Got questions about b&w reversal process

[cinejerk]

Thank you very much Ian for sticking with me here. You have been a great help;-)

As you said in a posting above that 50gm of sodium carb is roughly equivalent to 5gm of sodium hydroxide.

So I am going to try adding the 5gm of sodium hydroxide and see how it works. What do you think?

By the way the film that was too dark I'm sure was under exposed also. I need to remedy that also.
thanks
Dennis

 

[Jordan]

The hydroquinone is also a "contrast-inducing" ingredient IIRC.

 

[Photo Engineer]

The bromide will restrain things, especially with KSCN there. This will keep the reaction from going out of control.

PE

 

[dr5chrome]

D76 1:1 especially at longer development times will produce a terrific quality image in some film types in reversal processing. The key would be to do some testing. Sticking with published recipes doesn't always render the perfect result.

It is very possible to modify your D76 if that's what you want to use. PX is a flat film as a positive so with that in mind you'll want to do what you need to do to the D76 or the 1st development to generate some contrast.

regards
dw

The only difference I see between D19 and D76 is 3 grams of hydroquinone and some sodium carb and pot bromide. What does the potassium bromide do to make it a better first developer?

 

[cinejerk]

Thanks dr5chrome for that info. You are the first to say something positive about d76.

What are your suggestions for increasing contrast?

 

[cinejerk]

Wow it worked. I added 5gm of sodium hydroxide to the developer. This is the best results I've had yet.

I do have a question though. After I added the lye the developer turned almost black. Is this normal?

 

[Ian Grant]

Sodium Hydroxide will cause developers to oxidise quite quickly and it may not be the best alkali to add to D76, Sodium or Potassium Carbonate would be better in that respect and finding the right amount is important.

Ian

 

[BetterSense]

Wow it worked. I added 5gm of sodium hydroxide to the developer

What developer? Are you back to D76 at dr5chrome's advice? Is the D76 diluted 1+1 before putting in the lye?

Watching this thread with interest, as I'm getting into 8mm and being able to develop my own plus-x reversal film using a reversal process would be a great boon. I always have D76, so all I would need is some bleach, if the D76+lye method works for development 1.

 

[cinejerk]

It still worked better with the lye. Maybe I shouldn't put in as much next time. I am using the dichromate bleach bettersense.

 

[BetterSense]

But are you using the D76 1+1+5g/L lye, for the original 9.5minute time, for the first dev?

 

[cinejerk]

No. do you think I should. It is not diluted. I developed for 6 min. Maybe it wouldn't oxidize as fast then.

 

[BetterSense]

Well, I don't know, I've never done it. But I want to process some reversal Plus-X 8mm film, and earlier you said you were getting decent results, and I was just wondering under what eventual conditions you got them. From what I understand now, your process is

1 straight D76, with 5g/L lye added, for 6 minutes as the first developer
2 wash
3 bleach with sodium dichromate bleach (what concentration?) for 2:30
4 wash, 5 minutes or untill water not orange
5 clear--kodak hypo clear, 5 minutes with inversion (I don't quite understand what this step does)
6 reexpose to room light
7 Second developer - D-76 - 7:00 @ 68F
8 Stop, fix, wash as normal.

 

[cinejerk]

This is actually what I did this time. Comments accepted. thanks

1 straight D76, with 5g/L lye added, for 6 minutes as the first developer
2 wash
3 bleach with sodium dichromate bleach (what concentration? 9.5gm dichromate 35ml battery acid) for 3min
4 wash, 2 minutes.
5 clearing bath 1 minute. 50gm sodium sulfite and water to make 1 liter (this clears out all the bleach)
6 reexpose to room light (actually I did sunlight for 30 seconds.) don't know if this is good.
7 Second developer - D-76 - (only 1 minute) @ 68F
8 Stop, fix, wash as normal.

 

[BetterSense]

So, the negs (err, pos's?) came out ok? That's pretty exciting, because you can buy B&W 8mm film for only $10 a roll. If I could process it myself, I could shoot it a lot more, maybe even enough to shoot a short feature.

9.5gm dichromate 35ml battery acid

I'm assuming you put that in 1L of water? I just looked up sodium dichromate, it's pretty nasty stuff.

 

[cinejerk]

Well they're still a bit dark. Probably because I underexposed.

Actually this is 16mm film. It's old (found it on ebay). Just recently bought some more. It's not exactly the same but it's worth a try. About 2000ft for $15. It will be interesting to see how it does. The camera is an old bolex. similar to the one in my avatar.

Yes it's all to make 1 liter. Actually I was more concerned working with the acid. Yes I Know the dicromate
is known to cause cancer in california. I don't live in california so I'm not concerned ;-) I don't plan on eating or breathing the stuff and I wear gloves when handling it.

 

[BetterSense]

I Know the dicromate is known to cause cancer in california. I don't live in california so I'm not concerned

Right on! That's why I'm glad I live in Texas.

The cheap ebay film is awesome. I would be so happy if I could find a big roll that cheap, but 16mm won't work without having more sprocket holes punched in it. Maybe I should get a 16mm camera.

 

[cinejerk]

The bolex is kind of neat. It was made around 1960 and is a spring wound camera. Some of the newest (70's) can be easily retrofitted with electric motors. There are a lot of them on ebay but you have to be very careful to get the right one. Most of the ones on ebay are non reflex and you can't focus through the lens. They are a real pain to load film. Especially if you wind your own loads like I'm doing. It may be a daylight reel but hand wound ones let in too much light. I've been loading it in a dark bag. (not fun). FYI http://www.bolexcollector.com/

Oh one nice thing about a manual load reel camera like this is I can take out short
strips and develop them to see where you are with exposure and process.
A 5 foot strip fits nice in a regular reel tank.