RichardH
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Some years ago one of the photography magazines tested enlarging lenses. They tested the EL-Nikkor 50mm f/2.8 (a plasmat) and a whole slew of f/3.5, f/4 (but not the Nikkor), and f/4.5 lenses (Tessars) including Schneider, Rodenstock, and Leitz. At f/5.6 the Nikkor resolved 80 and 65 (center and edge) line pairs/mm whereas the best of the others at f/5.6 was 50 and 40 (the Leitz - most were 45 and 35 or 40.) Test the two f/2.8s against each other and keep the best one if there is a difference. You will have the best 50mm you can get and then you can forget about the lens and work on the other big problems - the parallel alignment between the neg carrier, lens board, and easel and the flatness of your neg. An easy way to get a flat neg is to take a glass (preferably the anti-Newton one) out of a Gepe slide mount and glue it to the top half of your neg holder.
I've used old versions of both f/4 and f/2.8 El-Nikkors. The F/4 version is better than many of the other brand f/3.5 or f/4 three or four element lenses, but the f/2.8 version is better yet. Wide open it provides quick and precise focusing. Stopped down to f/4 it performs well from corner to corner. It might be at its best at f/5.6. When stopped down below f/8, the effects of diffraction become visible on the sharpness of grain. The effect in the center of the image when stopping down can conveniently be seen with a strong focusing aid. Some focusing aids permit this even at the corners of the image.
Decades ago I did a quick, but critical, test of about 35 camera and enlarging lenses. Four were better than any others: an El-Nikkor 50mm f/2.8, a Micro-Nikkor 55mm f/3.5, a Leitz Elmar 50mm f/2.8, and a GN-Nikkor 45mm f/2.8. Other 50mm lenses from Nikon and Leica lagged slightly behind those four. The Nikkor 20mm f/3.5 of 1967 was one of the sharpest in the center of the field, but much less so near the edges.
Hey Jim
Could you actually see the difference on the print or was it from the focusing aid? I have 3 focusing aids and I will check this also today.
I also have a couple of Rodenstock 50mm's and I want to check them also. I am not sure if my old eyes will be able to tell a big difference though.
All I am doing is making sure I have the best image I can get and box up the ones I don't want to use.
This will be a fun test to do just for my knowledge and information.
I have never done a lens test and it will be interesting to find out some questions that are in my mind.
I have questioned in my mind also how accurate the focusing aids are. Of the three I have, they seem to focus a bit different from one to the other. From the distance from the mirror to the view finder is what bothers me on this.
When they are made, I often wonder how accurate they are in relation to what is actually printed. The distance between the mirror and the base is what will make the difference. I am not sure I can relate what I am thinking but between the three, there is a small difference in adjusting for sharpness. Maybe I don't have a good enough focusing aid???
I am not very critical on what I print but I would like to know if there needs to be an improvement in the quality.
I have a hard time explaining what I am thinking but I hope you understand what I am looking for.
I have downsized from 4x5 and med. format to 35mm and with that small of negative, I need to know if everthing is in order as far a image quality goes.
Thanks
Richard
Richard,
I have used the 'opposing mirrors' method (search APUG, it's here) to align my Beseler 23CII. Having never used any fancy alignment tools I can't speak to the job they do but if you factor in the cost the homemade mirror tester is wonderful and should be tried first. I bought a 12" x 12" mirror tile from the local hardware bigbox and I had a glass cutter already. The glass in the tile was cheap so the reflected images had a green cast (iron in the glass I think) but it worked well and helped. A lot. I also bought a glass negative carrier (no $regrets, and 'four surface dust' has not been an issue), but the trick of using the glass out of a slide mount is something I wish I had thought of. I have a box of Agfa mounts somewhere...
Good luck, the results are worth the effort.
s-a
I have both the f2.8 and f4 Nikkors and apart from the fact that the f2.8 is clearly brighter for focussing, I'd be hard-pressed to tell the difference between them at the kind of enlargements I do (up to 11" x 14"). I only ever use a glass neg carrier for 2 1/4" square by necessity and find it a right pain. All those extra surfaces to collect dust and the occasional print that shows Newton's rings (despite the glass manufacturer's insistence that this is "anti-Newton's ring glass") leave me doing my utmost to avoid complicating matters even more by using glass for 35mm printing!
Steve
I haven't come across the rings yet but will deal with that when and if it happens.Richard
Last year I bought used metal El-Nikkor F/4 lenses to replace community DR crap 3 element and some F/3.5 optics. I found the F/4 had better contrast than older (somewhat dirty) Leitz F/4.5 optics. In my judgement (no testing data) the Nikkor F/4 performs as well at F/8 as the faster El Nikkor. If enlarging past 8X all bets are off since the F/2.8 is multicoated and 6 elements. The F/2.8 should be better to the corners on a wider range of apertures. The bottom line is the El Nikkor (Tesser) F/4 is a very good lens if used in it's sweet spot.
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