I found a great site for step rings.

this should fit just about every camera.

great prices too


http://www.2filter.com/prices/products/rings.html

Nope, no go on that site, either. Thanks for looking. I just don't think that size adapter is made. Is there any real issue in using two step rings?

Jason I've never seen a 72 to 52 anywhere. It's always been done with a 72 to 58 to 52. I don't know why, but the step ring guys just overlooked that one entirely. Probably never entered their heads that someone with a 72mm front would to put something smaller on it. What are you putting this on? A DVX? A Canon?

Joshua, it's going on a DVX. I figured the double step rings wouldn't be a problem, it'd just be nice to a) have one less part and b) save 10 bucks.

Fox

Another question: what size step ring do I need to go from the tube to the c-mount adapter? I can find the adapter's diameter anywhere. Thanks.

Jason

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

Vignetting
 

Richard, are you seeing any vignetting with your adapter? Have you tried it on a camcorder with a 72mm lens?

<<<-- Originally posted by Steev Dinkins : 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 -->>>

With both static adapters, wouldn't you have a screen of grain on your picture? Such as, a grain pattern that stays the same, I guess you can say an overlay.

Kyle, yes you would. Limiting grain in static adapters has been a big topic of discussion which has no very easy solution.

What optical parts are you using in your adapters guys? I just ask because I assume the distortion comes from a cheap macro lens?

Kyle,

It sounds like you're running into the wall all of us other XL1/XL2 users have hit. We've been trying for a while to build our own relay lens system so that you could mount the adaptor directly to the XL mount (without actually spending as much as a min35 costs) but so far, no luck.

<<<-- Originally posted by Aaron Shaw : 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, any luck on figuring out if a T-mount adapter will work? I can hardly even find such an adapter (only one on B&H for Canon EOS). Also, those macro lenses I ordered from eBay are actually 55mm -- I ordered them when I was going to build James Webb's adapter. I only got a +1, +2 and +4 anyway. But I know you can find +10's fairly cheaply on eBay if you go 55mm. 72mm is also there, just a bit more and I don't think they're as high quality.

So how the heck do we attach the lens to the tube? Is there anyway to avoid going Richard's route and hacking up the c-mount adapter and gluing it to a step right? Will another lens brand fit better with an adapter? I just bought a Canon lens for testing, but it was only 20 bucks, so I don't mind getting something else if need be.

Fox

<<<-- Originally posted by Fred Finn : I have some footage with this GG and Cnvx lens. I made the tube out of PVC.
http://hazardousproductions.com/films/chron_frd.mov
right click save link as.

I did have to use a macro on my gl-1. -->>>

Fred,

How did you mount the lens to the tube and what kind of lens did you use?

Fox

Jason,

I found that it does indeed have threads. I do not know if it has the right thread pitch though to connect with other photographic items. This is what I do know:

"The thread used on T-mounts, referred to as the T-thread, is a metric thread 42mm diameter and having 0.75mm pitch. It is correctly written as "M42-.75". If you’re more comfortable with inches and TPI (threads per inch), the thread would be 1.654" in diameter and have 33.866 threads per inch. The inside diameter is typically 1.615"."

As for using a different lens: I don't think that will make much of a difference. I haven't experimented with it myself but pretty much all 35mm lenses are the same with only slight differences in the mounting mechanism. Nothing extreme enough to make much of a difference.

<<<--

Fred,

How did you mount the lens to the tube and what kind of lens did you use?

Fox -->>>

Hey Jason,

I went a little unorthodox on this one. I took the whole 35mm lens apart. I stripped it of all non-essentials (focus ring f-stop ring). I used a rubber band to hold the aperture open all the way. The new lens was downsized in diameter quite a bit and fit nicely into the end of a piece of pvc. I used an adapter piece that fit a filter ring on the other end. I used hot glue around the perimeter to hold the lens on, then wrapped black electrical tape (very tightly like you see when you look at wires under the dash of your car) around the end of the lens and the pvc to block light and a backup for stability. I also painted the pvc black on the inside (flat) to prevent any reflection issues.

*edit I also tapered the end of the pvc slightly to allow the 35mm lens to slide into the pvc allowing for a really tight flush sitting seat.

Fred,

I think I'll just have to give that a "holy frijoles" and leave it at that. Well, almost. How did you focus that thing? Distance from lens to the GG? Crazy, I say. Crazy.

Aaron, I'm trying to determine the thread pitch of standard filters/step-rings. I found one reference on B&H to .75, but have yet to determine if that's standard. The filter companies I've visited don't list anything.

I thinking you could hack up a camera or adapter to get the body mount ring and then attach that ring to a step-up ring. Not having either item at hand at the moment I'm not sure how that would work. I'm voting for duct tape.

Fox

yes , you should take care.
T-mount exists in both version, one with 0.75mm pitch and the other with 1.mm pitch.
I got this problem when going for M42 (and obviously finding adapter from other mounts to M42 is impossible, while every mount as an dapter to use M42).
So i switch to nikon mount for my next adapter.

Does anyone know if the Nikon 6T/4T close up attachements are acrhomats? I seem to remember hearing this somewhere but I can't remember. If not it looks like I'll have to move up to a $119 Canon macro lens.

Alright found the answer to my achromat question. Next question:

Will a power of 3 diopters be enough or should I spend extra and get a 10 diopter strength macro lens? I'm using the DVx100A.

I keep leaning towards the Nikon +3 but something inside keeps holding me back. I don't want to end up with too little power. I know that +10 seems to be what has been used on other projects but I wonder if that was utilizing the full zoom?

Aaron -- don't yet know about the +10, but I did buy one of those cheaper 72mm ones off of eBay to test. I also have the equivalent of +7 in 55mm form that I will try as well. Should have everything but the +10 by this weekend. Still not sure how I'll hook up the lens, though. Grr. Arrg.

Fox

Re: Vignetting
 

<<<-- Originally posted by Kyle Cutshaw : Richard, are you seeing any vignetting with your adapter? Have you tried it on a camcorder with a 72mm lens? -->>>



I have not tied it on a 72mm. I do not get vignetting . It will depend on the cameras close up zoom .It seems to vary
between cameras

Okay, I have most of the parts now. The only thing I think I still need is the 10x macro I have on order. The 4+2+1 isn't cutting it. One question, though, how do I set the focal lenght between the 35mm lens and the GG? Do I make sure I can focus on it with the camera first and then adjust? I think I'm close just by looking at the adapter when it's off the camera, but can't tell for sure.

Also, I have an idea about attaching the lens to the ThorLabs tube -- take the set screws from the back of the C-mount adapter (remove the back, obviously), drill and thread holes in a 52mm to 58mm step-up ring and use the set screws to hold the C-mount to the ring. Worth a shot at least.

Fox

Interesting! Let us know if the c-mount to tube thing works. I'd be very interested in finding this out.

I guess I'll have to go order a +10 as well then :D

Success! With mounting the C-mount adapter to the step-up ring at least. Here's what I did:

1. Buy #2 diameter machine screws. I think I got them 3/8" long which was way plenty.

2. Drill 3 holes in the 52mm to 58mm step-up ring using a 3/32" bit.

3. Insert the screws, assemble C-mount and ring and adjust screws as needed. The screws ended up pushing the C-mount and ring apart just a bit, but it appears to be uniform all the way around so I'm not worried at the moment. I can always redrill the holes to get them more on-center and away from the slanted lip on the c-mount.

I may have to redo a couple of holes as I was a bit off-center and they might break through one side. But that's not a big deal.

Also, I bought some nuts to go with the machine screws. If they prove to come loose over time (since they basically threaded themselves as I put them in), I'll JB Welb the nuts on top of the holes to act as the threads.

It ain't pretty, but it seems to work okay. Hard to know for sure until my macro lens comes in and I can test it on the camera.

Fox

to fred finn
 

fred,

i can not go to your mentioned before page:

http://hazardousproductions.com/films/chron_frd.mov

is this moved somewhere or what?

thank you,

filip

35mm adapter parts for sale
 

Hey, hey kids. After building this adapter I've discovered that using it with a DVX100a is not the best idea due to its 72mm lens (it requires 2 +10 diopters), so I'm going to go a different route for mini35 stuff. My loss is, hopefully, your gain.

I have for sale:

- The ThorLabs 52mm tube with 3 retaining rings - $45 ($58 retail)
- The OptoSigma 50mm GG and 50mm PCLX lenses - $45 ($56 retail)
- 55mm - 52mm step-down ring - $3 ($6.95 retail)
- 52mm - 58mm step-up ring - $4 (7.95 retail)
- C-mount adapter for Canon FD lenses - $25 ($36.95 retail) (This has been drilled into and mounted onto the 52-58 step-up ring with set screws. Can still work by itself at a c-mount.)

I also have a set of +1, +2 and +4 Hoya 55mm macros if anyone is interested for $30.

I can post pix tonight or tomorrow if anyone is interested.

Fox

Jason I may be interested in the lens tube and retaining rings. I'll send you an email when I get some free time today.

BTW, what alternate route are you going?