Pushing HP5 to 800 and underexposing

drjoke

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All of my pictures are underexposed by 0.5 to 1 stop. My film is lab-developed, so I do not know what process they used. I definitely told them that my film is pushed.

Is this normal? For my next roll, I plan to take everything 0.5 slower.

DrJoke
 
Is what normal? Contrast is a bit higher than what I'd normally expect from HP5 @ 400, but that's what happens when you push. Is there something in particular that you are noticing?

allan
 
The fact that most of my shots are underexposed. Is that normal? The contast is expected. After scanning and importing into Aperture, I had to increase exposure by 0.5 - 1 stops for most of my pictures.

To push HP5 to 800, should I actually pretend that it is a ISO 600 film?

I don't develop my own film, so I don't have control over how my lab push my film.

DrJoke
 
The pushing comes in the processing step, so it's important that you convey to your lab guy that he needs to give the film a one-stop push in the developing. What you are doing by exposing a 400-speed film at EI 800 is, by definition, underexposing.

The push processing can restore highlight and most mid-tone densities for acceptable printing, with little benefit to shadows and other darker areas, so the contrast will be higher than with normal exposure + normal developing. Adjustments in scanning of your underexposed film, and subsequent computer editing of the scan, can give some of the look of the push developing too (assuming you didn't get extended developing at the lab).
 
I don't understand. Your shots are underexposed. The film is rated at 400, and you shot it at 800. Thus, you underexposed the film. Thus it looks like it is underexposed...

allan
 
I told the lab to push it to 800 specifically. May be the shot are not underexposed after all. May be it's the contrast where too many details are hidden in the shadow, and I am not used to this yet. Coming from digital, the pictures I am getting look unfamilair to me.
 
You will lose shadow detail when you underexpose film and increase development time. You could, of course, use a faster film. Neopan 1600 is nice shot EI 1000. I've also liked the results from Delta 3200 EI 1600.
 
1 stop underexposure is well within the limits of HP5. With Tetenal Ultrafin plus I don't push it with less than 2 stops underexposure.
 
800 ASA is one stop (not 600). It is possible to err by 1 stop up or down. HP5+ reacts nice for this kind of erring. Keep going. If you start pushing 2 or 3 stops for the whole roll, better to develop it yourself, or in lab that you can trust
Good luck
 
What you could do is ask the lab to extend development next time. Pushing one stop is not really worthwhile, IMHO, being within the range of normal development. I'd say if you are going to push 400 speed film, go right to 1600 or don't bother.

If you are going to push film, you really ought to be developing it yourself. It's cheap and easy, and the results are far better.
 
HP5 has pretty good tolerance, yes. But how do we define tolerance? does one mean to say that HP5 @ 800 will look the same, with the same shadow detail as 400? I certainly hope, because that's impossible.

You cannot, for the most part and certainly without some different development techniques (not just time, but actual techniques), make HP4 @800 look like HP5 at 400.

IMO, when people say that it has a tolerance of 1 stop underexpoure, it is traditionally referring to wet printing, and the ability to get acceptable prints with a bit of tweaking that looks kinda sorta same as 400. Now, that may _seem_ to contradict what I said earlier, but you can do the same tweaks when scanning - scan for shadows, then for highlights - and get something close. But you will lose shadow detail when you underexpose and you will get more contrast when you push. Period. It's physics.

allan
 
I typically push a film like HP5 or TriX by metering at 1250, and processing it as tho it was shot at 1600 - overdeveloping by 1/2 stop of so to compensate a bit.

Pushing to 800, I process for 1250. etc. But that's just me and I haven't done densitometer and calibration exposures to test the effectiveness, or possible drawbacks of this technique. I'm also doing semi-stand processing, which changes the characteristics of the development. (ie. YMMV)
 
I find my success in pushing depends quite a lot on the degree of contrast in the original scene. Just a random comment.
 
Give me the HP5+ roll shot @ 800, I'll develop it at 400 as usual and correct it in PS for any shadows and/or highlights if required. Nothing special can be seen in my opinion.
 
If you reduce the EI margin, then you need to be more careful with high contrast scenes, e.g. meter for the shadow you want to have detail in and two bath for the high lights.

free lunches are difficult to come by.

Noel
 
If you are going to push or pull a roll of black & white film then you need to take control all aspects of the exercise yourself. In other words process your own film and so take total control of the situation.

In your own words of the initial thread ".........so I don't know what process they used.....". Processing is critical when pushing / pulling a film so why trust it to just anyone?

Where they using dip-and-dunk processing with gas burst aggitation or a roller transport processor? Was it hand processed and if so for how long and with what aggitation cycle and temperature ? Too many variables to not know about. Even which developer used is critical.

Regards
Peter
 
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