BW developing question-under and over developing

[peter_kim2]

Ive been deveoping some Tri-x and the negatives look a little dark.

However I have shot the film with a couple different cameras (Canon

A-1 and Contax T3) so I dont think its a over-exposure problem but a

developing one. My quetion is, what happens to the negative when one

under develops and conversly, over develops? Do I get dark negatives

when I overdevelop (ie develop the film for longer than one should?)

 

Im shooting Tri-x at 400 with Xtol 1:1 68 degrees for about 8-9

minutes. agitate for the first 30 seconds then 5 seconds every 30

seconds after that (using a paterson tank, 2 full inversions).

 

Thank You...

[._._z]

<i> what happens to the negative when one under develops and conversly, over

develops? Do I get dark negatives when I overdevelop (ie develop the film for longer

than one should? </i><p>

 

 

http://www.libarts.ucok.edu/journalism/BasicProcess.html

[al_kaplan1]

The longer the development the darker the negative is the general rule. 1/2 minute can make a noticeable difference. "About 8-9 minutes" is sloppy! You should develop for EXACTLY whatever time gives you the proper results. Consistancy is important.

[peter_kim2]

Al, actually I develop for exactly 8.75 minutes...I guess I should have been more exact when I said that.

 

Hmm...so overdevelopment leads to darker (overexposed?) negatives and I assume slightly higher grain?

[d_poinsett]

In general, longer development not only makes the overall density greater but also increases the contrast and makes the grain larger as you mentioned. The same effects are produced by higher developing temperatures, higher developer concentration, and increased agitation. The converse is true for all of these things as well.

 

There are a variety of ways to determine contrast of the negative. Search photo.net and the web for further details.

[chris_waller]

Over-development wil give dense highlights but little if any extra density in the shadows, hence high contrast. Under-development gives low contrast. A good neg should print to give a full range of tones at grade 2-2.5. If your negs need a grade 1-1.5 to print a full range of tones then reduce film development time by about 15 percent. The difference between 8 and 9 minutes is about 12.5 percent and equivalent to almost a full grade.

[scott_walton2]

First off Peter, you might want to use 1 camera for testing... even your lens

might very well have differences from 1 focal length to another. This being

said, it has been stated that with an overdeveloped negative, your highlights

and some upper mid tones are going to be denser than desired. If it is a sunny

day, I tend to pull the negatives by 10-15% (all depending how bright the sun/

shadows are) and a cloudy day I push (overdevelop) by up to 10% to add

some sparkle to an otherwise dull scene. This was derived by me doing my

own testing with a densitometer and testing each emulsion I use.

When you develop your negative, the first thing that develops fully are your

shadows (thinnest part of the negative) and as you keep developing, you

develop the highlights more and more. If you go to far, your job in the

darkroom will be almost impossible to get detail in the highlights when

printing. If you stop early, or as it is called "pulling" your negative, your

highlights won't be developed as much. The old saying goes, lacking a

densitometer, you should be able to put a negative down on a newspaper

and be able to read through the highlights... but films have changed too over

the years but it seems to hold water just the same... Now if you over develop,

your highlights will keep developing, like I said earlier, and if you don't stop it

soon enough, your negatives will be know as being "bullet proof" which is a

bad thing! There are a number of changes you can do to slow the process

though. One being is to ease up on the agitation. This will help in lowering the

contrast build up. A good test for you to do to see the exact results is to shoot

a whole roll on one scene including sun and deep shadows. Now go into the

darkroom and do what are called "clip tests". This is the process of taking a

few frames from the roll and processing "normally" or manufacturer

recommended times. Look at the clip and get ready to process another clip.

This time doing it -10% off the time, the third clip do at -20%. Now for the final

few clips, from the starting time you did clip #1 add 10% and the next one add

20%. Now get into the printing mode and print a frame from each. Take notes

because this is the start of finding your perfect time for processing! Most of the

time, you will find that -10%, -15% of the manufacturer's time is better/

optimum. You will find, on a cloudy day though, with the info you have gained

doing this clip testing, you will push your film to add the needed snap to your

prints to make them sparkle more!

Doing this, prepare yourself for several nights in the darkroom but the info you

get on "your process" in invaluable! If you use different developers, it is wise

to do the whole process over for each developer you use!