Developing for Black and White

[David Wogan]

Advertisement (gone after registration)

I was reading through the M6 instruction manual the other night and came across some film processing tips that I had heard somewhere before. For B&W expose for the shadows and develop for the highlights.

 

I understand the exposure bit, but I'm wondering what the highlights bit means specifically. I assume we are talking about under-developing? And if so - by how much?

 

I use Neopan 400 and develop in ID-11 1+1 for 9.5 mins. By how much should I reduce the development time?

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[topoxforddoc]

I was reading through the M6 instruction manual the other night and came across some film processing tips that I had heard somewhere before. For B&W expose for the shadows and develop for the highlights.

 

I understand the exposure bit, but I'm wondering what the highlights bit means specifically. I assume we are talking about under-developing? And if so - by how much?

 

I use Neopan 400 and develop in ID-11 1+1 for 9.5 mins. By how much should I reduce the development time?

 

David,

 

When you have processed your BW film, the shadows are light/clear and the highlights dark on the negs. You can't retrieve information from the light/clear parts of the neg when you enlarge, as there is no detail in them. Conversely your highlights will look dark on the neg; no problem, just expose the paper longer when under the enlarger and you will get your highlight detail come up. If the shadows look too dark on the final print, you can always hold that part back by dodging that area.

 

As for development times, just look at your negs. If the shadow areas (light/clear bits on the neg) are too thin, then reduce your developing time for the film, or re-rate your film when you shoot it in the camera (eg reduce ASA from 400 to say 320).

 

Best wishes,

 

Charlie

[square_one]

... For B&W expose for the shadows and develop for the highlights...I understand the exposure bit, but I'm wondering what the highlights bit means specifically. I assume we are talking about under-developing? And if so - by how much? ...

 

Yeah, slightly overexposing to save otherwise-lost shadow detail while losing hardly any highlight detail is certainly smart––and the only way to go with single-sheet LF film or an entire roll of film devoted to a single basic scene where you can combine shortened development.

 

Problem is roll-filmers usually end up with 36 frames of 36 different subjects containing 36 different shadow>highlight ranges and 'special' development isn't on the table. For years I bought the 'insurance' of a lower ISO on everything ... but modern fast films are so forgiving I'm back to 'factory' ISOs and OXing just those frames that need it, then developing normally. Works for me anyway!

 

PS - I was into LF for years and the underdevelop/overdevelop Kharma always had me feeling inadequate, you know, N-1 = minus 20%D at 68º, or minus 30% at 74º, blah-blah-blah. if you want to pull your hair out trying to understand all there is to understand about such stuff get a copy of Ansel's The Negative.

[kartofale]

Expose to the shadows and develop for the highlights...

There's a given range that a film can record and usually an even more limited range for a paper to show.

In a well balanced print I would say that ~5-6 stops (between the darker area in the scene where details should be seen to the highlight where details should be seen) can still show details (depend upon the paper and the development though)

Unfortunately a street scene can vary for 7, 8, to even 10 stops differences.

Understanding that one must decide how the final print should be looking like.

The challenge is to bring down the single exposure from 7-8 stops to a 5-6 stops (where the print can perfectly show details in both shadows and highlights).

A meter reading and exposed film accordingly would result in an 18% grey density when enlarged in reasonable exposure times (of course long / short exposure can result differently.

Some developing idea: The developer is working harder and faster on the highly exposed area while the shadows cannot obtain much more details if develop time is increased (can be done only to a certain level and can result with foggy film).

So in order to get details in the shadows one should expose accordingly (as a general idea take a reading off the shadow area where you still want details in and underexpose in 2-2.5 stops).

This will result with a negative that holds details in the shadows...

But the scene had 7-8 stops and the print would hold 5-6 stops the highlight will be burned (too dark in the negative)?

For that you should develop the film in a shorter time... what will happen?

The shadows (the light in the negative) will be processed after ~1/3-1/2 of the development time because it does not have enough exposed material to continue and develop. It means that if exposed to the shadows you will have details in that area after a short development time.

The rest of the time is to continue the development of the highlights. But as we want the highlight not to be to dark (in the negative) in order to pull details, we will shorten the development time.

So in general:

Expose to the shadows - Reading and underexpose that reading in ~2-2.5 stops while develop to the highlights means shorten the film development times...

It takes some trial and error based on the film / developer / paper / developer.

One should remember though that in a 36 exposure film different light conditions can be recorded...

 

Comments are welcomed.

 

Kartofale ;-)