- Joined
- Jul 14, 2011
- Messages
- 13,926
- Format
- 8x10 Format
It's quite easy to mount the lens board incorrectly so that it's slightly tilted. I think this would result in a sharp image through the grain focuser but slightly unsharp prints
OK, before this gets any more pointless, here are a few things that should be obvious (but apparently aren't) - if you adjust a Paterson Micro Focus Finder to your eyesight under white light, it is just as accurate as a Peak MK1 (adjusted to eyesight under white light too) - they are capable of getting the grain properly in focus. And this is across more than a dozen random samples of Patersons and more Peak MK1's (in varying states of preservation) than most of you will encounter in your lives. The paper thickness thing is nonsense - if you are getting the image in focus down the magnifier, but it wanders before exposure, the problem is in the head, not on the baseboard - the depth of focus at the baseboard is several times that of a sheet of paper, but not at the neg stage. Backlash from the rack and pinion on the column settling (or the focusing mechanism settling) are much more likely sources of focus error after focusing and before exposure - and nudging an enlarger of the relative lightness of build of the M605 during or between exposures is another potential cause of unsharpness, especially as you cannot guarantee it returning to the point it was beforehand (wall braces for enlarger columns don't exist for the good of people's health) - i.e. if you dial in a different grade to burn highlights, you are potentially knocking the head position out by just enough to affect ultimate sharpness - which may be less than most of you are thinking, but clearly noticeable when compared to working on a machine that isn't affected by accidentally bumping the column while burning-in.
And believe you me, you would really see a visible effect from a slightly tilted lens board without any comparison being necessary, it just would not be over the whole image - and isn't what the OP seems to be talking about.
I believe you do have to adjust the eyepiece of a Paterson finder to your own vision.
... or a baseboard or easel sharp in the center, but otherwise misaligned.
Lachlan - a Peak Critical Focus Magnifier is in a whole other league. They really do make a difference. Plus the tilting head allows one to inspect the grain at the corners of the field, not just the central area.
I always use the same paper I'm printing on, different runs are OK, but it's always best if you can use a trashed sheet, 'raw' or developed print, even if its only a smaller than full sheet, square that fits the foot on your grain focus device or devices, just put neat notations on each so you know what's what.
This will make no difference to accuracy of focus. If it did, every focus magnifier would have been designed and tooled in such a way as to compensate for it. The people who designed them knew what they were doing, unlike an alarming percentage of the end users.
Good point. Didn't someone, Greg Davis maybe, demonstrate in a video that a sheet of the same thickness or no sheet makes no difference in fact isn't the margin of error much greater than a sheet of paper
However such ideas and others will never die on Photrio and will continue to be cited
pentaxuser
While split grade printing I'm always holding my breath while carefully replacing contrast filters on my Beseler 23. I see that time as the greatest chance for focus mishaps, and also the best reason for not engaging in split grade printing in the first place, but people in those debates generally don't mention it. Still I like the split grade approach so I'm as careful as I can be.i.e. if you dial in a different grade to burn highlights, you are potentially knocking the head position out by just enough to affect ultimate sharpness - which may be less than most of you are thinking, but clearly noticeable when compared to working on a machine that isn't affected by accidentally bumping the column while burning-in.
I use the paper method when focusing as well. First for the tolerance issue you correctly raise, but also the bright white paper is easier to focus on than the easel.Now I don't like systematically using up 10% of my tolerance in focus when printing, so I have gone back to putting that piece of paper under the grain focuser.
Where could the loss of sharpness be located ,despite having a very good lens on my enlarger??
okWhen you find a solution please post it here. We will be interested to hear the results.
HelloJus a few questions and thoughts to consider (but not necessarily the cause of your problem):
If, in any case, there is an Anti Newton glass in the negative carrier, is it mounted on top, and not below?
If, in any case, it is a glassless negative carrier, does the negative is held flat, and not 'bulged' [convex (I suppose I don't know the correct word in English)]?
Is possible that the negative is bulging (plopping?), after focussing or during exposure, due to temperature fluctuations caused by the heat of the enlarger's lamp?
Are the negative carrier plane, the lens mount plane and the paper/easel plane parallel?
Some good suggestions above.
Here's my two pennorth.
As you have access to another darkroom, would it be possible to try your lens on the enlarger there that produced good results?
Has the negative been placed in the holder the correct way up? That is glossy side up.
Also, when I started out, I read in a few books that the red swing filter could be used to make the exposure.
The method was with the filter in, switch the enlarger on, keeping an eye on the stop clock swing the red filter out of the light path, then when the time was up swing the filter back in to stop the exposure. A better cause of vibration in the enlarger column would be hard to find.
Good luck in your quest. Some here should hit on the solution for you.
There's nothing wrong with focusing with a piece of paper in the easel. It's virtually impossible that it could matter, though, No paper is actually thick enough to make a difference, and no enlarger lens has a large enough aperture to make a difference. Maybe if you decide to put that otherwise useless Canon 50 0.95 ltm lens on your enlarger, you'd notice something.
I'm afraid the answer to this entire thread is likely that the guy's negatives are fuzzy.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?