Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Leica & Alternative Gear | Join Upload & Sell

1      
2
       end
  

Archive 2016 · Really "Alt" way of getting f/1.2 (updated...)

  
 
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #1 · p.2 #1 · Really "Alt" way of getting f/1.2 (updated...)


Very cool! This is a 1.2 lens? Lovely colors. I have not tried shooting at longer distances like this.

For my next project I am going to go in a totally new direction: get back to a super soft messy lens project that I started a few years back but now want to pick up again now that I have the Sony and helicoil focussing system...



Dec 25, 2016 at 12:47 PM
BlueBomberTurbo
Offline
• • •
Upload & Sell: Off
p.2 #2 · p.2 #2 · Really "Alt" way of getting f/1.2 (updated...)


Yup, same as what you have, just different branding:

https://g1.img-dpreview.com/5DB70431EF9844F1BDA2A39A7E41BB37.jpg
https://g4.img-dpreview.com/4EA70AC6C4404BBFA97EA38BDC22B876.jpg
https://g2.img-dpreview.com/257F7B29786C4C5B844153C8C455F2D7.jpg

Really like this lens, so I'll probably pick up a focusing helicoid for it soon to make it easier to use. Wonder if there are any wider projector lenses out there that are just as fast and perform anywhere near as well?



Dec 26, 2016 at 08:14 AM
BlueBomberTurbo
Offline
• • •
Upload & Sell: Off
p.2 #3 · p.2 #3 · Really "Alt" way of getting f/1.2 (updated...)


Oh yeah, one question. What hood are you using on your lens? Noticed the lens can flare quite easily outdoors without a hood.


Dec 26, 2016 at 10:15 AM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #4 · p.2 #4 · Really "Alt" way of getting f/1.2 (updated...)


I am not sure how easy it will be to add a helicoid system here?

As to the hood: there is a thread on the inner section of the front lens barrel but the outer section, where it counts, lacks any thread. I tried snugging in a metal 55mm hood that I had lying around. It is close but a tiny bit too wide in diameter. Duck tape would "fix" this but the issue is when you need to move the projector lens back towards the sensor you get vignetting. A hood just makes this worse. It does on my full frame a7RII, might be different on your camera though...



Dec 26, 2016 at 10:24 AM
AmbientMike
Online
• • • • • •
Upload & Sell: Off
p.2 #5 · p.2 #5 · Really "Alt" way of getting f/1.2 (updated...)


Just saw this thread, cool project! I have made an aperture for both a Sigma 400/5.6 macro (too early for digital, works wide open) and a lens I rigged up out of 3 achromatic doublets I had from astronomy.

I used green card stock on the 400, a dark-ish flyer that came in the mail on the one I rigged up. So you might be able to have a couple for f/4, 8, or whatever.

Black construction paper or matte black painted cardboard would probably work better, though.



Jan 19, 2017 at 08:11 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #6 · p.2 #6 · Really "Alt" way of getting f/1.2 (updated...)


Went out for a fun evening a few weeks back with this lens. Tried some "night" stuff...

























Feb 08, 2017 at 06:45 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #7 · p.2 #7 · Really "Alt" way of getting f/1.2 (updated...)


Lens update:

As previously noted I deployed a very DIY focussing system for this lens. The body of the lens was inserted into a Sony E mount three extension tube set with the actual lens body wrapped in black velvet that had an adhesive backing. This acted as a primitive focussing system. It was ok but after some time the primitiveness began to bug me.

What to do? The goofy thread on the barrel of the projection lens did not match any lens thread system I know of. I tried a few things and then found eventual success. I bought a M52 - M42 focussing helicoid adapter. I hoped the lens would fit into the M52 end. I also bought a super thin M42 - Sony E mount adapter to go on the back end of the focussing helicoid adapter.

Problem: the threaded body of the lens was just a bit too thick in diameter to fit into the focussing helicoid adapter. I thought about grinding off all the threads on the lens myself but that would mean removing a couple of inches of material. Doing that evenly with a grinder or Dremel tool was not appetizing. I then went wondering down into a part of town that had boat yards and a couple of machine shops. I found a small enthusiastic shop. After looking at the focussing helicoid adapter and the lens we decided to remove some of the inner material of the focussing helicoid adapter itself rather than touch the lens. This had to be done carefully so as not to remove too much of the inner focussing helicoid adapter which might make the back of the lens recede too far into the camera.

The shop did a great job. The lens now fits into the focussing helicoid adapter just perfectly. I can now get really close focus plus infinity focus. To make sure the lens stayed secure I added some silicone to the machined section of the focussing helicoid adapter. I also added a rubber O-ring to the back end of the system to help keep moisture out and make it it look more polished.

Bonus: I found that I could unscrew the ugly front threaded ring on the projector lens and substitute two of the threaded extension tube sections. This helps keep everything snug and tight and looking good!

The lens now focuses more easily and accurately. The focussing helicoid adapter is not as smooth as a real high end lens but it is certainly good enough for this project.

I thought about adding some kind of aperture system but quickly abandoned that idea: the fun part of this venture is the fast f/1.2 fixed aperture.

Here is how the lens looks now...




Feb 08, 2017 at 07:15 PM
BlueBomberTurbo
Offline
• • •
Upload & Sell: Off
p.2 #8 · p.2 #8 · Really "Alt" way of getting f/1.2 (updated...)


I went down the same path, and also found out the lens is like 53mm vs the 52mm opening in the helicoid. Also got sliced by the lens barrel when I took the hood off. Didn't even notice till 10 min after. Thinking of getting a larger helicoid, since I don't know any machine shops.

Also picked up one of those 50mm F/0.75 X-ray lenses, which I'm messing around with. Acts more like an 85mm F/1.0, though.



Feb 08, 2017 at 07:26 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #9 · p.2 #9 · Really "Alt" way of getting f/1.2 (updated...)


BlueBomberTurbo wrote:
I went down the same path, and also found out the lens is like 53mm vs the 52mm opening in the helicoid. Also got sliced by the lens barrel when I took the hood off. Didn't even notice till 10 min after. Thinking of getting a larger helicoid, since I don't know any machine shops.

Also picked up one of those 50mm F/0.75 X-ray lenses, which I'm messing around with. Acts more like an 85mm F/1.0, though.


I did not have much luck finding a focussing adapter that was larger than the M52 - M42 unit I found in the USA. There might be something available from China though? I was too impatient to wait for shipping from China. The adapter I bought cost more than the actual lens ($25) but I still preferred not to attempt removing all those threads from the lens itself.

All in all this whole project has been loads of fun. The various obstacles might have played a big part of that...



Feb 08, 2017 at 07:37 PM
rico
Offline
• • • • •
Upload & Sell: Off
p.2 #10 · p.2 #10 · Really "Alt" way of getting f/1.2 (updated...)


Great alt engineering, and superb photography! I have a pair of projector lenses from my, uh, projectors, but they are Leitz branded and likely too well corrected for the characterful rendering you guys get from that f/1.2. Being 90mm, they should successfully free-lens in front of my A7ii. Weekend experiment.


Feb 09, 2017 at 06:14 AM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #11 · p.2 #11 · Really "Alt" way of getting f/1.2 (updated...)


Thanks!

I would like to see how the Leitz projector lenses work. I almost bought a Leitz projector just to try the lens.

I also bought a really compact 3" Dukane projector lens. It performs more like a macro but the images were not as interesting as my main projector lens project. So far all I have done with the Dukane is play with it using an old macro bellows...



Feb 09, 2017 at 12:02 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #12 · p.2 #12 · Really "Alt" way of getting f/1.2 (updated...)


One more: 100-year-old glass bead sash...





Feb 09, 2017 at 12:14 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #13 · p.2 #13 · Really "Alt" way of getting f/1.2 (updated...)


Some closeup tests (that little car is tiny)...










Feb 10, 2017 at 03:17 PM
PhotoMaximum
Offline
• • •
Upload & Sell: Off
p.2 #14 · p.2 #14 · Really "Alt" way of getting f/1.2 (updated...)


A couple of new attempts...

Gasworks park in Seattle


Valentines Day rose


Quick model test





Feb 25, 2017 at 06:17 PM
1      
2
       end




FM Forums | Leica & Alternative Gear | Join Upload & Sell

1      
2
       end
    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.