Revisiting Push Processing

[thronobulax]

I've seen discussion here and there (and here again) on whether you can push film X with developer Y to an EI of Z.

I had asked this question yesterday, but the subthread in question was mercifully exterminated for other reasons (and well done that!) but I'd like to re-ask here. I have no agenda, only genuine curiosity. My question here is entirely in the context of monochrome film, not C-41, E6, Kodachrome (!) or any other color variant...

I was taught that you actually cannot push film much beyond box ASA. More development will raise the effective EI slightly but not multiples of the stated ASA as often claimed. Most of what was called "pushing" really involved sacrificing shadow detail due to underexposure and increasing both grain and highlight contrast due to extended development. I have no particular objection to this, it's another valid aesthetic.

More specifically, for a true EI "push" we'd require the method we use for determining EI to still be satisfied. For example, if we use the Zone System 0.1DU over FB+F for Zone I, then the push scheme would have to satisfy that at the pushed EI. Similarly, if we used the ASA gradient method for figuring out film speed, that would have to be satisfied at the new pushed EI. My understanding is that beyond slight increases in EI from the longer development, you just don't get no ... satisfaction.

What say you all - you closet sensitometerists, you emulsion mavens, you developer dilletente's - is what I wrote above incorrect and has there been some magic I've missed to actually speed up effective EI?

P.S. I can think of no example of any image I have seen done with pushing techniques that didn't lack shadow detail, that didn't have more grain than usual, and that didn't have harsh highlight contrast. But that's just what I've seen. I am well aware there may be possibilities outside my experience. Hence, the question...

 

[Ian Grant]

I did start to reply, last night/this morning.

You can use developers like Microphen/ID-68, Diafine, original Promicrol, that will give you maybe 1/2 to 2/3 of a stop speed increase, no loss of shadow detail, but slightly more prominent grain, of the three Promicrol was possibly the best.

There are NO examples of push processed films showing good shadow detail, well shot in normal lighting conditions.

One of the arguments linked to in the deleted thread was that with HP5 over exposure & normal development gave finer grain and higher definition/resolution. But over exposure kills definition, and does not give finer grain. XP3 on the other hand gets finer grained with more exposure, and the 3rd party link had muddled the two films in terms of exposure etc.

Ian

 

[thronobulax]

I did start to reply, last night/this morning.

You can use developers like Microphen/ID-68, Diafine, original Promicrol, that will give you maybe 1/2 to 2/3 of a stop speed increase, no loss of shadow detail, but slightly more prominent grain, of the three Promicrol was possibly the best.

There are NO examples of push processed films showing good shadow detail, well shot in normal lighting conditions.

One of the arguments linked to in the deleted thread was that with HP5 over exposure & normal development gave finer grain and higher definition/resolution. But over exposure kills definition, and does not give finer grain. XP3 on the other hand gets finer grained with more exposure, and the 3rd party link had muddled the two films in terms of exposure etc.

Ian

Thanks @Ian Grant, that kind of confirmed my suspicions.

I'd emphasize that I in no way object to "pushing" it's just that the net effect is not faster speed but the aforementioned artefacts.

P.S. You'd be very proud of me. I've briefly suspended my foray into standing development to explore - for the time being anyway - divided Pyrocat-HD

 

[Ian Grant]

Thanks @Ian Grant, that kind of confirmed my suspicions.

I'd emphasize that I in no way object to "pushing" it's just that the net effect is not faster speed but the aforementioned artefacts.

P.S. You'd be very proud of me. I've briefly suspended my foray into standing development to explore - for the time being anyway - divided Pyrocat-HD

Ignoring the previous poster, (post now removed) discussion in the now deleted thread was about push processing HP5 and XP1/2, and more importantly acknowledged Ilfords's recommendations, In particular the lack of push processing recommendations for XP2, dropped because labs hadn't like the non-standard XP1 C41 development time or being asked to push process it. However XP2 (and Super) canstill be push processed.

It's a bit academic though on an LF forum, XP2 sheet film was once available for a very short time, but there was probably only one coating run, it didn't sell. Then few of us would ever need to push process sheet film.

Push processing is a compromise, as soon as you increase effective EI with longer development times, you increase contrast, grain, and lose shadow details,I push processed a lot of 35mm HP5 until XP1 and later XP2 were released.

I have push processed HP5 sheet film more recently, around 5 years ago, to somewhere around 1600/3200 EI, not out of choice rather the 0 light was dropping fast, I needed ideally the fastest speed of the lens shutter 1/100 band f16, but ended up 1.25 f5.5. I processed in Pyrocat HD for 50 minutes 1+1 to 100, negative was OK and printed easily. However even with 5x4 the grain was becoming noticeable, at 800EI it would have been way better.

Ian

 

[David M]

I took the liberty of Googling HP5Plus. In fact, Ilford says it can be exposed at 3200 (not 1600) and they give development times for Microphen (16 mins stock). They also suggest Ilfotec-DDX for “Maximum Film Speed” but without any further details.
Rating at 3200 isn’t listed under “Best overall image quality.”
I had always supposed that pushing film was propelled either by necessity, in cases where any kind of image was preferable to no image at all, or where empty shadows, harsh contrast and prominent grain were part of the aesthetic aims of the photographer. This was fashionable in camera clubs some time ago.
It would be a very unusual ambition for a large format photographer.

 

[Ian Grant]

Page 3 of the HP5 datasheet,Ilfotec DDX is the first developer in the table of EI and development times.

Yes, most people only push process out of necessity, but there are one or two who like that gritty, more contrasty look. Personally because I work on projects I don't want a print that sticks out like a sore thumb in terms of contrast, tonality, grain, etc in sequences.

There are circumstances with LF where push procesing might be useful, I'm thinking particularly of hand held work. We do have a member here wandering around Edinburg shooting a Crown Graphic hand held

Ian

 

[David M]

I find I associate pushing film much more with 35mm roll film. In low light, the format makes much more sense. Lenses with a 1.4 aperture are unknown in large format, but common in 35mm. That’s equivalent to several stops of pushing. (I may be wrong here, as LF photographers are endlessly ingenious in attaching unlikely chunks of glass to their cameras.)

On the whole I’d expect low-light or high speed photography to have migrated almost completely to the digital realm, where ISO numbers seem to be working their way towards infinity.