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David Rude |
21:14 8 Sep 02 |
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Re: Film testing with Zone VI cold-light enlarger |
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David Rude |
21:54 8 Sep 02 |
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Ok now I have solved it I think. I did a couple of things here.
First I'm using my 210m camera lens since it has a larger maximum aperture (5.6) just in case I ever need that.
Secondly I am picking an arbitrary but repeatable focusing point that gives me even light and a large illumination area. It's defocued but it's easy to mark a focusing point on the Zone VI for repeatability.
And finally I am removing the negative carrier to let more light through to the lens and get an even larger illumination area. My light head has a huge 6x10" illumination source and by removing the negative carrier it lets a lot more light through.
So now I can easily get an EV reading of even greater than 5.0 using only F11 with a huge illumination area and I can use the lens shutter to control the exposure time. And I think this setup should be easy to repeat.
I did try the same ‘remove the negative carrier’ setup with the enlarger lens but it is dimmer than the camera lens method since it forces me to not use the focusing switch to brighten the light source so that I can use the enlarger timer again. So the enlarger ends up having to be quite a bit lower and I have to really defocus to get a large illumination area but I can do it although I have to use F8 to get an EV reading of 4.0, which doesn't leave me a lot of room for slower speed film testing.
So I’m not sure which method is better. I am leaning toward the camera lenses method as that would allow me to use the lens shutter to control the time which is probably more accurate for film testing than my compensating enlarger timer. I guess I’ll run a test and see how it works.
David
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Larry Francis |
18:15 9 Sep 02 |
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