Exposing Rollei IR

[Vlad Soare]

I want to try infrared photography for the first time. I've got an IR filter,

ordered a few rolls of Rollei Infrared, and searched Photo.net for information

on this subject. I think I understand the main idea, but there are still a few

things I'm not very sure about.<br>

<br>

Firstly, I understand that in order to get any IR effect with the Rollei you

need an opaque filter. Mine has "IR 720" engraved on its side, and looks opaque

at first glance, but when I hold it against a light bulb or the sun I see it as

a very dark red. Is this normal, or does it indicate a poor quality filter?

Should it be 100% opaque to the naked eye?<br>

<br>

Secondly, although I've read a lot of threads on this subject, I'm still not

sure how to get the exposure right. I read that Rollei with an opaque filter

should be rated at ASA 12 or 6. So far, so good. But what exactly do I measure?

I guess spot measuring and the Zone System are out of the question, since the IR

makes notions like "highlights" and "shadows" meaningless. <br>

Do I take an incident reading in open sunlight? Supposing that I want to

photograph some brightly sunlit trees and grass, an incident reading at ASA 6

would be something like 1/6 or 1/8 seconds at f/16. Somehow, that seems a

little too short. On the other hand, someone recommended 4 minutes at f/11 in

strong sunlight, which seems awfully long.<br>

I understand that the correct exposure depends on the subject and its IR

reflectivity, and that some bracketing will always be necessary, but I'd like to

have at least a starting point. A point to bracket around. Based on your

experience, what would be a good starting point for, let's say, lots of grass

and green trees in strong sunlight?

<br><br>

Thank you.

[wolf_rainer_schmalfuss]

Hello Vlad,

 

I can provide you with detailed information, if you would contact me!

 

Regards

Wolf

[jim_graves1]

The 720 is very dark red and is not completely opaque.

 

There are infrared meters but virtually everybody uses their regular meter (spot or whatever) and meters the scene as they would for a regular shot ... then calculate your exposure as if ithe film is ISO 25 (or lower.) It'll be close enough to get you in the ball park if you bracket.

 

Rollei's recommendation from their website reads as follows: "Note: To achieve strong IR effects we recommend exposing the film at a maximum of ISO 25 and using a Hoya R72 dark red infrared filter or deeper infrared filter. (Standard Red 25A filters are not recommended). Individualized exposure testing is necessary to realize optimal results."

 

A lot of people use ISOs of 12 or 6 which is the equivalent of 5 or 6 f-stop correction from the rated 400 ISO.

 

You can also use lesser red (or orange) filters but the IR effect will also be less (as would the filter factor.)

[Fotohuis RoVo]

About your filter: 720nm seems to be OK. After a while looking into strong light you can see something through the filter.

 

Always make a shot without the filter so that later you can check at least your development is correct. iso 320-400 like a regular panchromatic film.

 

With the 720 nm filter you will have around iso 12. You can use this setting by your external exposure meter and for the first time bracket a bit around that value.

 

Further you have to correct a little bit for your focus according the red dot IR focus marker on your lens.

 

With a SLR and a 720nm filter you will not see too much through the mirror so you have to remove it for the composition. With a R.F. camera you will not have this problem.

Avoid exposure times in the reciprocity failure of the film (> 1/2 S)because then things are extra complicated.

 

With a SLR in the range 1/2 - 1/30S use the mirror up to avoid blurr and of course use a tripod. With a moderate aperture f=8 or f=11 you will be in this range.

With some 35mm R.F. cameras it's sometimes just possible to shoot without tripod. 1/15 - 1/30S.

 

When using an orange or red filter with the Rollei IR 820/400 film you will have a dramatic cloud image but you will not get the 'wood' effect.

 

Here some general information about IR photography.

http://www.vividlight.com/Articles/2915.htm

 

Best regards,

 

Robert

[guy bennett]

I found this to be very helpful. I recommend you check it out:

 

http://www.digitaltruth.com/products/rollei_infrared.php

 

Guy

[ruicardoso]

Hello,

 

I use an hoya R72 with Rollei IR. I set my spot meter to ISO 6 and aim for an average reading just like when using any other film. The only difference might be that most times I don't include the sky in my exposure calculations, this probably means that my exposures will have a bias towards shadows, but I do get nice looking negatives this way.

 

Regards,

 

-Rui

[Vlad Soare]

Thanks, guys,<br>

I'll get back here with the results.

[carrotblog__miffy_]

Any results yet Vlad?

 

With a 720nm red filter I'm not finding a huge infrared effect. It looks very weak compared to Konica IR750 (no longer) and miles weaker than Efke 820 or Kodak HIE.

 

Has anyone got any results from a 780nm infrared filter? Looking at the spectral response curve I suppose the filter times will need to be massively larger.

[Vlad Soare]

I did some tests yesterday, but I haven't printed them yet. The negatives look impressive, it seems like there's a strong IR effect, but I can't draw a firm conclusion until I see the printed pictures.<br>

I'll get back here when I have the final results.

[Fotohuis RoVo]

http://www.heliopan.de/produkte/infrarotfilter.shtml

 

If you look at the RG780 (780nm) filter curve and the characteristics of the Rollei IR 820/400, you can see that no bandwith is left anymore for the film, due to the fact the sensitivity is doing down fast over 750nm with this Rollei IR film.

 

You could use this filter with the Efke IR820 because this film is more straight sensitive till 800nm and then have a drop quickly. HIE is also possible (>900nm) but this film is running out of stock worldwide now.

 

So the possible available filters for the Rollei film: SFX/Cokin 007, 89B, 88A and 72R.

For sure you can use red or orange but then you will not get the 'wood' IR effect.

However the resolution of this Rollei film is pretty high for an iso 400 film but then also expensive when using as panchromatic film only.

[carrotblog__miffy_]

That's good to hear Vlad.

 

Did the negatives curl badly?

 

I'm going to have to go back and try it again with a gelatin IR filter instead.

 

Thanks Robert. That makes sense. I was hoping that I could still use a 780nm filter with the Rollei and just increase the exposure (by a few minutes reciprocity!).

[Vlad Soare]

OK, I printed the pictures. The infrared effect is impressive, albeit not as dramatic as the one of HIE. On the other hand, although it's a bit weaker than HIE's, it's very "clean": no extra-large grain (quite the contrary) and no hallos.<br>

I made an exposure at ASA 400 with no filter and a series of exposures from ASA 12 downwards with the 720nm filter. The best exposure was obtained at ASA 6. The frames exposed at ASA 6 have the same density as the normal frame and print with the same contrast filter and the same exposure time. At ASA 12 it's quite underexposed, but it seems like it could be printed with a little effort. At ASA 3 it's a bit overexposed, but not overly so. Below ASA 3 the overexposure is pretty bad.<br>

<br>

Light level in the sunny areas: EV 15<br>

Unfiltered exposure: 1/400s at f/16<br>

Filtered exposures: 1/15s at f/8<br>

<br>

I don't have a medium format film scanner. I have scanned the printed pictures. The scans turned out unsharp due to my poor scanner and possibly to the fact that I have printed on matte paper. In reality the pictures look great.

<br><br>

So, here's the one exposed normally:<div></div>

[Vlad Soare]

The same picture, made at ASA 6 with the 720nm filter:<div></div>

[Vlad Soare]

And another one:<div></div>

[Vlad Soare]

Development: HC-110 dilution B, 9 minutes at 20 degrees Centigrade.

<br>

I forgot to answer your question. No, the film did not curl. It gave me no trouble at all.

[Vlad Soare]

I made a mistake above. The filtered exposures were 1/30s, not 1/15s.

[carrotblog__miffy_]

Hi Vlad!

 

Looks very good from here. I imagine it must look better if you can get the scanning issues sorted.

 

I think you've got a much better infrared response due to rating the film (overexposing slightly?) lower at ISO 6!

 

 

 

Many thanks for showing!

 

xo

 

Miffy

[Vlad Soare]

I "overexposed" in regard to their recommendations, but the frame wasn't actually overexposed. On the lightbox the ASA 12 frame is clearly underexposed. It's thin and low in contrast. On the other hand, the frame exposed at ASA 6 is indistinguishable from the frame exposed at ASA 400 with no filter, as far as density, contrast and detail level are concerned. A further proof was that I printed the ASA 6 frame with the same contrast filter (2+1/2) and the same exposure time as the normal frame. It's a straight print - no dodge/burn, no split contrast.<br>

<br>

Now I'm thinking of something else. The IR filter doesn't work exactly like an on-off switch. It has a 50% transmission level at 720 nm, which rapidly increases above 720 and decreases below 720. What would happen if we used two stacked filters? Theoretically, the amount of light above 720 will not suffer (at least not to a noticeable degree), but the amount of light below 720 will be greatly reduced. Will this enhance the infrared effect?

[carrotblog__miffy_]

Sounds like it might work. I was looking at a 750nm filter, but then the spectrum suggests this would require severe compensation just to register an image. Maybe the 780nm is too extreme.

 

The stacked 720nm filters would then introduce a huge filter compensation factor! Then nothing will be sharp unless it's a rock.

 

There's plenty of IR effect in the images with the coniferous vs deciduous trees and foliage.

 

xo

 

Miffy