Rollei Infrared exposure with Hoya r72

[Ivo Stunga]

Focus correction is not necessary with current IR films

That's my finding exactly - the extended red being so close to visible that no practical compensation is necessary.

All we need is an ortho film with IR dyes and no AH layer.

Or wash off that layer and glue white sticker to the pressure plate to emulate the effect pretty closely. This neatly increases the practical speed too due to missing AH layer + reflections/scattering from the now white film pressure plate. Up to about a stop or two. Goes best with soft/underperforming lenses to further the bloom/dreamy effect.

 

[Helge]

That's my finding exactly - the extended red being so close to visible that no practical compensation is necessary.


Or wash off that layer and glue white sticker to the pressure plate to emulate the effect pretty closely. This neatly increases the practical speed too due to missing AH layer + reflections/scattering from the now white film pressure plate. Up to about a stop or two. Goes best with soft/underperforming lenses to further the bloom/dreamy effect.

Still would not get the hole in the response that allows use of red or even yellow filters for Woods, Rayleigh, haze penetration and contrasty shade.

 

[Ivo Stunga]

Of course, but this makes a rather nice emulation exercise.

 

[Jimi3]

Well, I shot/developed/partially scanned a few rolls of 120 with my 4x5 and 6x9 back, and I’m consistently getting good results at 50 or 25 iso when overcast, and 100 or 50 in sun. My shutter speeds are accurate, so unless my Sekonic light meter is off, I’m sticking with those ratings.

I’ll try to post some examples soon.

 

[pentaxuser]

Well, I shot/developed/partially scanned a few rolls of 120 with my 4x5 and 6x9 back, and I’m consistently getting good results at 50 or 25 iso when overcast, and 100 or 50 in sun. My shutter speeds are accurate, so unless my Sekonic light meter is off, I’m sticking with those ratings.

I’ll try to post some examples soon.

I look forward to those Given accurate shutter speeds and a Sekonic light meter which is a reliable make with a good reputation I have hope that I may be able to re-appraise the general advice on suitable EIs

pentaxuser

 

[Sirius Glass]

Well, I shot/developed/partially scanned a few rolls of 120 with my 4x5 and 6x9 back, and I’m consistently getting good results at 50 or 25 iso when overcast, and 100 or 50 in sun. My shutter speeds are accurate, so unless my Sekonic light meter is off, I’m sticking with those ratings.

I’ll try to post some examples soon.

With or without a red filter of some flavor?

 

[reddesert]

3 pages of this thread and it hasn't been resolved whether the OP's iso 50 is metering through the filter, or without a filter.

If the film is nominally ISO 200, and you take a reading without filter and compensate by 5 stops for R72, that's ISO 6. But if you set ISO 6 on the camera meter and meter through the filter, now you're going to overexpose by however much the filter cuts light to the meter (depends on the meter, could easily be 3 stops).

 

[pentaxuser]

3 pages of this thread and it hasn't been resolved whether the OP's iso 50 is metering through the filter, or without a filter.

If the film is nominally ISO 200, and you take a reading without filter and compensate by 5 stops for R72, that's ISO 6. But if you set ISO 6 on the camera meter and meter through the filter, now you're going to overexpose by however much the filter cuts light to the meter (depends on the meter, could easily be 3 stops).

So what would you ask him to establish whether he is metering though the filter, in his case an R72? His #54 and all his previous replies suggest to me that he gets to EI 50 from what he regards as the speed of Rollei 400 i.e. 400 so EI 50 from that equals 3 stops and that is what he applies for the R72. Yes it is remarkably high by consensus standards

However on the general subject of trying to be sure we know exactly what any person means I do agree that we often "tell" (usually what we do and works for us) rather than ask more questions. Sometimes we even get sidetracked into having conversations with each other instead of the OP

I also agree that being persistent in being absolutely sure we know what someone is telling us is actually what he is telling us can be difficult and can seem to some to be rude so isn't done as thoroughly as it should be but unless we do this it can be a disservice to the OP

pentaxuser

 

[Jimi3]

So what would you ask him to establish whether he is metering though the filter, in his case an R72? His #54 and all his previous replies suggest to me that he gets to EI 50 from what he regards as the speed of Rollei 400 i.e. 400 so EI 50 from that equals 3 stops and that is what he applies for the R72. Yes it is remarkably high by consensus standards

However on the general subject of trying to be sure we know exactly what any person means I do agree that we often "tell" (usually what we do and works for us) rather than ask more questions. Sometimes we even get sidetracked into having conversations with each other instead of the OP

I also agree that being persistent in being absolutely sure we know what someone is telling us is actually what he is telling us can be difficult and can seem to some to be rude so isn't done as thoroughly as it should be but unless we do this it can be a disservice to the OP

pentaxuser

Yes, I’m exposing through an r72 filter. So I am metering at, say, iso 50 and that is already taking the filter into account. Of course, I could meter at the film’s speed of 400 and apply a filter factor of 3 stops to arrive at the same exposure.

I’m not finding it necessary to apply more than a four stop filter factor - or set my meter for iso 25. And that’s primarily on cloudy days. I realize this seems unusual, and I’m not sure how to explain the discrepancy. But when I metered at iso 6/6 stops I was massively overexposing the film.

 

[Sirius Glass]

Yes, I’m exposing through an r72 filter. So I am metering at, say, iso 50 and that is already taking the filter into account. Of course, I could meter at the film’s speed of 400 and apply a filter factor of 3 stops to arrive at the same exposure.

I’m not finding it necessary to apply more than a four stop filter factor - or set my meter for iso 25. And that’s primarily on cloudy days. I realize this seems unusual, and I’m not sure how to explain the discrepancy. But when I metered at iso 6/6 stops I was massively overexposing the film.

Ok I start at ISO 400 and adjust 5 f/stops, and you start at ISO 50 and make 3 f/stops

400 to 200 1 f/stop​

200 to 100 2 f/stops​

100 to 50 3 f/stops​

50 to 25 4 f/stops​

25 to 12.5 5 f/stops​

​

Versus​

50 to 25 1 f/stop​

25 to 12.5 2 f/stops​

12.5 to 6.25 2 f/stops

So we are 1 f/stop apart and using a filter factor of 4 would be "massively overexposing the film."

​

 

[Jimi3]

Ok I start at ISO 400 and adjust 5 f/stops, and you start at ISO 50 and make 3 f/stops

400 to 200 1 f/stop​

200 to 100 2 f/stops​

100 to 50 3 f/stops​

50 to 25 4 f/stops​

25 to 12.5 5 f/stops​

​

Versus​

50 to 25 1 f/stop​

25 to 12.5 2 f/stops​

12.5 to 6.25 2 f/stops

So we are 1 f/stop apart and using a filter factor of 4 would be "massively overexposing the film."

​

No, I’m also starting at 400, but then applying only three stops to reach 50. I’m not exposing at three stops over 50.

 

[Sirius Glass]

No, I’m also starting at 400, but then applying only three stops to reach 50. I’m not exposing at three stops over 50.

So overexposing by 2 f/stops compared with my exposure. Not as close as I had assumed. The filter factor of 5 f/stops is from the manufacturer. Well you have something that works for you and you have information from my work that you may want to try so see what the difference is for you. Also the type of light meter may be in play here. I use the Hasselblad 45° PME prism which was factory calibrated. Which light meter do you use and have you ever had it calibrated at a lab with a calibrated source?

 

[Jimi3]

I’ve been using a Sekonic l-478dr that I picked up used. I haven’t calibrated it, but I’ve had good results when using it with other (visible wavelength) films so I’m assuming it’s fairly accurate. The other variable is that lately I’m using a 5 degree spot attachment - I’ve been trying to read off objects that should fall in the middle of the gray scale. Obviously that’s a little tricky with infrared, but my results have been fairly consistent. And on a totally overcast day, a lot of the scene falls in the middle.

 

[Sirius Glass]

I’ve been using a Sekonic l-478dr that I picked up used. I haven’t calibrated it, but I’ve had good results when using it with other (visible wavelength) films so I’m assuming it’s fairly accurate. The other variable is that lately I’m using a 5 degree spot attachment - I’ve been trying to read off objects that should fall in the middle of the gray scale. Obviously that’s a little tricky with infrared, but my results have been fairly consistent. And on a totally overcast day, a lot of the scene falls in the middle.

I have not used my Pentax Digital Spot Meter [1 degree] for infrared photographs. I am using a general reading without the sky in the field of view of the sensor.

 

[Jimi3]

I have not used my Pentax Digital Spot Meter [1 degree] for infrared photographs. I am using a general reading without the sky in the field of view of the sensor.

yeah, a wider average of the scene would probably be better, but my meter is either spot or incident, so I’ve just been trying to judiciously use the spot function.

 

[Ivo Stunga]

I’m not finding it necessary to apply more than a four stop filter factor

My experience exactly with Hoya RG715 / Digital King IR72 + current NIR sensitive films + BW reversal + OM-1n built-in meter:
https://www.flickr.com/search/?user_id=108634366@N07&tags=InfraredSlides

 

[reddesert]

Yes, I’m exposing through an r72 filter. So I am metering at, say, iso 50 and that is already taking the filter into account. Of course, I could meter at the film’s speed of 400 and apply a filter factor of 3 stops to arrive at the same exposure.

I’m not finding it necessary to apply more than a four stop filter factor - or set my meter for iso 25. And that’s primarily on cloudy days. I realize this seems unusual, and I’m not sure how to explain the discrepancy. But when I metered at iso 6/6 stops I was massively overexposing the film.

Sorry, in order to understand this a little more information is needed. When you say you are "taking the filter into account," what literally are you doing? For example some possibilities:

Example 1. TTL metering through the filter: I am setting the camera's iso at 50, putting an R72 filter on the lens, and exposing at whatever the camera's meter says to do.

Example 2: TTL metering w/o filter: I set the camera at iso 50, meter without the filter, set the exposure, then screw the filter on the lens and shoot.

Example 3. Filter factor: I am setting my separate light meter (like your Sekonic) at iso 50, metering without the filter, and then applying a 3 stop filter factor when transferring the exposure from meter to camera.

Example 4. No filter factor: I am setting my light meter at iso 50, metering without the filter, and transferring the exposure directly to camera w/o filter factor. (That's what I think you said above, but just trying to be sure.)

Example 5. Non-TTL metering with filter: I'm holding the filter in front of the light meter to take the reading before putting the filter on the lens, etc.

This may be belaboring the subject, but these examples wind up with different effective ISOs, and you have both a TTL and a non-TTL meter, so it's hard to know exactly how your process might be the same or different as other users. As far as I know, the usual ISO 6 advice builds the filter factor in for non-TTL metering (like example 4, but setting the non-TTL meter at ISO 6).

 

[Jimi3]

Sorry, in order to understand this a little more information is needed. When you say you are "taking the filter into account," what literally are you doing? For example some possibilities:

Example 1. TTL metering through the filter: I am setting the camera's iso at 50, putting an R72 filter on the lens, and exposing at whatever the camera's meter says to do.

Example 2: TTL metering w/o filter: I set the camera at iso 50, meter without the filter, set the exposure, then screw the filter on the lens and shoot.

Example 3. Filter factor: I am setting my separate light meter (like your Sekonic) at iso 50, metering without the filter, and then applying a 3 stop filter factor when transferring the exposure from meter to camera.

Example 4. No filter factor: I am setting my light meter at iso 50, metering without the filter, and transferring the exposure directly to camera w/o filter factor. (That's what I think you said above, but just trying to be sure.)

Example 5. Non-TTL metering with filter: I'm holding the filter in front of the light meter to take the reading before putting the filter on the lens, etc.

This may be belaboring the subject, but these examples wind up with different effective ISOs, and you have both a TTL and a non-TTL meter, so it's hard to know exactly how your process might be the same or different as other users. As far as I know, the usual ISO 6 advice builds the filter factor in for non-TTL metering (like example 4, but setting the non-TTL meter at ISO 6).

You’ve got it with your example #4. I’m shooting 4x5 film or 120 film in a 6x9 back on the view camera, so there’s no internal meter. Hence the external Sekonic handheld meter, set to iso 50, or even 100 in bright sun. The exposure that yields is transferred directly to the camera with no additional filter factor applied.

 

[Ivo Stunga]

Then I'd be surprised if you don't have underexposed film on your hands. By 2 stops at least. Can you provide examples?

I know from my experience/processing that "filter factor" of 6 will yield overexposed slides, but doing absolutely no "filter factor" - underexposed. So based on my preferences and observations, I'm somewhere in the middle of consensus: in my experience and processing I know that I need "filter factor" of 2-3 stops in sunlight and 4-5 in shade/overcast + a tad more for shooting IR in premises.

EDIT:
To elaborate, my process is:
1) I read the scene with my OM-1n built-in light meter exactly the way I'd like to capture it in visible light, sometimes I double-check it with Android app;
2.1) When I have a tripod, I'm prioritizing aperture, therefore I set it to my liking;
2.2) sometimes I do handheld IR on the go, then I prioritize the shutter speed: I'm setting it at/above focal length to avoid camera shake.
3) I set the parameters in camera and give the according "overexposure"/"filter factor" to arrive at the exposure I like. It's recommended to bracket the scene and usually the first value gives me best exposures.

Handheld IR is very doable with SLR and that magnetic filter adapter.

 

[Jimi3]

Then I'd be surprised if you don't have underexposed film on your hands. By 2 stops at least. Can you provide examples?

I know from my experience/processing that "filter factor" of 6 will yield overexposed slides, but doing absolutely no "filter factor" - underexposed. So based on my preferences and observations, I'm somewhere in the middle of consensus: in my experience and processing I know that I need "filter factor" of 2-3 stops in sunlight and 4-5 in shade/overcast + a tad more for shooting IR in premises.

Sure, I have some scans I can upload. It’s late here though, so probably tomorrow.

 

[Ivo Stunga]

Please do so and provide the pic of the negative if possible, please.


Some examples from my exposures:

Māras dīķis by Ivo Stunga, on Flickr
4 stops in cloudy sunlight resulted in slight overexposure, reduced it in Lightroom


Pareidolia | Kodama by Ivo Stunga, on Flickr
IR close-up, 4 stops in shade


URBEX LV : Infrared by Ivo Stunga, on Flickr
IR in premises, 5 stops

 

[markjwyatt]

You’ve got it with your example #4. I’m shooting 4x5 film or 120 film in a 6x9 back on the view camera, so there’s no internal meter. Hence the external Sekonic handheld meter, set to iso 50, or even 100 in bright sun. The exposure that yields is transferred directly to the camera with no additional filter factor applied.

I would be curious to see your shot in direct sunlight. I find 5 stops (equivalent of ISO 12) works well for me, similar to Sirius. I meter reflected whole scene or incident, ISO 12 then transfer to the camera with IR72.

The difference may be that you are using a spot meter on "rocks or grass" to put those in zone V (or interpreting term as zone V), which should be consistent. The two pictures you shared looked good and exhibited Woods effect, but perhaps had less Woods effect than I normally get, but if that is what you are after, that is fine. In my case, I may have some highlights blown out in some shots, so dropping a stop, maybe even two may be consistent with your results.

I think you easily have 1-2 stops latitude, and it depends on the effect you want to get. Even at ISO 12 or even 6 equivalent, sometimes the Woods effect is less than I expect, so if I were to use ISO 25 or 50, I risk not getting enough Woods effect in those scenarios. I have always been taught that IR film can be pretty tricky, and we cannot meter directly for NIR, so there will always be surprises.

Then I'd be surprised if you don't have underexposed film on your hands. By 2 stops at least. Can you provide examples?

I know from my experience/processing that "filter factor" of 6 will yield overexposed slides, but doing absolutely no "filter factor" - underexposed. So based on my preferences and observations, I'm somewhere in the middle of consensus: in my experience and processing I know that I need "filter factor" of 2-3 stops in sunlight and 4-5 in shade/overcast + a tad more for shooting IR in premises.

Your 3 stops in sunlight is consistent what Jimi3 is getting (50X2X2X2=400).

 

[markjwyatt]

Please do so and provide the pic of the negative if possible, please.


Some examples from my exposures:

Māras dīķis by Ivo Stunga, on Flickr
4 stops in cloudy sunlight resulted in slight overexposure, reduced it in Lightroom


Pareidolia | Kodama by Ivo Stunga, on Flickr
IR close-up, 4 stops in shade


URBEX LV : Infrared by Ivo Stunga, on Flickr
IR in premises, 5 stops

Your shots are definitely moderated to not lose highlights. You keep a lot of detail in the Woods effected areas, but it is still clearly Woods effect, and look great.

 

[markjwyatt]

Here are mine: https://www.flickr.com/search/?user_id=157638541@N07&view_all=1&text=IR and Rollei

They are either shot at ISO6 equivalent (the late March dates) or ISO 12 (the early April dates). That is 5-6 stops. I do lose some highlights, but get some dramatic effects. It is also clear that some vegetation does not respond the same as others, and that is a lot of the variability.

 

[Sirius Glass]

yeah, a wider average of the scene would probably be better, but my meter is either spot or incident, so I’ve just been trying to judiciously use the spot function.

Try the incident meter. People underrate its usefulness.