Infrared photography with the Mamiya RB 67 SD - a couple of questions

Neutrino · 2015-05-25T19:54:48+00:00

So, jetzt belebe ich mal hier wieder ein wenig das Forum... ? Ich habe mir nun ein Infrarotfilter von Hoya 720nm zugelegt um mich auch etwas in der Infraro...

Neutrino

Right, I’m going to liven up the forum a bit here... ? I’ve just bought a Hoya 720nm infrared filter so I can have a go at infrared photography. Since you can only manage infrared shots with a tripod anyway, I thought I’d go straight for a 77mm one, which fits my Mamiya lenses. If I’m using a tripod anyway, I might as well work in medium format. ? First off, just generally speaking: ? Perhaps no one will believe me, but what really amazed and surprised me is that the famous Wood effect is actually visible to the naked eye when looking through the viewfinder! The eye does take quite a long time to get used to the extremely low light intensity, but once it has, you can see it quite clearly. Much of it is almost black, but leaves, when viewed at a certain angle, really glow. In other words, the eye must also be at least very slightly sensitive to infrared light. So that would actually mean you don’t necessarily have to take photos ‘blind’. Of course, if the filter is attached to the lens and I look through the viewfinder, I won’t see anything, as the maximum aperture of the Mamiya lenses is far too small, but if you look straight through, you could at least find good spots and angles for positioning the camera. This might at least give you a rough idea of what the finished image could look like. Is it completely out of the question to proceed in this way? ? I’ve also noticed that the effect isn’t just visible in direct sunlight (where it’s certainly much more pronounced), but also in indirect light with an overcast sky. So are infrared shots with the Wood effect possible even without direct sunlight? ? Now specifically regarding the Mamiya: ? I have the PD prism viewfinder with a built-in light meter for the RB 67 SD. The correct exposure is indicated by LEDs. Is it still possible to work with this effectively, provided there is sufficient light for the meter, or is it better to use a handheld light meter and apply correction factors? ? As I understand it, with APO lenses, no focus correction is required, as these lenses are corrected right into the infrared range and all light waves converge at the same point. Is that correct? However, I don’t have these APO lenses anyway. So what about standard lenses? More specifically, the KL 65mm and the KL 127mm. Logically, there are no infrared markings on the lens, and there is nothing to be found on the scale on the barrel either. The description of the RZ 67 II devotes a short section to this topic. However, only correction values for infinity are given, and unfortunately no value for a 127mm. I assume, however, that one can use the 110mm as a rough guide. Is there a formula or an approximate value to help with this? ? Best regards, ? Thomas

Urnes

Hi Thomas, So, set up the camera. Frame the shot without a filter. Adjust the focus. Screw the filter on. Take the photo. Alternatively, you could use an 8x red filter (3 stops); you’ll still be able to see through it. The IR effect will still be strong enough. Adjust the focus as described in the instructions. You can use the ‘infinity’ setting for other distances too. And always stop down a little. That way, you’ll achieve good sharpness. With the 65mm, stopping down might even be enough. With a wide-angle lens, the focus difference is smaller. Measure exposure either using manual exposure and a correction factor, or without a filter through the prism and a correction factor. With a red filter, you can take a chance and use TTL metering. But it tends to turn out too dark. The Wood effect is also present without sunlight. It depends on the chlorophyll content in the leaves. However, sunlight enhances it. It’s all great fun if you have a botanical garden nearby and plants with large green leaves. Otherwise, just get started. Regards, Sven.

grommi

Urnes has already covered the most important points. But who says you can only take IR photos with a tripod? Even on a cloudy day, I can still take decent handheld shots at 1/60s and f/4 with an exposure equivalent of 25 (RR 400s with a 720 filter). Incidentally, my ‘IR camera’ is an Olympus RD, and with the correct distance correction (determined by trial and error) and, of course, without camera shake, the IR images have greater sharpness than without a filter. Especially with super-panchromatic films without a filter, an apochromatically corrected lens is likely to offer significant advantages. Perhaps the limited sensitisation of ortho films is also a reason why they often appear so sharp. IR example: https://flic.kr/p/pihCjF

Urnes

Hi Grommi, You're right. With a red filter, the Kodak HiE 400 worked well even when shooting handheld with a 35mm SLR. Regards, Sven.

sputnik

But who says you can only take IR photos with a tripod? Even on a cloudy day, I can still take decent handheld shots at 1/60 and f/4 with an exposure equivalent of 25 (RR 400s with a 720 filter). (...) My ‘IR camera’ is, by the way, an Olympus RD, and with the correct distance correction (determined by trial and error) and, of course, without camera shake, the IR images have a higher level of sharpness than without a filter.

+1 And since the OP is apparently a fan of roll film, I would recommend a twin-lens Rolleiflex or Rolleicord for infrared photography. With this, you can still shoot freehand even in medium format at ISO 12. Advantages: - Always a bright viewfinder image, as the filter sits on the taking lens - No focus correction required when using the Rollei IR filter* - The absence of mirror shock and a vibration-free central shutter allow for long exposure times handheld without camera-induced shake *Experts disagree on exactly how this is supposed to work. But ultimately, it’s enough that it works. An IR indicator is really only suitable for a very specific type of IR film. In that respect... :-)

Neutrino

Thanks for your replies... ? ?

But who says you can only take IR photos with a tripod ?

? With Rollei Retro 400S, Rollei Superpan 200 or Rollei Infrared, is there still enough speed left to shoot handheld? The true ISO for these is supposed to be somewhere between 100 and 200. If a strong red filter already reduces the light by about 3 stops, as Urnes writes, then surely a 720 infrared filter will be even more extreme. How on earth are you supposed to get ISO 25 out of that? ? ?

And since the OP is clearly a fan of roll film, I’d recommend a twin-lens Rolleiflex or Rolleicord for infrared photography. ?

? ? Well, I’m not going to go out and buy a new camera with a new infrared filter just for that. :D But thanks for the tip anyway, of course. I think I’ll manage quite well with the Mamiya. ?

? You can also use the infinity setting for other distances ?

? OK, thanks, I’ll give that a go then. And unfortunately, I can’t find any instructions for the 127mm. Should I just use the values from the 110mm on the RZ? ? ?

grommi

"How on earth are you supposed to get ISO 25 out of that?" ? Without a filter, I expose the 400s/Superpan as if it were ISO 100 in thick clouds and ISO 200 in sunshine. The film has a significantly increased speed from the yellow to the IR range, so that with my 720 filter, I still have 25 left. Just give it a go – the proof of the pudding is in the eating. ? PS: I develop the film in homemade para-aminophenol (like Rodinal) 1:50, 17 mins, 20 °C, agitating 3 times for 2 mins each. It’s the only film so far where Caffenol doesn’t work at all! And I don’t like it in sulphite-rich (fine grain) developers.

piu58

Three stops is not enough for the SP400. Even 4 stops is a bit tight; 5–6 stops will give you well-exposed negatives. Starting from 100 ASA (which is the film’s ‘actual’ speed), that leaves 3 ASA. Even with that, you can still get something decent from handheld shots. Mainly because IR photography is usually done with a wide-angle lens at a standard focal length, and you can use a shutter speed of 1/30 or even a longer exposure.

Urnes

The focus difference is approximately 1/300 of the focal length. So, at 50mm, you need to set the focus to approximately 15m instead of infinity. (Infrared, Rudolf Hillebrand) Regards, Sven.

grommi

A reduction of 3 f-stops is not enough for the SP400. Even 4 f-stops is barely sufficient; 5–6 f-stops yield well-exposed negatives. Assuming 100 ISO (which is the film’s ‘actual’ sensitivity), that leaves 3 ISO.

Consequently, not a single one of these images could have turned out well: http://www.ipernity.com/doc/imagesfrugales/album/391819?view=0 Incidentally, all were taken without a tripod and all negatives were well developed with good ‘coverage’. No fiddling around was necessary.