I've got an enlarger Omega D3 with head dichroic.
No problem with format until 6x7 .
I bought a shredder schneider-s 150mm for negative 4x5 and there are two problems.
-It focus only with a projected format 30x40
but I solved the problem buying the bellows focus attachment instead of the cone of 5'' and 1/4
-When I project the negative in the base there is a 'ring of light' on the edge that cause a vignette.
I tried in this forum and in the net, but I couldn't find a solution.
I read in a post that you have to adjust the distance between the negative and the head of the enlarger or the mixing box, but you can't, because there are not adjustments .
After I also red that the rail of the auto focus has to be 'perfectly' coupled with the lent.
So I look at it and there are 3 plates: Rodagon 50mm…Rodagon 105mm … and Rodagon 150mm.
So I tried with different lenses (75mm Rogonar… 105mm Galileo) coupled with the rails but I still got the problem with the componon-s 150mm projected 4x5 negative.
It seems that the up bellows ( to take off the 'ring of light') should be extended, but is not possible because is on the maximum length.
So I had a look on the characteristics of the Rodagon and the Componon-s; it seems that the Rodagon has got a cover and a draw more suitable with my Omega D3, so I thought that changing the lens could solve the problem.
1 Is anyone using, or have used the Omega D3 with the componon 150mm?
2 Do you have a solution for this problem?
3 Is possible that the Componon-s 150mm (look at the link below) doesn't cover the 4x5 format? Or that anyway is not coupled with the Omega D3?
4 Eventually do you advise me with a Rodagon 150mm or a 135mm??
Componon-s 150mm characteristics:
"recommended negative size: 90x120 mm" ????