View Full Version : LF Lensbaby

George Stewart
17-Dec-2006, 07:12
I'm in the contemplation phase of creating the subject lens. I would purchase an achromatic doublet, from either Edmund or a surplus house, and have SKGrimes mount it into a Copal #3. To go a bit further, I'm thinking of getting two lenses, one of 150mm focal length and the other of 300mm, for 4x5 and 8x10 respectively-for use in the same shutter. I know there will be some (or a lot of) vignetting when shot at or near wide-open. SKGrimes has indicated that it might be better to mount the lens behind the shutter.

Has anyone attempted such a project? What were the results?

I'm also interested in opinions and suggestions. Thanks.

Ernest Purdum
17-Dec-2006, 09:10
This is an interesting project. It seems to me, though, that mounting the lens right away in a Copal 3 shutter is a rather large investment in an experimental situation. Unless cost is not a factor, trying it out without a shutter would seem prudent.

The vignetting problem would be lessened by using a large old #5 shutter, a Compound, Ilex or Wollensak. If you can find one, the Compound has the largest opening.

The Grimes people are correct in stating that better results would be expected from mounting the lens behind the shutter. This gives a barrel distortion, generally preferred to the pincushion. The distance between the lens and the stop is also significant in several ways, so you might want to experiment with this before choosing a final arrangement.

There can be significant differences between different achromatized doublets of the sme focal length, particularly in regards field flatness and coma.

Jim Jones
17-Dec-2006, 11:06
The versatile mechanical features of a Lensbaby are unnecessary in a decent view camera. The optical problems were solved long ago. A behind-the-lens shutter like the Packard might be more versatile than mounting the lens in a Copal #3. The only advantage I see of using a lens from Edmund or Surplus Shed is the satisfaction of improvising a system to perhaps do poorly what an inexpensive hundred-year-old lens might do better.

Henry Ambrose
17-Dec-2006, 15:49
I'd think about taping some old crappy lens to the front of a lens I owned that was already in a shutter or unscrewing the elements from a good lens and taping the crappy lens onto that shutter. Duct tape - its completely in tune with with your project. (not meant as criticism)

Maris Rusis
17-Dec-2006, 16:35
I've used 150mm and 300mm achromats on view cameras as taking lenses by sticking them on the front of a Copal #3 shutter with Blu-Tac. I never did anything more elaborate because the results did not seem worthwhile. Image quality sucks.

There is some lateral chromatic abberation at the edges of the field. Astigmatism is very strong and limits vaguely sharp images to the very centre of the ground glass. Field curvature is extreme with a focus shift up to 20mm between the centre of the image and the edge. Highlight points are dramatically smeared by coma. In fact all the first order abberations, except longitudinal chromatic, are in abundance. Vignetting (optical plus mechanical) as such is not remarkable; just the usual cosine to the fourth power fall off that one sees with standard lenses.

I have also tried a 700mm achromat on 8x10 to try to ease the avalanche of abberations. Pictures come out mainly sharp though with slightly smeary edges when the lens is stopped down to f.256.

Maybe someone with more vision and talent than me could work out a legitimately expressive purpose for such grossly abberated images.

Frank Petronio
17-Dec-2006, 21:44
Any 80 to 120 year old Jim Galli lens plus some strategic subtle Photoshop blurcraft can do just about anything you want....

Alan Davenport
17-Dec-2006, 22:59
I think your idea of hacking together a lens is great. I don't understand why you'd spend top dollar to have someone else mount your hack job to a shutter. YMMV...

25-Jul-2007, 15:51
Wow, this is a very technical forum and I thought I was a professional photographer!

I have a lensbaby 2.0 :)

26-Jul-2007, 00:01
You remember Mark Tucker's PlungerCam?


Helmut Faugel
26-Jul-2007, 00:21
Has anyone attempted such a project? What were the results?

I'm also interested in opinions and suggestions.

Well, I can only tell you what I tried on my 135-cameras:

I removed the front cell from a Voigtlaender Skopar 10,5 cm f/3.5
(a Tessar type lens from the 1930s). The back cell is more or less
an achromat which has about half the focal length the complete
lens has, in my case about 50 to 55 mm. The results were interesting
especially when I used this "lens" for night shots.

So I recommend to use a 300 mm Tessar with a removed front cell
which will give you more or less the same results as a Lensbaby.