The setup…
I’m thinking about 20 three inch prints will take me through the range of sharpest focus. I’ll cut the sheets to three inches, mark a diagonal line across so I can reassemble them in order after processing. I will focus with 10 sheets in the film box. Then I will put 9 more sheets in the box and one in the home made speed ez-el. Expose, put the exposed sheet in the paper safe and take the next unexposed piece of paper out from under. Each exposure will lower the height of the film box under the speed ez-el by the thickness of one sheet of paper until they are done.
That would deal with differences at the film/negative plane.What if you took a sheet of clear film, mark an X with a sharpie on the right side of the film. On the left side, make an X on the reverse side of the film. Stick it in the enlarger and see if both Xs are in critical focus at the same time at 5.6 or 8. It would tell you if the offset of the film thickness is enough to make any difference.
That would deal with differences at the film/negative plane.
This thread is struggling with differences at the plane of the easel/paper.
3. Neither improves nor worsens focus.The last thing I need is to see a bunch of naked guys (including myself) so I’ll have to pass.
I’ll just accept that using paper under the grain focuser does one of two things:
1. Improves focus
2. Worsens focus
Haaaa.Well before I make a print, I use a scanning quantum microscope to determine the average depth of grains within the emulsion. I then recalibrate my enlarger focus to this depth and hey presto the image is in focus.
Stopping down would make
3. Neither improves nor worsens focus.
However putting paper under the magnifier puts the focus aim where the paper will be, in the exact right place. Not introducing an error can be psychologically reassuring. Even if it makes no practical difference in this application.
In other applications deliberately ignoring a known error is unforgivable. Some applications most of us won’t see such as making archival color separation negatives from studio masters of a Hollywood blockbuster. But other applications may be encountered, like making reductions instead of enlargements.
When I get out the extension bellows I put paper under the grain magnifier.
I was thinking 2.8 to show “even wide open you can not tell until x sheets.” Hoping to find it’s less than 10 where you can see the difference. Going to make a video you can loop through and see where it becomes crisp and where it starts to get fuzzy
for everyone arguing the toss about all this, no one has said what is wrong with Greg's experiment
I am satisfied with Matt’s depth of field (focus) calculation. It is much more persuasive than someone, no matter how well intentioned, telling me what he did or didn’t see. Neither will change my workflow. I always have a sheet of paper in the easel anyway for rough focus and composition. I am not a fan of trying to rough focus and compose on the yellow surface of an easel. I am not going to take the paper out to use my grain focuser. That makes no sense.
It's no worries for me now...retired from that job and I now only contact print using UV wavelengths!Ah yes. Alignment. That opens another 200 posts!
Whaddya see? whaddya see?19 prints are in the wash. I think there’s something there.
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