Ilford SFX and red windows

[TheFlyingCamera]

Red windows can be a bit more complicated than just a red window. My Zeiss Ikon cameras also have some felt around the edges of the red window where the hole meets the pressure plate. The idea is to prevent the light from leaking beyond the hole. If the backing paper is doing its job than the film should be fine but if the red window "leaks" light beyond the small area that enables you to read the backing numbers then it could fog film. It would surely reduce the chances of fogging to cover the window except when winding on the film.

That's what I was doing with the Maco... but the window very clearly bled through, even during the winding.

 

[Svenedin]

Ok but is it light going straight through the backing paper or leaking beyond the red window? It really shouldn’t be able to fog through the backing paper if you are opening and closing a window cover just to wind on. Is the film held taught and firmly against the pressure plate? You could test your camera in a dark room by holding backing paper in place on the pressure plate and shining a torch through the red window.

 

[Svenedin]

PS I have a Zeiss folder with 2 red windows (no covers) and it does not fog even with Ilford Delta 3200. I’ve rated that as high as 12,500. Ok that example isn’t IR but....

 

[Andrew O'Neill]

I have shot a few rolls in my Holga, but only with the red window covered with black electrician's tape. No leakage. If it can survive a Holga, it can survive anything.

 

[TheFlyingCamera]

Ok but is it light going straight through the backing paper or leaking beyond the red window? It really shouldn’t be able to fog through the backing paper if you are opening and closing a window cover just to wind on. Is the film held taught and firmly against the pressure plate? You could test your camera in a dark room by holding backing paper in place on the pressure plate and shining a torch through the red window.

Winding film through a 6x18 with a hemispheric film plane and no pressure plate is not a two-second affair. It is leaking exclusively through the red window, and I've only had it happen with the Maco 820c IR Aura. I've put Tri-X, PanF+ and Portra 400 through it with no problems.

 

[cowanw]

Ah. brain wave, now I understand your question, is the red window (and the paper) an IR blocker? Which is a different question than is it a visible light blocker. Some large format bellows do not block IR, for example. I fear only testing will tell.

 

[Svenedin]

Winding film through a 6x18 with a hemispheric film plane and no pressure plate is not a two-second affair. It is leaking exclusively through the red window, and I've only had it happen with the Maco 820c IR Aura. I've put Tri-X, PanF+ and Portra 400 through it with no problems.

OK. I looked at the information sheet for Maco 820c IR (http://www.maco-photo.de/files/images/MACO_TA820c_ENG.pdf). It appears to be much more easily fogged than the SFX and Rollei IR that I have successfully used in red window cameras. I assume that is due to the extended IR sensitivity as compared with Rollei IR and SFX. For 35mm Maco say it must be loaded in complete darkness.

All I can say is you should be OK with SFX. I have been and it does not have sensitivity nearly so far into the infrared.

Just out of interest, here are some pictures of the red windows on one of my Zeiss Ikon cameras. You can see the black felt that contacts the backing paper preventing spread of the light.

 

[Sirius Glass]

If it comes with a backing paper with numbers, then the intention is that those numbers will be read through a window.

If the backing paper does its job properly, it should be ok.


Steve.

I agree.

 

[trendland]

PS I have a Zeiss folder with 2 red windows (no covers) and it does not fog even with Ilford Delta 3200. I’ve rated that as high as 12,500. Ok that example isn’t IR but....

Yes I agree with you - it is almost relative from the dosis of light.
Light stenght x time !
Hold the backing paper agains a 12 kw floodlight and it will leak after a period of time.
At least it will burn due to temperature in concern of distance.
But normaly backing paper is just enough. It has to be light tight. ....
with regards

 

[pentaxuser]

We have different opinions here, as is often the case with Photrio. The key question is surely: What material can the spectrum of near IR and IR penetrate. Can it penetrate backing paper? If you placed the same kind of red window that you get on the back of folders plus a piece of backing paper over the lens such that it was completely covered and took a picture would you see anything on the film?

We know a lens cap made of plastic prevents all light entering the lens so that is safe with IR film. Is this because it is plastic and not paper or would thick paper in the form of a very thick paper lens cap which we call cardboard do the same job and if it does the same job as a plastic cap does the thickness matter such that stiff paper such as backing paper fails simply because it is not thick enough?

Given how long we have had Ilford near IR film such as fsx and given that you'd expect Ilford to recognise that amongst film users there still has to be a lot of folder users, albeit getting greyer and more wizened by the minute you'd expect Ilford to have issued a warning about the risk of using a red window folder with its film but it does not appear to do so. This would seem to be reinforced by its statement that sfx can be loaded in subdued light

pentaxuser

 

[cowanw]

And yet some plastic film developer tanks are not IR proof. Patterson's are apparently OK

 

[Svenedin]

We have different opinions here, as is often the case with Photrio. The key question is surely: What material can the spectrum of near IR and IR penetrate. Can it penetrate backing paper? If you placed the same kind of red window that you get on the back of folders plus a piece of backing paper over the lens such that it was completely covered and took a picture would you see anything on the film?

We know a lens cap made of plastic prevents all light entering the lens so that is safe with IR film. Is this because it is plastic and not paper or would thick paper in the form of a very thick paper lens cap which we call cardboard do the same job and if it does the same job as a plastic cap does the thickness matter such that stiff paper such as backing paper fails simply because it is not thick enough?

Given how long we have had Ilford near IR film such as fsx and given that you'd expect Ilford to recognise that amongst film users there still has to be a lot of folder users, albeit getting greyer and more wizened by the minute you'd expect Ilford to have issued a warning about the risk of using a red window folder with its film but it does not appear to do so. This would seem to be reinforced by its statement that sfx can be loaded in subdued light

pentaxuser

The OP had a fogged roll of an out of production film that has sensitivity further into the infrared than SFX has. My conclusion is SFX is likely to be fine in his camera based on SFX and Rollei infrared in my red window cameras. The Maco IR820c data sheet says 120 film can be loaded in subdued light but that the 35mm version must be loaded in complete darkness due to the possibility of light leaking through the light trap of the film cassette. No such advice for complete darkness is given by Ilford for SFX.

 

[trendland]

The OP had a fogged roll of an out of production film that has sensitivity further into the infrared than SFX has. My conclusion is SFX is likely to be fine in his camera based on SFX and Rollei infrared in my red window cameras. The Maco IR820c data sheet says 120 film can be loaded in subdued light but that the 35mm version must be loaded in complete darkness due to the possibility of light leaking through the light trap of the film cassette. No such advice for complete darkness is given by Ilford for SFX.

Yes thats right.The difference from advice to handle 135 IR films in total darkness (I often noticed such recomandations) and subdued light to 120 films is a little strange.
But it has obviously to do
with the part of 135 film at the beginning.
The film itself may transport the light.
So IR light (the part of spectrum) will pass a little distance from the first frames. That is a possible way I could imagine (we were using such phenomenon at the Air force with acrylic glass)

with regards

 

[pentaxuser]

And yet some plastic film developer tanks are not IR proof. Patterson's are apparently OK

Not wishing to divert the thread but this intrigues me. Can you say what those tanks are and why some plastic used for tanks should not be IR proof.? Thanks

pentaxuser

 

[Svenedin]

Yes thats right.The difference from advice to handle 135 IR films in total darkness (I often noticed such recomandations) and subdued light to 120 films is a little strange.
But it has obviously to do
with the part of 135 film at the beginning.
The film itself may transport the light.
So IR light (the part of spectrum) will pass a little distance from the first frames. That is a possible way I could imagine (we were using such phenomenon at the Air force with acrylic glass)

with regards

Yes it's to do with "light piping". Acetate base films are not too bad but PET base is a problem (Rollei IR is PET base as is 400S, 80S etc).

 

[Svenedin]

Not wishing to divert the thread but this intrigues me. Can you say what those tanks are and why some plastic used for tanks should not be IR proof.? Thanks

pentaxuser

This appears to be rather complicated.......

https://physics.stackexchange.com/questions/146451/what-common-materials-absorb-most-infrared-light

 

[cowanw]

Not wishing to divert the thread but this intrigues me. Can you say what those tanks are and why some plastic used for tanks should not be IR proof.? Thanks

pentaxuser

I am afraid not. I was pointing out that visible light blockers are not necessarily, or even likely, to be IR blockers, like the plastic bags in Svenedin's post. there are reports about the failure of both developing tanks and bellows. I suppose test and see are the watchwords.

 

[E. von Hoegh]

If you use 120 film the funktion of backing paper is to avoid any light.
If your film is exposed it has to guarantee this also (with some layers of it on the spole).
Comming to red windows : This window has no funktion today!
It was used as standard protection from cameras with no other closing mechanism - so it has to work 24/7.
But friends - if you store a 120 camera with film inside in direct sunlight to many
many hours (with red window protection)
you have to trust :
1) your camera of having no light leaks
2) the backing paper
3) not getting temperature problems

And the funktion of red window ?
It is just decoration from the 20th.
Same is to infrared film.
The spectrum of SFX is not the best.
But you obviously know this.
Rollei Retro80s is nearly the same or better just out of mind and cheaper.

with regards

Rubbish. I have several old folders on which the red window is the only way to advance film.

 

[Svenedin]

Rubbish. I have several old folders on which the red window is the only way to advance film.

So do I.

 

[darkroommike]

Did the old Kodak B&W IR film made for 120 and 620 back in the 50's have paper backing with numbers for use in cameras with red windows? I think it did. Something actually before my time as an active photographer(!), doesn't happen that much.

 

[cowanw]

Don't forget paper backing has changed since 1896, likely not for the good.

 

[Gerald C Koch]

Infra red radiation does not behave like visible light. Remember that some of the IR filters are opaque but still pass IR. It is entirely possible that the paper backing will behave the same. True IR film must be kept cool or it will fog rapidly.

 

[Gerald C Koch]

Did the old Kodak B&W IR film made for 120 and 620 back in the 50's have paper backing with numbers for use in cameras with red windows? I think it did. Something actually before my time as an active photographer(!), doesn't happen that much.

The practice goes back much further than the 50's. Unless you have a camera like the C3's that mechanically measure the amount of film for each advance you must use a red window and backing paper with frame numbers. I have a roll film camera with a green window. Not sure how that works.

 

[removedacct1]

I have used Ilford SFX quite a bit. I find that it handles differently than the Agfa IR film, in that it doesn't fog nearly as easily as the Agfa IR does. I've used both in my wood Vermeer 6X17 curved-plane panoramic camera and the agfa film fogs easily in that camera, and the SFX doesn't. Mind you, the fogging problem is not due to the red counter window - its because the wood itself is semi-permeable to IR radiation. I've had to wrap that camera in aluminum foil when taking it out loaded with the Agfa film.

 

[Svenedin]

I have used Ilford SFX quite a bit. I find that it handles differently than the Agfa IR film, in that it doesn't fog nearly as easily as the Agfa IR does. I've used both in my wood Vermeer 6X17 curved-plane panoramic camera and the agfa film fogs easily in that camera, and the SFX doesn't. Mind you, the fogging problem is not due to the red counter window - its because the wood itself is semi-permeable to IR radiation. I've had to wrap that camera in aluminum foil when taking it out loaded with the Agfa film.

So the “red window” is a “red herring”! The wooden camera is not completely opaque to IR.