Push Processing

I havent experimented yet with push processing. I was wondering if I

was shooting at iso 100(actual film speed) and i shot like four shots.

Could I then push it to iso 200 or do i have to shoot the whole roll

at the same speed. Also if i push process do I have to let my

developer know

Changing the expsoure index( ISO 100 to 200), would require you to have your lab "push" the entire roll.

 

 

Pushing, amounts to extending the film's time spent in the devloper. "Pulling", would be less time in the developer. So yes, you have to ask the lab to perform these changes from normal development, for you. There is usually a small charge for the service.

Anyone who knows about this, I could use a little advice as well. I just finished my first roll of Velvia 50, and realized I had my metering set to ISO 100. Is this going to make a huge difference, or should I tell the lab to process it at ASA100? The difference between slide film and negative film is... well, could someone run over that with me again, I get the two confused pretty easily. I know I could look it up by searching the forums and the internet, but I know lots of people like to share their knowledge, so I'm going to leave this open for discussion. Thanks!

Mr Walker, how accurate is your metering, and how much did you bracket? A full stop of underexposure is pretty fatal to slides unless you were attempting something special. For me, pushing a roll means that I have to run it by itself (my processor will run two or four rolls at a time, but the whole tank gets the same process), which is a waste of chemistry. But in this case I would absolutely pay the price to save the session. (On the other hand, I might go shoot another roll at the same underexposure to fill the load.) I believe that you will lose a bit of contrast when you push, but that's probably not much problem with Velvia.

 

On the other hand, if you bracketed a full stop both ways, running it normally just means you've lost your bracket on the over side - your one over becomes your "center" exposure, your "center" becomes your one-under bracket, and your one-under probably becomes a useless two-under. If you can go back to the scene later, and finding someone to push this roll for you is problematic (speed, price, or hassle), accepting the risk could be a reasonable part of learning to shoot Velvia.

 

If the lab you normally work with can't handle the one-stop push, it would probably not be a good time to look for a new lab.

 

Van

Keith, although push and pull processing is common for E-6 (color slide) film, it is rarely done for C-41 (color print; negative) film, as very few C-41 processors are built with this capability.

 

Van, if the Velvia 50 E-6 film is underexposed one stop (at EI 50) and push processed one stop (8:00 in first dev), it will gain, not lose contrast compared to Velvia 50 shot at EI 50 and processed normally (6:00 in first dev).

 

In any case, you (Van) really should be running a replenished E-6 line, at least for the first & color devs, bleach & fix: You'll save a fortune, which you can put in your pocket (and use to pay for ferry trips for that expensive Seattle coffee!). Reversal bath & pre-bleach, though, can be tossed, since they are so cheap, yada yada yada...