BW reversal process

[bluenote]

My interest in reversal BW process has started when I saw medium format slides projected on the wall. Do you have any experiences with this process?
I have found reversal kit chemistry for T MAX 100 ( http://www.photoformulary.com/Deskto...earch=reversal ) - as the only available.
I know this topic is related more to MF than LF - anyway thanks for any comments.


Cheers, Jiri

[IanG]

Foma make a Reversal kit and also a reversal film on a clear base. They are based ? let me think ?

Oh yes Králové (ČZ)

I've done a lot of research into Reversal processing and have also posted many formulae Agfa, Gevaert, Pathe, Bauchet, Kodak, Orwo etc on APUG.

Ian

[georg s]

Jiri, maybe there's a solution next to your door - Foma does make a B&W-reversal kit. At least it's offered here in germany (sold here http://www.fotoimpex.de/shop/fotoche...s8-1x16mm.html for instance). It's not exactly cheap.
Hope this helps, georg.

[IanMazursky]

I have done it a bunch of times on tmax 100. The slides were amazing!!
Its something to behold, even a dull image looks great as a B&W slide.

I made my own reversal chemistry from published formulae. But a word of caution, sulfuric acid is dangerous.
Nitrile gloves, goggles, exhaust fan and a organic vapor mask are a must. Other then that, you can get everything from the Formulary.
Also remember to not splash any water in the bulb used for reversal. It could explode!!

Im going to get back into it and try to weed out the light reversal step. Its a real pain, especially now that i haves a jobo. No way to stop it.
I bought some stannous chloride (chemical fogging agent used in E6 reversal bath) a while back and i hope to use it instead of a light reversal.

I have attached the formula that i have cobbled together. I cant remember exactly where i got it or which parts came from where.
Its a word doc that i had to zip. I rated Tmax 100 at iso 40-50. 10 minutes 68F.

Have fun with it!

[Atul Mohidekar]

Few years back I got some Delta 100 MF rolls developed from Dr5 (http://dr5.com/). The 6x9 transparancies look stunning on a light table!


// Atul

[Sascha Welter]

Wouldn't a contact negative on some film with a transparent base work pretty well and not risk ruining your shot?

[IanMazursky]

Probably but not as fun! I did a few of those contact negs and i didn't like them.
They didn't seem as brilliant as the B&W reversal, but i didn't do any real tests so it could just be me.
Its worth a shot if you have a few hours to kill.
Btw, If someone has a formula with a chemical reversal step, id love to pick your brain.

[IanG]

Wouldn't a contact negative on some film with a transparent base work pretty well and not risk ruining your shot?

Reversal processed B&W has a far longer tonal range, some of the highest quality B&W prints I've ever seen were while at University in the 70's and a Ph.D. students research project shooting reversal B&W then printing by Reversal as well using B&W paper, his work would have been funded by one of the manufacturers.

So no it's not even going to get you in the same ball park.

Ian

[IanG]

Would someone comment on the pros and cons of reversal processing when the film is being developed to scan? I am interested in whether there would be more or less grain, less or more dynamic range, less or more film speed, less or more sharpness, etc?

Sandy King

It could well be all Pro's Sandy in terms of overall image quality, a higher dynamic range, excellent sharpness, film speed can be adjusted.

The downside, the Cons is the need for tight process control and a much longer over all process cycle, and also a need for tighter exposure control, but you should be there anyway.

Ian

[Helen Bach]

You can get extra benefits if you tailor the reversal process for scanning only - you can forget about the need to make something that looks good to the eye. This means that achieving the greatest possible density range is not necessary - you only need to achieve a density range that is a better match to the scanners range than most negatives would be without over-development. The exposure/first development stage does not have to be as close to the film's inherent DMin (film base + unavoidable fog) as when making a slide for viewing - ie you can pull back a little on the first developer. This all helps to improve the possible dynamic range.

There is no need to control the image colour. This is quite a big benefit. It means that you can use plain sodium sulphide as the second developer, with no need for a reversal exposure. This results in quite fine grain. The formation of the final image is separated from the initial development/image amplification stage.