Jump to content

Rear lens filters and Diopters on Sigma Cine FF Primes PL Mount


Recommended Posts

After hearing about Arri Signature Primes adding diopters to the back of the lens to give a vintage lens look I got thinking about how if you unscrew the back PL mount flange element on a Sigma Cine Prime it looks like a lens filter screw. Did some measurements and its 50mm and found a not very common step down adapter ring from 50mm to 49mm on ebay. It works! I can now add any 49mm filter onto the back of my sigma primes. 

The adapter from 50mm to 49mm is actually necessary to add little space and clear the lens from hitting a filter when focusing to infinity, some go back further than other. I have 14mm, 20mm, 24mm, 35mm, 50mm, 85mm, 135mm and this setup clears all of them.  

The back element I had to unscrew off its not super easy, not glued but sigma screwed them on tight, so they don't come off easy. Use caution. On really tights ones I removed the whole PL mount off the lens to safely apply force and not risk hurting the glass, also screws on the PL mount are delicate so lots of caution to not strip them. Once its loosen its easy as screwing and unscrewing any lens filter. Maybe pay a lens technicians to safely loosen them for you.  

Also I am playing around with some cheap diopters off amazon and with adjusting the back focus on my RED Gemini I am getting some really nice results of faking a vintage lens look. The Diopter is also acting like poor quality speed booster shirking my Full frame lens down little bit. Not sure what it would look like on a full frame. 

Next I'll buy diffusion filters to try since 49mm are a lot cheaper than 4x5.6 to experiment with. I can strip down a camera rig and still have a filter on my wide lenses that don't have a front filter thread, and play around with effect filters creating different effect being on the rear.

Here is a link to images of this and my first test with rear diopters. There is examples of the 49mm +2 diopter compared to clean and 4x5.6 1/2 bronze glimmerglass. https://drive.google.com/drive/folders/1Zh8Sk0bKzt0GIFkuru_ToTQvO3pJuiyM?usp=sharing

 

Edited by Alexander Sutton Hough
wrong url link
  • Like 1
Link to comment
Share on other sites

  • Sustaining Member

That's a very nice discovery. Do we know if there's any intention from Sigma that this be possible?

I wonder how it would work with something like the Vantage squeeze dioptres, which are effectively a dioptre with an area in the middle ground flat to create a filter that softens the edges of frame.

Link to comment
Share on other sites

  • Sustaining Member

Very cool little discovery! I've just ordered a set (to make life MUCH easier when I want to use nets). And maybe some more interesting things like centre spot or star filters.

Manfrotto make their Xume magnetic adapters for a 49mm diameter (which are brilliant for quick changing filters) I wonder if there's enough space behind the lens to fit the additional magnetic filter layers without any hard vignetting?

If so, that would make it really nice and convenient.

 

Link to comment
Share on other sites

7 minutes ago, Mark Kenfield said:

Very cool little discovery! I've just ordered a set (to make life MUCH easier when I want to use nets). And maybe some more interesting things like centre spot or star filters.

Manfrotto make their Xume magnetic adapters for a 49mm diameter (which are brilliant for quick changing filters) I wonder if there's enough space behind the lens to fit the additional magnetic filter layers without any hard vignetting?

If so, that would make it really nice and convenient.

 

On a standard pl mount there alot of space and I think it should work. The +2 diopter I had to remove the glass on a few others and use their metal ring as a spacer to move diopter closer to the sensor to get the back focus to work for infinity. 

  • Like 1
Link to comment
Share on other sites

On 6/15/2021 at 7:22 PM, Mark Kenfield said:

Very cool little discovery! I've just ordered a set (to make life MUCH easier when I want to use nets). And maybe some more interesting things like centre spot or star filters.

Manfrotto make their Xume magnetic adapters for a 49mm diameter (which are brilliant for quick changing filters) I wonder if there's enough space behind the lens to fit the additional magnetic filter layers without any hard vignetting?

If so, that would make it really nice and convenient.

 

The Manfrotto Xume works! At least on my Red Gemini and Wooden Camera PL mount. I can use the magnet to hold different nets and fabrics in place. Also combined with a stepdown ring to 46mm the diopter gets very close to the sensor and able to adjust the back focus for plus 4  diopter and get a nice vintage lens look along with a net at the same time. The max I can go is 20mm and for plus 4 diopter it needs to go back as far as  possible. 

I tested out a glimmer glass at 49mm screwed on to the back. At this size I can get more filters for cheap, and stay compact. But there are less available options than in 4x5.6 size. Tiffen says they do custom orders and I am waiting on quote for 49mm.

Bought bunch of different fabrics and been testing them, this really opens up a lot more options to have a stylized look to these very clean and sharp lenses.

Another note is the Sigmas PL Mount rear lens cap will not fit on these. I got Fotodiox PL mount lens cap and fits all this (also tried the Tokina PL rear cap and to short).

The 50mm to 49mm was hard to find. This is the seller I bought it from. https://www.ebay.com/itm/384201182715?var=652426027644

PXL-20210623-015635064.jpgPXL-20210623-015733950.jpgimg%5DPXL-20210623-031824667.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

Forum Sponsors

Abel Cine

Tai Audio

New Pro Video - New and Used Equipment

Gamma Ray Digital Inc

Broadcast Solutions Inc

Visual Products

Film Gears

Wooden Camera

Metropolis Post

Glidecam

Serious Gear

VidGear.com - Broadcast Video Warehouse

FJS International

CineLab

Cinematography Books and Gear



×
×
  • Create New...