240mm, 360mm or 135mm/150mm for 4x5 enlarger

[Patrik Roseen]

Thanks alot for you comments I have certainly learned alot from you. I have a Linhof enlarger for 4x5 and the filmholder can move in 3 different directions which mean that I can always put the cropped area into the main field of the enlarger lens, hence I could use a smaller lens for even better sharpness. The lens is attached to the enlarger using normal linhof lensplate.

I think I made a mistake about using the 360mm on the tech III (it was after midnight in Sweden), the bellows need to be much longer and distance to the paper is very long. I checked by putting my 360mm apo-ronar in front of a halogen lamp and projecting the image on a wall in my apartment...man those 8x10 enlargers must be HUGE...not only did I have to put the lens further away from the lamp, but the projected image was much smaller compared to if I held a 150mm in front of the lens!

I guess the stability of the enlarger is a real killer when using these larger lenses.

Again, thanks for taking the time to share your knowledge with me. /Patrik

[neil poulsen]

If it's not the room height and the length of your arms, it's the distance between the negative and the lens that will get you. For example, you'll need a distance of at least the focal length between the negative and the lens. (360mm=14.17".) If you have twice that, you can "enlarge" to 1:1. (Not that you would want to.)

For a 2X enlargement (e.g. 4x5 negative to an 8x10 print) using a 360mm lens, you'll need to allow for a distance of just over 63" between the negative and the print. For 4X, this distance becomes just over 88"!

8x10 enlargers that can handle these enlarging lenses are huge and usually have motorized focusing.

[Richard Kelham]

Back in the days I did this for a living, I had a Kamm 10x8 enlarger – it was huge: column about a foot wide bolted to the wall and heavy duty chain drive from the front of board controls. Nothing short of an earthquake was going to shift that b*gger! And it had a 300m Rodagon lens for 10x8 negs. Superb.

Don't mess about though – for 5x4 use a 150mm Rodagon.

[paulr]

you can see everything you need to see on the schneider site (they're the only manufacturer i know of that publishes the data). as an example, compare the 150 componon S to the 180 componon S:

http://www.schneideroptics.com/photography/photo_enlarging/componon-s/pdf/componon-s_56_150.pdf

http://www.schneideroptics.com/photography/photo_enlarging/componon-s/pdf/componon-s_56_180.pdf

on page 2 of each chart, look at the far-right column, which represents f11 at three different magnifications. it should confirm that you'd see more evenness, but lower overall performance, with the 180.

this is just two lenses in one lens family, but in my experience it's a universal phenomenon. as Ken points out, the trend is for lower performance as the focal length increases, just like with taking lenses.