What Lens Mount for Diy 35mm Adapter (Hf s100/Gl1)

[Cris Hendrix]

I'm going to try to build a 35mm adapter for my Hf s100 (58mm lens thread - same as Gl1/Gl2), the adapter I'm going to build is based on this static design: YouTube - NEW how to build a static 35mm adapter with less vignette (2009)

Basically it'll be a 35mm lens attached to 2 macro lenses, some hallowed uv filters for space and a ground glass somewhere in between.

I'm a bit confused on what type of "lens mount" I need to buy though. I'd like to use Canon fd lenses..

EDIT: Nevermind, after reviewing his video it looks like he just scooped out the rear 35mm lens cover and glued a hallowed out uv filter to it, would this be very durable/modular for switching out lenses?

I found this lens mount on ebay (item 270402801397) "New adapter for Canon FD Lens to EOS EF mount NO GLASS" - if I followed his tutorial but substituted this lens mount and then glued a Uv filter to it would this work as well (or better)? Or is there possibly some way to screw this mount onto some type of EOS to 58mm thread adapter so that no gluing is involved? -My concerns being a solid build and ease of swapping out lenses

Actually would this work to attach the EOS part on one side with a 58mm thread on the other (so that the UV filters for space could then be connected to the 58mm thread side)? - http://www.amazon.com/Fotodiox-Rever.../dp/B001G4PA36 - I'm thinking the threads might be facing the wrong way when trying to attach to the camera and camcorder though, right?

[Bob Hart]

Using plastic end-caps is the first dead-end new home-builders back out of. They wear, they break, they flex, = pop" + "thud" if you are lucky, "pop" + "crunch" or "pop" + "crash-tinkle" if you are not. Good FD lenses are good, not for letting fall onto the ground to be destroyed forever.

Try to find a genuine FD lens mount replacement part for cameras or see if you can find an older FD extension tube either for the mount on front or to integrate the tube into your design.

[Cris Hendrix]

Ok thanks, that sounds a lot better.

Sorry for all the noobish questions, but I was looking at a Canon Fd25 at B&H - Used Canon | FD25 Universal Extension Tube | 42532401 | B&H - it looks like it's fixed (wouldn't screw less from camera side mount?) but I see some offbrand "macro extension" tube sets on ebay that look like they possibly come with a front mount and then several extender tubes with filter threaded ends before then connecting to a camera side mount (ie item 190318022643 "Macro EXTENSION TUBE SET FOR CANON FD F1 AE1").. I'm guessing one of these off brand type sets is what I should be ordering?

Thanks again

[Cris Hendrix]

The macro tubes from ebay worked perfectly! Shot some footage this weekend and it's looking good, can still see some grain on a 52" lcd though so I may go further and try to modify the design to allow spinning (also need to get a faster lens, using a 35mm fd 3.5).. so far I seem to get the best results with a macro lens as close as possible to the 35mm lens, the ground glass as close to the macro, a good amount of space, then a macro attached directly to the camera.

I'm wondering what would happen if I put a diffusion filter directly after the ground glass, would most likely muck up the image but hopefully could reduce some of the ground glass grain? Will try it when I get a chance

Anybody have any tips for camera settings? I'm using a Hf s100, was first trying shutter mode at 48 with a locked exposure and low sharpening, but seem to get better results with Cinema Mode which seems to reduce the grain better, though I wish there was a way to control the shutter while in Cine Mode.. would be interested in hearing other Canon users experiences

[Bob Hart]

(The macro tubes from ebay worked perfectly! Shot some footage this weekend and it's looking good, can still see some grain on a 52" lcd though so I may go further and try to modify the design to allow spinning)

Unless you are using a very large image off the groundglass or using microcrystalline wax blends Boss screen style, you are stuck with moving the groundglass.

In meantime, you can try using f1.2 or f1.4 lenses at f1.8 and achieve a more acceptable result with a static groundglass. You may need to add some ND in front of the lens to keep the light levels under control and the shutter speed acceptably slow.

(so far I seem to get the best results with a macro lens as close as possible to the 35mm lens, the ground glass as close to the macro, a good amount of space, then a macro attached directly to the camera.)

The macro lens close to the groundglass. What is it and what power? The original Letus flip had a similar arrangement, a single bi-convex element reversed so that the face with the least curve was closest to the groundglass and behaved as a condenser, so it seems you are onto a valid method. The Letus however placed the condenser between groundglass and camera.

(I'm wondering what would happen if I put a diffusion filter directly after the ground glass, would most likely muck up the image but hopefully could reduce some of the ground glass grain? Will try it when I get a chance).

There is nothing to be lost from trying, however adding a diffusion filter will lose you more resolution and apparent sharpness.

[Cris Hendrix]

I'm using 2 Opteka 10x HD macros (58mm), one between the 35mm lens and ground glass, and one before the camcorder

I put in an order earlier this week for a ground glass 1500 from optosigma and a bk7 plano convex lens from thorlabs (opto was sold out), as well as a fd 50mm 1.4 off ebay so I'll be eager to try these out once they get here and post the results (I'm thinking of putting the condenser/convex lens between the macro and gg, or seeing how the plano convex works in place of the macro)

I'm hoping the plano convex will spread out the light a little better allowing me to zoom out a bit more, as I'm thinking zooming in slightly to decrease vignetting might also be increasing the grain

[Cris Hendrix]

Here's some raw footage shot this weekend with the adapter before I had the proper macro spacing set up (this was my first time shooting with the adapter), this is through a 35mm fd 3.5, shutter mode at 48, no color correction or post processing

YouTube - Sluts Movie Test Footage - Shooting Summer & Fall 2009 in Dallas TX

[Cris Hendrix]

Well I can post up some footage later but it looks like the macro actually does a lot better job than the condenser (pcx) lens. Overall the image is much improved now though with a 50mm 1.4 lens and the Optosigma gg (which appears possibly a stop or 2 brighter than the thorlabs gg).

Through the condenser (Thorlabs LA1401 N-BK7, 60.0 mm focal length) there's still some slight vignetting and a kind of circular distortion, the vignetting virtually disappears through the macro and the distortion is greatly reduced, so it looks like I'll be sticking with the original design for now, the only substitution being the better Optosigma gg.

[Bob Hart]

My own jury is still out on the benefits of only a single PCX or BCX as condenser on the camcorder side instead of a matched pair on either side of the groundglass.

Unless the condenser and achromat are matched and positioned by a optical engineer and if the second identical condenser is not used in front of the groundglass, I think and this is only a think, that the average home-builder might be better off doing without and being satisfied with using a smaller groundglass area, say 22mm - 24mm wide.

There is the possibility that a single unmatched and incorrectly positioned condenser may confer the illusion of eliminating corner brightness falloff by forcing the observed image larger within the same camcorder frame by magnification.

You would achieve a similar benefit by simply zooming in closer on the groundglass inside the hotspot for the same magnification.

With your pcx, try reversing it before you throw it out, make sure the flat side faces the groundglass. Otherwise, if it is creating a distortion, it seems to me it may be of too short a focal length.

There are a whole lot of variables in the positionings, front of camera lens <-> achromat, achromat <-> condenser, condenser <-> groundglass. All interact and playing around with combinations may yet get a good result for you.

It is hard to be sure just how much of the groundglass your camera is viewing.

I suggest you make a thin cardboard disk shape to fit inside your tube against the fixed groundglass. Perfectly centred inside that disk, you cut out a rectangle 24mm wide and 18mm high. This is a mask you put hard against your groundglass to give you a reference.

[Cris Hendrix]

Hmm yeah I was actually using the condenser right after the 35mm lens (with the flat side of the condenser facing the ground glass). The condenser and ground glass are both mounted in their own Thorlabs tubes (the smallest tubes that would fit each piece) to make it a bit more modular. So the design was 35mm > Condenser > Groundglass > Macro Lens > Camcorder.. though I'm having better luck with 35mm > Macro > Groundglass > Macro > Camcorder

I suppose I could try the condenser near the camcorder position, but it sounds like to effectively go this route I would probably need another identical condenser to play with (basically swapping out both identical macros for identical condensers)? I'm not sure I'd really wanna invest any more at this point unless I was relatively sure it would be an improvement though - I'm pretty happy with the macro setup though I admit there's still some slight room for improvement