The Rogonar series are budget line of the Rodenstock enlarging lenses. The Rogonar-S series are optimized for enlargements up to 10x the original negative size. Even the bottom of the line series performs admirably. This lens achieves its optimal optical quality at around f8 to f11. At this aperture, the far corners are as sharp as the centre on full frame.
One of the problems making a lens out of an enlarging lens, is that there always seems to be some slight fogging in the center of the image. It's probably caused by the reflection of the internal lens barrel. Or, it could be just flare entering the lens. Since these lenses usually have odd filter sizes, finding a hood for them is not easy. Shielding the lens with my hand does seem to help a bit.
Another challenge is the small maximum aperture of enlarging lenses. Most of them are slower than f2.8, especially in longer focal lengths. f4.5 to f5.6 are common. This makes manual focusing difficult. Another reason why the Panasonic G1 is better suited for small aperture lenses--the EVF automatically adjusts the gain in the viewfinder or LCD until a viewable image is obtained.
I found that with the Yashica 55mm f2 lens is just slight too short for the 80mm lens, that it can't focus to infinity, and sligthly too long for the 90mm, which focuses a bit pass infinity. The 50mm version of the Yashica may be just right. I think I have one of these and will try it when it permits.
If you are bored with your multi-thousand dollar auto focus lenses, and you are looking for something more challenging and ultimate fun, make your own lens, and it won't cost you an arm and a leg.
Untiltled -- Canon 5D & Rodenstock Rogonar-S 90mm f4.5. Larger Picture.
New Sign. After more than 10 years, the Black Bull finally changed its hanging sign. I like the new design of the sign -- 5D & Rodenstock Rogonar-S 90mm f4.5. Larger Picture.
The Hugging Tree -- Canon 5D & Rodenstock Rogonar-S 90mm f4.5 @ f4.5. Larger Picture.
Untitled -- 5D & Rodenstock Rogonar-S 90mm f4.5. Check the 100% below. Larger Picture.
100% crop from the picture above. This is the far corner of the picture. Puts the L lenses to shame. Larger Picture.