[Leica] Re: LUG Digest, Vol 30, Issue 26

[mark_wilkins at yahoo.com (Mark R. Wilkins)]

On Jun 11, 2005, at 5:15 PM, lug-request@leica-users.org wrote:

> I find that when I push Provia F400 one stop, the results are quite  
> good. Two stops seems to make it much more grainy, and also the  
> shadow detail really does not get improved much. Put differently,  
> the low values don't get two stops of push, the high values do, and  
> so the darker parts of the image (which the push was supposed to  
> rescue) seem not so much improved. Is this all standard for those  
> of you who do this regularly?


Pushing has the effect of taking all values higher, both darks and  
lights, though since they're proportionally scaled, darks end up  
being brought up less than lights.

Beyond a certain point, all you're doing in the dark parts of the  
image is bringing up the noise slightly.  The only way to actually  
increase detail in the shadows is to increase your exposure.  This is  
why most films' spec sheets talk about "loss of shadow detail" as a  
consequence when you underexpose and push (which is what you're doing  
when you shoot Provia F 400 at 800 and push one stop.)

If you're looking for more shadow detail, you need to expose more and  
develop less, but if your goal is to shoot handheld in a dark  
environment then that may not be possible.

Usually, pushing is a means to bring up the value of midtones and  
highlights while sacrificing the shadows, in a case where you really  
need to get an image without as much light as you'd like.

-- Mark