Two Enlarging lens questions.

[Sjixxxy]

1. 135mm vs 150mm for 4x5 negatives. I'm guessing the differences are subtle, but can someone compare/contrast the two for me.

2. I got an Omega D-II, with just a flat lens board for my small format stuff, but not the little board that lens mounts too, which attaches to that board. I've never mounted an enlarging lens to a board like this. Is it the same as mounting a large format lens? I'm not seeing any refernces to the word "Retaining flange" on the lenses that I'm looking at on eBay. Do they mount this way (where I could build my own boards to attach to the big boards), or do they screw in directly onto the smaller board requiring me to find an actual little board?

 

[papagene]

1. I use a Schnieder Componon-S 135 f5.6 for 4x5 and it works quite well for me. Bought it used on the recommendation of a friend. It will give you larger enlargements at a lower head height.

2. i can't answer this as I have an ancient Beseler 57MB.

gene

 

[sergio caetano]

Sjixxxi
Ask Harry at www.classic-enlargers.com

 

[bmac]

I have a 135mm for 4x5 on mt D2v. You need a cone not a lensboard for anything longer than 105mm.

 

[Donald Miller]

When I used my D2 I had a cone that my 135 mm Schneider was mounted to. This was as a cold light enlarger...so the condensor considerations did not apply.

 

[gma]

135mm will cover 4x5 for enlargement sizes that can be made in a darkroom. If you were projecting to billboard size the 150mm would be needed.

 

[Jon Shiu]

The lens is held in the small lens disc by a retaining ring (also called jam nut) in the same way as a camera lens. Most lenses use a standard 39mm ring, but other sizes are also made, eg Schneider Componon s 150mm is 50mm.

 

[rogueish]

any lens for sale on ebay that does NOT list the retaining ring, make sure you e-mail the seller and ask if it is included.
www.khbphotografix.com is also a good place for info (aswell as parts and service).

 

[wdemere]

The round lense board that fits in the cone is just like any other. I've used pressboard for it, which is a little thicker than the metal, but works. I have found that the retaining rings usually used for mounting enlarging lenses sometimes don't work, and you need to get a flange-like one that is a little thicker (but not a threaded flange).

A better answer is that if you can't get a retaining ring, or it doesn't work on the lens and board, contact SK Grimes. See:

http://www.skgrimes.com/lensmount/index.htm

Measure the lense you need to mount, and the threads, and they can get you the right retaining ring.

I use a 135mm for 4x5 and don't have any issues with light falloff in the corners, but I understand this can vary from lense to lense.

Good luck,

William

 

[John Koehrer]

For something more rigid than press board, try your local hobby shop for aviation grade plywood usually available in 4x12" and various thickness. Cut your disc from that, it'll be less prone to holding dust.
Finding the lens cone will be more problematic. Although the cones for the Dll are available in the used market you need to be sure about what you're shopping for. It's been a while since I had a Dll but it seems that a 150mm needed a 6" cone. Maybe you'll luck out here.

 

[David A. Goldfarb]

Check Classic-Enlargers, mentioned above, for lens disks. The flat board is for lenses up to 105mm, the next size (2-1/2" or something like that) is for 135 and thereabouts, and the long 4-1/2" cone is for a 150. You can also find the lens disks on eBay. Some disks have a flange attached, and some just have a 39mm hole, and you use a retaining ring that screws on from the back. You can get 39mm rings from B&H and most any dealer that sells enlarging lenses. Some older or long lenses may take other sizes.

Some lenses can mount in more than one way. My 150mm Apo-Componon comes with a mounting ring that works directly with the Omega 4-1/2" cone and no disk, but it is also threaded for a 55mm retaining ring, and you can remove the mounting ring, which has some built-in lens extension, and mount the lens in a lensboard with a 39mm hole, by removing the rear cell and re-attaching it with the lensboard in place.

 

[Sjixxxy]

Thanks for the input so far, its been real helpful.

Right now I'm looking at the EL-Nikkor line. They are well priced on eBay, and the rings are only ~6.50 at adorama & B&H, so I don't feel like I have to hold out for one that has the ring included. I figure once I get them I can take them, and the lensboard/cones back to the shop where I bought the enlarger. I know a bunch of the old lenses they had there were mounted on the smaller boards, so hopefully there will be a match somewhere in teh boxes. That place always gives me good prices when I start cleaning out their own inventory, so I would expect to probably pay $5 per disk/ring combo if I can find them.

D. Goldfarb is selling me the appropriate cone for the 135mm lens. I'm just wondering what the hole diameter is on that since it looks like the 135mm has a build in 50mm-39mm adaptor which would mean I could probably attach the lens as he describes in the previous post by removing the rear cell.