Found this on Schneider Optics site:

C-Mount

Mounting Thread = 1 inch x 32 tpi UN 2A
Length of Lens Thread = 3.8mm
Lens Flange Focal Distance = 17.52mm
Camera Depth (C-Mount Face to Image) = 17.52mm

I have a funny feeling that the size, and especially the thread configuration, is going to be hard to match with step-down rings (going from metric to inches). And what is UN 2A?

Anybody know for sure?

That appears to be for the C-mount itself; what about the C-mount adapter? I'm assuming Richard has this info; he just hasn't been on for a couple of days.

Anyone here know how powerful an macro adapter I will need to use one of these things with a DVX? Will +3 be fine or will I need to go higher?

One more question: How many retaining rings did you end up using Richard?

Do T-mount adapters have the same type of threads? The only problem with the C-mount is that it limits the light that can pass through.

Aaron, don't know the answer to your macro question yet -- I ordered a set of +1, +2 and +4 off eBay, so I'll let you know after I get this thing built (hopefully next weekend; still waiting on answers about the c-mount adapter before ordering the stuff from B&H). I ordered 2 retaining rings along with the tube from ThorLabs per Richard's instructions.

Fox

Thanks Jason - very helpful! Do you have a link to a similar diopter set on ebay? I have been having trouble finding one that doesn't cost several hundred (which I am not willing to spend yet).

EDIT: Never mind! Searching for macro worked - I was previously searching for diopter.

I'm still wondering why this is assumed to be a valid parts list when there hasn't been any documented footage, stills, or anything. I've looked amongst this thread. Have I missed this?

Yeah I've posted footage. I think it's on page two. http://www.dvinfo.net/conf/showthrea...5&pagenumber=2
It's just a rough edit piece to test the lens but the point is there.

Ground glass?
 

Im makeing an adapter like james's design at enormousapparatus.com and i was just wandering is the filter ring that he encases the ground glass 55mm while the ground glass is 50mm? Because i cant find 55mm gound glass, but theres 50mm gg at thorlabs and optimo sigma.

Thorlabs has 2" diameter glass that fits into a 55mm ring. Optosigma has 50mm ground glass that does NOT fit into a 55mm ring, but DOES fit into a 52mm ring.

If you're using a 52mm style adapter standard, that's good news, since the Optosigma is superior. The Thorlabs 1500 glass seems to come with imperfections that require manual grinding to get rid of them. I've bought and received 2 of them and they both had swirls. Richard Mellor also reported flaws with the Thorlabs.

I'm still awaiting a Beattie screen that I'm predicting will have less grain than any ground glass available.

c-mount
 

Hi everyone:

I went to a local camera store yesterday. I took apart one of their Nikon c-mount adapters. When the back was removed, I was able to fit a 52mm step ring in the back. It would have to be epoxied in place, but with this adatper it would be a straight 52mm directly from the c- mount . This would save some step ups and downs.

The Canon adapter was built differently -- more like 60.5 mm.

I think each one of the adapters will be a little different . I can not tell how many of the adatpers online will work to mod this way, but I will be going to more camera stores and take apart as many as I can.

c-mount & ground glass
 

Richard -- can you take a look at James Webb's set up and see if you can tell what he's using to attach his Konica lens? He goes uses a step-up ring to go up to 58mm and the attaches that to a "lens mount" which is pictured but not described. I have not received a response from him about this.

Kyle -- I think James is using a sanded, 55mm UV filter as his ground glass.

I've got everything but the step-rings, c-mount stuff on order (got a Canon lens for 20 bucks on eBay for testing, woo-hoo!), so I'll try to figure out exactly what I need for that lens when it arrives.

Fox

Richard -- forgot to give you the link to James's adapter: http://www.enormousapparatus.com/35adapter.htm

The problem with James' adapter is if you look in the four corners, not only does it appear to vignette, but there also appears to be some strange optical distortion in those corners. And that you can see in just the web version - I can't imagine how odd it must look on a TV.

But it's so hard to tell with all these screen caps and down-rez footage samples. Anybody got just a piece of uncompressed video available to download so we can see the proof in the pudding?

It is true, the distortion is an issue with James' design, and I have this issue as well with the adapter I have built that is modeled on his.

I'm using an XL2 which does allow for creative front end relay lens options. Has anyone built something with standard parts for the XL1/XL2 that is distortion free?

Here is example DV footage of where I'm at so far.

http://www.holyzoo.com/111/xl2/35mm/...er_V1_DV25.mov

For details on the what and the how:

http://www.holyzoo.com/zoo_updates.php