Help: Diagnose exposure problem 35mm negative

I just developed some Kentmere 400 and have an odd issue that looks like dead fixer but only on the frames, not the blank spaces as I have seen before. It is also not on every picture in the roll and I developed 4 rolls in the same cannister at the same time. The other negatives do not exhibit the problem but the images were all taken with the same camera, Nikon FG and mostly with the same lens, series E 50. The only thing that could be different is that I may have used an orange filter on this roll instead of a yellow one.


The images are of the same neg, one reversed, one as transparency. The reversed is scanned very dark to enhance the problem. Last image is just a closeup, and even though this is not something I want to happen to all my negatives, I like the look in this photo. I cant figure out if its a camera light leak, film canister leak or something in the developing stage.
Any ideas?

The film is quite flat, so it cant be that. The top two are flat on glass scanned.


This was scanned in the carrier.

Why don't you do a clip test on the fixer?

You are referring to the effect on the edges of the frames where the positive looks much lighter on both sides of some of them? I really don't know, pretty sure it's not your chemicals. My guess is a sporadic light leak in the camera. It might take a lot of ambient light to cause the problem, so it only shows up in frames you took after standing around in the bright light for awhile.

Are you re-using cassettes at all?

It might explain why only one film had this light leak...

RR

Michael W said:

You are referring to the effect on the edges of the frames where the positive looks much lighter on both sides of some of them? I really don't know, pretty sure it's not your chemicals. My guess is a sporadic light leak in the camera. It might take a lot of ambient light to cause the problem, so it only shows up in frames you took after standing around in the bright light for awhile.

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I also think this is the most probable answer. Try to shoot one roll of film: half indoor, half outdoor. And outdoor try to get controlled ambient light: some frames shoot fats, and some shoot after you get camera in bright sun for some time from one side, then another side...

darkosaric said:

I also think this is the most probable answer. Try to shoot one roll of film: half indoor, half outdoor. And outdoor try to get controlled ambient light: some frames shoot fats, and some shoot after you get camera in bright sun for some time from one side, then another side...

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The light leak has affected the sides nearest to the outer edges. If it had been a camera fault would not the light leaks be spread over more of the negative even if for only one frame that just happened be the one in position as the camera was in strong light? That's why I was guessing a cassette fault...

RR

Regular Rod said:

The light leak has affected the sides nearest to the outer edges. If it had been a camera fault would not the light leaks be spread over more of the negative even if for only one frame that just happened be the one in position as the camera was in strong light? That's why I was guessing a cassette fault...

RR

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I used to have a camera that the back didn't fasten down tight enough because the latch got bent. Light could get in on the edges if the camera was held just wrong (if the sun shone directly onto the back, basically). It would do the same thing as these examples. However, mine had more on the rebate than these. These seem to end right at the edge of the frame. I still don't think it's a processing fault, but something is leaking.

If you used the FGs TTL meter it won't be the filters

Since it is not in the rebates apart from bleed over looks like a shutter leak. But Id have expected the mirror to have protected half of the frame.

remove lens and open back and see if you can see any leaks. through the shutter blades don't be tempted to touch...

Xmas said:

If you used the FGs TTL meter it won't be the filters

Since it is not in the rebates apart from bleed over looks like a shutter leak. But Id have expected the mirror to have protected half of the frame.

remove lens and open back and see if you can see any leaks. through the shutter blades don't be tempted to touch...

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Ah! Missed that bit!!!

Can't be cassettes as the rebates would also be black in the negatives...

RR

Hi Rod

Not happy with the diagnostic can't see a mechanism.

Noel

I would check the light seals in the back of your camera. There is some evidence in the positive images of light leaking onto the outer edges of the rebate. If the camera uses foam in channels on top and bottom of the back, it may have turned to mush. Normal pressure when holding the camera to your eye could cause some movement in the back. This could possibly cause an intermittent light leak. Given the age of this camera, the seals are likely to have deteriorated. If so, they are easy to replace on most Nikon SLRs.
Alex.

OK, just to follow up, I checked the light leaks by shining a flashlight in my darkroom (laundryroom) through the lens opening with the mirror propped up. No sign of light at all through the shutters. I tried the reverse by closing the film door and shoving the camera on my face and could see no light through the door with shutter open.

The camera was bought from a camera dealer and has new seals and was even CLA'd, well at least the seals and mirror bumper are new. 90 day warranty even! Its in great shape and a super camera for weight and ease of use. If only it had AE lock.

I think I will try a roll of film and leave the camera in the sun a couple of different ways, one way per exposure and see if I can replicate the problem. Maybe there is something with light coming in the eyepiece?

try the shutter leak test as you wind on...

Xmas said:

try the shutter leak test as you wind on...

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Shutter leak test as wind on? What do you mean by wind on? Do you mean while I am winding the film?

Could this be caused by shutter bounce? This camera has an unusual shutter sound that sounds a bit bouncy, but its a low end camera so does the EM also sound bouncy?

Also, theses light issued only seem to show up with that lens, if I look at shots with others, the images look consistently exposed.

sorry

fire the shutter and with lens off, back open, flash light pointing under mirror then wind on slowly.

Can't really see any mechanism for your leaks a shutter capping issue is normally characteristic.

The lens should not be able to do that either.

But you need to look carefully as minor leaks will cause lots of image density.

The other test is with lens on with cap on lens and back open, shutter open on B. to see if there is any light leaks into mirror box.

The FG, FG20 and EM should sound identical as they are on same chassis. The cladding and software is only difference. If you compare mirror boxes this is clearer.

If you have a warranty return with sample negs.

They are normally reliable.

The FG has a backlight compensation button for auto modes?

But if you need exact exposure use manual mode.

It looks like overdevelopment on the edges to me rather than a light leak.

What is your agitation scheme?

polyglot said:

It looks like overdevelopment on the edges to me rather than a light leak.

What is your agitation scheme?

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I agitate for one minute then 10 seconds every minute. Its a gentle inversion, just twice...
D76 1:3

I just scanned the last roll from the same tank and it looks like I have more of this but it seems isolated to the middle of the tank or the end of the roll that gets loaded first.

I am using stainless steel.

It appears equally frequent with the reels in the bottom and the top of the tank but maybe top reel was slightly worse on the innermost image. There was a double exposure like the roll had been removed and reinserted in the camera on that first shot though, so don't read too much into that.


Wouldn't light leaks effect the rebate?

I am starting to think developing.

Would slightly old developer do this? My D76 stock is December 20 dated but was clear and worked fine with a clip test. Many exposures do not show this top & bottom edge effect but since this edge is close to the reel rings, perhaps the technique or chemistry could be a factor.

I agree with polyglot. I think it's not a light leak issue, but an agitation problem. I've seen it happen with certain types of 120 film I've processed and had to change my agitation regime. I haven't used D76 1:3, but have used Perceptol and D23 at 1:3 and have not had this problem. I also don't agitate for a full minute in the beginning either. 30 sec and 5sec every 1/2 minute afterwards. The most important thing I found was not to agitate like a maniac. I use "gentle" agitation and my edges are much more uniform in density. When I first started out I agitate like you'd shake a Martini and with some films it was still OK, but later I tried some other films and started having edge density issues. With the old Tri-X and HC110 dil. B I could get away with a more vigorous agitation, but not some other films. Lesson learned was that not all films and developers are create equal. JW

I also believe it looks like over-agitation of the film in the developer has caused over development near the sprocket holes.

Thanks, I have 2 more rolls from same trip. I will try hc110 and d76 at even gentler agitation. I am gentle with it but maybe too much of it.

trythis said:

Thanks, I have 2 more rolls from same trip. I will try hc110 and d76 at even gentler agitation. I am gentle with it but maybe too much of it.

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Make sure to let us know how they come out. I really hate it when folks don't tell us if their mystery has been solved or not. It's like reading a Sherlock Holmes book halfway through. Good luck! JW

Ok, promise but it may take time...newborn in the house.

trythis said:

Ok, promise but it may take time...newborn in the house.

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Oh boy, I remember those days like they were yesterday! Yes, it might be a spell then. Enjoy now 'cause before you know it it's graduation day. JW

trythis said:

I agitate for one minute then 10 seconds every minute. Its a gentle inversion, just twice...
D76 1:3

I just scanned the last roll from the same tank and it looks like I have more of this but it seems isolated to the middle of the tank or the end of the roll that gets loaded first.

I am using stainless steel.

Click to expand...

I suspect under-agitation and that you have overfilled the tank. It's pretty easy to do with stainless. It's kind of anti-intuitive but you need a good big chunk of air in the top of the tank which must travel through the spiral on each inversion to dislodge all the exhausted developer from the film surface. Inverting a mostly-full container of developer provides almost no agitation whatsoever because the developer just stays in basically the same place or shifts a little side-to-side.

Since you're using fairly high dilution, agitation is more important because the developer will exhaust locally. If you don't agitate at all, that can be OK (stand development) as long as there is no bromide drag (dark streaks descending from bright highlights). If you agitate properly, it's also good. But you're partially agitating only, which means that the developer is refreshed near the edges of the film and not in the middle, and you get this result.

Make sure your tank isn't full so that when you invert, you get a big sloshing noise. And do 10 inversions (180 degrees each per second) at the top of each minute - you need to make sure that the developer across the whole surface of the film is completely replaced. Two gentle turns won't move everything around, and you get the problem seen here.

If you were over-agitating, you would see bright stripes (flow marks) radiating from the sprocket holes, and there are none. So you definitely don't need to be gentler!