again for the help everyone.

[Ron Marshall]

The Hoya R72 is similar to a Wratten 89B. An 87c has a cutoff that is really high when compared to the sensitivity of this film. An 87 filter may be used with this film. It has the highest cutoff wavelength of the range of filters (89B, 88A, 87), with the 89B having the lowest cutoff wavelength.

Keep the 87c for use with digital. :D

Thanks Diane: I was thinking 87 not 87c. As you said, the 87c is pretty much useless with this film as its cutoff is about 800 nm wheras that of the 87 is about 740 nm.

[vinny]

you can make your own cardboard mounts with thin cardboard like the stuff used on the back of a notepad. cut a square with a hole in it.

[drew.saunders]

I have the Lee "gel snap filter holder" but no mounts. What would be a good way to affix the filter to the camera? I would assume that light can 'leak' if the filter is not tight enough on the lens. The cheap holder doesn't seem like it would be sufficient. Should I try putting it inside the bellows (after composition, focusing, etc)? I've heard that few pieces of tape folded over on itself can work for these gels when putting them on the lens.

Also, I forgot to ask, but how should I go about focusing/compensating for differences in focus between IR and normal light?

Thanks again for the help everyone.

I'm just going to cough up the $20 for a 10-pack of the mounts, but I suppose making a 2mm thick cardboard sandwich could do. Having just used the hood with filters this weekend, I've determined that there is the possibility of flare if the two filter slots are empty, so I'm going to get to use 3 of the 10 mounts (one for the 87, two empty to fill the slots in the hood when I'm not using any filters).

As for focus, open no more than f/16 and guesswork works for me. I tend to focus on the nearest thing I'll want, stop down to see if far is in focus, and hope for the best.

Drew

[robertojoven]

I'm thinking that I might as well test the 25a filter I have, or is this going to be pointless?

Vinny, with the cardboard mounts you're talking about, how do you attach it to the camera/lens?

[al olson]

Robert, I have never had problems with light leaking around the filter. I shoot 820c with either a Hoya R72 or a Cokin 007. Both cut off at around 720nm. The Cokin holder keeps the 007 filter offset from the lens by about 1/4". I have exposed a lot of IR film and I do not find this to be a problem.

Generally an EI of 1.5 usually works for me. I normally develop in D-76 (1:1) for 11 minutes. However, over a year ago I had a strange experience when I was shooting above 11,000' in late November. The light was bright and sunny and near mid-day. Using the above EI I found that my negatives were extremely thin and unprintable.

I went back a week later under the same light conditions, but used an EI of 0.5 and developed for 16 minutes. Again thin negatives. Contrary to my belief that bright sun at that altitude should be IR rich, it seems that the low sun angle near the mid-winter solstice causes the IR to be absorbed by the atmosphere.

Later in June I was in the woods in New Hampshire and photographing at EI = 1.5 again and all my negatives had normal contrast. Like was mentioned earlier, there are many different conditions that can affect the intensity of IR and time of year appears to be one of them.

I should mention that with this film the effects of the 25A are rather bland. 720nm is a reasonable cutoff.

[brianam]

I'll chime in to add that EI 1.5 sounds about right. I shoot a lot of the Rollei IR, and I found it to be slightly faster than the Efke. An IE of 3 or 6 seems to work well (for me) with the Rollei. So maybe the Efke is a stop below. (?)
All of my observations are with a Hoya R72 round glass filter.

[Maris Rusis]

Here my Efke IR820 exposure strategy through a IR720 filter. Light metering is via a Pentax Analog 1 degree spotmeter.

Front lit landscape, typical sunny day: EI = 1.
Subjects in the shade on a sunny day: there is still some IR kicking about but the ratio of IR to visible is lower so I set EI = 0.5 on the meter.
Cloudy day, even light, no hard shadows: there is even less IR for every bit of visible so I set EI = 0.25 on the meter.

Except for infrared bright leaves and brilliant clouds I have a deuce of a time overexposing this film at any remotely reasonable camera settings. If in doubt give more. Still unsure? Give much more!

[vinny]

I'm thinking that I might as well test the 25a filter I have, or is this going to be pointless?

Vinny, with the cardboard mounts you're talking about, how do you attach it to the camera/lens?

lee rubber band filter holder or tape. you can tape it to the rear element as well. The lee plastic snap together gel filter holders aren't that great for the money but they do work. I've made several out of mat board which work fine. I don't use gel filters much, they're hard to clean, store, and you don't want to get them wet. Resin or glass remain new condition much longer.

[drew.saunders]

I just shot a roll of 120 Efke Aura 820 on my Mamiya 645E. I used both the Lee 87 in a snap-holder, and the Hoya R72 filters. I used the TTL meter without the filters, set at ISO 125, then calculated ISO 2, 1 and 0.5 and shot the same scene at all 3 settings with each filter. The Aura seems a tad more sensitive than the regular IR 820. With the regular IR 820 and the R72, I was using ISO 1, while with the Aura, ISO 2 is a better choice. With the Lee 82 filter, which lets in less visible light, it seems ISO 1 or 0.5 is the best choice.

I'm still scanning the negatives, but just holding them up to the light makes it pretty clear that, with the Aura film, if you have a good ISO for your meter and the R72 filter, then use 1 or 2 stops lower ISO with the Lee 82 filter. I presume that the results would be the same with the non-Aura film, but I'll test that later. I didn't want to burn a bunch of sheets of IR820 without testing first.

I sort of like the "glow" effects more with the Lee over the Hoya, at least with this film.

[rguinter]

I have read a small (but substantially confusing) amount of information regarding infrared photography as it relates to filters and was hoping that someone might be able to offer some clarification.

I purchased a 25 sheet box of Efke 820IR film the other day, as well as a Lee 87c gel. I am still unclear as to a few things:

Thanks

Robert: The 87c filter has a cutoff that is way too high for the Efke IR film. I recommend you don't waste your film with it.

I have been using an 87 ( which is marginal) and a B&W 092 which works quite well.

The attached photo was taken last weekend. Exposure was f22 at 5sec with the B&W 092 filter. Green foliage and grass in the sun across the pond was measuring eV 13 or so at the time. bob G.

[robertojoven]

I got done with two test runs, and thought I would put my results out there in case anyone else comes across this thread.

I shot with the 87c, which did work in fact. I was shooting at 12-3pm and the air was clear, although slightly hazy.

I set my meter to ISO 3 (because that's the lowest my meter would go), and the meter gave me a reading of 1 sec at f22 (incident). I then opened up three stops to give me an effective ISO of ~.30. This then gave me an exposure of 8 seconds. Due to the extreme amount of reciprocity failure that I read about (can't remember the actual data, just remembered it was really bad), I started with an exposure of two minutes. Then I bracketed to 3 and 4 minutes at the same aperture. None of these were exposed enough.

I will be going back up there with a roll of Efke IR820 35mm, and also a roll of Efke IR820 Aura (which is supposed to lack the anti-halation backing, like Kodak HIE).

I also got an 87 filter from Lee because I'm hoping that will make everything a little easier (and also because it should have been the filter I got in the first place :o). I will be shooting a Nikon F100 and D80 and am hoping that the infra-red 'sensor' for the sprocket holes won't fog the film too much. From what I've seen it only fogs about 1mm in from the top and bottom.