Grainy pictures, please help.

[Apple Juice]

Hello RFFers,

I have been shooting with my Bessa R2A + 35mm Summicron for a while now.

I don't have the time/skill to develop the photos myself so I would drop them off at a small photolab and collect them a few days later.
I usually ask them to directly burn the pictures onto a CD so I can see them on the computer.

Although I have been using Ilford 100, Lots of my pictures turn out quite grainy.
The weird thing is that on the same roll of film, some pictures are grainy and some turn out fine.

I know this is a really basic question but aside from the speed of the film, what are the other important factors that contribute to the grain of a film?

Thanks,

AJ.

[XAos]

Underexposing (or grossly overexposing I've found out) can increase grain. Also, I wouldn't expect this from commercial scans, but I've been getting a lot of grain and soft focus that of late I'm starting to think might be my scanner rather than the negative itself.

[jlw]

Any conventional (silver-based) B&W film that's scanned will have more exaggerated grain than the same film printed "wet" because of an annoying phenomenon called grain aliasing. It's caused by an interaction between the random pattern of the grains and the regular pattern of the scanner's CCD.

One way to reduce the effect is to throw the image out of focus slightly in the scanner, so the fact that some of your files are grainier than others may reflect a slight focus variation from one frame to the next.

[jyl]

Take some of the shots and have them printed from the negative. That will tell you if the apparent grain is in the negative, or in the scan.

[Thardy]

If you are viewing the photos from the CD provided by the lab you will be most likely disappointed.

I've found that those scans are low resolution and have the same function as an index print.

[Ariya]

The development of the negatives can affect the appearance of grain. The choice of developer, length of development, level of agitation, etc. all play a part. The very best way to control grain is to develop the film yourself. I personally use 510 Pyro developer for my 35mm negs and they come out very smooth.

[BILLC]

I was useing tmax 400 in my xa and had been in a shop so was wide open to get the exposure. I then went with our group to an apt. and saw a great shot out the window of a highrise apt. across the street. I quickly took the shot without changing the fstop. The camera took the picture but the negative was very dense, it took forever to print and unlike all of the other shots on the roll there was huge grain, so dense overexposure equals grain I guess.
Bill