Thank you. I’ve been reading more about the Rollei 400 IR and it seems most people prefer it over the Ilford SFX. I’ve ordered some and am looking forward to using it.
If I’m using the film unfiltered, I rate it at 160 ISO and when using the IR72 filter, I rate at 10 ISO, is that correct? I’d normally meter for the shadows and develop for the highlights, does this still apply with IR film?
Thank you for the info. Would the same apply to Rollei Infrared 400 (except the ISO rating). Just seen the price of Ilford SFX in the UK and it’s nearly twice the price of Rollei Infrared. Think I might try the Rollei first to experiment.
I prefer IR400, but it’s not 400. Closer to 160 probably. But the rating with a 720 filter is about the same. IE 10. Plenty fast for handheld in full sun.
It’s contrastier and finer grained than SFX.
Use a 40.5mm filter in the hood.
This is probably good: https://www.ebay.com/itm/4038950455...De7EmQ6S-q&var=&widget_ver=artemis&media=COPY
Never had problems with Chinese IR filters.
Thank you. I’ve been reading more about the Rollei 400 IR and it seems most people prefer it over the Ilford SFX. I’ve ordered some and am looking forward to using it.
If I’m using the film unfiltered, I rate it at 160 ISO and when using the IR72 filter, I rate at 10 ISO, is that correct? I’d normally meter for the shadows and develop for the highlights, does this still apply with IR film?
I strongly prefer Rollei Infrared 400 over Ilford SPF. With Rollei Infrared 400 is can get interesting differences between Red23, Red 25, Red 29 and 720.
...and Rollei IR is available in 4x5which is one reason why I choose it over SFX.
If I’m using the film unfiltered, I rate it at 160 ISO and when using the IR72 filter, I rate at 10 ISO, is that correct?
Not something that one should turn ones nose up on.
Use the meter for the whole scene, then subtract stops for how cloudy it is, or how deep the shade is.
For open sun I usually use the metering with no correction.
For a cloud across the sun, I subtract one or two stops.
In overcast weather it might be as much as three or four stops.
A powerful flash is actually helpful under such circumstances.
In a summer sunlit forrest there is a surprising amount of IR. Probably because the leaves diffuse and reflect IR. So you need only about one stop of compensation.
Can I ask. Is this metering without taking into consideration the necessary IR 72 filter or is this metering through the IR filter and then applying your rules shown above?
What kind of ISO do you use in each of the above situations with Rollei 400 IR film?
Thanks
pentaxuser
Not something that one should turn ones nose up on.
Can I ask. Is this metering without taking into consideration the necessary IR 72 filter or is this metering through the IR filter and then applying your rules shown above?
What kind of ISO do you use in each of the above situations with Rollei 400 IR film?
Thanks
pentaxuser
Meter at ISO 400, adjust 5 f/stops for the 720 aka 72 filter.
It’s not that simple. The response is rising after 700nm, where it drops of a cliff after 740.
And the 400 rating is pure fiction. You can push it that far, but it gets very contrasty.
If your bracket with temperamental film like this, you might be out of luck. And the nice thing about super panchromatic film such as AviPhot, is that you can remove the infrared filter and shoot “naked”, or with another filter without thinking about it, only adjusting the meter. For that you need the correct rating.Well Sirius's method gets him to 12 with a 400 film or 6 with a 200 which isn't much different to your baseline of 10 is it?
pentaxuser
Meter at ISO 400, adjust 5 f/stops for the 720 aka 72 filter.
Meter at ISO 400, adjust 5 f/stops for the 720 aka 72 filter.
It’s not that simple. The response is rising after 700nm, where it drops of a cliff after 740.
And the 400 rating is pure fiction. You can push it that far, but it gets very contrasty.
Well Sirius's method gets him to 12 with a 400 film or 6 with a 200 which isn't much different to your baseline of 10 is it?
pentaxuser
So, Helge with your baseline of 10 can you describe what you do in the scenarios you mention in #76 as follows:
For open sun I usually use the metering with no correction.
For a cloud across the sun, I subtract one or two stops.
In overcast weather it might be as much as three or four stops.
A powerful flash is actually helpful under such circumstances.
In a summer sunlit forrest there is a surprising amount of IR. Probably because the leaves diffuse and reflect IR. So you need only about one stop of compensation.
Can you also say what a powerful flash does. Yes it lights up the immediate foreground but that helps only the immediate and presumably shady few feet or is this for a scene in which there is only an immediate foreground which has a lot of IR producing material?
Thanks
pentaxuser
Yes, it is but it has only been working for me for over five years. Maybe after another five years it will stop working, you think?
But it consistently working.
There is working and there is Working™.
You can arrive at good enough results often, but it’s always good to know how and why.
OK, so there seems to be a difference of opinion and it’s very confusing for the beginner
Just to recap… if the box speed is more like 160, not 400 and I use an IR72 filter, which needs an extra 5 stops, my calculations would be to set my handheld meter to 5 ISO? I don’t have TTL metering, as I’m using a Fuji GF670W rangefinder.
I’ve also got used to metering for the shadows and placing them on zone 3 and with high contrast scenes, reducing the dev time. If this method doesn’t work, how can I capture a high contrast image without blowing the highlights or blocking up up the shadows?
OK, so there seems to be a difference of opinion and it’s very confusing for the beginner
Just to recap… if the box speed is more like 160, not 400 and I use an IR72 filter, which needs an extra 5 stops, my calculations would be to set my handheld meter to 5 ISO? I don’t have TTL metering, as I’m using a Fuji GF670W rangefinder.
I’ve also got used to metering for the shadows and placing them on zone 3 and with high contrast scenes, reducing the dev time. If this method doesn’t work, how can I capture a high contrast image without blowing the highlights or blocking up up the shadows?
Well, you can never be completely sure. Once in a while you will get a scene that totally overexposes or underexposes for seemingly no good reason.
That why it’s good to know the film, to factor as much of that uncertainty out of the equation.
My best advice WRT metering is to use incident metering where possible.
But often the most interesting scenes are impossible to meter with an incident dome.
For what it’s worth here is the datasheet for the emulsion: https://www.agfa.com/specialty-products/wp-content/uploads/sites/8/2017/06/AVIPHOT-PAN-200.pdf
Agfa G. rates it at 200, but that is through aerial perspective (ever-present haze) and for the generally low contrast targets of earth as seen from a plane. That will speed any film up.
Something like a Panaflasher would probably help with this film.
As for the exposure, that sounds workable, but it is always a good idea to bracket because the truth of the matter is that your meter doesn't actually read the same light you are recording on the film - it reads the light within the visible spectrum that accompanies the near-infrared light the filter is passing.
And the ratio of near-infrared to to visible varies due to a bunch of factors that are hard to measure or control - things like how much the foliage in your subject is reflecting near-infrared.
Using these films involves a certain amount of experience based educated guessing. That is part of the fun!
As for "contrast", I think your concern is probably better referred to as Subject Luminance Range - how "bright" the highlights are, vs. how "dark" the shadows are. You may notice that "bright" and "dark" are in quotes here, because it isn't how "bright" or "dark" they look, but rather how much or how little near-infrared light is reflecting off those parts of the subject, something that neither our eyes or our meters can see.
The flash is of course to light up foreground if it’s on camera flash. Can be useful in the shade and for pure effect.
But I have tried crazy stuff like bringing all my nine Cactus V5 triggers to the park with V285s on each.
That sure creates some interesting effects. But you probably need an assistant to watch the equipment, time to set it up and of course clear intent.
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