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-   -   5D Mark II used as 8mm Projector CMOS Pickup (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/238324-5d-mark-ii-used-8mm-projector-cmos-pickup.html)

James Miller July 2nd, 2009 03:11 AM

5D Mark II used as 8mm Projector CMOS Pickup
 
Nothing to do with filming using the 5DMK2, just thought I would tell you what I've been up to with the 5DMK2.

I was playing with a bit of telecine with some super 8mm footage recorded from a screen using the 5DMK2 at 1/50 (UK) thanks to the manual mode, to eliminate the lighting flicker from the 100w bulb. And although it did a fairly good job I though about using a lower 20 watt bulb and projecting the image directly into the 5DMK2 (without lens) straight onto the CMOS chip.

I changed the lens on the projector from the standard version on the Eumig 610D to the better 1,2 lens from my Eumig Mark DL, also allow greater control on frame throw size.

The 5DMK2 has to be positioned square on about 2 inches from the lens (depending on what crop you want), its then just a matter of focusing the projector lens onto the CMOS chip, with the ability of x10 zoom preview on the 5DMK2 you can focus on the front or back of the film.

The 12v 20w bulb was just for testing and plan on using a dimmable luxeon star led for better control. Any shutter speed above 1/50(UK) causes flicker. There will alway be a slight flicker due to the 3 blades in the projector. You could use 4x4 ND filters hung in front of the 5DMK2 to control brightness or a pair of sunglasses as I tried.

The results so far are amazing, the detail resolved from 8 & Super 8mm footage is fantastic. A real option for quick telecine over frame scanning.

You have to do a bit of post work like rotating the 180˚ but thats not a problem.

I will post some final results when the luxeon arrives.

Tom Hardwick July 2nd, 2009 04:03 AM

You're running the Eumig at 18fps, James? To remove the flicker with a three-bladed projector shutter you'll need to project at 16.67 fps and speed it up in post. Same goes for 24 fps sound stripe film.

Of course 18 film frames will be spread over 25 video frames, so a lot of them will be combination frames on the final film. You could try stopping down the f/1.2 lens with a waterhouse stop - this should give you better flat-field coverage of the 8 mm film, as well as evening up the exposure corner to corner.

tom.

James Miller July 2nd, 2009 04:18 AM

Hi Tom, Thanks for the info. I'll give the 'Waterhouse stop' a try, would I have to get the drilled aperture within the 2 lenses?.

Not sure how to get the Eumig down to 16.67fps. I know some people have used a 5 blade shutter in the Eumig, also the 5DMk2 only records at 30fps. But it's early day for me on this one. Thanks, James

Tom Hardwick July 2nd, 2009 04:34 AM

I'd try something like a matt black cardboard disc pushed carefully up against the f/1.2's front element - you have lots of spare light so that loss isn't important.

Your Eumig is probably electronically speed controlled at 18 and 24 fps, but I'm pretty sure there'll be an 'end of line' pot on the speed control PCB somewhere inside the machine.

James Miller July 2nd, 2009 10:15 AM

Hi Tom, Ok tried the disc aperture, it works well, even a crude pencil hole in a piece of card sharpens up the corners. It's easy to sandwich in from of the first element as the main lens assembly unscrews from the housing, a rebate inside the housing allows the card to sit tight.

The speed control on the eumig is all mechanical so no pentometer adjustments.

Chris Barcellos July 2nd, 2009 10:37 AM

Us Canon EOS owners are absolutely whacko, we think this camera can do anything....!!!

I would love to see some converted footage, as I have tons of 8mm stuff to mess with.

Tom Hardwick July 2nd, 2009 10:39 AM

There's certainly a lot less enthusiasm for its 30 fps this side of the water.

James Miller July 2nd, 2009 10:45 AM

1 Attachment(s)
Here is a quick grab of projected verses direct cmos capture.
10w bulb used instead of the 100w. Trying with dimmable luxeon Star led tomorrow.
Just trying to minimize the edge softness. The projected WB is out but you get the idea.

The 6mm aperture used was made using a copper 2 pence, sprayed matt black (sorry Queen)

Also, I have focused on the front of the film, should have been the emulsion, hence more scratches.

James Miller July 2nd, 2009 11:47 AM

1 Attachment(s)
Here is another frame from a different reel. (Full resolution frame exported from quicktime)

Tom Hardwick July 2nd, 2009 12:01 PM

What's interesting is that your projected image is sharper into the corners than the direct to 5D frame Also the dof of the latter means you're capturing the scratches on the substrate, and you really need a very shallow dof so that only the emulsion is sharply focused. Maybe make the hole in the washer larger. And use something very thin for this aperture so that you get as little flare as possible from the edges.

Unless the projector's gate is allowing the film to curl (which I doubt) it looks as if the fast projection lens doesn't have a very flat field. The design intent was (in 1973) to put as much light onto the centre of the screen as possible, and pretty much all else was side-stepped to get this result.

I use a Schneider Xenovaron f/1.1 zoom in my Elmo GS1200. It has a wonderfully flat field and is noticeably better than Elmo's f/1.0.

Can uoi use a macro lens on the 5D to photograph the frame directly in the projector's gate and bypass the projection lens? There are some fascinating pages here on building your own machine out of an old Eumig projector:

Construction of a home made Telecine machine

tom.

James Miller July 2nd, 2009 01:26 PM

Hi Tom, thanks for the link. Sounds like another project, the wife will be pleased. I will investigate direct recording from the gate. Extension tubes here we come!!

But at the end of the day I would be happy to watch the family movies even at this stage. They have a nice organic feel.

James Miller July 2nd, 2009 02:13 PM

3 min test footage, with current setup.
Super 8mm - Test with the 5D MK2 on Vimeo

Chris Barcellos July 2nd, 2009 04:04 PM

Very nice indeed. I am going to have to get the projector out now....maybe add tubes and ND and shoot at the gate.......

Douglas Akers July 2nd, 2009 07:44 PM

Wow, great thinking James!
This is very interesting to me. I have 8mm footage I need to digitize at high rez for a doc project.
One more reason to buy the Mk. II.
Please keep us posted on further development of your technique.

Tom Hardwick July 4th, 2009 05:26 AM

James - though it's beautifully sharp in the middle circle, outside of that the image quality falls off dramatically, so sommat's up. If you look through the 5D's v/finder you should see the same situation, so I suspect the projection lens rather than bowed film in the gate.


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