Exposure Time

[Ektagraphic]

Many people have said that starting off making an 8X10 on RC VC paper, use f/8 and expose for 20 seconds. What is the starting point for an 11X14 VC RC? Thanks

 

[bdial]

Assuming that the 20 second exposure is good, the 11x14 exposure would be 40 seconds (1 stop more).

 

[bsdunek]

Note that each paper size is half or double the area of the next size. Exposure goes by area, so doubling the area means doubling the exposure time.

 

[polyglot]

It depends entirely on the strength of your light source. With my enlarger, my typical 8x10 exposure time from 6x7 is 10-15 seconds at f/11 - less than half as much. If you're printing from 35mm, your exposures will be longer (more magnification therefore illuminating the same size print from less negative area). If printing from 4x5", your exposures will be shorter because the magnification is reduced. If you have an adjustable condenser enlarger, changing the condenser will change the exposure times.

You do need to run test strips/patches. Once you have the exposure for a particular magnification off a particular negative, you can scale that exposure with the relative area of the print.

 

[Christopher Walrath]

I still think that a test strip is the best way to guage printing exposure. I use the 32-16-8-4-2-1-1 timing.

Once I decide on a time I can then, as mentioned before, double the time for each standard (for lack of a different term) size increase. Halve the time for each decrease. Another way to look at is the short dimension.

• 4x6
• 5x7
• 8x10
• 11x14
• 16x20
• and so on.

Look familiar? 4/5.6/8/11/16