Sun Anamorphic & Helios-44M rehousing idea

[Gábor Ember]

I have been thinking about a rehousing project for a while now. What I want to do is rehouse the taking lens and the anamorphic adapter in one lens body.

Originally I though about converting to a single focus system , calculating focus distances for each lens and adjusting the two helicals or grooves so that the Helios and the SUN would move together with the turn of a single focus ring. Now the calculation and the actual creation of at least one nonlinear helicoid would not be an easy task so for now I am designing a lens body for dual focus.

 

There should be two lens groups that move separately:

Front group is the front lens group from the SUN

Back group is the back lens group from the SUN and both lens groups from the Helios

 

This way when I turn the rear focus ring not only the taking lens focuses, but also the distance of the two SUN glass parts changes (the anamorphic part focuses in the right direction, but not exactly the right amount). The front focus ring would only need minor adjustment.

 

Goals:

• Two lenses in one body
• Easier focusing
• Reversing the focus ring turn direction on the SUN glass part
• Reduced minimum focusing distance
• Tough, durable body (probably an inner shell from one piece of aluminium)
• Very small amount of parts (harder to machine so we'll see)
• No alignment issues
• Canon EF mount
• Built-in tripod mount (proper balance on a tripod)
• non-rotating 58mm filter thread (the current mod has a rotating thread)

 

I will post some drawing to clarify what I wrote above.

[Gábor Ember]

http://megafile.hu/swf/rajzos.html

 

This flash sketch shows the basic layout of the glass groups and their movement. The camera would be on the right side.

 

Front lens group:

Sun front

 

Rear lens group:

Sun back + Helios

 

The front focus ring moves the front group while the rear focus ring moves the rear group. This drawing just represents the position of the glass elements related to each other. The aperture mechanism is currently not in the design, I'll see how can we implement it.

 

The exterior design will not be a simple tube of course. I am currently looking at a bunch of cine lens photos to find one that looks right for the job. The interior is just a tube so the exterior can be shaped freely. I don't plan on using geared focus.

 

Every custom part will be made of aluminium.

 

Oh and maybe 58mm filter thread will be too small, because the Front group will move to the inside of the lens so it might vignette.

[Gábor Ember]

This animation is almost what I had in mind:

http://www.pierretoscani.com/images/echo_shortpres/Figure-18-anim-UK.swf

 

www.pierretoscani.com/images/echo_shortpres/Figure-18-anim-UK.swf

 

The main difference is that I wanted to put the Cam Ring on the outside, not the inside.

http://www.lensrentals.com/blog/media/2013/01/helicoidsml.jpg This is how i planned it.

 

The anim represents a single focus system.

 

My friend does magic with aluminium so once I have the design he could probably machine the parts in a week. I am open to any suggestions about the project.

[Gábor Ember]

The donors

[sharedmedia=gallery:images:700]

 

Sun disassembled with all its parts

[sharedmedia=gallery:images:701]

 

Sun glass parts that I will use

[sharedmedia=gallery:images:702]

 

Helios glass parts that I will use

[sharedmedia=gallery:images:703]

[Caleb Genheimer]

This is awesome. hope it works. Could be tricky seeing as anamorphic optical alignment of elements needs to be very precise.

[Gábor Ember]

Well there are only 2 anamorphic elements so alignment is not that hard but it has to be done when the system is attached to the camera so I can see if the image is sharp. I have disassembled the Sun a couple of times now and it is not hard to adjust the alignment, just have to use a caliper and turn the glass element. I am not worried about that part, it may take some time, but it can be done.

 

The hardest part might be putting the optical blocks inside the one piece body.

[Julian]

Cool project. Keep us updated! Would love to see the result.

[Gábor Ember]

I was looking at pictures of Pana lenses and they got me thinking. Maybe if I put those things that look like eyelids in front of the anamorphic glass they will reduce the white vignetting caused by incoming light. I don't know this lens of course, it probably has a square front lens, that is why it looks like that, but you can see the eyelid looking things in front of the front lens at the top and bottom..

 

 

 

I got a very simple 3d model of my current design at my home PC. I'll post some renders tonight.

[nazdar]

Here are some x-ray pictures of Hawk and Lomo anamorphic lenses. That can maybe help you to see more whats going on there. :)

http://www.reduser.net/forum/showthread.php?75869-FS-LOMO-Anamorphic-Roundfront-set-F-35-50-75-NEW-PL-mount-ARRI-gear-rings&p=974248&viewfull=1#post974248

[Gábor Ember]

Thank you! I looked at this picture, but I think that I can only use the mechanich part of it since I cannot change the optics, only how they are positioned and moved. I will probably copy the look of these lens bodies.

[Gábor Ember]

http://a3dplayer.com/scene/deab14a4c48fed31c6a89486b19a5027/#.UjCVNMaccvg

Rotate with mouse. This is just some testing from yesterday. Once I have a design that I like I will render it in Max with proper paintjob and such.

[Gábor Ember]

I really like how these Hawks look:

http://www.filmanddigitaltimes.com/wp-content/uploads/2012/10/FDTimes-N13_0933.jpg

[Nikkor]

Show plans made in solid or autocad, renders are useless :p

[Gábor Ember]

I want to do CAD but I need a few days to get to know it first. It should not take more than that, I have everything on paper, I just need to draw in on my PC.

[JohnBarlow]

Good luck with this.

 

I am curious to know how you are going to solve the issue of matched focus.

The Helios 44-2 I have, has a throw of about 3mm from 1.5m - INF so I am not sure if the 44M is similar, whereas the Sun most likely has a much greater throw of maybe 10mm over the range 1.5m - INF. First thoughts are that some gearing is necessary, but the track length at any focus position between the two may not exhibit the same linearity. If the focal length of the rear anamorphic group was the same as the 58mm Helios then it would not be a problem, but you would be extremely lucky if this was the case.

[Gábor Ember]

For now I am thinking of a dual focus system, 2 focus rings.

 

Gearing is not needed though for single focus. It can be done with two spiral grooves (or helicals or whatever) that don't have the same angle, steepness. The anamorphic part shoudl have a steeper groove which would mean that when the the Helios moves 3 mm the anamorphic front can move 7mm  (in the opposite direction). The helical grooves can be linear on non-linear, the travel of the glass depends on them.

 

Here is a very extreme example:

http://www.lensrentals.com/blog/media/2013/01/helicoidsml.jpg

 

This is why I want to make a dual focus rehousing first, and after that maybe the single focus.

The 2 focus ring will have the same turning angle, that is not a problem, only have to mach the minimum focus and infinity, the 2 endpoints. After I have that I can see how wildly the focus of the 2 lenses differ.

[Gábor Ember]

Excuse the crudeness of this sketch:

https://docs.google.com/file/d/0B8zMWSjUuUsKRllZX3A2ZUtWakk/edit?usp=sharing

 

The straight grooves are the inner body, the helicals are a separate outer tube (either one single tube for single focus, or it is cut in half for dual focus). As you can see by turning the outer tube 90 degrees clockwise you will move the Helios 3mm while at the same time move the Sun front part much more in the opposite direction. I know, I know, I will make some proper drawing in CAD with measurements on it. Damn work...

[JohnBarlow]

When I spoke about gearing I was talking about the relationship between the throws of the two optics, not necessarily toothed gearing.

 

The slotted approach is a well tried and tested solution.

 

I would advise you to accurately plot the throw of the scope and the lens on the same axes, to see the difference in the focus profiles. Set up some targets from 1.5m to INF at say 0.5m intervals, to get a high resolution plot of this behavior to assist you with the design of the slot. I would be surprised if it was not some snaky shape as you illustrated above.

[Rudolf]

Very interesting and impressive attempt. Hope you get it done! This could result in a better image than SLR Magics product... 

Looking forward for your updates  :)

[Gábor Ember]

Hehe, the image will be the same as you can see in the Sun Anamorphic Topic. The glass is the same, only the body will change. Don't expect anything great from the image quality of this. This is a cheap setup.

 

Yesterday I checked the alignment of the Sun because I had issues before at the edges of the frame. Mostly noticeable at night when streetlight are at the edges, they have very interesting streaks on the right edge and on the left edge they are vertical. If I gather correctly this means a misalignment, not radial misalignment but angular. The front and rear glass in the SUN (original body) are not parallel and one edge of the image has backfocus while the other has frontfocus. I will try to counteract this.