Do you develop -same EI, same negative contrast- MF longer than 35mm in general?

[Juan Valdenebro]

I'd like to read a good explanation on this subject.
I remember seeing Ilford's charts that recommended longer MF development times for HP5, but not for other films...
I've read there's more flare presence in MF, and that lowers contrast of course...
I've read about backing papers, and antihalation...
But never a clear complete explanation.
My practical non Scientist but Photographer approach some years ago, has been developing MF +10% but I also expose MF with a third more light, and that works for VC printing for me.
The reason I haven't tested this subject very much is I use speed and acutance developers for 35mm for fast work, while I use tripod and metol developers for MF for the best image structure, so both EIs for the same film are 2-3 stops away...
Thanks.

 

[MattKing]

Traditionally, many photographers would develop 35mm a bit less and print from the lower contrast negatives on a higher contrast paper.
The purpose of that was to minimize grain - with traditional films, a more dense negative tended to exhibit way more grain.
With many modern 35mm films, grain isn't as big a concern. For that reason, I personally don't do that.

 

[Juan Valdenebro]

Thank you, Matt.
Why did Ilford recommend longer development for MF HP5? They did not recommend it for their other films, if I remember well...
Your answer fits anyway, as HP5 was grainy for 35mm.
Maybe this needs no more thinking, as materials changed through time.
I'll stop the 10% more development and the third more light, and see what happens.
Thanks again!

 

[brian steinberger]

I know if I develop my 35mm HP5 for the same time as my 120 I’ll have bullet proof negatives. I have always had to develop 35mm HP5 about 20% less time than 120 HP5. I’ve often wondered about this as well. I’m using ID-11 1:1 and shooting in both 35mm and 120 at 250. 35mm gets 9 min at 70 degrees. 120 gets 11-12ish (depending on camera) at 70 degrees.

 

[Neil Grant]

... I think there may be a couple of explanations for the 120 format HP5 needing more a longer development time than the 35mm version for the same contrast,
1. the 120 format presents a greater 'load' to the developer due to the lack of emulsion where the sprocket holes occur.
2. the HP5 emulsion in 120 and 35mm are not identical or perhaps not coated to the same thickness.

 

[Keith Tapscott.]

When did Ilford mention this?
The box of 35mm HP5 Plus and 120 film have the same times printed inside.

 

[Sirius Glass]

I just follow the instructions for xtock XTOL or replenished XTOL.

 

[Bill Burk]

Traditionally, many photographers would develop 35mm a bit less and print from the lower contrast negatives on a higher contrast paper.
The purpose of that was to minimize grain - with traditional films, a more dense negative tended to exhibit way more grain.
With many modern 35mm films, grain isn't as big a concern. For that reason, I personally don't do that.

This makes a lot of sense. 35mm demands less development than medium format.

 

[foc]

I have never noticed any different dev times with Ilford HP5 in 35mm and 120.
The same times are shown for ID11 and Ilfosol 3, both on the Ilford site and the Massive Dev Chart.
Am I missing something?

 

[Bill Burk]

Developing the same times produces negatives with the same contrast. But 35mm gets blown up so much more that every little image quality trick helps.

Standard development basically aims to give you a negative that’s good print on Grade 2 paper. If you develop 35mm less, maybe to aim for Grade 3 paper, you make negatives with greater definition.

So for a little better negative you can develop 35mm for less time than medium format.

The tradeoff (harder to print, fewer contrast options when printing, less tolerance for underexposure error) is not necessary for medium format.

 

[Stephen Benskin]

It would be helpful to see the source. There might be some missing context in your explanation. One of the main factors affecting the amount of flare for a given situation is the number of lens elements. On average, 35mm has more flare than large format. and medium format is somewhere inbetween.

Ilford's film data sheet for HP5P doesn't indicated any developmental change between 35mm and 120mm.

 

[Bill Burk]

I don’t know but think the source for my comment might be a book or magazine related to Leica.

Stephen, you taught me that ASA parameters aim to fit an average scene with average flare on Grade 2 paper in a diffusion enlarger.

 

[Stephen Benskin]

I don’t know but think the source for my comment might be a book or magazine related to Leica.

Stephen, you taught me that ASA parameters aim to fit an average scene with average flare on Grade 2 paper in a diffusion enlarger.

Sorry for the confusion Bill. I meant the OP's source material.

 

[Bill Burk]

No worries, as I look at old Leica books “they’re saying” 0.6 to 0.8 gamma…

Willard Detering Morgan, ‎Henry M. Lester · 1951
Generally Leica negatives should be developed to a gamma between 0.6 and 0.8