starting point for increasing contrast

The best route is change overall contrast is through devlopment. On-camera filters will change the contrast based on the colors in in the image (e.g. red makes red things lighter and red's compliment (blue) darker). A good starting point it about 15-20% more development.

 

I'd just experiment and see what happens. IMO, the best thing to do is to shoot a whole roll (or two) of the same exact thing, on a tripod. Try a shot as the meter tells you, followed by a shot half a stop under. Then another half stop under. Then a half stop over the first shot, then another half stop over the first shot. Then do it over and over. Keep notes as to what each exposure was. Then cut the roll into three pieces, and develop each one for a different time. Then proof the entire roll and examine the contacts to see what the changes in exposure and development did. You will get to see what an underexposure, normal exposure, and overexposure look like with normal, +10%, and +20% development.

 

Exposure determines negative density; film development determines contrast.

 

Increasing the development to increase contrast works - if you are taking pictures of a low contrast subject.

If you have a normal contrast subject then increasing development time may lead to a hard-to-print or unprintable negative.

The normal way to increase the contrast of the final photograph is to print it on a higher contrast paper and dodge/burn as needed to get the highlights and shadows back into the printable range.

OTOH, if you want to do it just for the fun of doing it and seeing what happens - charge right ahead.

You can get some quite lovely effects by taking pictures of a very low contrast subject and then expanding the contrast range by over developing. A. Adams took this picture at twilight - there was no sun shining - and increased the development time to get the contrast you see:




How much to increase the development time depends on the developer and the film. TMAX and Delta films only need a 10 - 15% increase in development time to add a stop of contrast (i.e., the luminance range the film will capture (assuming normal printing) is reduced by one stop). For Tri-X/Plus-X and HP/FP films a 20-25% increase may be needed. D-76 (ID-11) and Xtol are the best developer choices if you are going to bump development.

 

Try to get a bok on basic photography. There are many on the market, used and new, and do some reading. You will find answers to most of your questions and be way ahead.

 

Henry Horenstein: http://www.buy.com/prod/black-white-photography/q/loc/106/33905960.html

The book all my college students use.

Exposure controls density; development controls contrast.

 

Although film development controls contrast, there will be occasions that a portion of the print requires more or less contrast. In that case variable contrast paper and filters for the enlarger or a variable contrast light source such as one from Aristo Grid Lamp Products give you such control. You can also reduce or increase overall contrast for a negative that is too little or too much in the contrast department.
Jeffreyg

 

Dektol for 1.5 minutes. If you don't care for the results, at least you'll know you can use Dektol for your negatives. And if you ever find yourself stranded on an island and that's the only developer available . . .