exposure time/developing time affecting contrast?

[ambrogea]

Hi all,
i'm a newbie in developing, i develop with a beseler c23i, with ilford dev and ilford rc paper.
my question is how exposure time will affect my pictures ex: 4 second on f8 vs 8 on f11?
i did my test strip and try to get the best range of tone... does long exposure provide better grain?
regarding developing time what should i be careful of? i do check my temperature and follow recommended times.
thanks for your help.

 

[ann]

should be the same amount of light. you have decrease the amount of light by going from f8 to f11, but adding the light by going to 8 secs.

The grain is a product of the negative, but if you burn in highlights too much the grain will appear to become mush. Tones without detail will reveal the grain pattern of the film type your using.

Developing times should stay the same, i.e. 90secs per Ilfords insturction, unless your using Cooltone paper which is 2 minutes.

 

[Derrel]

An exposure of 4 seconds at f/8 is an awfully,awfully short exposure time to work with. It doesn't allow hardly any time for manipulations,and even very brief variances in time would make a huge impact in the exposure. Are you making really tiny prints?

 

[Helen B]

I think that it is well worth finding out, by experiment, how variations in development time affect the results with each paper/dev combination you use. Paper development is not like negative film development - you are usually developing to finality (ie as far as you can go) or near to finality with paper. For example, once you have agitated the print for the recommended time, try just leaving the print face down in still developer for a few minutes.

If you want a full range of tones, always make sure that the exposure is adequate to give maximum black, or near to it. If you wish , you can use a fogged and fully developed piece of paper, wet, possibly with a hole punched in it, to judge how close you are to max black (DMax) - but remember that you may not always achieve full DMax without losing a little separation in tones close to DMax.

Best,
Helen

 

[ambrogea]

thanks all for you help, . i brought a gralab digital timer , that will certainly help me to be more consistent and precise on my exposure time.
as well i did try to develop a ilford fp4 iso 50 , which i think they been under exposed...
so i need to shoot a proper pictures and then try to make a descent print.
@ Derrel size print are 5x7" i will defenetly try to extend that exposure time. might go minimun f stop
@Ann ilford recommend 32sec @ 75f/25c , i will try to play with that time though.
@Helen i will give a shot to do a test strip without a negative and try to reach the "dmax" you mentioned, but you need a good shoot and have to be perfectly balanced.

thanks for your help again, developing/printing film is really fantastic...:mrgreen:

 

[ann]

why develop at 75 degrees?, minium fs top is going to shorten the exposure, you need to increase the time which means to stop down f16
do a test with the rebate of the film for finding the Dmax.

 

[ambrogea]

Hi Ann, i located in Houston tx, home temperature is set for 75f , usually chemical are around 70f ish but by the time i set up everything, it reach room temperature...
for exposure i got it the wrong way but understood the concept

 

[ann]

use some cold water to mix the developer, or a cold water bath.