BnW reversal attempts

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Uniform color cast, like the silde was lightly toned.

It could be related to bleaching and light exposure. According to Haist, some dichromate bleaches leave a residue of chromium and silver on the film which is not cleared by the sulfite bath. This residue is light sensitive and redevelops post light exposure as yellow-brown stain.
 

Lachlan Young

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Uniform color cast, like the silde was lightly toned.

I've only really seen very mild shifts, usually only slightly warm - apart from Adox CMS 20 ii, which was close to absolutely neutral.

I find a proprely developed and printed negative sharper than a slide

Same here.

This shouldn't be surprising - all the manufacturers' data for many decades firmly backs up your observation. Compare the Agfa MTF curve for APX 100 and the MTF curve for Scala 200x (they are essentially the same emulsion) and it's pretty clear what impact reversal processing has on perceptible sharpness. And the grain isn't finer either - though it may be less obvious.

The bigger problem is the easily mislead (and those doing the misleading) making all sorts of error ridden claims about the supposed superiority of transparency films - they're useful and offer some interesting aesthetic possibilities, but they aren't the magical panacea that some apparently want them to be.
 
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YoIaMoNwater

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I haven't seen a brown/olive cast in the 2 rolls I've developed. Which film types were they?
 

DeletedAcct1

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I FULLY agree with you, Lachlan!!
 

DeletedAcct1

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I haven't seen a brown/olive cast in the 2 rolls I've developed. Which film types were they?
Custom made process, Agfa Apx100, eFKe 25 and Fomapan 100.
Also the Foma kit with Fomapan 100 R has a slight warm hue to it.
 
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YoIaMoNwater

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Custom made process, Agfa Apx100, eFKe 25 and Fomapan 100.
Also the Foma kit with Fomapan 100 R has a slight warm hue to it.
Do you have any images of how those film look like on a light box? I want to compare them with my Fomapan 400 as I think the base film is still too dark/not completely bleached.
 

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I use permanganate
 

DeletedAcct1

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Do you have any images of how those film look like on a light box? I want to compare them with my Fomapan 400 as I think the base film is still too dark/not completely bleached.
Unfortunately I don't have any light table (I wish I have it).
I'd look at the leader after having reversed the film. The leader is the part that had the longest exposure. If the leader is still grey then it's the base.
To confirm that take a piece of undeveloped film and put straight into the fixer and let there to clear completely. What you'll get is the pure base: still grey?
How does it compare to the leader taken from the reversed film?
 
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Donald Qualls

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A laptop, tablet, or phone screen displaying a blank image in a viewer can stand in for a light table for low resolution purposes.
 

destroya

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here is a small pict of my light box with 4 different films all done in my reversal process. you can see that the film base plays a large part in the slide film base color.
1) RR 80
2) tri-x
3) hp5
4) xtreme 100

 

DeletedAcct1

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here is a small pict of my light box with 4 different films all done in my reversal process. you can see that the film base plays a large part in the slide film base color.
1) RR 80
2) tri-x
3) hp5
4) xtreme 100

To me it's not the base color, but the grain type and structure that imparts those color hues...
 
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DeletedAcct1

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If this is true then it contradicts the other claim you made:
There's no contradiction. You forgot to add "in terms of grain structure (all fine grained) and in terms of general "look"
That's what I'm referring to.
 
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YoIaMoNwater

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here is a small pict of my light box with 4 different films all done in my reversal process. you can see that the film base plays a large part in the slide film base color.
1) RR 80
2) tri-x
3) hp5
4) xtreme 100


Looks very nice!

Well I had a go with KMnO4 bleach this time (for 5 min) with Rollei Superpan 200. Microphen as usual for 1st (15 min) and 2nd (15 min) developers. The film seems way darker than it should be and the leader portion looks almost brown. Also the film edges weren't as black as before. I don't know if this was due to incomplete bleaching or that 15 min for the first developer was way too long than the 7.5 min recommended time on MassiveDev. The film's drying now and I'll update it here tomorrow.

I still have parts of the Fomapan 400 @ 800 roll (I accidentally cut the film short while putting it in the reel last time) and will give it a try with the same settings as before but with the permanganate bleach.
 

DeletedAcct1

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I'd like to see the leader. Can you post it?
You need metabisulphite clearing bath with permanganate bleach. You can't just use the clearing bath for the dichromate bleach.
 
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Donald Qualls

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In reversal, film too dark means either underexposed or first dev was too short. However, you might gain something by adding a little silver solvent to the first dev. I've used Dektol, 2 parts stock to 1 part water, plus 8 g/L sodium thiosulfate (clears highlights) and 4 g/L potassium bromide (prevents fog from reducing Dmax), though nearly any one-shot film or universal developer can be used with added thiosulfate and sufficient time. This first developer is the sole determinant of the quality of the final slides (all following steps should be run to completion, and based on times, the first dev might be to completion as well); it determines contrast, effective film speed (via the silver solvent), and to a large extent grain in B&W reversal (by developing the larger halide grains, those are bleached away and only the finer, harder to develop grains left to be fogged and redeveloped).
 
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I still have parts of the Fomapan 400 @ 800 roll (I accidentally cut the film short while putting it in the reel last time) and will give it a try with the same settings as before but with the permanganate bleach.

Please take a pic of the film (with emulsion side facing the camera) after each step of the reversal process and post the pics here. It helps in debugging your process. For example, if your first development is not adequate, it's easy to figure that out by looking at the emulsion side of the film - it will look too white/cloudy.
 
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YoIaMoNwater

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I'd like to see the leader. Can you post it?
You need metabisulphite clearing bath with permanganate bleach. You can't just use the clearing bath for the dichromate bleach.
Will do first thing in the morning. I did use metabisuplhite even with the chormate bleach (just to mention again I used potassium chormate and not dichromate).

Yea I definitely think a strong silver solvent is needed in the first developer. I will try adding 0.5% sodium thiosulfate to Microphen next time.

Raghu I don't think it's possible to take the film out after each step, I can post a pics of the steps after reexposure though. When I took the film for reexposure it definitely looked white and clouldy.

Also, I think my developer has probably gone bad. This Microphen was from 2018 after I developed a lot of HP5+ @ 3200 and 6400 years ago. We'll see if that's the case with the Fomapan 400.
 
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Raghu I don't think it's possible to take the film out after each step, I can post a pics of the steps after reexposure though. When I took the film for reexposure it definitely looked white and clouldy.

Hey! No worries if you can't take pics. Good luck with your reversal experiments.
 

iandvaag

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I don't have too much to add here, but I have sunk quite a number of hours into B&W reversal and I do have some suggestions for testing. It takes a lot of testing to get excellent results, and it's very easy to deceive yourself unless you expose some step wedges and measure them with a densitometer. Next best is to take identical exposures of the same scene under controlled lighting and directly compare the slides.

The experimentation can be simplified considerably by only changing the critical step: the first developer. All other steps can be considered to be "to completion", so as long as you have a working process and you maintain fresh solutions and good washes between steps, you just need to focus on the first development. If you can mix your own chemicals, I would suggest going for a tried and true formula, such as Ian Grant has posted here. Choose one developer, choose one film, shoot a test strip with several frames of the same scene at different exposures and develop it.

If the slides come out too dark, increase the FD time. If the Dmax is reduced, you've increased the time too much.

If the slides come out too bright, decrease the FD time. If the Dmin is increased, you've decreased the time too much.

If you cannot find a combination of exposure time and development time that gives an acceptable brightness without compromising Dmax or Dmin, you'll need to try a different developer composition or give up on that film and try a different one.

First developers are complex beasts and it is challenging to come up with your own formulation that will give excellent results that are backed up by densitometric data.

Since you mentioned it, if you are interested in Superpan 200, I can share the best results that I have obtained with this film.

Film: Superpan 200
FD: D67; 6 min at 20 °C
gamma = 2.6; Dmax = 2.8, Dmin = 0.1



 

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