Homemade lens for 8X10

Back in August I had posted this image in the X-ray film shooting and developing thread:

https://www.dropbox.com/s/r0fmui9ko6...g845b.jpg?dl=1

I noted that I used a 13" homemade lens. Some were curious about the lens so I described it. Another member asked for a more detailed description of the lens but I had not visited the thread again until today - so - apologies for the delay - for any interested in my amateur attempt at lens making...here it is. Please bare in mind that I barely graduated high school many years ago and have no higher education, other than life's failures over and over again.

https://www.dropbox.com/s/ramwmvhl9f...hm001.JPG?dl=1

Materials

1 - Tiffen Photar Plus 3 Series 7 close-up filter (like you would screw onto the end of your 35mm camera lens for shooting close-ups of flowers - only this one has no threads, so I had to use the adapter and retaining rings - this lens has a focal length of about 13" or 330mm)
1 - Tiffen Series 7 Adapter Ring
6 - Tiffen Series 7 Retaining Rings (I used 6 retaining rings simply because I had them - I figured they would make a decent lens tube)
1 - 77mm-58mm Step-down ring (to make a mounting flange for mounting the lens to homemade lens-board)
1 - Black construction paper for making an aperture (cut round to fit inside retaining ring)

https://www.dropbox.com/s/e06wsnc7bx...hm002.JPG?dl=1

I tend to use what I have on hand, and my calculation method of determining what will work and what will not is to waste hours making it, and if it doesn't work, throw it in the scrap pile and go watch TV. If it does work, my calculations were correct.

I made this lens after the fashion of a Walloston Landscape (Meniscus) lens - the lens is at the rear, concave side facing front-words, and the aperture is at the front of the lens, in my case, about 1" from the lens. I believe I tried it both ways, flipping the lens with the concave side facing the film, and I believe there was a difference, and I liked my current configuration better. For my configuration, the lens is about f/7 without the aperture installed, and f/16 with it - the aperture hole is 20mm in diameter - cut with razor knife.

https://www.dropbox.com/s/5bn6duvtsr...hm003.JPG?dl=1

I taped the center retaining rings so that they wouldn't loosen - leaving the front end ring so I can remove the f/stop if I want, and the rear ring so I can remove the lens for cleaning.

More photos momentarily...

https://www.dropbox.com/s/im2ip5p11a...hm006.JPG?dl=1
This shows the rear adapter unscrewed from the retaining ring.

https://www.dropbox.com/s/r6g53bug87...hm007.JPG?dl=1
The Tiffen +3 close-up filter

https://www.dropbox.com/s/bg6a4gjp93...hm009.JPG?dl=1
The 77mm-58mm step-down adapter - these things are great for making experimental lens flanges because they allow enough space for drilling holes for mounting to a lens-board.

https://www.dropbox.com/s/9iwailj8ov...hm010.JPG?dl=1

That's it in a nutshell. Hope this helps answer any questions.

Nice work. I made a lens with a magnifying glass. It's a swirly impressionistic lens. Fun stuff.

Neat stuff. Many people spend a LOT of money buying soft-focus lenses, when they can do what you have done -- for basically nothing. There are a LOT of close-up lenses that can create all sorts of results:

http://www.subclub.org/fujinon/close-up.htm

I use close-up lenses an a Copal #1, but the shutter, as the lens, is completely variable. Good CU lenses can create results from very blurry to pretty sharp..

I like the image a great deal. A little disturbing... It's working on me.
Nice job!

I have done something similar, mounting a 250mm FL achromatic close up lens behind a shutter, with empty filter rings for spacing from the diaphragm:
https://www.flickr.com/photos/michae...in/dateposted/

In point of fact, I gutted my Fuji 250SF for its shutter for this project because I found the SF aspect of the lens to be quite disappointing. :-)

Stepping rings, especially if you can find one made of brass, do make good mounting flanges for odd jobs. I have my EL-Nikkor 240mm mounted on my Beseler using one.

I have a +3 simple meniscus as a push-fit in an old Seikosha-S shutter. It is totally the 'wrong' way around - convex surface forward, lens in front of the shutter - but surprisingly good, if a bit specialized. And since it came from the parts box, I can't complain.