Can`t Get 50mm El-Nikkor to Focus on Chromega enlarger

[foto-r3]

Dear friends,

Can anyone tell me what I need to get an El-Nikkor 50mm enlarging lens to focus on my Omega Chromega D type enlargr? I have an 80mm and a 150mm which focus correctly on the turret style mount. I tried mounting the 50mm flat, and with an extended lens plate. The best results come when the bellows are completely compacted, but still it is not capable of focusing fully.

Thanks

 

[Nick Zentena]

Sounds like you need a recessed board.

 

[Zathras]

Dear friends,

Can anyone tell me what I need to get an El-Nikkor 50mm enlarging lens to focus on my Omega Chromega D type enlargr? I have an 80mm and a 150mm which focus correctly on the turret style mount. I tried mounting the 50mm flat, and with an extended lens plate. The best results come when the bellows are completely compacted, but still it is not capable of focusing fully.

Thanks

Your 50mm may not work with the turret. My 50mm 2.8 Rodagon is NOT recommended for turret use, and older 50mm 2.8 El-Nikkors are also not recommended for use in the turret you need to use a slide in single lens lensboard on a D-5 with these lenses. Click Here to go to a web page that has info for the different lenses and lensmounts required.

Hope this helps...

Mike Sullivan

 

[Jim Jones]

I agree with Nick. My DeJur 4x5 enlarger required a home-made board recessed about 45mm for a 50mm El-Nikkor. A 30mm long sleeve pressed over the aperture ring made changing the aperture easier. II that model of Omega uses condenser lenses, you may also have to make some changes to the condensers.

 

[foto-r3]

thanks everybody for the replies. i don't think a recessed board can be applied to a functioning turret.

having determined this, can anyone recommend a good enlarging lens for 35mm negs for use with the Omega turret? according to that KHB chart, it would seem there are some good ones that would work.

thanks!

 

[Ronald Moravec]

There are two kinds of turrets, but I can`t remember the differences. They are small differences, but they are not imterchangeable. My D6 works with a turret and 45mm APO Schneider, 50mm Focotars. They mount on a flat oval plate threaded for 39mm.

Easiest solution is a single lens adapter for the 50 or a 60mm Nikkor. I will guarantee the 60 will work.

 

[Lee L]

How large are you printing? You could just use the 80mm you already have if that gets you to the magnification you want.

Lee

 

[David Brown]

having determined this, can anyone recommend a good enlarging lens for 35mm negs for use with the Omega turret? according to that KHB chart, it would seem there are some good ones that would work.

I use the Nikkor 63mm on the turret. No problems.

I'm not sure which model D you have. I have a D5. On this one, the lens stage is also adjustable by sliding up and down on the focusing mechanism itself by disengaging the "bellows locking lever" (right behind the lenses) and it may be possible to compress the bellows a bit further this way. (Hard to explain without a visual) I could be wrong - maybe older D's don't do this and maybe you have an older D. Just a thought.

 

[foto-r3]

I am going to try a Componon-S 50mm mounted on a flat threaded lensplate. I hope this will be effective.

I am unsure of the exact model, but it is a Super Omega D with the switch on the bottom of the lamphouse to shut off the display lights, so I am assuming it is a modern one (it also has the bellows locking lever, but jamming it up as high as it can go and then some does not let me focus).

I stand corrected: it is a 100mm lens and a 150mm lens I have, not a 80mm as I stated originally, or else as per your suggestion I would just used that one (80mm) for my 35mm work. My max. enlargements are 12x16".

Thanks again for the friendly suggestions/advice.

 

[foto-r3]

As a postscript, the Componon-S I tried did not focus either. I am going to go with a longer focal length, it looks like either 60/63 or 80mm.

I did not realise this about the turret, but it is a real shame, since there are some great short focal length lenses out there which are also generally cheaper than the longer ones. I was nearly tempted to get a 75mm but I understand these are all "repro" lenses and not really well suited for enlarging...

 

[Nick Zentena]

I forget which company but at least one makes an APO 75mm. Won't be cheap even today. It would be well suited for enlarging.

 

[foto-r3]

About the Rodagon APO D 75mm:

"
Not necessarily enlarging lenses, these models are optimized for near 1:1 reproduction ratios, for purposes such as duplication of transparencies, or preparation of internegatives. They are 6-element, 4-group designs, and optimum f-stop is 2 stops below maximum aperture.
"

I believe the El-Nikkor 75mm is also in this same category.

 

[Nick Zentena]

No the Nikon 75mm is their budget MF lens. It's similar in design to the 50mm F/4.0.

 

[Paul.]

No the Nikon 75mm is their budget MF lens. It's similar in design to the 50mm F/4.0.

Dont know if it is their buget MF lens or not but I get stunning results with one from my MF negs, and would recomend them to anyone.

Regards Paul.

 

[foto-r3]

I think what Nick refers to is that the 75mm is the 4-element design as opposed to the 6, but as you suggest, Paul, I'm sure in the right hands it is more than capable of excellent results.

 

[jordanstarr]

i'm currently having the same problem. i'm anxious to see if you guys can come up with something creative. i have the componon-s 50mm f2.8 and it's a great lens. i hope i don't have to replace it. at least the 80mm will work for 35mm negs and you can make prints up to 16x20 it seems.

would the 35mm images be sharper on a wider aperature with the 80mm lens because the image is concentrated on the "sweet spot" (center) of the lens?

 

[Arvee]

Yes, you will be using the sweet spot but as focal lengths increase (larger format lenses) lenses tend to resolve fewer l/mm so I don't think there will be any great differences.

 

[jordanstarr]

actually, i just found out if you really crank up the bellows, you can get the 50mm lens to work. you don't have a lot of room to play with the focusing and you risk getting out-of-focus prints 'cause the bellows might move under the extreme pressure, but it will focus at least. you just have to make sure that there is no plate or pin that blocks the bellows from moving up past it's recommended distance.

 

[fschifano]

Chances are better than good that you simply have the lens mounted on the wrong mounting plate or cone. I have a D4 and that enlarger requires a flat lens mounting board for the lens to focus properly. As it is, I cannot make a print smaller than 5x7 with that rig and must use a longer focal length enlarging lens for that. The head simply cannot get close enough to the baseboard with the 50mm lens attached. Don't know if it would focus if I could get it closer, but that doesn't matter.

Have a look at http://www.classic-enlargers.com, then give Harry a call. He can set you up with the right part for the job if you know the model of the enlarger (D2, D3, D4, etc.) Be sure to let him know if you have an autofocus model. There is no need to get another enlarging lens, especially since the one you have already is plenty good.

 

[Dave Krueger]

I have a Chromega D head and use the El- Nikkor 50mm f2.8 lens mounted on a flat oval lens plate on the turret. I don't rotate the turret, but if I remember correctly, the lens just barely prevents the turret from rotating. I have some 39mm spacer rings that I can put between the lens and the oval lens board that will keep the lens from protruding as far into the turret. That should allow it to rotate.

Since I don't actually use the turret for multiple lenses, I don't use the spacers, but I think I tried it once to make sure it would work. Or maybe I dreamt it...

In any case, you should be able to see of the turret will rotate if you don't screw the lens all the way in. If it does, then a spacer ring of the right thickness should do the trick. It brings the lens out far enough to allow the rotation, but no so much that it can't be focused.

 

[Dave Krueger]

Ok, now that I'm at home, I was able to verify what I said above. I put two of the spacer rings between the lens and the flat oval lens board at it rotates in the turret just fine and focuses just fine.

Unfortunately, I can't find the black metal spacers in the Omega catalog. I have three that are different thicknesses. They are 50mm outside diameter and 39mm inside diameter. You might be able to use a 39mm locking ring (P/N 421-010) as suggested in the catalog. You could do a search on ebay for omega lens spacer.

Another option would be to have one made at a machine shop.

Good luck.

-Dave