frustrating focusing problems

jordanstarr · Jun 7, 2007

I've been having some nasty focusing problems lately trying to make prints. It seems that it's only really in my 35mm film that I've been having focusing issues. All my photos come out a little soft when making 8x10s. I doubt it's my eyes as I have great vision. The difficult to understand part is that my medium format pics come out as I'd like. my 50mm enlarger lens is flawless and apparently one of the best on the market. I use Zeiss lenses for my 35mm shooting with film speeds of 125 and 400 -so I doubt it is that. I don't get what the deal is, but it's driving me mad. I'm wondering if my negatives are just not sitting flat or something -after all I do file the edges on my carrier? Maybe it's my grain focusing magnifier? I don't know!....Any help on the issue would be great. Thanks.

eclarke · Jun 7, 2007

It would help if you described your procedure step by step all the way through development..EC

percepts · Jun 7, 2007

could be many things causing the problem. First elliminate anything to do with the enlarging lens. The fact is a reputedly top notch lens is irrelevant. There are always bad lenses in any batch. However I doubt thats the problem.
There are significant and very visible differences in the sharpness of enlarging lenses at different appertures. The difference in sharpness between f5.6 and f8 can be a lot. Do some test prints of the same neg at different apertures and you will see.
Some lenses suffer from focus shift as you adjust aperture although a modern lens most likely won't. test by opening up and focus then close down and check focus.
Could be the lens alignment for the lens is out. i.e. is the sharpness is not the same across the image. i.e. is there a sharp line through the image.
Could be that you are just used to the increased quality of your medium format negs.
Is your grain magnifier focussed?

bdial · Jun 7, 2007

Have you examined the 35 mm negs with a magnifier, are they sharp?
Are you stopping the lens down more than 2 or maybe 3 stops?
Try a print with the lens you use for MF.
Unless you are use a glass carrier, the negative won't be perfectly flat, but it should be flat enough to make a reasonable print.

jordanstarr · Jun 7, 2007

alright...my process is pretty basic and normal

i eyeball the amount of light i want on the picture (i usually aim for a 10 second exposure under the light with a 2-4 contrast filter) stopped down between 5.6-11 (i usually aim for 8). i get the desired exposure from my test strip, refocus, then expose the paper. i've checked out the negs and they are sharp too. i doubt it's the enlarger lens because i've had great sucess with it on a different enlarger.

it could very well be that i'm used to the medium format negatives and adjusted my taste to that quality, but looking back on some of my 35mm stuff from a year ago, it was much sharper focusing.

percepts · Jun 7, 2007

just do the print test of making a print at different apertures. You may be very surprised at the results. besides its definitely worth knowing which aperture is the sharpest.

Nick Zentena · Jun 7, 2007

Contact print the negs. Are they sharp?

Is it just 8x10s? How about smaller prints? Are they soft to?

You don't describe the enlarger,lens etc. It could be anything. Motion? Maybe the lens is too short for the enlarger and that's causing problems.

highpeak · Jun 7, 2007

How about enlarger alignment?

I found out my enlarger alignment is off last time when I print. The negative is sharp but the print shows softness at the bottom, it turned out it was the enlarger problem, a lillte tape sloved it but I need a better enlarger now.

Alex W.

Roger Hicks · Jun 7, 2007

Have you tried enlarging just the centre of an MF neg with the 35mm lens?

Have you tried scratching an MF neg lightly, edge to edge, with a pin, and focusing on the scratches?

Either trick may help you find the problems.

Cheers,

R.

David A. Goldfarb · Jun 7, 2007

Do you use a scrap sheet of paper under the grain focuser when you focus?

Is heat causing your neg to pop out of focus (shouldn't in 10 sec., but not impossible)?

bdial · Jun 7, 2007

jordanstarr said:
... i've checked out the negs and they are sharp too. i doubt it's the enlarger lens because i've had great sucess with it on a different enlarger.

If the negs are sharp, it's got to be the lens, or something else in your technique. As David said, you should use a sheet of paper of the same thickness as what you're printing on under the grain magnifier. Otherwise it's due to movement, damage to the lens, alignment, or some kind of problem with the way the lens is mounted on this enlarger vs. the other one.
Did you use similar fstops with the lens on the other enlarger?
Have you reprinted a neg you printed successfully on the other enlarger and compared the prints side by side?

Paul Kinney · Jun 7, 2007

It sounds like the only variables are the enlarging lens and negative carrier assuming your negatives are sharp. Try enlarging 35mm using your 2 1/4 enlarging lens and see if it's sharper. Use masking tape with your 2 1/4 negative carrier and see if that works. Though, I gotta think it's the lens. Check the lensboard for flattness and check to be sure the lens is mounted properly. Hope this helps.

pentaxuser · Jun 8, 2007

Maybe just one more to try. Once you achieve sharp grain focus, leave the enlarger for a few moments and then check again. If the grain isn't as sharp on re-checking the problem may be that your bellows moves if sharp focus is only achieved with the bellows tightly compressed.

If this is the case then it raises the question of why no problems with MF. The answer may be that sharp focus with MF involves less compression of the bellows.

As a matter of course I re-check sharpness with the grain magnifier each time. There should be a screw or other tightening device that makes the bellows movement stiffer but should hold the sharpness if tightened enough.

pentaxuser

ic-racer · Jun 8, 2007

Sounds like negative pop to me. Grain focuser off by paper thickness is unlikely at 8x10 enlargement, F5.6-11 probably all OK based on physical properties of light irrespective of the lens (asuming reputable brand lens). If the grain was blurry in the grain magnifier you would have told us (right?).

If it is negative pop, I am sure there are a lot of suggestions, as everyone has their own method to manage it. If it is not negative pop, I am really stumped on this one.

To manage negative pop, I do a number of things. One is to have a glass carrier available. For some smaller formats I use it all the time. Second, I leave the enlarger with the light on and after a variable amount of time re focus. Sometimes the air pressure changes from moving the bellows will get it to 'pop' as you move the focus in and out. Sometimes I take the filters out of the lighht path to speed up the heating, but sometimes with the filters in place it never gets hot enough to pop and cause a problem in the first place. Once I think the image is stable, I put the lenscap on and put the paper on the easel. Then in a smooth controlled way I turn off the enlarger, gently remove the cap, wait just long enough for the harmonic vibrations from touching the enlarger to die, but not let the negative cool (a second?), then start the exposure. Occasionally it still pops, in which case I will give it a couple more tries then get out the glass carrier.

Jon Shiu · Jun 8, 2007

Make sure your grain focuser is adjusted properly for your eyesight. If there is filament in the eyepiece, that should be sharp at the same time as viewing the grain.

Jon

Andrew Moxom · Jun 8, 2007

Jordan, how does the neg look in the carrier outside of the enlarger? I've had some instances where the film takes a set that is not completely flat when installed into the carrier. When removed, the film looks normal, and no curl etc.

Try placing film in carrier, and clamp shut with your hands and see if the film stays flat.

jordanstarr · Jun 9, 2007

woah...lots of questions, so i'll answer the best i can.

-the magnifier shows sharp grain, just like it always has. focusing this way is no problem at all.
-the lens is bought brand new. it's a schneider componon-s 50mm f2.8. it is flawless. i used it on my old durst and it worked fine.
-the enlarger is on the dryer in my laundry room -don't worry, it's turned off.
-the negs are super sharp when i look at them on a window with my 50mm lens against it aperature opened up.
-the contact sheet also shows sharp negatives.
-the film in the carrier appears to be flat (i can't notice any bending with the naked eye.
-i don't think it's negative pop as the negatives are cold when i pull them out (or at least warm).

i'm way too lazy to set up my other enlarger and try that out again 'cause i know the other enlarger would work as it always used to.
i think the aperature stopped down would be a great idea, so make a few prints at different f-stops. i'll try that one out. i also think it might be the paper thickness as well considering all the prints are ever so slightly off. you can notice it up close, but far away you really can't that much.

i'm wondering though, maybe my contrast filters are too scratched up or something along those lines? i've dropped them in photo chemicals before, scratched them to hell on occassion, etc. i never thought of it as an issue until about 3 seconds ago. just a thought.

i wish i had a scanner to show some examples, but alas. i'm way too analog even for a 25$ used flatbed. however, it is soft throughout the picture and (depending on the lens), a little softer at the edges. so i think that explains a little better.

percepts · Jun 9, 2007

two points.

stopping down more than f8 is likely to soften the image. Find your sharpest aperture with the print test. I have recently been using a lens whose sharpest aperture is 5.6 and ther is a big difference between f5.6 and f8.

Another possibility is paper flatness. The paper should be really flat on the baseboard. Many papers have a curl and even when in an easel they tend to bow up slightly on the baseboard. So ensure paper is absolutely flat on baseboard when you do any tests otherwise tests are worthless.

bdial · Jun 9, 2007

You're using under the lens filters? They, or more likely one or two, are certainly possible suspects.
Do the tests Percepts suggests, first without a filter, then do a test with the filter.
Ideally pick a negative that you've printed on the other enlarger so that you can compare.

Jon Shiu · Jun 9, 2007

Just to clarify, if the grain focuser is not calibrated to your individual eyesight, focus will be off, even if you see sharp grain when focusing.

Jon

jordanstarr · Jun 9, 2007

those are all great tips. thanks a lot guys for the advice -it's must appreciated. there's so much to consider with every little step.

dancqu · Jun 9, 2007

jordanstarr said:
The difficult to understand part is that my medium
format pics come out as I'd like.

From 6 x ? you've less than twice the enlargement
to 8 x 10.

Another issue may be at play; your light source
and the paper being used. In a nut shell the paper is
exposed by the light it sees and that can be by
some measure not the light used for focusing.
From one to another enlarger? Dan

jordanstarr · Jun 11, 2007

out of pure coincidence, this happened as i switched to ilford paper too, but i doubt that the paper is the problem, but i'll explore that variable. thanks.

jordanstarr · Jun 15, 2007

it seems as though by putting the paper down on the easel first i was able to focus a little more accurately. it's still not 100%, but it's better -that's for sure.

percepts · Jun 16, 2007

two assumptions which may or may not be correct.

First is that any grain magnifier has been manufactured and tested to be accurate for its height.

Second that the manufacturer didn't allow for thickness of the paper.

curious thing is that I assume you were using the same magnifier on the enlarger which wasn't causing you problems so if its now the magnifier which is at fault then how do explain that it was working OK on the other enlarger?

frustrating focusing problems

Moderator

Privacy & Transparency

Privacy & Transparency