What is wrong with my 360mm Apo Ronar?

[Daniel Grenier]

So I went out and bought an older Rodenstock Apo Ronar 360mm in Copal 3 for my 8x10.

Problem is that on the edges, say 5 to 6 inches from center, wide open the image can't be focused and is always fuzzy (to varying degrees, but never sharp). This is when looking at, say, a wall, a tree, or other close but fairly flat surface. The center can be focused properly and is sharp. There are no marks or defects on the lens that I can see, the elements are srcewed in properly, the lensboard is new and not warped etc....

So why in the world is this lens sharp in the center and not on the edges?

[Dan Fromm]

Nothing is wrong with it. According to Rodenstock, it covers a 308 mm circle at f/11 and 318 mm at f/22. Stop it down a little and it will just barely cover 8x10. Narrow angle lens.

Cheers,

Dan

[Christian Nze]

As Dan Fromm wrote it is a narrow angle lens and the border look unsharp when wide open. But it is usable with an 8x10 camera but keep in mind that it is better to focus on the closest thing to get a wider image circle. you should have a no impression of unsharpness if you focus at 3 meters. Iuse this lens for soem of my work in 8x10 and remind that I get good result.

[Daniel Grenier]

"Nothing is wrong with it". I was afraid you'd say that! I was not aware of this "non-problem" before buying this thing (blame my lack of interest/knowledge in lenses!). I find this to be a serious nuisance and an all around drag to be honest. Reason enough to sell and go out for a more 8x10-appropriate lens with none of this narrow covering angle.

Thanks for the info Dan and Christian.

P.S. Christian: Just curious... did you take the "Normandy" shot I just bought from you with your 360 Apo?

[Steve Hamley]

Just to add a little more info, the Apo-Ronar is the same design as the Apo-Artar, and the shortest focal length Goerz recommended for 8x10 at infinity was 16-1/2", or 420 mm.

Steve

[Christian Nze]

Daniel

if you want a good and small lens for your 8x10 just search a Fujinon A 360 :9 that's a great jens with a big circle. For the normandy image I use a 355 repro glaron also a good lens for 8x10 as I also use it with a 7x17 inch and a 12x15 inch camera.

[roger michel]

this lens will be a frustration for you. it is a bear to focus wide open and really only adequate for 8x10 in a pinch. i think you will be much happier with a g-claron 355mm if what you want is a slow, lightish, normalish 8x10 lens. also think about the 305 mm g claron which, over the years, has (for me) proven to be a more useful f length than the 355/360.

[chris jordan]

Daniel, let me know if you're interested in the Fuji 300f/9. I have one in mint condition that I might be selling in the near future.

~cj

www.chrisjordan.com

[CP Goerz]

I think there is something wrong with the lens, probably the spacing, cells too far apart. Is the lens a factory mounted one or a cobbled together effort? I have both barrel and shuttered(factory) lenses and to get a fuzzy unfocusable image just 5 inches out of center is way out of line. I REGULARLY use a 10 3/4" Red Dot with movement on my 8x10 and have no trouble whatsoever and this design/version you have is even sharper. If you send me a pic of the lensmount/barrel I'll be able to tell you if its a factory version.

CP Goerz

[CP Goerz]

PS:Just thought of another thing it may be...if the lens was dis-assembled the elements may not have been put back correctly. Take a peep at the design of an Artar and see if the curves of the glass match. I had a similar problem a few years ago and when I turned one external cell over the problem disappeared.

CP Goerz

[Jason Greenberg Motamedi]

Herr Goerz's second comment is of real value: I have bought a shocking number of lenses in which the elements had clearly been put back together incorrectly.

Check the schematics! (http://www.butzi.net/rodenstock/apo-ronar/p12.htm)

[Daniel Grenier]

Andrew, Jason. Following your suggestions, I took my lens apart and had a good look at the elements under a low-powered microscope.

Here's what I found:

1- The front and rear elements are absolutely identical to the naked eye.
2-There was a 0.2mm thik ring/spacer on the front element and none on the rear.
3- The convex part of the front element is not screwed in all the way as is the rear element's part. A problem? (I tried to gently screw it in but it wouldn't move).

Is this consistent with a "normal" 360mm Apo Ronar then?

Thank you kindly for your assistance.

[roger michel]

when you said 5-6 inches from the center, i assumed you meant exactly that; i.e. basically at the very edge of an 8x10 view screen (which is a little more than 6 inches from the center to corner. i am not sure what is meant by the above comment "just five inches from the center) -- 5-6 inches is the absolute edge. the image circle on the apo ronar, wide open, will certainly peter out at that point. a 12 inch circle is 300mm, close to the stopped down image circle of the apo ronar (which is about 310 at f22 i think).

the effect you describe does not seem out of line to me.

do things sharpen up at f22??

[Daniel Grenier]

Upon closer examination, the front lens element is actually loose and does rattle a little bit. When that is fixed, however, it appears that this is simply a case of the wrong lens for the wrong format. Aside from this rattle, there is probably nothing wrong with this lens per se. I should have bought something other than this lens and I realise that now (see what happens when you're into photography and not the hardware to create it?).

Anyhow, thanks for all the good info. I am that much more hardware-savvy now.

Cheers

PS Thanks Chris for the Fuji 300 offer but I'd rather stick to 360 as it is right in the middle of my 240 and my 480.