Macophot Infrared

[Guy Stewart]

Recently, I shot some 8 x 10 Macophot AURA (no anti-halation layer) using an 87C infrared filter (a gel). I know the Macophot PDF on-line brochure says not to use the 87 Series, but I had been assured that I could, using an ISO of 8 with extensive bracketing. Accordingly, I bracketed 6 different sheets of film in successively larger apertures at a one second exposure. The images were processed as positive transparencies, but when they were developed, they were completely black - and I mean nothing! The Lab owner is highly experienced, and his Lab does nothing but process film. Although he has never processed the 8 x 10 film, he has processed 120 (roll) AURA, and he does not believe the emulsions would be different. He also is the person who told me using an 87C would not be the culprit - there would be an image, however faint, of some kind.

Obviously it has occurred to me that I had forgotten to take out the dark slides, but on this shoot I was the assisted by a friend who is very methodical, and I don’t think he would have let me do that. In addition before the IR shots, I had taken some color transparencies of the same subject, and they were perfectly exposed. Not proof positive that the dark slides weren’t pulled, but . . .

Can anyone suggest what went wrong?

So, if I shouldn’t use the 87 Series, which filter should I use to obtain the maximum IR effect, at what ISO should I set my light meter (I used a reflected light spot meter) for that (given) filter, and should I adjust the indicated meter exposure for that (given) filter factor?

Now, with the next question:

Can one create an artificial infrared source of light? I have an old 250 Watt General Electric infrared heat lamp with an internal, built-in reflector. Can I use it as a light source? Or, can I mount an infrared filter in front of a Speedotron strobe lamp putting out 5500 Kelvin?

Thank you for any assistance you can render.

Guy Stewart

[Scott Davis]

try to get your hands on either an 89b or a Hoya rm72 . They will provide a lower threshold for cutting off visible light, so you should get something resembling a decent exposure. Start your exposure testing at 6, and bracket down from there (slower ISO). I'd try shots at 6, 3, and 1 ISO. Alternately, I'd also wait until Maco releases their new, updated version of 820C, which is at least one if not two whole stops faster than the current lot.

I'd also suggest using an incident reading, instead of taking spot readings, for IR, until you get used to how IR exposes and prints.

Any light source will most likely be useable for Infrared. You can even use strobes, but you need to test them to figure out how to adjust your exposure. You won't need to filter the strobes if you filter your lens.

Most halogen/regular photoflood lamps toss off plenty of IR, and are more than adequate, at least when shooting Kodak HIE. They won't help you much when working with the Maco, because of its extreme slow speed. I've tried that in my studio, and I get exposures in the neighborhood of 1/4 second at F2.8 to F4, (with a pair of 500 w photo floods, or slightly better, maybe f5.6, with my 1300 w halogen light), which is marginal for a 35mm camera on a tripod, and dead useless for an 8x10 unless you're aiming for REALLY impressionistic photos.

[Alan Davenport]

You kind of did leave the darkslide in, only it was over the lens.

Simply put, you should have heeded MACO's recommendation. The Macrophot AURA film has virtually zero sensitivity above 825 nm, while the 87C filter is already well into its cutoff there and passes almost nothing below 800 nm.

Translation: they aren't lying and you can't use that filter with that film.

[Roger Scott]

I've used both 89B and 87 IR filters with Maco 820c but as others have mentioned I'm not sure an 87C will let much light through which is visible to the film. As a rough estimate in midday sun in the lower latitudes of Australia I meter at ISO 50 and then adjust by 4-6 stops for the 89B and 5-7 stops for the 87 (the usual is 5 and 6 respectively). This puts the film down around ISO 1 with these filters when processed in ID-11 (1+1).

Regards,

[Gene Crumpler]

A 72 is what works for me with MACO. EI of 6 and some bracketing.

[Brian C. Miller]

I use B&W 092 as the darkest filter. There is no difference between it and the Hoya. The 87C is only good for Kodak HIE.

[Scott Rosenberg]

first, why did you develop the film as transparancy film? i have great success with Maco 820C developing it as B+W NEGATIVE film.

second, the 092 filter transmits above 650nm; the R72 transmits above 720nm, so technically there is a difference between the two filters. practically, however, I don't think the 70nm difference will amount to much at all... unless maco 820 is changed to maco 700!

[Steve Hamley]

Roger's experience is consistent with mine - around EI 1 with an 89B (B&W 092) filter.

Steve

[Yaakov Asher Sinclair]

Is there a difference between the regular Maco IR and Aura in terms of being able to use the 87 filter? I've had success using the regular Maco IR with an 87. V thin negs - but very good night time effect - which is what i wanted
See here: http://ohr.edu/seasons/photos/
I use the Lee filter system, and the only IR filter I could find to fit was their 87. Is there another option when using the Lee system?
thanks to all.

[Brian C. Miller]

Rabbi Sinclair, have you thought about using filter gels? They are cheap and are used mostly for flashes. One of the photography stores I frequent has a tall rack of them in the corner, and there are some very deep reds in there, and I'll bet there is one which is Kodak #29. Lee makes a gel snap, and then you could use those. They are easy to mess up in use, but they are also cheap and repacement is a pair of scissors away.

Also, I bet you are probably developing the film yourself, while Guy went to a lab for development and wanted the film processed to produce positives. That's an extremely different process! :-) Like you say, you are seeing a very faint image. How are you developing the film?

A filter with the proper cut-off would give you a normal-looking negative. The Maco 820c technical data doesn't recommend an 87 filter: "The cut-off wavelength of even stronger filters such as 87C (cutting off at about 830 nm) lies so high that these filters are also opaque for MACO IR 820c and MACO AURA. Such filters are therefore not suitable for use with these films."