Omega/Peak Enlarging tool question

[Robbie Bedell]

OK, I have a question about my long mirror Omega/Peak focuser which I have been using for decades. How far 'into the corners' of a projected enlargement are they effective and accurate? With mine the grain will be 'sharp' on the mirror for about 8x10 inches of an 11x14-inch enlargement when looking at the projected image on my easel. Then, when looking through the focuser and adjusting the black rectangles accordingly, the grain begins to 'fall off' towards the more extreme edges. If I then lift the tool up about and half inch or so the grain then gets sharp on the mirror. I have two Focomat 1cs and a bunch of lenses, every Focotar, a Rodagon and a Componon S. They all 'fall off'. The enlargements I have made all look fine. Of course for the prints I am always stopped down a bit. So I am just wondering if there are 'limitations' of the tool itself. At first I thought there was something wrong with one of my enlargers but I have narrowed it down to the enlarging tool itself. I am curious as to what your experiences are if you are a long mirror owner... Thank you! Robbie

www.robbiebedell.photoshelter.com

[Jac@stafford.net]

Robbie, the long mirror (model1) has an acceptable angle view of only ~30° from the center/axis of the enlarger lens. FWIW, I stop down before using the Peak.

[Drew Wiley]

The Peak "Critical Grain Magnifier" with the TILTING head can distinctly focus upon grain clear in the very corners of the easel at any f-stop, provided the coverage illumination of the enlarger lens is sufficient for the film format. This is useful for both calibrating how precisely level your carrier and easel are relative to one another, as well as visually assessing the performance of any specific lens at a specific stop. The optics of this unit are also superior, making general focus easier and more precise too. The non-tilting models are more limited in application, and are generally useless at the far corners of the field.

[Robbie Bedell]

Thank you Drew! Yes, I have the tilting one. That's why I am a bit concerned. I have always thought this unit was supposed to be good at the extremities. I actually have used it to level my D2 but I am sure I was using longer lenses for that chore as I only use the D2 for larger formats. I will check and see what the D2 does with a 50mm on it. I am concerned as the Focotar 2 (and others) that I have should be good to the corners on the mirror, but it isn't. I am having a difficult time figuring this one out. There could be something wrong with my focuser. It was handled by people other than me when I was generous enough to use it in newspaper darkrooms where I work..

[Doremus Scudder]

Robbie,

Like Drew, I have used my tilting Peak grain focuser to align my enlargers by making sure all four corners and the center of the negative stage are in focus (I use an empty carrier with thin wire stretched across both diagonals). If your corners seem out of whack in relation to the center it could be you have one of several problems (in no particular order here):

1. Your enlarger needs aligning.
2. Your lens has a curved field of view/projection.
3. The grain focuser itself is not adjusted properly.
4. Your observations are skewed by viewing the image through different parts of your glasses (especially if you wear progressives).
5. The negative you are viewing is bowed, resulting in the center being in a different plane than the corners (highly likely I would think).
6. The baseboard or easel is not level

There are probably a couple of others I haven't though of too.

Hope this helps some.

Doremus

[Robbie Bedell]

Robbie, the long mirror (model1) has an acceptable angle view of only ~30° from the center/axis of the enlarger lens. FWIW, I stop down before using the Peak.

Thank you Jac. Yes this one is the long mirror one.

[Robbie Bedell]

Robbie,

Like Drew, I have used my tilting Peak grain focuser to align my enlargers by making sure all four corners and the center of the negative stage are in focus (I use an empty carrier with thin wire stretched across both diagonals). If your corners seem out of whack in relation to the center it could be you have one of several problems (in no particular order here):

1. Your enlarger needs aligning.
2. Your lens has a curved field of view/projection.
3. The grain focuser itself is not adjusted properly.
4. Your observations are skewed by viewing the image through different parts of your glasses (especially if you wear progressives).
5. The negative you are viewing is bowed, resulting in the center being in a different plane than the corners (highly likely I would think).
6. The baseboard or easel is not level

There are probably a couple of others I haven't though of too.

Hope this helps some.

Doremus

Thank you Doremus, Well my two Focomats are always level. They could not both be off. I've tried the best lenses and they all do the same thing. I have glass holders for my Focomats in addition to the upper condenser contact and I have checked both uprights and baseboards with spirit levels and they are plumb. The image on both easels is not keystoned in any way. That leaves my glasses or my eyes. I think it very well might be my eyes or my glasses. It's all very strange.... Or it may be that these fine lenses have more curvature than I thought!

[Robbie Bedell]

Thank you all! I just went back and tried again with the glass negative holder. The Focomat 1c, as I am sure most know, have a condenser that holds the negative flat at the top. This is a very good system but I suppose not perfect. I have a glass holder (Leica made) that will hold glass at the bottom so the neg. is sandwiched. I did that (once again) and the negatives this way are perfectly flat. The image this way is perfect all the way across. Again, thank you all! Robbie

www.robbiebedell.photoshelter.com

[Jac@stafford.net]

Robbie,

Like Drew, I have used my tilting Peak grain focuser to align my enlargers by making sure all four corners and the center of the negative stage are in focus (I use an empty carrier with thin wire stretched across both diagonals). If your corners seem out of whack in relation to the center it could be you have one of several problems (in no particular order here):

1. Your enlarger needs aligning. [...]

For 35mm I have found the C1 (and Valoy) almost immune to alignment problems - except when the column attachment has been over-tightened to crush the wooden baseboard, even just a bit. The remedy is an alloy plate placed under the column mount (and if you wish to retain autofocus, a different pin to the column.) An aside: I was disappointed with Leitz Focotar lenses, and found a Rodenstock much better. At my daily newspaper we used Nikkor enlarging lenses with good outcomes. YMMV. Very best of luck to you!

[Robbie Bedell]

Thank you very much Jac! For sure the enlargers are not out of alignment. I think the problem here is in the negative holders. The 'traditional' one with grooves milled out. I filed mine to allow borderless prints and maybe I overdid it. They still seem flat but who knows. I will just use the glass holder in the future for both enlargers. Best of luck to you also!

www.robbiebedell.photoshelter.com