CoExist said:
Got a rather easy qns out for the experts but confusing for a newbie
if i have only 1 flim @ ISO 100, take lots of shot wif this and at night,some night shots, i push the sensitive to ISO400, snap snap some shots then back to ISO 100. Could i actually develop the flim to the majourity of the shots at ISO 100 then go to aldephi to push process the selected night shots at ISO 400??? Is this possible? coz of space constrain(cant bring 2 cams) and the fact the camera kinda scuk, i cant take out the flim half way to insert the ISO400 one.
First of all, I don't know wat film u're using, but pushing from 100 to 400 is a 2 stop push, and u are not likely to get very optimum results with a 2 stop push, not to mention the only place to do a 2 stop push cheaply is RGB color (no affliations), and not a lot of labs will do push or pull processing well. (IF AT ALL!)
Secondly, no u cannot push / pull half a roll and develop the rest normally. You got to develop the entire roll. Technically, you can pull out the entire roll in a dark bag, snip the film at places where u know was shot with ISO 400, and develop those accordingly, but this is only possible if u do your own processing, and I doubt u'll be doing your own home colour processing if u're asking a question like this one
Also, this is not a practical or feasible method since u would not know exactly where the part of the film was that was exposed with an ISO of 400 except by guessing.
The solution to your problem is to buy a film picker for about $15. This allows you to pull out the film leader from the canister even after your camera has rewound the film inside. Then you label the canister with the last shot count (say 24), pull in a fresh roll of ISO 400 film, shoot with that, and take it out when u're done with ISO 400. Mark the 400 film again with the last shot count (say 15), use the film picker to pull out the film from the ISO 100 roll, and put it in your camera. Put on the lens cap, switch to manual, change shutter speed to fastest possible speed, stop down the aperture to the smallest possible (typically f16 or f22), then press the shutter 24 times to advance the film to the last point where u shot, then advance 2 more times to ensure you cleared the last frame totally. Viola! Then continue shooting with ISO 100.
You may want to pull out the leader from the ISO 400 film as well so that u're ready to load when u need ISO 400.