Depth of field and enlarging lenses

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Hello,

Now that my darkroom is finally up and running, I have some concerns about maintaining the enlarger alignment of lens, film plane, baseboard and easel. My enlarger is a Beseler 45MCRX. While I've much success with the enlarger in the 1970's, it certainly doesn't allow for fine tuning the alignment. My late father bought this for me new so I do have a sentimental attachment to it (but I wish I had a Durst!!!) While I need to get a laser unit when funds permit, I do have Beseler's "groovy" alignment tool, which consist of metal plates (to insert in the film plane and lens standard) and two float levels. I THOUGHT after spending two hours with shims and the limited adjustments available I had everything aligned. BUT, upon examination with a 25X grain focuser; moving to various points on the easel; lens wide open (150mm APO Componon HM)...uniform focus cannot be obtained without stopping down the lens. I will continue to try and align everything better. Here is my question: Do depth of field charts exist for the common focal lengths of enlarging lenses? For example, using a 150mm lens on a 4 X 5 negative enlarged 4X (16 X 20) lets say at f/8...how much depth (in inches or millimeters) will be in focus. I would love to be able to use my lenses at their ideal f stops but I'm afraid if I don't stop the lens down enough I am always going to face out of focus areas on my prints. OR, please give me some suggestions...I'm just getting back into printing after several years and I am rusty.

Another issue while on the enlarger subject....I have read several posts (usually on Leica sites) that the Leica Focomat enlargers will perform MUCH better than competitors and to get the most out of your Leica shots, one needs to use a Leica enlarger. Now I may be missing something, so please educate me!!! If another condensor enlarger is used and aligned properly (UNLIKE MINE!!!) with a high quality lens such as a APO Componon or APO Rodagon, wouldn't the enlargements be just as good? What is the magic about a Leica enlarger? I realize this is a large format site, but many of you have good in-site for all equipment. I'm afraid this question to the "Leica Users Guide" (LUG) website may result in bias answers (no disrespect meant to the LUG).

Thank you for your time, as always.

Best regards,

J. P. Mose

-- J. P. Mose (j.p.mose@lmco.com), June 05, 2002

Answers

Zone VI/Calumet used to sell a kit for aligning Beseler enlargers. Depth of field at f/11 should help. Any 150mm enlarging lens should be sharp at f/11... diffraction shouldn't be a problem until f/22 at least. Make some prints and see what happens. Might be a smaller problem than you think. As far as the Leitz Focomat goes... I've never used one. One thing I know for sure is that Leica-philes have a reverent worship for all things made by Leica, and are absolutely certain that the only way to good photography, happiness, and/or moral superiority is to use only Leica gear, and to obsess about it incessantly. I think any good enlarger and lens will do the job just fine, and I've been using Leica gear since 1978.

-- Mark Sampson (MSampson45@aol.com), June 05, 2002.

J.P., the "magic" about the Leica enlargers is that they have the name "Leica" on their nameplates. It's all an illusion. Your Besseler enlarger is a fine piece of equipment for large format work. You will never be able to get 100% perfect alignment with any enlarger. Adjust the alignment as close as you can. Focus with your grain focuser, lens wide open. Close your lens down two, or three stops , and enjoy your printing experience. There are so many variables introduced into the enlarging process, like wrinkled paper, slightly curled negatives, dust, scratches, uneven light,etc. It's not worth the effort to worry about depth of field with an enlarging lens. It's only a few millimeters.

-- Eugene (TIAGEM@aol.com), June 05, 2002.

I just recently aligned my Beseler 45M. I suppose the adjustment mechanisms are somewhat primitive, but every necessary adjustment is allowed for except for tilting the lensboard front to back in relation to the negative stage. However, this can also be done by placing a shim behind the washer where the lens stage casting attaches. All other adjustments are allowed for mechanically, thought they might not all be obvious. I called Beseler; they were friendly and sent me a photocopied set of instructions for enlarger alignment. I was able to make one or two adjustments that I could not figure out on my own. This may not be the most refined enlarger, but it is capable of making great prints, I think. I stop down 1-1/2 to 2 stops to allow a long enlarging time to make it easy to dodge and burn.

-- John McDonald (jmcd@napanet.net), June 05, 2002.

JP and All: I respectfully take issue with the poster who said that simply the name "Leica" was the difference, and that difference was an illusion. After 45 years as a very successful photojournalist and advertising photographer, I can say, with total confidence, that there is one heck of a difference. Yes Bessler and Omega make fine enlargers, as do others. During my four years at Art Center, many of us opted to purchase our own enlarging lenses and switch out the lenses in the school's photo lab which used Omega D-2's. Most of us had pros for instructors, and most of us selected the 50mm Leitz Focotar for our 35mm work. The difference we detected using the Focotar over the Schneider Componons was dramatic at large blow ups. Later in my career I operated the second largest commercial studio in Colorado and selected the Leitz Focomat IIC. It was, without a doubt, the finest enlarger I ever used. I left photography for 15 years to help build the new Denver airport....and sold all of my hundreds of thousands of dollars of equipment. The one piece of equipment I regret selling...was the Leica Focomat IIC. Now that I have come back into the world of professional photography, in my senior years, I use a Leitz V-35....the last enlarger Letiz made. It is the Rolls Royce of 35mm enlargers. I also own a Omega Pro D-5 with three lens turret. A fine machine, as is the Bessler, as long as you calibrate it with a laser tool. Why do I believe the Leitz enlargers are the ultimate. #1, they are built like 'tanks', and very well designed. #2., they are almost hand made, and the tolerances are incredibly tight. #3. The auto focus on the IIC and the V-35 are 'spooky' in their accuracy. ...unlike most autofocus enlargers which just give you a guide, and then you fine tune your optimum sharpness by hand. #4. The optics, including condenser. The IIC is so precise there is an adjustment for placement of the enlarger light source, 360 degrees, for fine tuning of where the #212 bulb is positioned for best and most uniform illumination. Although I am not a sharpness freak...I always 'wring out' any new lens or piece of equipment when I first purchase it. Over my career I have owned more than a dozen Leicas, a dozen Nikons, and many Hasselblads and Linhofs...and Sinars too. The sharpest optics I have ever tested are Leica Elmars and Sumicrons, and on enlargers, Leitz Focotars and V-Elmars. I use Canon EOS-1VHS and Linhofs now. For those who would say that the name Leica is an illusion....to me, that just means you have never used one. Respectfully, Richard Boulware - Denver.

-- Richard Boulware (boulware-den@att.net), June 05, 2002.

You have to use a Leica enlarger to see the difference. I have used Valloy's and 1c's and they are as perfect as they get.The best condensors,best autofocus,never have to align them and the 50mm focotar you can use wide open no problem and the corners will be perfect.Try that on a D-2, Besseler or Durst!

-- Emile de Leon (knightpeople@msn.com), June 05, 2002.


Richard and Emile, we are talking Large Format here. I was un-aware that Leitz makes an enlarger for large format. Please excuse my criticism of the Leica God. J.P.'s question was regarding getting back to using his Besseler enlarger after several years layoff. The Bessler he is using has sentimental value for him. It is a fine instrument for large format printing. I was merely encouraging him to go ahead and use it. If he was asking about 35mm enlarging, I would have encouraged him to use his Leitz Focomat, if he had one.

-- Eugene (TIAGEM@aol.com), June 05, 2002.

Richard and Emile, we are talking Large Format here. I was un-aware that Leitz makes an enlarger for large format. Please excuse my criticism of the Leica God. J.P.'s question was regarding getting back to using his Besseler enlarger after several years layoff. The Besseler he is using has sentimental value for him. It is a fine instrument for large format printing. I was merely encouraging him to go ahead and use it. If he was asking about 35mm enlarging, I would have encouraged him to use his Leitz Focomat, if he had one.

-- Eugene (TIAGEM@aol.com), June 05, 2002.

For aligning the lens stage of the Beseler, definitely search out the Zone VI gizmo. I found one and it makes alignment alot easier. Zone VI (now Calumet) used to sell them new for around $30 if memory still serves.

But to really save time, frustration and kicking the cat, find one of the enlarger alignment tools such as Saunders, Zig Align etc. They cost less than $200 new, and of course much less used if you can find them, and use mirrors, lasers and whatever. They make alignment a snap compared to using a level or examining the image through a focusser (sp?). Many folks balk at the prices but, in terms of actually doing what they are supposed to do, and doing it well, they are worth 100 times all the useless or seldom used gadgets photographers inevitably accumulate.

-- Alan Shapiro (ashapiro@yorku.ca), June 05, 2002.


It is possible to make a very accurate alignment tool quite simply, and one that aligns by optical principles. Buy two silvered mirrors (preferably high quality). Drill a small hole in one of them. Place the mirror with the hole in the negative stage and the other mirror on the lens stage. Look through the hole in the mirror. If the two mirrors are absolutely parallel to each other, you will see a series of concentric circles. If the concentric circles veer off to one side that means the alignment is off. Adjust and repeat. Then place the mirror without the hole on the baseboard and repeat. Once you are done, the lens stage, the negative stage and the baseboard will be perfectly aligned to each other. It is very simple to make and pretty easy to use. It assumes you can make adjustments to the various stages though.

Cheers, DJ

-- N Dhananjay (dhananjay-nayakankuppam@uiowa.edu), June 05, 2002.


Eugene et al: JP originally asked the question about Leica enlargers, and we, as good buddies, answered. Perhaps to Minox shooters, 35mm or 2 1/4 X 3 1/4 (Focomat IIC) IS large format. Why don't we all just mellow out on this one. Kind wishes, Richard.

-- Richard Boulware (boulware-den@att.net), June 05, 2002.


There are many alignment tools available, all do a pretty good job but the Beseler one you have is among the worst. I had one for a while about seven years ago. As I recall, there is some fairly fundamental problem in using it. Perhaps it's that you can't see one or both bubbles while the tool is in the negative stage? Or maybe it's that you can't perform the alignment with the tool in place, so that you have to keep removing it and putting it back, removing a putting it back, until you finally guess right? I forget the exact problem but whatever it was, it caused me to use the thing once and then I tossed it in as a freebie when I sold my color head. I now use a simple adjustable level sold by Delta for about $15. I've always found the problem to be not with reading what a tool is telling me but rather with making the adjustments once I've used the tool. This is particularly a concern with the older Beseler 4x5s. The later version of the MXTs were changed so that it's easier to align the lens stage though other things are still difficult.

I don't know the answer to your depth of field question. However, enlarger lenses suffer from diffraction just like camera lenses so you don't want to be in a position of having to stop down below about two stops from wide open to gain even illumination.

-- Brian Ellis (bellis60@earthlink.net), June 05, 2002.


"uniform focus cannot be obtained without stopping down the lens"

This common observation (ideally made using a PEAK 2000 grain focuser which allows to see the corners) may reflect two very different situations:

1) the four corners are not focused together; this is indeed a misalignment of the enlarger.

2) the four corners are focused together but, at the same time, the center is not in focus; this is field curvature of the lens and I observe it for all my enlarger lenses used wide open (usual six element lenses, I have no experience of "apo" lenses). It disappears when stopping down the lens (two stops).

-- Matthieu ls (lstrauss@infobiogen.fr), June 06, 2002.


J.P. Mose,

The second item on this page (DELTA 1 Enlarger Alignment Lens Board for Beseler Enlargers) looks like the Zone VI lens stage alignment fixture referred to within this thread. I think I will try one. http://www.camerastore.com/dl_cat_J/-J20_exposure.html

John

-- John McDonald (jmcd@napanet.net), June 06, 2002.


It has been mentioned above that one may not want to stop down more than 2 stops in order to avoid diffraction limitation effects. That may (or may not) be true, but the actual MTF charts for 150mm f/4 APO Componon-HM lens show that 2 stops down (f/8) is much better than 1 stop, and it is possible that 2.5 or 3 stops are just as good or slightly better. Unfortunately, the smallest aperture opening shown on the charts is 2 stops closed at f/8. These test charts referenced below are inclusive of diffraction limitation effects.

http://www.schneideroptics.com/photography/photo_enlarging/apo- componon_hm/pdf/apo-componon_40_150.pdf (Please remove any spaces in the web reference that were inserted by the forum software).

My understanding is that the APO Rodagon lenses are optimized for use at about 1 1.5 stops closed, which does not appear to be the case for the APO Componon-HM lenses.

-- Michael Feldman (mfeldman@qwest.net), June 07, 2002.


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