Mini35 Oscillating Ground Glass Idea - Page 15 at DVinfo.net

Go Back   DV Info Net > Special Interest Areas > Alternative Imaging Methods

Alternative Imaging Methods
DV Info Net is the birthplace of all 35mm adapters.


Reply
 
Thread Tools Search this Thread
Old October 21st, 2004, 02:26 PM   #211
Major Player
 
Join Date: Oct 2003
Location: Southern Cal-ee-for-Ni-ya
Posts: 608
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
Les Dit is offline   Reply With Quote
Old October 21st, 2004, 03:24 PM   #212
Regular Crew
 
Join Date: Apr 2004
Posts: 56
hi les i am also interested in ur mini35... i would be happy if you sent me info to dosealas at tumgorsel.com...
Dogus Aslan is offline   Reply With Quote
Old October 21st, 2004, 03:27 PM   #213
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
ocillating adapter

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...ctGroup_ID=142
Richard Mellor is offline   Reply With Quote
Old October 21st, 2004, 03:30 PM   #214
Major Player
 
Join Date: Jul 2004
Location: Phoenix, AZ - USA
Posts: 300
Re: thorlabs

<<<-- 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.
Joel Aaron is offline   Reply With Quote
Old October 21st, 2004, 03:51 PM   #215
New Boot
 
Join Date: Oct 2004
Location: Toronto
Posts: 16
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
Jonny Dee is offline   Reply With Quote
Old October 21st, 2004, 04:01 PM   #216
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
spanner

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
Richard Mellor is offline   Reply With Quote
Old October 22nd, 2004, 03:30 PM   #217
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
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
2) 58mm to 49mm step-down ring
3) 2" external thread coupler joining the step-down ring to the 2" dia. tubing
4) 3" deep, 2" diameter tubing, with an extra retainer ring and two 49mm UV filters with microwax sandwiched between them inside
5) Adjustable focusing element (to set proper FFL)
6) F-to-C mount adapter (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 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
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old October 22nd, 2004, 03:54 PM   #218
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
static adapter

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
Richard Mellor is offline   Reply With Quote
Old October 22nd, 2004, 04:21 PM   #219
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Quote:
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
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old October 22nd, 2004, 04:28 PM   #220
Major Player
 
Join Date: Dec 2003
Location: Anaheim, CA
Posts: 445
"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
Brett Erskine is offline   Reply With Quote
Old October 22nd, 2004, 05:54 PM   #221
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
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/ProductDetai...oduct_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
Richard Mellor is offline   Reply With Quote
Old October 22nd, 2004, 05:59 PM   #222
New Boot
 
Join Date: Oct 2004
Location: Toronto
Posts: 16
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
Jonny Dee is offline   Reply With Quote
Old October 22nd, 2004, 06:07 PM   #223
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
rail system

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/ProductDetai...oduct_ID=27061


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

http://www.thorlabs.com/ProductDetai...oduct_ID=26756


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

http://www.thorlabs.com/ProductDetai...oduct_ID=31705

Richard Mellor is offline   Reply With Quote
Old October 22nd, 2004, 07:42 PM   #224
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Quote:
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.

Quote:
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
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old October 22nd, 2004, 08:08 PM   #225
Major Player
 
Join Date: Nov 2003
Location: cambridge ma
Posts: 247
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/ProductDetai...roduct_ID=1486
Richard Mellor is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Special Interest Areas > Alternative Imaging Methods

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 12:10 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network