Canon XL-1 Relaylens (original, now merged w/ consolidated XL1 thread)

[Anders Floe]

Actually wouldn't these lenses be perfect:

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1546&search=1

or

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1281&search=1

Which size would then work to our advantage?

Thanks

[Stephen Birdsong]

I have no idea. Only real way to find out would be to buy one.

My first incling is to say no. But on second thought, if it is that wide, then maybe you could stick it less than 1 inch from the GG.

That would rock, because the length of the total lense is something that we really need to keep down.

Working distance:
The distance between a subject and the lens surface.
Field of View
the size of the image that is visible. (not to be confused with the Angle of view, which is measured both in mm's and degrees. for example a 50mm focal length is an angle of view of 45 degrees)

Im definately in over my head, but Im trying to tread water.

Im guessing that we need a minimum working distance of under 1ft and i dont understand what field of view we need.

http://www.sweeting.org/mark/lenses/

if someone else can figure it out, go for it.

anders, i just wouldnt know which lense to buy.

Stephen

[Anders Floe]

I would think that we need the widest lens, (the one with Angular FOV >43°)

But I have no idea nor the money to test several lenses!

You are right - we need help from somebody who really know optics!

Could somebody please help!!?

Thanks

[Valeriu Campan]

One type of lens I saw used in capturing the groundglass for the video taps on 35mm movie cameras is a Cosmicar brand. Don't know the model number yet.
Also, this site will give a crash course in optics and how to calculate FOV and whatever...
http://www.1394imaging.com/resources...4b2e8d354d986f

[Kevin Burnfield]

anyone done anything new with their XL1 35mm adapters???

[Stephen Birdsong]

no, I've all but given up.

stephen

[Dino Reyes]

just ask. i've built 2, now finishing up my 3rd 35mm adapter... i had accidently broke it while shooting but it gave me a chance to take it apart and do improvements...

here is a schematic that might help you envision it...
http://www.dinoreyes.com/images/lens_xl1_v4.jpg

-dr

[Kevin Burnfield]

:) it makes my brain bleed when I try and understand it, Dino.


I understood the basics of the idea back when it all started but the complications involved in doing it for an XL1 are what threw me off.

Too bad I didn't have a cheap, simple, low end camera that would make it easier but I don't . :)

[Brett Erskine]

I think this thread is going to get more popular pretty soon here with the new XL-2 coming out. I wonder if Canon will offer the camera "body only". Most likely you will have to buy it used for that.

[Stephen Birdsong]

Ok, so this is where Im stumped.

I've been experiementing with 16m cine lenses, and have had little success...

It has a great minimum focal distance, less than 3 inches from the film plane. I've been using a 1 inch lens. But its way too small, Im only able to focus on a square about 1-2 mm's wide, no bigger... going from infinity to closest focus has nearly no impact (maybe the lens is bad).

I decided to try 35mm lenses, but I dont know what focal length I need.
Obviously I need as wide and fast as possible, but I dont know how wide I need. Im afraid it will be so wide that barrel distortion will become a deterrant. Dino, have you had problems with that?

What speed/focal length have you had success with?

I dont want to spend hundreds of $$ experimenting with this only to find that it is less than desirable (plus I just bought the manual 16x lense)

Stephen Birdsong

[Kevin Burnfield]

I'm taking this resurection of the XL1 topic into the other topic that exsists already 'XL1 Progress' since this one is about the "relaylens"

[John Jay]

I know someone who successfully solved this problem

here's the theory...

a super8 film projector can focus on a screen very close to the lens and produce an image roughly the size of a 35mm transparency,

therefore the reverse is true, ie; a 35mm sized image can be projected to the size of a super8 frame

bear in mind a super8 frame is bigger than a 1/3" chip

from what I could see she had the projector lens (I think it was an F1.2 zoom from and old Canon projector) mounted into Canon 2x extender (which had the elements removed) - there was some extra tubing made to beef it all up but that is essentially it.

[Anders Floe]

I'm indeed still working on my adaptor. I just recieved the following lens for use as relay lens:

http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1281&search=1

I have yet to test it. It seems like it has to be mounted about 10 cm from the ccd chip - but then you can put the GG less than 1 cm from the lens!

So perhaps it could work - it doesn't seem to create much distortion.

I will make some tests and keep you updated! If it works it would be a way cheaper solution.

[Bob Hart]

Steven.

The 16mm motion picture camera lenses will not give you a significant advantage.

My main objective was to be able to use my specialty 35mm still-camera lenses in my case a set of old Tamrons. I had made up a c-mount adaptor for some to use on a 2/3" JVC KY-F50 camera ported into the PD150 via S/video. This was good but the Agus/Aldu option gives the advantage of the larger image size and the creative effects available as well as being able to use the long telephoto lenses and the MTO 1100mm into the PD150.

It would seem you've done most of the hard yards so the jump to 35mm still-camera lenses may not be as difficult as you may think. The 35mm frame resolution off the GG must improve over that of a 16mm image frame as it needs to be magnified less.

[Stephen Birdsong]

I was referring to the relay lens. I've attempted using 16mm cine lenses as the relay lens. Im not sure if I understood your post completely...

I'm simply stuck at being able to fill the frame with the gg image.

Dino, what is your suggestion to my previous post?