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-   -   Brevis35 XH-A1 footage! (https://www.dvinfo.net/forum/canon-xh-series-hdv-camcorders/81214-brevis35-xh-a1-footage.html)

Dennis Wood December 7th, 2006 04:49 PM

Brevis35 XH-A1 footage!
 
Here's a clip featuring my favourite subject :-) I've included audio straight from the XH-A1 onboard mic which is set at the camera defaults. The mic is about 2 inches above and 1 inch back from the adapter and the adapter of course is running. We've been working on making the adapter verrry quiet.

104 MB full frame HD, 10K Kbps wmv
52 MB half frame HD, 5K Kbps wmv

The 50mm Canon FD f1.4 lens is set at f2.8. The camera settings varied from f2.4 to f8. The Brevis is using our prototype CINEFUSE 3 imaging element (diffuser).

EDIT: The chromatic aberration on the man's hair is the A1! Here's a clip. I guess the lesson here, is that if you're worried about CA, don't shoot at f2.4 !!

Alex Leith December 7th, 2006 06:18 PM

Very nice quality on the footage. Imperceptibly quite too. Great stuff!

Dennis Wood December 7th, 2006 07:08 PM

Thanks Alex. Did I mention how much I like this cam? ... scurries off to config another raid 0 array ... :-)

Yasser Kassana December 7th, 2006 07:17 PM

8 Windows for free!

Nice footage. nice to know it works. Would love to see it outside.

Dennis Wood December 7th, 2006 07:26 PM

Well, it's -22C (wind chill in) right now. How badly do you want that footage?

Chris Barcellos December 7th, 2006 07:46 PM

Great looking, Dennis. So I still need to know if this works with the FX1 without adding an extension tube.... Have you had someone run it with FX1 yet ?

Dennis Wood December 7th, 2006 08:03 PM

The Sony HD cams are right on the edge in terms of proper framing/focus. A small extension (20mm) gives them plenty of room to zoom in, but rather then do that, we're simply manufacturing a second specification of achromats for this application...about 10 weeks or so.

Wes Green recently finished a series for Nike Australia using the standard diffuser and achormat..they are posted as "Athlete Stories" on the Nike Australia and New Zealand sites. Due to the site design, I can't provide direct links...you have to navigate there from this. At this point, there's a fair number of FX1 Brevis users.

Jack Jenkins December 7th, 2006 09:55 PM

Sorry if this is a silly question, but what is the cinfuser doing exactly?

Insung Hwang December 8th, 2006 02:50 AM

Looks a tad soft. Any thoughts?

Is it the focus? Or is it the adaptor?

Dennis Wood December 8th, 2006 10:25 AM

It's not soft....look carefully at what is in focus, and what is not. You bring up a good point on effective use of DOF though. I should have stopped down the 50mm until his whole face was in focus...not just his cheeks...that's too shallow. His nose is long!

Also, I've demonstrated that the chromatic aberration on the man's hair is the A1! Here's a clip. I guess the lesson here, is that if you're worried about CA, don't shoot at f2.4 !! I'll have to redo this stopped down a bit. The Christmas tree was shot at f8 or so on the A1...so no CA, and sharper.

Chris Barcellos December 8th, 2006 11:10 AM

Quote:

Originally Posted by Dennis Wood
The Sony HD cams are right on the edge in terms of proper framing/focus. A small extension (20mm) gives them plenty of room to zoom in, but rather then do that, we're simply manufacturing a second specification of achromats for this application...about 10 weeks or so.

Hmmmm. Only 20 mm ?? Using your Achromat, I've tried moving closer than 120mm and start losing focus if zoomed to avoid the vignetting showing up on my Micro35 adapter. I assumed the same thing would occur with the Brevis and I would need that type of extension. Is there additional optics involved with the Brevis that allow that ? If not, I must be doing something wrong. I will do further testing and look at some alignment issues.

Dennis Wood December 8th, 2006 11:19 AM

The Brevis is a whole different application..and yes there are optics differences for sure. Really there are so many variables at play given camera close focus distances, condenser performance, image size, light efficiency, edge falloff in our application etc. etc. that I could not possibly predict what distances a DIY adapter would use. For example, if your effective image size is a lot smaller than 24x36 (which is possible if edge falloff is high) then you need a lot more magnification than the Brevis does...and all the variables shuffle about.

Chris Barcellos December 8th, 2006 11:36 AM

Okay, got ya. But my experience with this in working with mine says that if I cover to the edges of the vignetting from the prime lens itself, in my zoom, through your achromat, I would should not experience anything different than you do. I do know that my prime lens actually focuses through infinity a bit, so I am going to adjust distance of prime from ground glass, and that could enlarge the effective area of the image. I'm guessing that is my problem, along with the fact the I am training my zoom a bit above the center of the image circle. Those two things will likely make a big difference.

Dennis Wood December 8th, 2006 08:42 PM

Chris, try this. Cut a frame 24x36 frame from a piece of black bristol board or something like it, and mount it just behind your GG (on the camera side), centered over the projected image. Zoom out a bit, so your frame edges are visible, then grab a frame and email it to me. Usable image size will have the largest impact on the relationship between the camera, achromat and GG distance. I started out with a few spinners of my own, and found the usable image size was far less than 24x36 due to edge falloff. That might explain why you're spaced so far back...120mm is much further back than anyone has used on the Brevis. As you pointed out, not having the image centered will require even more zoom in.

Jack, sorry I missed your question. The diffuser (we call them CINEFUSE 1, 2, and 3) are the diffuser elements in the adapter. They are the component that actually images the 35mm lens..and therefore the heart of the adapter. They function as a ground glass would. Like changing film in a camera, swapping out the diffuser changes the image properties and light efficiency of the unit.

John Huling December 9th, 2006 06:34 AM

50mm Lens on Canon A1?
 
Probably kind of a dumb question... but I keep reading Canon XH A1 users saying they used a Canon 50mm lens. The lenses are interchangeable. So are they referring to the Fixed lens being set at 50mm?


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