Originally posted by gabro822 Yes sorry, I didn't stated that. I develop myself. So I have to develop it like a 400? Or there is another way?
Let's start from the beginning. What film (brand) are you shooting and what developer (brand) are you using? I'll assume BW.
Go find the data sheet for both your film and developer. Read it! Your developer's data sheet should tell you some development times for a selected number of films. Of course they favor their brand but often cover others. They may tell you push times too. Kodak and Ilford are good at that. Also think of push and pull as exposure indexes. That is, you expose a box speed film at a different ISO and hence an exposure index. Often tables list development times by that instead of saying something to the effect of push 1 stop, push 2, pull 1, pull 2, etc.
Here is a link to
Ilford's Development Chart. It is a good reference. It gives development times for different exposure indexes (EI). A 100 film metered as 400 film is shooting at an EI of 400.
If your film/developer combo is unusual, you may find published push/pull times hard to get. I'd strongly recommend you start out with something that is on a published chart and when you're comfortable pushing film you can branch out on your own and experiment with less popular film/developer combinations as you'll have to do some experimenting on finding a development time for them often. But you can also search the Massive Development chart out there you can find where people have input almost everything under the sun.