Les,

is it possible for you to send me the e-mail with the info about the adaptor you are selling? i really want to buy it.

thanks

ciao

forgot to tell my email adress.

danielaragao at gmail dot com

ciao

the system I am working on is to fit ball bearings inside the cage plate. then shaft inside of the ball bearing. pulley system on the shafts. three plates, 12 ball bearings , 4 shafts . 8 pulleys . my plan is to test parts, before I tell people to buy them . the cool part is when the focal plane is made it will be right in front of a 50mm tube .precisely in line to the c-mount and lens. this has to get to the ground glass perfectly and be focused on from the camera perfectly. the tube on the front will most likley be 1 inch it will be tightened down on the cage plate @ the focal length needed for the 50mm lens about 1.4 inches get sharp focus and tighten tube down in the cage plate . don,t try boca bearing they are no way near as good as the kbc bearings I am using. already. got a motor from surplus shed for $4.50 . I promise to give complete parts list, and part numbers when this is finished . need to find out from thor labs about connecting the system to a camera c -mount I see one for the smaller tube , but not for the 2 inch tube yet . http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=60&Product_ID=11138

http://www.thorlabs.com/NewGroupPage4.cfm?Guide=5&Category_ID=16&ObjectGroup_ID=180

I think the transition from static - ocllating parts list may look like this. 2 inch tube , 50mm ground glass ,50mm plcx 2 spacer rings
the plcx may be the only part that can,t be used in the ocillating model. the daily rental for a35mm adapter is$245.
I think when we precisly ocillate the 1500 ground glass in this cage system we can make this equal to any device for less than $500. most of the used optical parts seem to retain at least half of there value on the used market . plus we will all be on the same page when building this .

And to think, this all started with a guy, a glue gun, and some parts around the house...anyone know where Agus is these days?

Those of you ordering from Thor, are these 2" tubes 2" in diameter? I'm wondering if I can use some of these parts to update my adapter, largely based around 2" PVC and coupling parts (slightly larger than 2"). I'm wondering if I could still slip this tube over the 58mm achromat I've got...

- jim

this is the camera development wing of our museum .

http://www.dvinfo.net/media/mellor/rmtopview.jpg

http://www.dvinfo.net/media/mellor/rmfullview.jpg

http://www.dvinfo.net/media/mellor/aldu-test-44.jpg

http://www.dvinfo.net/media/mellor/35%20mm%20lens%20test.jpg

http://www.dvinfo.net/media/mellor/rmcameratop.jpg

http://www.dvinfo.net/media/mellor/rmsonywalkman.jpg

http://www.dvinfo.net/media/mellor/aldu%2035%20test%20002.jpg

jim thorlabs is in your neck of the woods over there in N.J ... maybe a road trip?

<<<-- Originally posted by Richard Mellor : this is the camera development wing of our museum . -->>>

Richard, is the mounting system you're using a part that can be purchased or did you make it?

the basic design is around this system . I have not recived all the parts yet. http://www.thorlabs.com/NewGroupPage4.cfm?Guide=5&Category_ID=16&ObjectGroup_ID=180


http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=1132&Product_ID=36117


http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=213&Product_ID=1481

these five components may be all you need for a static adapter.
As I said before I plan on using all the parts in the ocillating adapter except the plcx


http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=213&Product_ID=1481

http://www.optics-online.com/PXP.asp?PN=PXP157

http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=1132&Product_ID=36117

http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=848&Product_ID=1483

http://www.bhphotovideo.com/bnh/controller/home?O=NavBar&A=search&Q=&ci=300

The hardest, most critical part, is the part that generates the motion, and how that interfaces with the GG mounting platform.
That's where the focal plane stability is determined.
Thor labs does not have those elements, unfortunately.

The GG used is not very critical. The voodoo recipes for making your own GG aren't needed, because the motion removes the grain even if the GG has minor defects.

I am preparing a simple web page for those interested in my assembly, it will include more info and a picture of my first 3 shaft prototype that I used for the high def video I posted a while ago.
I'm going to ask for a small deposit of Paypal $30/person to go ahead with the project, I don't want to invest a lot of time and parts on this and get burned with no real buyers. Before full payment, I will post a video shot with the mechanism to make sure it's good enough for the people interested. Stay tuned!

-Les

hi les i am also interested in ur mini35... i would be happy if you sent me info to dosealas at tumgorsel.com...

the last part of the cage system will be the addition of right angle lenses. to solve the upside down image problem . this is the system used to flip the image in the $10,000 mini 35 .
http://www.thorlabs.com/NewGroupPage.cfm?Guide=49&Category_ID=140&ObjectGroup_ID=142

<<<-- Originally posted by Richard Mellor : the basic design is around this system . I have not recived all the parts yet. -->>>

Thanks. Looks like you're onto a good set of parts there. My rails were too wimpy. Hopefully those will keep everything rock steady.

Keep us posted! It's encouraging to see the good progress.

Does anyone know where to find a cheap spanner wrench? Or know a good alternative? Looks like we'll be needing one.
www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=58&Product_ID=15637

Jon

hi jonny this is not a spanner wrench but it has worked for me putting in filter rings. it opens and the blades fit the filter rings .
will only work only about 3/4 inch deep . but great to have anyway.

http://www.surplusshed.com/pages/item/m1612d.html

Did a little research and for those of you building this adapter for your GL1/GL2 you may find this info helpful:

Interior diameter of the 2" lens tubing from Thorlabs is 50.08mm, so 50mm UV filters (whether ground or with microwax) should be ideal.

I'm unsure but proceeding in ordering and testing the theory that I can run a 58mm to 49mm step-down ring from the front of my Century Optics achromatic diopter at the front of the GL1. My hope is that, given that 49mm is the closest standard diameter to the 2" tubing, my adapter will flow like this:

1) +7 CE Achromat (http://www.centuryoptics.com/products/dv/diopters/diopters.htm)
2) 58mm to 49mm step-down ring (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=98914&is=REG)
3) 2" external thread coupler (http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=848&Product_ID=1485) joining the step-down ring to the 2" dia. tubing
4) 3" deep, 2" diameter tubing (http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=213&Product_ID=11703), with an extra retainer ring (http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=848&Product_ID=1483) and two 49mm UV filters (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=23714&is=REG) with microwax sandwiched between them inside
5) Adjustable focusing element (http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=214&Product_ID=1486) (to set proper FFL)
6) F-to-C mount adapter (http://www.uniquephoto.com/index.php?parents=&expand=5775&page=6&startid=144&detail=C2VLANICJ) (B&H is currently out of stock)
7) Nikon F-series lens (f/1.4 or faster, used)

The entire rig will be held in place with this device (http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=126662&is=REG) which I've purchased and am very pleased with.

For those of you going the Thorlabs way, how do you intend to keep the focusing element in place once proper FFL is set? What's your rigging secret for that? :D

Thanks to everyone for the Thorlabs info, BTW -- the end product will be greatly enhanced by their stuff.

- jim

Hi jim this is a picture of a static adapter I made with lens tubes. the plcx will be replaced with a circular plcx.I think all that would be needed is camera lens to c-mount to tube then insert retaing ring ground glass next adjust retaing ring untill correct focal length then plcx and then
retaing ring the problem with the filter tube version was I could not get the focal length perfect . not enough adjustment in retaing ring, and the plcx would not fit directly on the ground glass .


http://www.dvinfo.net/media/mellor/aldu-test-44.jpg

the problem with the filter tube version was I could not get the focal length perfect . not enough adjustment in retaing ring, and the plcx would not fit directly on the ground glass .

Richard,

I can't get your link to show an image, unfortunately.

WRT to the focal length problem, my thoughts are that I will use the retainer rings to place the GG inside the tube at an appropriate distance from the achromat at the front of my camera, and also from the rear of my 35mm lens. Then, using the adjustable focus element from Thor, adjust flange focal length.

For the moment, I've got my GG sitting inside PVC coupling measuring about 3" deep, with the GG about 1 inch from the front (where the 35mm lens goes), 2" from the back (where the achromat is inserted.) I've manually adjusted ffl simply by moving my 35mm lens element forward or back, eyeballing for the sweet spot. I bet the adjustable focal element will make this task that much more precise, but the problem then becomes -- how do I keep it from moving once it's in the right place? Attaching a slip ring to the adjustable segment isn't the answer -- it will always be able to move in one direction. I guess I've got to build something special...

- jim

"For those of you going the Thorlabs way, how do you intend to keep the focusing element in place once proper FFL is set? What's your rigging secret for that?"

I checked out the lens support you want to use...If you decide to switch to traditional rail system instead you could solve the above problem the same way they support long telephotos in film. Simply tighting down on the hardware that goes between the rails and the lens itself. Heres a picture of one system: http://www.members.optusnet.com.au/mike.k/jpg/lens_2.jpg

hi everyone I just fixed the link. as you can see in the picture just thread retainer ring and ground glass untill you get sharp focus, then plcx on top and retaining ring.

I am going to try and build a rail system from these parts too this is what 1 of the parts might look like.

http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=179&Product_ID=26353


this is a still from the static adapter made with filter tube . can,t get sharp focus.

http://www.dvinfo.net/media/mellor/PDVD_540.BMP

Jim,
I looks to me like the outside of the SM2V10 is threaded, so that when you tighten the included locknut down against the static part it will secure itself. Maybe I'm seeing the tech drawings wrong. I do think the combination of those two parts will be a great setup.

On another note: I own a DVX100A and am wondering whether a 72-49mm stepdown setup would be unheard of. My concern is that it will it cause vignetting? Looking at James Webb's set up below, he goes from 72-55 with little or no vignetting, but is 49 pushing it?

www.enormousapparatus.com/images/StaticAdapter_JWebb_03.jpg

Thanks everyone for your help
Jon

funny if you look real close at the overpriced arri system in bretts photo . you will see this part in the sale dept at thorlabs.

http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=115&Product_ID=27061


I guess this and a few other parts and you have a rail system.

http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=858&Product_ID=26756


I found this one it's more money but it is as long as a key board.

http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=858&Product_ID=31705

On another note: I own a DVX100A and am wondering whether a 72-49mm stepdown setup would be unheard of.

You'd have to step down in two stages. 62mm to 49mm is the biggest leap, I believe, so find yourself a 72 to 62 and you're set.

I looks to me like the outside of the SM2V10 is threaded, so that when you tighten the included locknut down against the static part it will secure itself.

Indeed it does -- thanks for the eye-opener!

- jim

I think the distance from the c-mount to ground glass is just around 1 1/2 inches to focal point . it may be just right to fit between c-mount and ground glass. this would be a dream to get super sharp focus on the ground glass. this may be all that's needed to make a static adapter . I am not going to buy it because it won't work in my ocillating adapter.I think the front will be 1 inch tube. in side cage plate. and make the focal adjustment from there.

http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=214&Product_ID=1486

You gotta work on your coding skillz, Richard :D

All these Thorlab parts and great quality and affordable. Its probably the way to go for most people but its important to keep in mind two things when using these parts:

1)Your no longer using a 15mm rail system so your missing out on important parts you will need later like a follow focus, powered zoom motor, etc.

2)Because the largest tube is only 2" wide you will not be able to make a adapter that works with medium format lenses. As mentioned before using medium format lenses has two benifits. One the GG is much larger and so is the projected image so the grain and softness of the image is greatly reduced. Second - You dont need to zoom in on your video cameras built in lens to frame up the picture on the GG so this means your shooting with a wider f/stop (brighter and better in low light - already a problem with these adapters). You also should be able to get away with not using a close up diopter which means you save some money there and have a even sharper picture yet again.

Of coarse if you plan on only shooting with cine lenses for their focus ability then a medium format adapter is a waste of time and your better off in many ways to use the great parts from Thorlab but if you want the ability and benifits of using any format lens from a cine lens, 35mm still and even a medium format lens then a medium format adapter is the way to go but keep in mind most of these Thorlab parts wont be useable.

Personally I've noticed what I feel is too much softness in most of the clips posted on here. Thats just me though. Never the less thats why I've been looking into doing a medium format adapter. Just laying out the options for everyone. Anyways things are looking good. The quality of the adapters are looking great now. Lets keep this going.

-Brett Erskine
www.CinematographerReels.com

hi brett I sent away some time ago for the demo dvd from ps teknik and they tested there system on the three major hd cameras
and all the great lenses they did ab testing with and without the mini35,and that is when I wanted to make one of these. rai orz has given us drawings that layout a design, that promises to be as good as the device I saw in the test dvd. we are so close. the parts in thorlabs must be 90 % of what is needed to finish this.
if you have any parts that you could recomend for the vibrating plate: counter balance, offset bearings I think we could finish this . I think the key is the machined tolerences of the thorlab parts . the tube from the camera lens to the slr lens must be perfect . that can be done . we just need to ocillate a ground glass plate in the middle of this system. I spoke to thorlabs
customer service ,and they said making the part do what we wanted to do was no problem. I explained the indie camera market. and hope they will return my call .

I have the same DVD. They make a demo DVD for their HD setup and another DVD shows off the MiniDV adapter.

There is no doubt that P+S Technik shows the highest sharpness of all the adapters - homemade or not. At the same time its a fact that you loose apparent resolution whenever you use any mini35. The homemade adapters can be close to the mini35 at best and at the same time I've heard HD shooters make a choice not to use a Pro35 due to the overly soft footage. I think the softness issue is one of those things that generally goes unnoticed because we dont know what were missing. But then again maybe Im being just too picky.

How many of you want to use the adapter for HD ? For SD, I think my previous video sample of my oscillating adapter clearly showed that it maintains pretty much all of the 720P HD resolution. It certainly would not decrease the sharpness of SD because the limiting factor with SD is the SD format itself ( 720 pixels across ).

Just some observations from my first version!

-Les

i really need this adaptor for HD shooting with my HD10U

bye les, good work, and try to give us info about it as soon as possible

thanks

ciao

Again I dont want to force any bias or step on any toes. Instead just throwing out an alternative to consider. I've been working on this project since the beginning of these threads (and then some). In doing so I've gone down many paths (some great and some very costly) - always posting the good and bad here for everyone to benefit from. Very early on I first turn people towards using things like achromat diopters, focus tubes, PCX lenses and filter rings as parts so before you discount what I say this time lets instead post some unaltered "with" and "without adapter" screen shots of the same scene. It's all about the characteristics of the GG one chooses to use. They are all different. Grains not the only factor. How much it diffuses the light is important too. Too much and the image becomes softer and the highlights tend to glow noticeably. One thing is for sure though. Any short comings of your GG will be reduced by a factor of about 4 times if you step up to a piece of GG that is 4 times as large.

Absolutely Bret.
Grain is only one factor. The diffusion of the light, due to scattering, can reduce the sharpness of the image.
Grain is a non issue for moving GG systems.

A simple test for sharpness, lets say for HD: Resize the HD video to SD resolution, then upsize it back to HD . If the result is looking the same as the original HD , then you had no detail in the HD sized image that was actually at the HD detail level.

In other words, if you are able to re-sample the HD to a lower res, and effectively cut the potential high frequency detail out, and size it up again, it should look softer than the original HD.

These concepts are hard to describe in words, I think.

If anyone mistakes the test video I shot for SD , then I'd like to see that SD video camera! While it may loose a bit of detail on HD, those high frequency details don't even exist in SD.

A more extreme example: If we make an adapter for an IMAX camera, and it looses a very tiny bit of detail on the IMAX screen, the same adapter used with a SD video camera ( SD = web cam in my book ) , it won't show any loss of detail in the SD world. ( assume same GG image plane size used for intermediate image )

GG for moving adapters should have minimal diffusion. Bigger GG is always better for that. The engineering question is where the diminishing returns are.

Next time I test my setup, I'll shoot a res chart, with and without. Both in SD and HD.
-Les

Les do you have a HD camera or a HDV camera. I want to know how compressed the example we look at will be. Anyways thanks for checking into the GG issue. Look forward to seeing them.

well the mini35 is a product that gives and takes at the same time. you get shallow depth of field but lose some sharpness
when 35mm ccd chip become the norm no one will use any of these devices. but for the next three years the current options.

use nothing. and have no ability
to create a shallow depth of field .

buy a$10,000 ps tecknik.


finish project and have a under $500 ps tecknik clone .

people that have not seen the test dvd from ps technik. can judge for there selves. here are some still from there first model
http://www.pstechnik.de/sheets/downloads/focus_pull.pdf


this project is 90% complete with a source for the ocillating plate fitted in this cage it will be finished. we will have grainless capture up to hi def , and the members here will have a parts list to build one of there own , from thorlabs cage system and tubes.





I think the look that it gives to video is well worth it.

this whole category {alternative imaging} started with towards a film look that is what brought most of us here .how to help video look more like film . one of the last components of this was

the holy film look, shallow depth of field. the only device that
could do this was $10,000 . people would pay it to create .
bokeh.bokeh is sometimes an addiction in the art world , and
I agree .I see more and more tv using the film looks and I think it's getting better. our 50mm canon and nikon normal lenses are considered the best lenses to capture this look . I think this is a worthwhile project and worthy of our efforts.

http://www.photo.net/mjohnston/column49/


I am most interested in the trees.

tough bikers against a green velvet blanket

http://www.dvinfo.net/media/mellor/PDVD_540.BMP

Richard-
Very interesting link! I completely understand and a big fan of the Boken approach to photography. At the same time I know I want to at least start each project with a clean slate. In other words work with a camera that starts with images that are (for the lack of better words) "irreversibly bias". If I want a soft look for one project I'll throw a filter on the front of the lens and take it off for another - instead of working with a camera as if that same filter is permanently mounted inside the camera. Again thats just me being picky. I think for anyone thats doent feel its wourth the extra effort to go after that last 10% in quality I would say that the Thorlab/static adapter is the best design so far. Its made up of tough, precision parts that are easy and quick to build so definately the way to go.

Brett: It's a JVC HDV camera. It's video holds up well at about 8 megabit media 9 compression.

Richard: How much is Thor charging for the eccentric shafts ?

Brett: You mention the tough, precision parts that Thor makes. Maybe I missed it, but where are the parts that.... ummm .... move ? ( the heart of the matter, as you know ! )

-Les

Les-
You must have misunderstood. What I meant by tough precision parts was not moving (ie. oscillating parts) but parts that are strong and accurately made parts. ;-)

Sorry I had to say it. Im only messing with you. Seriously though these parts like the focus tube are precision pieces (unlike the PVC plastic tubes used before). Its important to keep things from shaking around at all because flange focal lengths are measured in fractions of a mm.

As far as the current issue with the oscillating parts I'm still using the micro offset shafts that I told you about awhile back. Its posted a few pages back. They are basically two small threaded shafts spot welded together to create one offset shaft. I'm still trying to find the same part ready made though. No luck. Beyond that my oscillating mechanism looks and acts the same as the P+S Technik. Variable speed control, tally light and camera battery powered. Im having a optical engineer look over my setup to make a calibrated field lens right now. Its a lot like your first one. Have you made some changes? Well thats about it. Let me know if you have any questions.

hi.. i have also been studying for a while now..i have come to production level..i have made protypes pf the mills..and the metal parts of the tool are now being cut with laser cutters...this is the second protype we have made the first was very big and the design had faults..this one is improved..it has a 2.5 milimeter radius of the revolving ground glass..i thought that the multiple of the daimeter and speed of revolution is stable..so i increased the diameter to 2.5 milimeter, this was i will increase the revoltion speed and with it decreasing the sound..the bearing and mills where produced with a 0,001 +- mm sensitivty..this way decreasing vibration...i am expecting vibration in levels of not recognizing..but if there will be noticible vibration..counter weights will be added...i have tested the system stablely with a large format and a medium format beatie screen..i have found that the medium format gives better sharpness due to its finer structure...as soon as i compile the tool i will test with both..i have tried dozens of other galss but all seem to reduce f-stops in a great amount..the beatie screens are a miracle..(many thanx to mr.fresnel)..i will plan th motor power and speed later, it is easier to do than to calculate weights and friction..of course i have not entered the subject of turning the image around...i belive using to many parts other than gg will decrease quality, and increase the number of paramteres of a perfect image..i am planing to get an external lcd screen and simply rotate it..of course post production will fix what is on the tape...i have done some stable shots with the screen and pentax 1.1.2 lens.....since i have not put the thing together yet i have not been able to take mobile shots...the lens will be screwed on with a premounted c-mount, and will be screwed on to the camera (trv-940) with the 37mm diameter screw..of course we have designed the
platform which holds the whole thing which is aprox. 1.5 kilograms in maxiumum...

here are some links to the process:

http://www.tumgorsel.com/dosealas/dodo35/dodo.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo2.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo3.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo4.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo5.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo35-1.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo35-2.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo35-3.jpg
http://www.tumgorsel.com/dosealas/dodo35/dodo35-4.jpg

great work dogus. your design looks great.

could you tell me the diameter of your eccentric shaft .

the outer diameter is 10mm and inner is 5 mm..which makes a 2.5 mm diamterer of motion...
( the measurments of the mill on dodo35-4.jpg picture)

so it looks like the inner diameter of the ball bearing is 10mm . what would the outtside of the ball bearing be .

the diameters are inner outer

big bearing ... 10 19
small bearing .. 5 16

Jim, Richard, Dogus, Les, Brett, etc., etc... i've been off the thread for a bit but you all have great new ideas and links to quality parts guys that i couldn't find previously. i'm very impressed. a couple of questions...

Dogus, what type of motor are you using in your schematics, looks like a low voltage Radio Shack type motor(?)

Jim, as far as parts, i'm looking at 52mm fittings, it would only seem right that the 2" lens tubes from Thorlabs you showed probably would work on 52, but it might be you are using 49mm type of housings for the inside(?)

Richard, also thanks for your great efforts also and your recco's and links to boot. i'm having some trouble visually seeing how the "oscilating glass" works, but i'm VERY interested in seeing if i can improve sturdyness and quality even more. would it be possible if you could give me another example that might help me understand more.

Les, i've had some success with the lens adapters i've made so far, i am also interested in the quality you've achieved so far, could you send me a link to your video tests so far??? please send to dinor@hotmail.com

tkx all...

Dino, link emailed. Send me your comments.

Dogus: I can't wait to see your sample video too, gook luck with your project! Please keep the video high quality as far as compression, if and when you post. Stills of the video are useless to see whats going on, as you know.
-Les

I spent some time with this. And I think this is going to work perfectly. great job

Jim, as far as parts, i'm looking at 52mm fittings, it would only seem right that the 2" lens tubes from Thorlabs you showed probably would work on 52, but it might be you are using 49mm type of housings for the inside(?)

Dino,

I'm unsure about the fittings of the parts. I've gone ahead and ordered the coupling because my best guess is that:

Given that the tubing is 2", with an interior diameter of 50.08mm, threaded on the inside, I will at the very least need an externally threaded coupler to attach the tubing to a filter or step-down ring. That said, 49mm is the closest from among the choices of standardized camera parts to 50mm. So, it's my best guess that this setup should work. Consequently, I'd also bet that 52mm parts will be too big -- nevermind the fact that the tubing is threaded on the interior side.

My parts have already shipped, and are due to arrive on Tuesday -- I'll let all here know right away as to my success or incorrect guesses :D

- jim

I found a c- mount adapter for the 1 inch tube but don't know about the 2 inch tube yet.

http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=217&Product_ID=1454

Dino great geat work! We're on the same page - design and medium format wise. I've been pulling my hair out trying to find offset shafts like yours. You said you had them custom milled. If possible, could you quote me a price to have four more made and sent to me? Drop me a email and I'll send you my phone number.
(berskine@mail.com)

Also I noticed you were using a Beatie screen w/ grid markings. I take it that they have no effect on the image once the GG is in motion. The second issue that is surprising to me is your using a focusing screen with the fresnel and GG as one piece. I tried this and encounted a problem and wondered if you have yet to test it and if so how you got over the following issue:

As we all know fresnels exist on one side of focusing screens because it helps reduce the issue of having a hot spot in the middle. It does this by bending/colminating the light to a point - the point where your eye, or in this case CCD is located. Sounds good but put that same focusing screen in a oscillating motion and you move more than the GG. You move the fresnel around right there with it. This causes a problem because that point the fresnel is focusing the light is shifing all over the place - moving to and away from its intended target (the CCD sensor) because the focusing screen and CCD are moving independant of each other. The effect is you begin to see the problem of light fall off show up again. If you turn it very slowly you will see one edge of the frame bright and clear while the other side the light is falling off. Now put it in fast motion and it appears as if only the center of the frame is bright. I hope that makes sense.

So Dino did you see this effect too? If so what are you doing to get around it? Personally I'm fixing the problem by making the GG and the fresnel seperate pieces so that the fresnel is static and always in line with the CCD while only the GG moves. Then I took the idea one step further. I knew that frenels dont produce images that are as optically clear as a traditional lens so I plan on replacing it with one or possibly two field lenses (PCX).

Thats where Im at right now. I'm working with a camera optical engineer to help me find the proper field lens(es) to take over the job of the fresnel lens to produce the ultimate in picture quality.

P.S. Let me know if your interested in a source for custom calibrated medium format screens without gride lines.