Enlarger alignment - what is "good enough?"

[tkamiya]

I have been trying to align my newly refurbished Omega D-2. I recently was able to borrow an alignment tool made by Bessler and am using it with D-2.

Alignment itself was not a problem. Baseboard to lens stage to film stage. All fairly well aligned all within about 1/5th of a bubble. But, the problem is repeat-ability!

If I align it at one height, move the lamp assembly up and down, focus knob right and left, and re-measure, I read differently. Do it again, and it is yet, again, different. Everything is/was tight and there are no obvious "slops."

I soon realized, expecting this machine to align and repeat with precision of a highly calibrated scientific instrument is, probably not realistic. Not only is this equipment over 50 years old, is simply isn't made with that kind of precision.

So the question - at what point, is it good enough? For a point of reference, I do not expect myself enlarging to any bigger than 10x14 using 35mm or MF negs. I do crop some times and my lens is NOT an APO type.

 

[tlitody]

getting lens perpendicular to neg stage is critical. Then getting easel perpendicular to lens is easy to do with a grain magnifier. Start at top of system and work down. Not from bottom up because if lens and neg aren't right then setting easel will be wrong.

 

[tkamiya]

Can't do that because of inter-dependency of adjustments. The question still remains - what's good enough?

 

[Bob Carnie]

Putting the top of the column braced to the wall will help by keeping the top stable.
This should help keeping the top to bottom alignment.

Whats good enough? depends upon you and how edge to edge critical you will accept with your work.

 

[Mike Wilde]

A thumbnail alignment tool -that I use for checking from time to time that important things are still working and in alignment.

DIY - take a black film leader of the format in question, and put it in the neg carrier with the emulsion side up. Scratch the outline of the neg carrier with a pin/needle. Take the neg out, and draw diagonals from corner to corner.

Put the film back into the carrier, and mount the carrier in the easel. Focus on the neg at the desired head height under test, with the lens cone, lens etc. under consideration. The diagonal lines should be sharp from end to end, and the distances of the opposing sides should measure the same.

 

[domaz]

You can always stop down the enlarger lens more. This gives you some slack in the system at the expense of possibly hitting diffraction limits.

 

[tlitody]

Can't do that because of inter-dependency of adjustments. The question still remains - what's good enough?

Well you have to un-inter-dependancy them.

Lens mounts/board can always be shimmed with silver foil so it is always possible to align them and they will stay put unless you move them.
Depth of field at the negative is very narrow so needs to be spot on. Even a small tilt of lens off axis can make a big difference on the paper edge.

 

[Steve Smith]

Well you have to un-inter-dependancy them.

Indeed. Have a good look at what affects what to determine the correct order of setting things up. There will always be a way of doing it and if it's a factory produced enlarger it will be a simple process. If the lens alignment goes out just by moving the lens stage up and down then there is a problem somewhere else.

Depth of focus at the negative is very narrow so needs to be spot on.

Aligning the lens to the negative carrier is the first thing I would look at. Once you have got this right, the baseboard alignment will probably be fine. If the baseboard was out enough to make much of a difference you would probably be able to tell just by looking rather than needing any fancy measuring tools.


Steve.

 

[Ian Grant]

Putting the top of the column braced to the wall will help by keeping the top stable.
This should help keeping the top to bottom alignment.

Whats good enough? depends upon you and how edge to edge critical you will accept with your work.

And then throwing the spanner in the works - you need a bit of tilt to correct verticals so raise the front of the paper easel up an inch

With a good lens stopped down a couple of stops it's critically sharp again, corner to corner.

Alignment's important but good lenses more so.

Ian

 

[tlitody]

With a good lens stopped down a couple of stops it's critically sharp again, corner to corner.
Ian

Not if the neg to lens is out of alignment. Stopping lens down will improve it to a point but you'll never get it really sharp if lens is not perpendicular to neg.

 

[tkamiya]

I have the same problem with my enlarger, an Omega B66. .... it's difficult to ever get the same reading twice.

Exactly.... hence my original question of what is "good enough?" I just discovered, putting a tool on the lens board itself actually causes enough of off center weight that the bubble moves off center by just a little.

I got it to a point where projected image is square and the image at 20x20 or so is sharp to my unaided eyes. I'm going to stop right here.

Thanks everybody.

 

[ic-racer]

I'm always curious how these grass roots movements get started. I know it is not limited to the internet because even back in the 70s I had self proclaimed experts tell me I didn't need the acetic acid.

I think I'm going to start an internet movement claiming that it is bad to cook pork, and just eat it raw...

 

[tkamiya]

I think I'm going to start an internet movement claiming that it is bad to cook pork, and just eat it raw...

You can actually buy pork that you can eat cooked rare. As long as your enlarger is aligned correctly, you will not get sick.

 

[ic-racer]

You can actually buy pork that you can eat cooked rare. As long as your enlarger is aligned correctly, you will not get sick.

OOps...my comment was supposed to be for the "I don't use stop bath thread"


With respect to this thread: Seems like you have success!

 

[Curt]

In the evolution of equipment there have been some good and bad designs. Some got lucky with a buy and it worked perfectly, others got poor designs and they always had troubles. It's like cars, some are good and a few are not. My Beseler 45 has so many struts and racks and pinions to allow the head to rise and fall at an angle that it's really odd that it was a viable option for the design. The Durst enlargers have a massive post and the head moves up and down in a straight line. The lack of precision caused by years of mechanical movement and wear makes the Beseler a nightmare to align and keep aligned. When you put a lens that was made to high optical specifications on an erector set type enlarger instead of an optical bench there is going to be difficulty in alignment.

 

[kuad]

Is this something I can check on a leitz focomat v35?
just getting back to printing after a long layoff and I heard of this.

 

[Ian Grant]

Not if the neg to lens is out of alignment. Stopping lens down will improve it to a point but you'll never get it really sharp if lens is not perpendicular to neg.

Most good enlargers allow the lens to be shifted & tilted from the perpendicular, and the head to be tilted to allow some movements to correct verticals etc. This is only ever sideways though..

I have a high contrast reference test plate that came boxed with a Johnsons V45 enlarger in the 70's, this allows accurate alignment of an LF (5x4) head and lens.

My point was though that deliberately going off alignment, it doesn't matter whether lens to negative or lens to paper, by even quite a significant amount can be controlled by careful focus & the enlarger lens DOF stopped down even a couple of stops.

Normally I'd use the enlarger tilts & shifts but it was a panoramic negative which wouldn't allow fitting in the enlarger front to back (only side to side).

Ian

 

[kuad]

what would I notice in printing with the v35 if it is not aligned?

 

[MattKing]

what would in notice in printing with the v35 if it is not aligned?

Parts of the negative will be be focus in the print, while other parts will not.

AND/OR:

Shapes in the image will be skewed and angles in the image which ought to be square, won't be.

You can check for this using the test that Mike Wilde suggests in post #5 of this thread:

A thumbnail alignment tool -that I use for checking from time to time that important things are still working and in alignment.

DIY - take a black film leader of the format in question, and put it in the neg carrier with the emulsion side up. Scratch the outline of the neg carrier with a pin/needle. Take the neg out, and draw diagonals from corner to corner.

Put the film back into the carrier, and mount the carrier in the easel. Focus on the neg at the desired head height under test, with the lens cone, lens etc. under consideration. The diagonal lines should be sharp from end to end, and the distances of the opposing sides should measure the same.

 

[kuad]

so using like an f8 would remedy any possible mis-alignment?

 

[Bob Carnie]

Absolutely not

Enlarger Process Lenses do not behave like camera taking lenses
and have very , very , very limited depth of focus at the paper plane.

I would hope that none of the experts here would suggest this is an option.

so using like an f8 would remedy any possible mis-alignment?

 

[Ian Grant]

so using like an f8 would remedy any possible mis-alignment?

It might bring the image into sharp focus, but it won't remedy distortion from the mis-alignment, and what happens when you can't stop dow ?


Some professional enlargers have adjustable fittings to align the based board. These need to be set up properly particularly if they've been moved etc.

Few enlargers have any or much adjustment. It's more a case of using a good spirit level to ensure the enlarger head is level front/back as well as sideways.

This is depedent on how well the column is secured and to what, whether there's flexing or bowing. As Bob Carnie said the top of the column should ideally be brace to a wall or ceiling. De Vere's have adjustable brackets, and I had something made to mount my Durst to a wall rather than the baseboard, and a stabiliser bar to the wall at the top.

Once the head's level then you set the baseboard with a spirit level as well. That works in practice and a test negative will tell you if its sharp all over.

Ian

 

[tlitody]

Exactly.... hence my original question of what is "good enough?" I just discovered, putting a tool on the lens board itself actually causes enough of off center weight that the bubble moves off center by just a little.

I got it to a point where projected image is square and the image at 20x20 or so is sharp to my unaided eyes. I'm going to stop right here.

Thanks everybody.

say you want to make a 12x8 inch print from a 35mm negative. Thats roughly an 8.5 times magnification from the negative. The software I have indicates that the depth of field with 50mm enlarger lens aperture of 5.6 (roughly sharpest) would be 0.08mm. That's depth of field at the negative. You can see from that that negative needs to very flat and the lens must be truly perpendicular because with only a very small error the plane of focus will be tilted outside of the negative plane.
At the easel things are different. The depth of focus will be 3mm either side of sharpest plane so you have a lot more room for error. But if the neg and lens aren't perfectly aligned, then it will be impossible to get it any sharper in the print. Closing down the enlarger lens will increase depth of field and depth of focus BUT at the expense of introducing diffraction. At F11 depth of field is 4.5mm and depth of focus is 16.5mm either side of plane of sharpest focus BUT the circle of confusion has grown to 0.2mm(required for no diffraction) on the print which means it ain't as sharp as it would have been at f5.6. So if you need to close down because your enlarger isn't aligned properly, then you are going to lose sharpness regardless of having huge depth of field at the easel. (well you might see increased sharpness if your enlarger isn't aligned correctly but not as sharp as it could be.)
So it comes down to whether you want the sharpest possible or whether your viewing criteria accept less than optimum which brings us to your original question. What is good enough? The answer is get it as close as possible to perfectly aligned, especially neg to lens stage. Yes it's difficult to do but its worth it.

And the bigger your enlargement the narrower the depth of field at the negative plane. i.e. for big enlargements it's even more critical to get alignment correct.

 

[ruilourosa]

i have two laborator´s 1000 and some meoptas and another durst, i align the best i can, but they stay aligned for a long time, i just recheck when i bump into them or after cleaning the lab, i never had problems. But in my university there were some enlargers very resilient to go on alignment, some meoptas, some beselers, but that was perfectly visible on prints.

 

[Ian Grant]

i have two laborator´s 1000 and some meoptas and another durst, i align the best i can, but they stay aligned for a long time, i just recheck when i bump into them or after cleaning the lab, i never had problems. But in my university there were some enlargers very resilient to go on alignment, some meoptas, some beselers, but that was perfectly visible on prints.

Sometimes base boards warp, others are made of covered chipboard, and if knocked go off alignment as the fittings move into the board slightly on one side or the other.

Ian