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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Everything you wanted to know about the EPIC Canon Mount

Jarred Land said:
The Tokina 11-16 works.. although it clips at full 5K on the edges below 14mm.
Click to expand...

Here's a frame grab at 11mm from a recent shoot I did. I didn't notice any vignetting. What you see at the bottom right corner is the door jam and the bottom left is an adjacent hallway. All the other corners seem clean to me? This was 5K FF too. Jeff Kilgroe was there, maybe he remembers something different, haha. EDIT: I should clarify that we were using the Duclos 11-16, not the Tokina. Same lens, just re-housed and PL mounted. Maybe that has something to do with it....

Screenshot2011-09-01at93816PM.png


EDIT: Here's another shot we did at 11mm. Much better example.

Screenshot2011-09-01at94208PM.png
 
Jonathan Stevenson said:
Here's a frame grab at 11mm from a recent shoot I did. I didn't notice any vignetting. What you see at the bottom right corner is the door jam and the bottom left is a second door jam. All the other corners seem clean to me? This was 5K FF too.

Screenshot2011-09-01at93011PM.png
Click to expand...

Thanks for posting this, Jonathan. I just bought the Tokina 11-16mm for my Epic and I would be pretty bummed if it turned into a 14-16mm.
 
Julio Quintana said:
Thanks for posting this, Jonathan. I just bought the Tokina 11-16mm for my Epic and I would be pretty bummed if it turned into a 14-16mm.
Click to expand...

I changed the grabs in my post. I scrubbed through that shot and found that I had pushed in a smidge on one take, so I reposted where it was at its widest. Also added another grab. Seems clean to me, however I would certainly think that Jarred knows more than me. He's spent a little more time around Epics than I have!

Also, to clarify, we were using the Duclos 11-16 (modified Tokina 11-16), so maybe the modification changes something about the image circle?
 
sorry guys my bad.. I thought you were talking about the Tokina 11-16 still lens with canon mount here, I didn't know you were talking about rehoused lenses.. I can't answer that one.
 
Jarred Land said:
sorry guys my bad.. I thought you were talking about the Tokina 11-16 still lens with canon mount here, I didn't know you were talking about rehoused lenses.. I can't answer that one.
Click to expand...

My fault. I posted the pics and then remembered that we used the Duclos version, not the original. I didn't think there would be a difference between the image circle on the two. But it makes sense that the PL mount could have different characteristics than the unmodified original... The plot thickens!
 
I was talking about the Canon version:

Tokina11-16mm_Epic5KFF_framing.jpg


That's a quick still taken with my Canon 5D MkII and the Tokina 11-16mm set to 11mm and f2.8 (wide open) with guidelines showing what I calculated to be the Epic sensor size at 5KFF (5120x2700 pixels).

It's always possible my numbers are off so if someone who knows for sure can confirm them I'd appreciate it:

The Canon 5D MkII's active sensor area is listed as 35.8mm x 23.9mm with pixel dimensions of 5616x3744.

The Epic's active sensor area is listed as 27.65mm x 14.58mm with pixel dimensions of 5120x2700 (pixel pitch of 0.0054mm, assuming no space between them).

Based on that I created framing guides in Photoshop of 730 pixels from top and bottom of the 5D frame, and 639 pixels from the sides, to give the Epic 5KFF guidelines.

Incidentally I also calculated the Red One active sensor maximum for 4K to be 24.192mm x 10.368mm with pixel dimensions of 4096x2304 (pixel pitch of 0.0054mm).

That gave me (using the 5D frame again) 1060 pixels from top and bottom of frame and 910 pixels from the sides.

Whew!

Anyway, based on those dimensions (with the Epic 5KFF guidelines shown in my picture above as I understand them to be) the Tokina 11-16mm wide open at f2.8 gives just the slightest vignetting at 5KFF and essentially none at 5K 2.40:1. Stop down a bit or change to 4K or 4.5K 2.40:1 and there should be no vignetting at all.

Lastly, bear in mind that with the Epic sensor actually exceeding that of Super35 in dimensions, an 11mm lens effectively looks like a 10mm or 9mm lens on the full 5K image. So even if my calculations are a bit off, I'm confident that the 11mm end of the Tokina is more than useable for all but the most extreme of wide angle shots (where you could use Sigma's 8-16mm lens if you wanted to stay with DSLR stills lenses).

Hope this helps (and please, check my calculations and let me know if I'm off)!

Cheers from Tokyo,

Paul :)
 
Matthias Hutter said:
@Paul: Don't forget that vignetting changes with subject/focus distance too.
Click to expand...
True, but it will likely not be very much and given the usual usage of an ultra-wide lens I'm not too worried. For reference the camera bag in my image is under 1m away from my camera position.

Cheers!

Paul :)
 
Great work Paul.. you pretty much nailed it. Its actually a little less visible than your image depicts. The Vignette isn't as hard as you show in your simulation. Since I have all the pieces here its probably just easier for me to go take a shot and post it.
 
Tokina 11-16mm on EPIC with Canon Mount full 5K frame ( 5120x2700 )

1315005769.jpg
 
Jarred Land said:
Great work Paul.. you pretty much nailed it. Its actually a little less visible than your image depicts. The Vignette isn't as hard as you show in your simulation. Since I have all the pieces here its probably just easier for me to go take a shot and post it.
Click to expand...
Thanks Jarred! Glad that my maths wasn't way off! :D

Can't wait to have the Epic/Canon mount combo in hand....

Cheers from Tokyo!

Paul :)
 
yes 11mm. focus depth didn't affect things that much.
 
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