Consolidated XL1 35mm Adapter Thread

[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]

Let's start with the basics:

Adapter and Acromatic Diopter options.

That's the basic starting point for the majority of Aldu / Aldus option. Get that so you can view the image on the ground glass (spinning or otherwise).

what works, what doesn't work?

I'd be happily resolved to a spinning GG if I had to be and figure out a nice looking little box line the P&S unit... if there were a simple, basic option.

[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?

[Bob Hart]

My apologies Steven. I misunderstood your post.

[Sarena Valilis]

hi,
i just found this forum,,,

i was working on the homebuilt mini35 when i discovered
that just a simple physical adapter worked pretty nice with
standard arriflex lenses....

i was actually in the process of making them to sell but am
waiting for the first production run to return (ten adapters)

check out www.xl1adapters.com

the sample video was shot with a schneider lens that i bought for about 50 bucks on ebay....


the problem is that you are not getting the whole frame on the ccd so a 25mm acts more like a 45mm lens...

but for a quick fix it gives nice depth of field control....



---------------

ive spent the last month and 500 dollars (a lot to me) trying to get one condenser lense that would fit inside the adapter and reduce the image to fit full screen on the ccd....

gotta check my physics, but dont think it is an easy task and i dont think i can do it with just one lens...

but i will review the forum here and see if i missed anything, then i will settle for a multi lens system...

----------


if any one sees the web page above and want the plans email me... as long as you agree not to produce it other than for yourself i will send the plans.... (that is pretty much everyone here)....

thanks,
sarena

[Brett Erskine]

Look to Ziess for help making that adapter. A few years ago they came out with one but theirs work with 2/3 inch video cameras. Never the less the concept is exactly the same.

Im pretty sure you already know this but just like with the Ziess, simply reducing the size of the image so you maintain the FOV WILL NOT maintain the same DOF. Damn I wish it did. But not all is loss. In fact when your done you'll realise it has a different, yet very useful feature, the ability to make your camera work much better in low light conditions. Yep. Just like a kid with a magnifying lens this adapter will refocus the light to a even tighter spot thus making the lens basically "faster". Hope you make it. Your probably looking for achromat lens btw. Good luck.

[Bob Hart]

I had a bit of a play once trying to make a video tap for a CP16RA using a Kampro security camera. It did work but I did not complete the hardware in its final form.

My guess is what you need is :-

A C-mount to Canon XL1 mount adaptor. I think an adaptor is made for C-Mount to B4 mount for the broadcast cameras so there may be something around already to adapt C-Mount to Canon. Fujinon might be worth an enquiry. They have a large selection of C-Mount lenses for 1/3"; 2/3"; 1" for security, machine vision and some more specialised for 3xCCD cameras.

If such an adaptor is available, then much like a 16mm motion picture camera video tap arrangement, you might be able to use a "C" mount lens with a spacer against the face where it would normally mount up to on the adaptor, to bring it forward for closer focus on the GG.

To view the 16mm film frame in a CP16RA viewfinder, a 25mm Cosmicar C-Mount lens has to be brought forward from a 1/3" CCD security camera about 1/4" to focus closer and frame the 16mm viewfinder screen. For the Aldu and a 4:3 movie frame, you might get away with a CS to C mount adaptor which is about 1/8". These are a common piece of hardware in the security industry and are just a piece of threaded nylon which is adequate in a permanent installation. You would have to sit your GG furthur away than for a 16mm viewfinder screen or use a wider C-mount lens with maybe a thicker spacer to go in closer.

To experiment without breaking banks, maybe try to find an old Sony B&W portapack video camera lens (by Tamron) This was commonly a 12x75mm zoom and is believed to have imaged onto a 2/3" tube target. This has a C-mount and in combination with spacers at the C-Mount end, and moving the zoom, you might be able to figure out the correct fixed C-Mount lens needed. There was a Canon 17x85mm zoom for early Panasonic colour tube portapack cameras which was also C-Mount but it may not go wide enough. I have seen both on ebay but they might well be found buried deep in junk in high-school basements or attics.

If you are in no hurry for a result soon, I could try this with the 1/3" Kampro and an old lens I have and report but there is no guarantee this will work for your application.

[Sarena Valilis]

check out the clips on the website i posted.... how much dof control do you want????

achromat ?? yep.... been using them.... but experimenting with different degrees of magnification... etc...

basically ive been using the ocncept of a focal reducer....(check out the telescope web sites)
the problem faced is that the focal length on the xl1 is largely
taken up inside the prism in the camera...


thus---- dont waste your money on c-mount lenses....

(as if canon didnt know this)


.....

ive seen a few of the relay lenses (rather pricey) but i was trying to keep the image going thru as few pieces of glass as possible....

i mean, why by a really expensive prime lens, the film the image thru a scratched up cd if there is another way.....

[Dino Reyes]

Stephen, let me see if i understand what your saying, i'll refer to my chart as a basic reference... just so we can talk the same language (http://www.dinoreyes.com/images/lens_xl1_v4.jpg) and excuse me if i'm being duplicitus, as you may already know what i talk about...

you'll need 2 lenses. the first the primary, mounted on the camera, closest to the ccd chips. the second lens will be your master or prime lens - both are greyed out in the schematic.

so you have mounted a 16mm lens as your primary, and your having trouble grabbing more the image area from your gg. so my first question would be are you sandwiching either a acromat or condesor lens between the gg and the primary lens? the condesor lens is cheaper the acromat is better but slightly expensive. the acromat will cost around $80 i found mine on ebay for $50. the great properties is it focuses the lens and keeps the focus tight.

the second thing, keep i mind that ccds shoot in a straight line, they don't widen out to let more light, image in. so it's important you "put" the image infront of the ccd path hence:

master lens+gg+acromat(or)condonsor lens+relaylens

is that your configurartion?

also, as for my relay, i use a 24mm f2.8, that works well. as the primary lens - i try and go a bit wider and fast if possible. you could also consider, using your 16mm as your master lens, this way you can get even more image striking the gg...

does that make any sense? hope a bit...

-dino