Projection Print Calculator Scales

Discussion in 'Enlarging' started by bmac, Mar 8, 2003.

  1. bmac

    bmac Member

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    Saw them hanging in the local camera store this morning, how acurate are they in getting a base time for a work print? Pros and cons of using them vs a regular test strip of say 3 second exposure, vs a test strip in stops as Les talks about in his book. Let the debate begin!
     
  2. Nige

    Nige Subscriber

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    Are you talking about the thing that looks like a pie graph with different density slices that you wack on the paper, make a 1min exposure (or 30sec) then pick the one that looks good?
     
  3. SteveGangi

    SteveGangi Member

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    They work pretty good, but they just get you in the ballpark. You will find you still need to "fine tune" with a test strip and do the usual burning and dodging. The chart may say (for example) the best exposure is somewhere say between 15 and 20 seconds... so from there, you make a test strip that only covers that 15 to 20 range. It helps more with dense negtives for me, in case I initially grossly understimated the overall time.
     
  4. GreyWolf

    GreyWolf Member

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    I have one and find it practically useless. The thing is too small in circumference to properly cover a good area of an 8x10 let alone an 11x14 sheet of paper. I find that I am making my judgment on too small of an area of the print.

    Probably whan I was just beginning to learn how to print it helped, but now I find it far easier just to do a step series on a single 8x10 sheet. I still fine tune in the next print or two to get the right grade but I am much more confident in where I am going. Also because I have done density/print grade testing on the four papers I commonly use at a few specfic enlarger head heights, I already know where abouts (aproximately) in time I should be printing to get my maximum black without excessive over exposure.

    As a side note.... the time it took me to do the density/paper grade testing has proved to be worth it's weight in gold both in teaching me about paper grades as well as making it easier to select a starting print time.

    Cheers
     
  5. Eric Rose

    Eric Rose Subscriber

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    I'm with GreyWolf on this one. Proper testing should pay off in the end. Beyond that I do the usual test strips, usually at least two per neg. One for the highlights and one for the shadow details. From there I apply a liberal dose of voodoo and wing it.
     
  6. clogz

    clogz Subscriber

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    Just an idea: why not photocopy and enlarge the Print calc.Scales on a transparent A4 sheet?
     
  7. SteveGangi

    SteveGangi Member

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    Not really worth the bother, because then you still have to fiddle with the new sheet to get it close.
     
  8. clogz

    clogz Subscriber

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    Hello Steve

    A glass plate will sort that out.
     
  9. SteveGangi

    SteveGangi Member

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    I had to think a moment to figure what you meant there. I wasn't saying close as in physically close, I meant close density-wise. Not worth the bother.
     
  10. Nige

    Nige Subscriber

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    Others have given my thoughts on these things. Good for when you've got absolutely no idea of likely exposure and suits the image in that the pie slices all cover important (equal) areas.

    One hint that I learnt well after I'd stopped using the thing was the minute expose suggested (on the Kodak one) can be halved (etc) to suit your enlarger brightness then divide the selected exposure by the factor that you used less than the minute. eg say you exposed for 30secs and the 14sec segment looked good, then divide 14 by 2 (60 / 30) to get the 7sec time required. Easier in practice than trying to describe it but you might need a calculator!

    Once I got my film exposure/developing a lot more consistant, I found it wasn't much use as I knew my enlarger exposure was going to be within a small window and the steps between 'slices' is too big. The good old test strip works for me.
     
  11. lee

    lee Member

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    I have a thingy that is attached to my timer (Metrolux II) that will give me the exact time for an enlargement and a reduction if I have a good time and need to move the enlarging head. Very accurate.. Without it I would just make new test strips.

    lee\c