B&W Reversal Process in JOBO ? Need help

I was wondering if anyone had tried any B&W Reversal processing in a JOBO ALT1500 processor. I have been playing with Photographers Formularys version of the Kodak TMAX reversal chemistry and having mixed results.

Can anyone tell me why in most B&W reversal processes we need to re-expose to light after the clearing bath step?

While reading Kodaks official TMAX reversal process data sheet I notice they do not use the re-exposure step. How are they getting away with this?

When re-exposing film to light in B&W reversal process is it important to take film off reel, expose then reload ?

One of the problems I am having with this process is ghosting of 35mm sproket holes in middle of images and some light streaks. Not sure if exposing while on reels is causing this or how long I am re-exposing for is causing problem.

I am running this process at 75 degees instead of the normal 68 degrees because JOBO atl1500 will not allow 68 degree process. My contrast and densities have been pretty good but these streaks and little deffects are very irritating.

Thankyou in advance for any enlightenment, anyone can give me.

Jamie

Re-exposure is necessary because the silver halide left after first development and clearing wasn't exposed in the original camera exposure.

Reversal exposure is very simple, depending on the type of spiral you can usually get away without removing the film from the spiral. Just make sure you use a reasonable strength tungsten bulb, if it's 100 watt expose at about 18 inches from the light source, for at least 2 or 3 minutes rotating the spiral all the time to ensure all the film gets exposed. You canincrease this exposure if necessary, but don't expose to daylight.

It is possible to use a direct reversal bath & no re-exposure, these rely on a fogging developer and the Tmax kit uses one.

Ian

..the below statement is quite incorrect.

Re-exposure is only necessary if you are using a recipe that requires it. Since a jobo is being used your processing will be more consistent. Light reversal can and is unpredictable, as you have seen. I haven't looked at the Kodak kit of late and i thought they discontinued it. It is possible it uses a reversal bath, similar to E6. If you have to use a light reverse you must do the same thing consistently. The scala process was a light reverse process, very exact in its light re-exposure. it would be best if you used steel reels. the film is easier to put back on wet. I dont know if you can use steel reels in a jobo.
before you hit the lights the film must be completely off the reel or you will continue to have ghosting marks.

regards
dw

GO OBAMA!

Ian Grant said:

Re-exposure is necessary because the silver halide left after first development and clearing wasn't exposed in the original camera exposure.

Ian

Click to expand...

I used light reversal for over 10 years from the time I was about 12 and had no problems. The key is to use a BRIGHT light. I used a Photoflood #2 for about 30" to each side of the film while moving the reel(s) around underneath the light. Do NOT place the reel to the side or above the light or a drop or splash will shatter the bulb and probably blow a breaker.

I put my light into a 12" reflector aimed downwards.

Kodak used an acidic stannous chloride solution in later kits, but this is just extra expense and trouble. It goes bad with no warning whatsoever.

It is time and intensity that are important, along with uniformity.

I use my Jobo all the time for reversal of color! And, Ian's statement was correct. It should probably read "Re-exposure or chemical fogging....." to be more precise though.

PE

Thankyou to all who have replied. Here is a look at my first B&W Transparency see image attached. This is my bird Zoey, she is 3 months old. Image was taken with a Norita 66 , 80mm Noritar lens wide open at f2.0



Jamie

dr5chrome said:

..the below statement is quite incorrect.

Re-exposure is only necessary if you are using a recipe that requires it. Since a jobo is being used your processing will be more consistent. Light reversal can and is unpredictable, as you have seen. I haven't looked at the Kodak kit of late and i thought they discontinued it. It is possible it uses a reversal bath, similar to E6. If you have to use a light reverse you must do the same thing consistently. The scala process was a light reverse process, very exact in its light re-exposure. it would be best if you used steel reels. the film is easier to put back on wet. I dont know if you can use steel reels in a jobo.
before you hit the lights the film must be completely off the reel or you will continue to have ghosting marks.

regards
dw

GO OBAMA!

Click to expand...

If you had bothered to read the whole post you would have seen that I mentioned direct reversal baths.

Ian

Ian,

I tried to run 4x5 B&W transparencies in the JOBO today. The film was the new TMAX400. I got really nice tones but got some wierd chemical deffects across the whole 4x5. See my attached scan. You can see it really well in the top part of the image. I know that in developing tmax sheet film for negatives in TMAX developer you need to use the RS version. Could it be something in the developer? My 35mm and 120 tmax 400 don't have any deffects like this.

Jamie

Looks like severe water spotting or a very unusual type of reticulation.

PE

Hi PE,

I wondered about that but nothing has changed in my process (time, temp, etc). I process in a JOBO at 75 degrees. The deffect looks like it is in the emulsion of the film when you look at it on a light table. It is even in the black area on the edge of the film. What causes riticulation besides drastic temperature change?

Jamie

Look at it with a loupe directly down and at 45 degrees. See if there are surface defects or if it is in the film. Look on the back and front to see if you see a difference.

Severe alkali stress, and some swelling agents can cause this problem.

PE

Looking at the emlusion side at a 45 degree angle. Defect is definitely more viewable on this side of film. Looks as if some chemical reaction has taken place.

Jamie

PE,

While your online I have been wanting to ask you about the KODAK TMAX REVERSAL KIT. They don't re-expose film to light so from what I gather from various threads here is they have some kind of a Chemical fogging going on in the second developer. What chemical would they add to the second developer to acomplish the re-exposure step.

Jamie

Jamie;

There are many chemical reversing agents that have been used. IDK what is in the kit you mention but acidic Stannous Chloride is or was, Kodak's preferred fogging agent.

If you can see the defect, and it looks kinda like fish scales, then it is blisters caused either by a "bad" chemical or a really hot blast of water. This is actually called fish scales, and under a safelight you can see blisters form from the very hot water or the chemical reaction. It can also be caused by defective (poorly hardened) film.

I would have to go into this in detail with you or examine the samples myself to give a better answer, but even so it would be just a best guess.

PE