Chamonix 45n bellows not infrared proof?

[Kirk Keyes]

Bill - have you tested your film holders? Maybe it's the holder and not the camera?

 

[keithwms]

Kirk raises a good point, and some of the IR films are especially susceptible to fogging from the sides- you can get a sort of light-piping effect from the film edges, and if your film holders aren't tip-top, you can see that. On that point, it is especially critical not to withdraw a darkslide all the way out. The way I track down light leaks from the holders and darkslide hatch is very simple- just re-insert the neg into the holder, the same way you loaded it for shooting. If the holder is the culprit then it will be immediately obvious. It's also a good idea to sort holders and their contents carefully when you develop so that you can track back any problems. I have set aside quite a few holders based on this simple detective work.

My own feeling is that if there is *any* doubt in the integrity of your bellows and/or particular holders then set them aside. With so many things that go wrong with an IR exposure, one has to eliminate each and every possible source of trouble... or else shooting simply becomes an exercise in frustration.

 

[Marco B]

The way I track down light leaks from the holders and darkslide hatch is very simple- just re-insert the neg into the holder, the same way you loaded it for shooting. If the holder is the culprit then it will be immediately obvious.

I think in general it's quite obvious with holders: light leaks are most likely at the top part of the holder, where you insert the darkslide, and it usually starts at the sides of the holder, in my experience. This leaves a very typical exposure pattern on the neg, and is probably easily distinguishable from the general IR fog Wildbill is writing about. If you still doubt it is the holder, you can use a small, strong, bundled flashlight (like a mini-maglite) to shine "through" the darkslides slit, and look from the other side. I have been able to confirm leaks at the sides of the darkslide's slit with it.

On that point, it is especially critical not to withdraw a darkslide all the way out.

I think there are two drawbacks to this: It may "hide" an already leaky holder, so if you are not consequent with removing the slide or not, you may find yourself wondering what went wrong on those occasions you do...

In addition, it makes the whole camera setup even more prone to camerashake caused by wind, than a LF rig already is. I always pull the darkslide fully if there is any wind at all.

 

[wildbill]

Bill - have you tested your film holders? Maybe it's the holder and not the camera?

I do have holders that aren't good for the kodak HIE but those only create leaks in specific corners and such. Read through my posts, I've ruled leaky holders out. When I switch the bellows to the leather shen hao bellows, the fogging issue goes away.

 

[BradS]

... When I switch the bellows to the leather shen hao bellows, the fogging issue goes away.

Sounds like you have pin-pointed the problem. The Chamonix bellows are not opaque to IR.

 

[storm]

I'm Chamonix 45n user, my first 4x5 IR shots on efke 820 was totally fogged, well I was thinking that it was holders light leaks, but fog was only on image area, 2 weeks ago I decided to shoot efke ir on 6x9 roll back. But this time I was using t-shirt as dark cloth, and fold it around bellows. Developed negative was clear from fog.
Few days ago I shoot some 4x5 efke ir with the same t-shirt on bellows. Holder was not cover by shirt, and in direct sunlight. Guess what? No fog

Well I will try to get ir proof bellows in future, but right now I will stick to t-shirt method.

 

[monst]

hiya all, have had no problems with my chamonix using rollei IR. here is a recent example:

 

[wildbill]

Monst, again, nice shot. That doesn't look like a situation where direct sunlight was hitting your camera but it does show what's most likely an issue with the bellows of your camera being from a different material than mine. What's your serial number?
Here's my latest from Hugo:
"Vinny,

The factory says that the bellows of serial #0201 was made earlier with a different cloth. They don't have that cloth anymore and they are not even sure that cloth is IR proof. The 45N-1 cameras was not designed for IR films. Now you have raised this issue and they will look at this thing in the future. Very few if any large format photographers use IR films in China.

You mentioned in your post that ShenHao has leather bellows that is IR proof. Can you use that bellows?

Sorry about this."

serial #0201 was from a camera that I saw had been used for ir w/o fogging issues. My camera is in the 034x range.
I've asked for specific serial numbers on the "new bellows" cameras but I'm still waiting for response.

 

[keithwms]

Well I will try to get ir proof bellows in future, but right now I will stick to t-shirt method.

Just be aware that cotton is not very IR proof! Other tshirts would be better.

 

[monst]

hiya wildbill, not exactly sure what my serial no is but it is quite low, will check it out. i did other shots in direct sunshine with exposures of 2-8 secs and they were good too.

 

[monst]

hiya wildbill,
0183 is the serial of mine.