beginer question's

Im about to develop some HP5 and PanF with D-76, when I mix the bag of D-76, that Gal is my stock solution right and then I dilute 1:1 or how ever I need too? I am using the digitaltruth site for my times, but other then being a shorter developing time what reason would developing in stock be?

Thanks

You are correct on your dilution . . . I wouldn't recommend using the stock solution when you are starting out. Follow the established procedures.

 

Stronger (stock) developer will be more active and will provide shorter processing times but can also cause problems. There can be other reasons that are based on the film in use or special purposes.

 

But, you're not there yet. Good luck and have fun . . . It's quite a journey!

As said, probably the best practice is 1:1 dilution of D-76, develop and then discard the used, diluted developer. That way no problem about "replenishment" and other such arcana.

Here is a pretty good discussion of D76 that goes into dilution: Film developing with Kodak D-76, dilutions 1+1, 1+3, 1+5, push and pull

Different strengths and times, other than changing recommended EI also change contrast.

 

As well as I know, both stock and 1:1 are fine for ordinary use.

 

The recommended capacity for stock is 8oz (or 240ml) per 135-36 or 120 roll.

This means about 16 rolls for one gallon.

 

The suggested capacity for 1:1 is half that, but you are supposed to be able to

do a 135-36 roll in 1:1 with a 10% increase in time. In this case, you get 32

rolls per gallon.

 

In all cases, 1:1 is recommended for one shot use. Throw away after using.

 

If you use stock, you can either pour back in the original bottle until you have

done 16 rolls, or use an appropriate amount for each roll. A good choice

is 8 oz for one 135-36 roll or, probably close enough two 135-24 rolls.

Or 16oz for two 120 rolls. That is, pour some into a bottle or other

container, use as described, then throw away.

 

Personally, when I did use D-76 (which was years ago by now), I used stock,

and back to the bottle each time.

 

Now I have Diafine, HC-110, and TMax developers.

The main reason for dilution is to supposedly improve sharpness or acutance, but at the cost of increased grain. There is no major effect on contrast or tonality if the development time is extended appropriately.

 

Stock D-76 contains a large amount of sodium sulphite, which is a mild silver solvent. The purpose of this is to encourage a degree of 'physical' development (crudely, the plating-out of silver from solution onto the latent image). Physical development generally gives a finer grain than chemical development.

 

So, by altering the concentration of sulphite, the balance of chemical to physical development is altered and the sharpness/acutance is supposedly increased, while grain also increases.

 

Personally, I think that any increase in sharpness is more imaginary than real, and results are pretty much identical from diluted or full strength D-76. The increased time needed for dilute use more-or-less cancels out the reduction in solvent activity.

 

Basically, just use the stuff however it's most convenient. Like; if you have 10 films piled up ready to process, it probably makes sense to use it at stock strength. Conversely, with one film a week use, it would make more sense to dilute it.

Lots of good info, appreciate all the help, The last time I did any darkroom was in school back in the 70's , so much good info on the internet now makes it much easier to understand, wish we had the web back then, lol

I do not use D-76 anymore, but when i did..... it was "Stock" for storage in bottles and 1:1 for development..... use it once and toss it out.