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younghoon Kil
18-Dec-2017, 08:05
172942


Hi All,
I would like to ask you for advice.

I develop B&W films using SP-445 tanks.
But like the attached image, the edges are often exceptionally bright.
Sometimes one edge is bright, and sometimes two edges are bright.

However, not all films developed with SP-445 tanks will have this problem.
I wonder why this happens.

Thank you for reading.

p.s. I am sorry that my English is poor.

esearing
18-Dec-2017, 08:43
Tell us more - Film, Camera, Lenses used, exposure time/fstop. Development technique developer, volume, agitation, etc...

center brightness usually occurs with wide angle lenses - in some cases one has to use a center filter. More light is transmitted by center than edges of lens on 90mm or wider.

one Edge lightness - not enough developer or exposure issue. If it was always at top I would say not enough developer. Otherwise may happen in camera with blockage by internal shutter/bellows.

koraks
18-Dec-2017, 09:24
one Edge lightness - not enough developer or exposure issue. If it was always at top I would say not enough developer. Otherwise may happen in camera with blockage by internal shutter/bellows.
The illustration makes clear that the issue is edge lightness in the positive, not the negative, so excess density along the edge(s). This points towards either a light leak, or overdevelopment.

younghoon Kil
18-Dec-2017, 09:30
Thank you for your comment and advice.

I shot three of the same scene with the same lens, and each photo was taken with only the aperture and shutter speed changed.
(Chamonix 045N-2, 58mm ~ 400mm lenses, Ilford/Kodak/Foma films).
And I developed these three films together with the SP-445 tank, but I got this edge lightness problem in one film.
This problem also occurs with films taken with other lenses.

This edge lightness is linear and occurs at the vertical or horizontal edge.
This edge lightness may be narrow or wide.
It looks like it was made with Photoshop's gradient tools.
It does not occur in elliptical shape.

Usually I shoot the same scene by changing only the aperture or/and shutter speed and developing it together with the SP-445 tank.
And I have this edge lightness problem in 1 ~ 2 of 3 ~ 4 films developed together.
(Kodak XTOL Developer (1+1)(475ml), Ilford Ilfostop Stop Bath, Kodak Fixer, Kodak Hypo Clearing Agent, Edwal LFN Low Foam Wetting Agent).
(Normally I inversion for the first 30 seconds, then inversion for 6 seconds every 30 seconds.)

Because of this problem, I have taken several photos of the same scene.

younghoon Kil
18-Dec-2017, 09:48
The illustration makes clear that the issue is edge lightness in the positive, not the negative, so excess density along the edge(s). This points towards either a light leak, or overdevelopment.

Thank you for your explanation.
I have not much experience in B&W film developing.
Could you explain this in more detail?
And is there a way to test this problem?

esearing
18-Dec-2017, 11:26
The illustration makes clear that the issue is edge lightness in the positive, not the negative, so excess density along the edge(s). This points towards either a light leak, or overdevelopment.

The illustration #2 looks like lightness in the negative.

If it is DARK in the negative I would agree light leak. The chamonix spring back is not very strong so it is easy to lift slightly while reinserting the dark slide which causes a light leak along the edges, usually along the point where you insert the slide.

I do not think the tank is the issue unless you are using less than 475ml of developer or losing some to leakage while inverting.

younghoon Kil
19-Dec-2017, 03:31
172964


Thank you for your advice.
I will check the spring back and check the results.
(I will check whether it is spring back problem or holder problem.)

I would like to ask you one more question.
Some films were developed like attached image.
Sometimes this happens.
It looks like a cotton clouds.
Can you please tell me what is causing this?
I am troubled by these two problems.

Pere Casals
19-Dec-2017, 06:27
It can be that:

See this post: http://www.largeformatphotography.info/forum/showthread.php?132952-SP-445-4x5-Film-Processing-System-(Daylight-tank)&p=1349695&viewfull=1#post1349695

With some films and SP-445 anti-halation layer may not be well removed because film touching the back side to the plastic of the older, just fix again in a tray, lights open... and wash.

Also check your fixer is fresh: throw in a not developed 35mm film end and see how much time it takes to clear, fixer time should be x2 to x3 that time.

younghoon Kil
19-Dec-2017, 08:21
Thank you for your advice.
I'll check what you pointed out.

172969

Anyway, I use a new holder(Rev 2 design).
And the shape of this cotton clouds appears throughout the film.

peter k.
19-Dec-2017, 13:11
BTW as is shown and discussed on his website, there is now a new Rev 3 on his film holders.

https://www.youtube.com/watch?v=MwgBzyEkjKo&feature=youtu.be

esearing
20-Dec-2017, 06:04
With this many issues i am going to suggest it is due to inconsistent technique with camera and/or processing. I'm going to assume you are using quality film and fresh chemistry.

First go into a dark room and put a flashlight inside your camera and look for light leaks around bellows, lensboard, and film holder (with holder in place and while removing/inserting darkslide). test all your holders and lens boards.

Second, Write down all the details and steps from Image capture through printing.
Load Film Holders in Darkness (no light anywhere)
Camera, film, film EI used, lens, bellows extension, fstop, exposure time, subject brightness range (stops/EVs);
Tank loading - Tank Dry? any light anywhere? any issues loading, top on tight.
DEVELOPMENT presoak time, presoak temperature, developer, developer dilution, volume (475mls), developer Time, temperature, agitation, room temperature
, stop, stop volume, stop time, stop temperature
, fixer, fixer volume, fixer dilution, fixer time, fixer temperature, wash time, wash temperature.
Measure your volumes after processing to make sure you did not lose any developer/fixer while agitating.
SCAN or PRINT write down all variables.

Third go to a nearby location and shoot a test subject with a normal lens 150-200mm, take 3-4 shots at same aperture/time being careful when inserting holder to make sure it is seated properly and when removing inserting the slide.
Process only 1 sheet adhering strictly to your steps. Process second sheet and third sheet together (assuming your developer dilution is adequate for 2 sheets).
Possibly repeat test with your wide angle lens to see if it exhibits the center brightness issues, though you might be able to tell that on just the ground glass by pointing camera at white card and spot metering the edges vs center.

If you were careful and consistent these 3 negatives should be nearly identical.

younghoon Kil
30-Dec-2017, 01:04
I have read this article now.
Thank you for your comment and advice.
I'll check what you pointed out.
Thank you again!

younghoon Kil
17-Sep-2020, 20:52
It was because of the light leaks of the rear standard.
I sent my 45N-2 to China last week, and they repaired it and sent it to me.
Chamonix's customer support is amazing!
Thank you all for your interest in this issue.