Please help me identify the source of this light leak on my negatives.

[cirwin2010]

Problem: Most of my hp5 4x5 negatives are fogged. The side of the film with the notch codes will be darker than the other side and it forms a bit of a gradient. The fog is present in the film rebate area which is where it is most obvious. I will occasionally get a "clean" negative, but I cannot pinpoint the cause of the problem. I originally thought it was an issue with my sp-445 developing tank, but switching to a Paterson tank has not resolved the problem. See first attached image.


Equipment:
-New Chamonix 45F-2 camera
-New Toyo film holders and older Riteway & Lisco Regal holders


What I have tried to reproduce the issue (see second image):

1. Developed a negative from my box of new film to see if the box got fogged. Negative came out completely clear

2. Put a film holder into the camera, removed the dark slide, and shined a bright light on the camera to check for light leaks. Negative came out completely clear.

3. Put a film holder into the camera, removed the dark slide, and pulled the film holder slightly away from the body. This was an attempt to compare this type of light leak to what I have been getting. Negative rebates came out completely clear unlike the "bad" images.

4. Over exposed an image in camera to test if the issue is light piping or internal reflections from long exposures. Negative rebates came out completely clear.

NOTE: all above tests took place with Toyo film holders since these are what I normally use.


The above tests would lead me to believe that "bad negatives" I have been getting were a fluke. However, I went and shot more hp5 after and got more of the same results. I also exposed some fp4 in some Riteway film holders. The film rebates on those are clear. I am uncertain if the problem with my other negatives simply did not occur for those images or if the film is not sensitive enough to show the problem.


This problem is really dragging me down. I want to use my new 4x5 camera for my serious projects, but I cannot with these unreliable results. Please help me.
230873
230874

[sharktooth]

That's a strange one for sure.

The tests you did to see if you could reproduce the problem seem to be appropriate. There is some fogging on the notched end of the one where you pulled the holder away from the back, but it's not quite the same as on your original problem shots.

The rebate area on the overexposed test shot is clear, so that seems to indicate the problem was only with your original shots. One possible scenario is that the box of film may have been opened and accidentally exposed to light. If that happened, the top sheet (or sheets) may have been partially fogged, but the lower sheets were protected by the ones above. Stranger things have happened, but that's all I can think of at the moment

[cirwin2010]

That's a strange one for sure.

The tests you did to see if you could reproduce the problem seem to be appropriate. There is some fogging on the notched end of the one where you pulled the holder away from the back, but it's not quite the same as on your original problem shots.

The rebate area on the overexposed test shot is clear, so that seems to indicate the problem was only with your original shots. One possible scenario is that the box of film may have been opened and accidentally exposed to light. If that happened, the top sheet (or sheets) may have been partially fogged, but the lower sheets were protected by the ones above. Stranger things have happened, but that's all I can think of at the moment

I thought that too regarding the box of film. However, this issue has survived through two boxes of HP5+ and occurred once again after running these tests. The film I am using should be fine.

[sharktooth]

The tests you've done all make perfect sense, yet they didn't display any unexpected problems. This begs the next question about why the test shots all came out as you'd expect. There has to be something different in how you're setting up your regular shots compared to your test shots. Either that, or it's an intermittent issue which your tests didn't capture. Based on your description, the problem seems to be more constant than intermittent.

Since the camera is new, I'd remove the bellows and back from the camera, and then reinstall them. Maybe the bellow or back hasn't been attached correctly, so a re-installation may correct that or make any fault more apparent.

[sharktooth]

Some other things to consider:

1) How are you loading film holders? Are you using a changing bag or doing it in a darkroom. What is the potential for accidental fogging?

2) How are you handling the film to get it in the processing tank? Are you doing this in a changing bag or in a darkroom?

3) Are you being extra cautious when removing the dark slide to ensure that you're not pulling the film holder away from the camera back?

4) Is the film holder held tight to the camera back by the spring back?

5) Does the film holder orientation have any affect on the problem (horizontal/vertical)?

[cirwin2010]

The tests you've done all make perfect sense, yet they didn't display any unexpected problems. This begs the next question about why the test shots all came out as you'd expect. There has to be something different in how you're setting up your regular shots compared to your test shots. Either that, or it's an intermittent issue which your tests didn't capture. Based on your description, the problem seems to be more constant than intermittent.

Since the camera is new, I'd remove the bellows and back from the camera, and then reinstall them. Maybe the bellow or back hasn't been attached correctly, so a re-installation may correct that or make any fault more apparent.

I've checked the bellows using a bright light source in a dark room. I've also refitted them to the camera and everything seems fine. I would not think a light leak from the bellows would fog the film rebates, but who knows at this point.

[cirwin2010]

Some other things to consider:

1) How are you loading film holders? Are you using a changing bag or doing it in a darkroom. What is the potential for accidental fogging?

2) How are you handling the film to get it in the processing tank? Are you doing this in a changing bag or in a darkroom?

3) Are you being extra cautious when removing the dark slide to ensure that you're not pulling the film holder away from the camera back?

4) Is the film holder held tight to the camera back by the spring back?

5) Does the film holder orientation have any affect on the problem (horizontal/vertical)?


1) Film is loaded in my blacked out basement, at night, with all lights and light sources off in the basement and the floor above. It is the darkest place I have ever been. My test of developing the film straight from the box should also prove that this is sufficiently dark

2) Film is being loaded into my processing tanks in a dark bag. My dark bag is known to be good since I primarily use it with 120 film and I've never had a light leak issue with those.

3) I've been exercising as much caution with removing the dark slide as I think I can. I pull it straight out while gently holding the back of the camera to ensure the film holder does not move.

4) I've checked by using a bright flashlight in a dark room while looking through the bellows. My other tests should also show this is fine as well. My deliberate light leak also demonstrated that if the film hold is not properly secure to the camera, the film edges covered by the film holder would not be exposed.

5) I think I have gotten fogged verticals, but I have not checked this recently.

[sharktooth]

4) I've checked by using a bright flashlight in a dark room while looking through the bellows. My other tests should also show this is fine as well. My deliberate light leak also demonstrated that if the film hold is not properly secure to the camera, the film edges covered by the film holder would not be exposed.


That's not entirely correct. Your test shot with the film holder pulled away from the back clearly shows fog at the notched end of the film, as well as a short distance along the sides at the notched end. It doesn't look the same as your other sample shots with the problem, but it trends that way.

Light coming through the lens can't expose the rebate area of your film, but light coming from other areas certainly can.

I'd be suspicious of anything that can be changed during normal shooting. For example, if you change the film back orientation from vertical to horizontal the back may not have been seated properly, and a light leak was the result. The problem would continue until you changed the orientation again and reseated the back properly. This may explain long term intermittency.

If you're new to large format work then it might be something as simple as not inserting the film holder far enough, or too far. There is a ridge on the film holder that drops into a groove in the camera back to set the position. In some cameras it's hard to tell if the film holder has been fully inserted. It can feel like the film holder has been fully inserted, but in actuality it's sitting on that ridge and not properly seated. A light leak will definitely be possible.

[cirwin2010]

That's not entirely correct. Your test shot with the film holder pulled away from the back clearly shows fog at the notched end of the film, as well as a short distance along the sides at the notched end. It doesn't look the same as your other sample shots with the problem, but it trends that way.

Light coming through the lens can't expose the rebate area of your film, but light coming from other areas certainly can.

I'd be suspicious of anything that can be changed during normal shooting. For example, if you change the film back orientation from vertical to horizontal the back may not have been seated properly, and a light leak was the result. The problem would continue until you changed the orientation again and reseated the back properly. This may explain long term intermittency.

If you're new to large format work then it might be something as simple as not inserting the film holder far enough, or too far. There is a ridge on the film holder that drops into a groove in the camera back to set the position. In some cameras it's hard to tell if the film holder has been fully inserted. It can feel like the film holder has been fully inserted, but in actuality it's sitting on that ridge and not properly seated. A light leak will definitely be possible.

I suppose you are right about the nature of the sheet with the deliberate light leak. I wonder if I pulled the film holder away from the other edge if it would look closer to the results I am getting. Might be something to try later.

I have ensured that back assembly of the camera is properly seated. Also each time I insert a film holder, I give it a bit of a wiggles to check that the ridge is properly seated in the camera body.

[Doremus Scudder]

If I remember correctly, some Toyo holders had problems with the dark slides not being completely opaque (search here and on Photrio; there were a couple of threads about the problem).

If that is your problem, then the holders that were exposed to the most light with the dark slides in place would be the ones that exhibit the fogging. You might test yours by placing them, loaded, in bright sunlight for a time and then developing the negatives.

Hope this helps,

Doremus

[jnantz]

was the film fresh when you bought it, or a partial box ?

[sharktooth]

Also each time I insert a film holder, I give it a bit of a wiggles to check that the ridge is properly seated in the camera body.

I'm not convinced that wiggling the film holder is a good way to ensure the holder has been properly inserted. From my own experience, I've done exactly that, and know that it isn't reliable. I use both regular film holders and Grafmatic holders, and I now do a visual check as well as the wiggle check. It's easy on my Linhof backs, since they have an end stop that prevents you from pushing the holder in too far. I always do the visual check that the film holder is all the way to that end stop. I've surprised myself several times by discovering that the film holder was nowhere near the end stop even when I was certain that it had been installed properly by feel.

I'd suggest creating some sort of secondary visual check for your Chamonix, but it will likely be different from what I do, since the Chamonix has a different back style. Unfortunately, you can't see if the film holder ridge is in the camera back groove, so you'll have to find some other visible indicator. Take the spring back with ground glass off the camera, and put the film holder in place with it's ridge in the camera back groove. Then check for something you can use as a visual reference point for proper installation.

I say this since you've pretty much ruled out other causes, other than the defective film holders/dark slides as Doremus Scudder pointed out.
,

[Vaughn]

Rebates are fogged...so the fogging happened when the film was not in the holders.
Developing tanks changed with no difference. Film in box okay.
Fogging therefore occurs while handling film while loading and/or unloading the film from the film holders...
...or into the developing tanks.

[Greg]

A few years ago when I finished construction of my darkroom, I seemingly randomly got fogged areas on some of my sheet film. At first I thought it was caused in-camera. In maybe one out of four developing sessions I got random fogged areas. Finally narrowed it down to what was happening... I have a hung ceiling in the darkroom except for foiled covered ducts. On the other side of the wall that the foil covered overhead air ducts come through is my worktable. Above my worktable is the foil covered duct with 4 foot LED hanging light fixtures on each side of the duct. Where the foil covered ductwork came through the wall, I studded the opening just a wee bit larger than the dimensions of the foil covered duct, and then used black caulking to seal 100% of it, or so I thought. Probably a mere 2% was not sealed and that was the problem. If the LED lights over my workbench were off, no problem. If they were on... problem. Light from them "light piped" along the foil covered duct and shined down onto the counter where I loaded and unloaded my film. Loading and unloading film on the right side of the counter - no problem. Loading and unloading film on the left side of the counter - big problem. Now here comes the clincher... since the 1970s I have always closed my eyes when loading and unloading film. Proved to be my Achilles Heel... I never noticed the light leak from above. Only when I had the LED lights above my workbench on, and I went into the darkroom and acclimatized my eyes to the dark did I see the light leak(s) shining down on to the counter.

[sharktooth]

Has the film been through any airport X-Ray scanners since you've had it? The general fogging could be caused by an X-Ray scanner, but I don't know how some sheets could remain unaffected. Maybe the sheets closest to the X-Ray source absorb most of the energy, and the sheets underneath are progressively less affected. I don't know if that's true, I'm just guessing. Another thing to consider anyway.

[jnantz]

X-ray damage doesn't seem to look like that
maybe there is something that glows in the dark in the OPs dark space

[Tobias Key]

Is it possible you have a bad light trap in one or more of your holders?

That would account for the random nature of the leaks as it would only happen when you use one particular side of one particular holder.
Might also mean that the you might have a trap that is 'good enough' in shady conditions or turned away from the sun but leaks if the sun shines directly on it.

I have had marginal light leaks that only reveal themselves in certain conditions but not in others. For example if you remove the slide and wait for the light the leak shows up, but not if you make an exposure and replace the slide quickly it doesn't.

Try making sure you drape your dark cloth over the camera when taking pictures - it is is a good habit to get into that will save you if a fault develops in field that you don't know about.

[sharktooth]

Other than fogging by light, there's also the possibility of chemical fogging.

How are you handling and mixing developer? Is there a chance for contamination of batches?

The E6 process uses an aggressive fogging agent prior to the color developer (or in the color developer, depending on the type of kit). There are other things that could contaminate developer, but we're starting to grasp at straws here.

I guess the key point is that you've made 3 test shots where you "intentionally" tried to recreate the problem, yet they showed no unexpected problems at all. You've got to figure out what was different about the entire process for those shots.

[Bernice Loui]

Changing bag story from long ago...

Some time in the late 1980's Photoflex sold a changing tent that poped up with internal supports and all. Looked like a R2D2 robot set up. This "light tight" changing tent had twin layers of "light proof coated frabic, dual layer zippers, elastic sleeves and all.. Worked ok when new, after some time this changing tent developed a light leak wrecking more than one sheet of film.. Add to this dust and similar undersiable residue on the film and migration of this stuff into the film holder was just not worth the "convenience" of having a portable darken space to deal with film... Gave up on the thing..

The better solution proved to be simply load and carry as many film holders as needed, in a seperate film holder case if needed.
Loading and unloading film into the developing/post process system in space specific to these needs are a far better way than a changing tent or similar device.


Bernice

[Vaughn]

On a road trip I might have thirty loaded 8x10 holders, a dozen 5x7, and a half-dozen 11x14. I go thru film slowly, so that's a couple weeks worth of traveling...usually not photographing all day everyday. Don't want to spend the rest of my life developing film...and I already have more negatives than I can print.

All fogged examples show a light even fogging from the notch end downwards, the decreasing quickly. That might tell you how it might have fogged the film in the loading tent. Was there a time when only the notched ends of the film would be more suseptable to fogging than the rest of the film?

[cirwin2010]

Okay everyone, I did some more testing and it has just left me with more questions than answers. Without going into all the details I think I can rule out bad film holders as the issue. I also think I can rule out light leaks in the camera causing the issue as well.

My last shoot consisted of HP5 loaded into two different types of film holders (Toyo & Riteway), and while the film edges don't appear fogged at first glance, compared to other negatives I have shot, they are slightly darker. With further inspection, the edges with the notch code are slightly darker on most of the shots (doesn't matter which film holder used). All the film in this "session" was loaded at the same time and developed in the same tank. Why are the rebates of some of the negatives darker than others? Shouldn't they all be the same?

I ended up taking a deep dive into all the 4x5 film I have ever shot. I have walked away with the following conclusions:
1. The problem only exists in my HP5 negatives, but the sample size of Catlabs 80 and FP4 film is comparatively small.
2. About 50% of my HP5 4x5 negatives display fogging and/or elevated base+fog
3. The edge containing the notch code is usually more fogged than other edges
4. The issue has occurred through 3 separate boxes of HP5
5. The issue has occurred through a variety of film holders and is intermittent with the same film holders

Concerning my development routine:
1. I use HC-110 dilution B or film rated iso 400 or higher
2. I only use HC-110 as a "one shot" solution
3. I use Ilford Rapid Fixer 1+4
4. Fixer is periodically replaced
5. Fogging issue is not linked to any changes in my development routine
6. Fogging does not occur with 120 roll film using the same development routine

Concerning my darkroom and film loading routine:
1. Film gets loaded into my developing tanks using a dark bag
2. My dark bag is known to be good. I have developed countless rolls of 120 film using this bag
3. For 4x5 I use a Paterson style tank and SP-445 and both have exhibited the fogging issue. I used a smaller Paterson tank for 120 film and that has never had a problem with light leaks
4. I load my 4x5 film into film holders outside of my changing bag to reduce dust issues and aid in ease of loading
4a. I perform this in my blacked out basement
4b. Only done at night with lights on the flood above turned off as my basement is not perfectly light sealed during the day
4c. All light sources are either turned off or covered
4d. I scan the room each time to check for any light sources after my eyes adjust


After reviewing all of my previously developed film and trying to replicate the issue, I'm looking at my film loading routine. Specially loading my film into the film holders as this occurs outside the dark bag.

Is it possible that there is some source of light that is not visible to the naked eye fogging a faster film (like HP5)? With paper you can get away with your darkroom not being perfectly light sealed, but film is obviously a lot more sensitive and iso 400 film is more sensitive still.

Is there any chance that long exposures (measured in minutes) could result in light piping through unexposed areas? I doubt this as not all my negatives shot in this way display this issue. But, of my last batch of developed film there was one negative that was more "fogged" than the others and this one happened to be overexposed in camera. Could be a fluke though.

There are two tests that seem obvious to me at this time:
1. Replicate my darkroom conditions for loading film and leave a sheet out for a long time then develop it. Check for any fogging.
2. Use my dark bag to load my film holders. I don't really want to do this because of dust, but I may need to for informational purposes.

[Vaughn]

If you can't see the light, there is none...especially after several minutes in the dark. Keep your eyes open.

One main clue is more fogging on the notch end. When is that end of the film more suspecptable to fogging than the other end?

[cirwin2010]

If you can't see the light, there is none...especially after several minutes in the dark. Keep your eyes open.

One main clue is more fogging on the notch end. When is that end of the film more suspecptable to fogging than the other end?

When I take the fresh film out of the box, I keep in in that cardboard folder its in. The notch side of the film and the adjacent boarders would be a bit more exposed I suppose. When loading the film holders, the notch side of the film would be exposed for very slightly longer than the rest. That is the only thing I can think of.

Also when I load film into my developing tanks, the notch side of the film is always facing up. But I put more than enough chemistry in my tanks to ensure that the film is covered.

[sharktooth]

Did you buy all your boxes of HP5 from the same store? Maybe they've got some issue with how they store the film (near a heat source maybe). it's still grasping at straws though.

[Vaughn]

When I take the fresh film out of the box, I keep in in that cardboard folder its in. The notch side of the film and the adjacent boarders would be a bit more exposed I suppose. When loading the film holders, the notch side of the film would be exposed for very slightly longer than the rest. That is the only thing I can think of.

Also when I load film into my developing tanks, the notch side of the film is always facing up. But I put more than enough chemistry in my tanks to ensure that the film is covered.

In those situations, the non-notch areas are more protected. Those are the times that need more attention. What is the possibility of an intermittent light in your film loading area? The fogging is being done from the notch end downward, slowly lessening. Light from one end would cause an even gradation like we are seeing.

IMO, it is not heat or chemical damage (that would be all or nothing), and not happening when the film is in the holders -- looking at the negatives rule that out for me. I spent a couple decades trouble-shooting students' 4x5 problems. Most likely not a factory-related problem...just one isolated case (single user) like this would be strange.

Keep on truckin'!

[sharktooth]

Some humidifiers and dehumidifiers use UV light to kill bacteria. You'd think devices like that would be well shielded, but who knows.

[Chuck Pere]

To get a more accurate check on film fogging you might want to give an unexposed piece of film a small pre-exposure. The film might be slightly fogged but not up to the threshold that is needed to show a density when developing an unexposed piece. If interested, you can search for film pre-exposure to find out how to do it.

[Doremus Scudder]

cirwin2010,

From your detailed explanation, I would, as you do, think to examine your film loading area for extraneous light sources. Don't just look from a standing position over the loading surface, get down to counter level and look from there. A mirror laid on the loading surface will help you to see what the film does as well. It doesn't take much of a leak to fog film that much. Phone screens, smart watches, indicator lights on things like electronics or GFI outlets, light from cracks in walls and window/door frames, etc., etc., are all enough.

A test might be to load a few holders in the dark bag (as much as you hate to do it) and see if any of those end up with the same fogging after exposing and developing.

There is a reason for this, so keep looking.

Best,

Doremus

[grat]

I'm starting to think UV or IR light coming from some source. FP4+ doesn't extend quite as far into the UV as HP5+, and it's slower speed.

If you've got a digital camera, try taking a really, really long exposure of your darkroom and see if anything lights up.

Or, if you have a friend who's into photography and hates you, see if someone put a glow-in-the-dark sticker inside your dark bag. :)

[cirwin2010]

I think I found the issue! TL;DR I think its stray light when loading the film holders.

I went out to shoot yesterday morning with film holders loaded up with HP5+ and FP4+. For each scene I took a shot on both film stocks. When developed the HP5+ displayed the same fogging as all my previous shots, but the FP4+ was not effected. Both were loaded at the same time in the same conditions.

Still trying to find evidence of the problem, I developed out four sheets of unexposed HP5 that I had loaded at the same time. Again, these were not loaded into the camera at all nor had their dark slide removed under any condition other than loading or unloading the film. This time, I got results.

The attached images are of the same negatives, but I tweaked the contrast of the second to try to better show the issue.

231296

231297

The fogging is not as obvious as on my other negatives, but it is there. If you look closely you will see a few things:

-There is slight fogging extending inward from the top and bottoms of the negatives
-One negative shows a clear line where light was blocked by the dark slide before I closed it all the way. Film rebates are also visible from light blocked by holder edges. A slight line if visible in person on another negative.
-There are a couple light patches near the edges of the film. I believe these are where light was blocked by my fingers when handling the film. This is more visible in person.

I think these negatives are clear evidence that the source of the fog is from something in the environment when loading the film. I still am unable to detect any light in my basement, but clearly there is a source of something that is not visible to my eyes that the HP5 is sensitive enough to pick up. I can't think of any sources of UV or IR in my basement, and I don't think there is anything radioactive down there (I hope).

I think my next course of action would be to get a fresh pack of HP5 and start using my dark bag for loading again. Not thrilled about that since it is a bit cumbersome and its harder to keep dust free. A changing tent may be a good investment, though expensive. Also maybe geiger counter as something to toy with ;)

[Doremus Scudder]

Maybe someone opened the box of film when the lights were on? Try developing a sheet directly from the box to see. Check the box for damage/holes as well.

Doremus

[Deyoung]

Would radiation be able to cause something like this? An old CRT screen (TV or Computer Monitor), microwave? or a high level of radon? It would seen these may have an effect, but only seen on higher asa film stocks. Just wondering out loud.

[cirwin2010]

Would radiation be able to cause something like this? An old CRT screen (TV or Computer Monitor), microwave? or a high level of radon? It would seen these may have an effect, but only seen on higher asa film stocks. Just wondering out loud.

Probably not. I'm not sure if radon gas would cause film to fog, but I got my basement tested for that and it would have effected roll film in my changing bag if it even could be a cause. I would also think that if putting slow film through an airport x-ray machine is "safe," then anything at home that is strong enough to fog film is likely a great cause for concern.

[Bill Poole]

+1 for developing a sheet directly from the box. Then from that box, or better yet a new one, maybe take a single sheet and leave it naked to your darkened loading area for perhaps 10 times longer than it would be exposed during loading. Develop both. If the first sheet is unfogged and the second one is distinctly fogged-- that would confirm your suspicion, yes? But I am betting that if you can't see light in your loading area after a few minutes with the lights out, then that is probably not the problem. Sorry for hassle. Must be very frustrating.

[Tim V]

I've been having a similar issue recently. At first I thought it was the tape seals / hinges of my 8x10" holders, but the more I thought about it and the longer I waited in the darkroom for my eyes adjust, I found the issue. Light was leaking in through a light fitting via the ceiling cavity. Impossible to see with the naked eye unless I'd been in the dark for more than 5-10 mins, but plain as day after that. It was so subtle I think under most circumstances it'd not cause a problem, but when loading film into my Jobo expert tanks I leave the the ends of the film sticking slightly above the tubes so I know which cavity has been loaded. Long story short, the first sheet loaded exhibited the worst effects, down to the last which was negligible. I'm really annoyed at myself, but live and learn. I can print them acceptably with extra care, so that's something.

[Vaughn]

Sheets have been developed straight from the box. (no fogging)
Film was NOT fogged while it was in the holders/camera. (rebate fogged)
NOT chemically fogged. (pattern of fogging).

I'll stick with poor handling while loading/unloading film from the holders.

[cirwin2010]

So I was wrong about everything. It was the Paterson dark bag. Turns out it actually isn't that dark. Was pretty apparent when I stuck my head in it near the light where I work. This would explain everything every single issue I've had. Never was a problem with my roll film due to how I would load that and it being a quicker process. The intermittent issues were from whether or not I had a particular light on in my basement when using the dark bag.

Sadly I think I may have lost over $100 of film though. Confident that the issue was from my space when loading outside of the dark bag, I loaded a bunch of Fp4 and HP5 last night from fresh boxes of film in my dark bag. This was in anticipation for a trip I'm taking today. But as a sanity check this morning I developed out a holder of hp5. I expected it to come out blank, but it was very fogged with shadow marks from the dark slide being partially removed. All of my film is potentially fogged now....

So turns out my dark space was fine, but the dark bag very much wasn't. I would have expected better from the Paterson bag, but it looks like I may need to look at a more expensive option.

Any suggestions on an actually "dark" bag/tent?

[jnantz]

if your space is dark and not light-leaky do you need a dark bag too ?
I would spend time making sure your space is light tight so you can load your film developing tanks and film holders
without the need of a dark bag. those things are always suspect

[cirwin2010]

if your space is dark and not light-leaky do you need a dark bag too ?
I would spend time making sure your space is light tight so you can load your film developing tanks and film holders
without the need of a dark bag. those things are always suspect

My basement is the only place in my house I can black out. But i isn't light leak free until night with all lights on the floor above turned off. It's definitely not dark enough for film during the day. It's not convenient at all hence why I use the dark bag for unloading the film typically. I think I may just need to buy a nice dark tent for loading film, it's just too bad they are so expensive (at least on B&H). But, might be worth it considering how much film I've burned through trying to figure out the issue.

[Bernice Loui]

See post# 19..
https://www.largeformatphotography.info/forum/showthread.php?170248-Please-help-me-identify-the-source-of-this-light-leak-on-my-negatives/page2

Highly suggest giving up the idea or try using a dark bag or "film" changing tent. IMO, they are a great source of great grief over the passage of sheet film usage. They all fail eventually, not a matter of if, matter of when.. and they usually fail with zero warning causing !_!_!_! when failure from light leaks can be least tolerated.

The better way, simply load as many film holders as needed and a few extra if needed in proven dark and film exposure safe area. This same area also serves to unload film and loading the exposed sheet film for processing.

You've lost FAR more than $100 over this episode.. consider your time lost (not replaceable), frustration, resources spent and much more.... what happened is waing to happen again if the dark bag/film changing tent is used again.

Personally, taken anywhere from 4 to 30 loaded film holders (5x7 or 13x18cm) on trips that go for a day or more days in the camera outfit case or a seperate film holder case. Make absolute sure ALL film holders are good with ZERO light leaks before doing this.


Bernice



My basement is the only place in my house I can black out. But i isn't light leak free until night with all lights on the floor above turned off. It's definitely not dark enough for film during the day. It's not convenient at all hence why I use the dark bag for unloading the film typically. I think I may just need to buy a nice dark tent for loading film, it's just too bad they are so expensive (at least on B&H). But, might be worth it considering how much film I've burned through trying to figure out the issue.

[Deyoung]

Not sure of your budget, but I really like the Harrison changing tent. I keep it unfolded when at home and roll it up in its bag when I'm on the road. Not had any problems.