Canon Wide Attachment C-8

Post by **Aseesl8er** » Tue Feb 07, 2006 7:45 am

I have a Canon wide attachment for camera. In the instructions, it says not to use any filters with the attachment or else vignetting will occur. What's the best way to shoot E64T with this attachment if I can't use a 85B filter? I guess I can always use the built in filter. Any suggestions?

Post by **Rick Palidwor** » Tue Feb 07, 2006 9:06 am

I guess the easy solution is to use the built -in, which will be acceptable, but I am curious because I have one of these and the instructions, which came with the camera, not the lens, don't mention this, though it contains recommendations about the lens (zoom to macro, focus to infity, f4 or better). If the filter is big enough, say in a matte box, you should be okay, but I could be wrong.

Come to think of it (correcting myself on the fly), I have an 85B and if I put the C-8 on, my matte box, with my 85B, does not fit, so I don't use them together. So maybe that is an issue. I have also notice that the C-8 has no filter thread, which might be a clue.

Rick

Post by **Mitch Perkins** » Tue Feb 07, 2006 10:03 am

Rick Palidwor wrote:I guess the easy solution is to use the built -in, which will be acceptable, but I am curious because I have one of these and the instructions, which came with the camera, not the lens, don't mention this, though it contains recommendations about the lens (zoom to macro, focus to infity, f4 or better). If the filter is big enough, say in a matte box, you should be okay, but I could be wrong.

Come to think of it (correcting myself on the fly), I have an 85B and if I put the C-8 on, my matte box, with my 85B, does not fit, so I don't use them together. So maybe that is an issue. I have also notice that the C-8 has no filter thread, which might be a clue.

Rick

The instructins for the wide attachment refer to mounting filter/s behind the attachment. This would cause vignetting due to increased distance between front lens element and back of attachment.
With mattebox and large enough square filter in front of the attachment, if you don't see vignetting, it's not there.

Mitch

Post by **Justin Lovell** » Tue Feb 07, 2006 4:00 pm

Strange that they would have made it that way. If they'd made the front diameter wider maybe they could have accomidated having the filter on the front diameter of the lens

Post by **Mitch Perkins** » Tue Feb 07, 2006 7:56 pm

jusetan wrote:Strange that they would have made it that way. If they'd made the front diameter wider maybe they could have accomidated having the filter on the front diameter of the lens

Also, as Rick points out, there are no threads up front for mounting purposes. We just looked at it two minutes ago - removal/replacement of front retainer ring with a lower profile retainer would leave some threads exposed for filter mounting...the right tool is needed.

Mitch

Post by **Justin Lovell** » Tue Feb 07, 2006 8:58 pm

yeah, i noticed there was no screw in on the outer diameter.

Oh well.

btw mitch, I just got a new color corrector and it is providing much better results with rendition of skin tones. Comparing my frames to stuff I got back from Yale on DVD, there is no real discernable difference in the saturation of the two images. The most common problem was the saturation of skin tones in hard sunlight, no so much anymore...

Huzzah!

Post by **skahde** » Tue Feb 07, 2006 8:59 pm

Mitch Perkins wrote:the right tool is needed.

How about a large enough stepup ring and some epoxy?
Just a thought...

Stefan

Post by **Justin Lovell** » Tue Feb 07, 2006 9:01 pm

nah, here in canada duct tape and a couple really big washers'll always do the trick ;)

Post by **Mitch Perkins** » Tue Feb 07, 2006 11:48 pm

jusetan wrote:yeah, i noticed there was no screw in on the outer diameter.

Oh well.

btw mitch, I just got a new color corrector and it is providing much better results with rendition of skin tones. Comparing my frames to stuff I got back from Yale on DVD, there is no real discernable difference in the saturation of the two images. The most common problem was the saturation of skin tones in hard sunlight, no so much anymore...

Huzzah!

Huzzah is probably my favorite word. Huzzah!

I really must make some time to visit your facility. Right now we're dealing with car problems...maybe I'll crawl out there on my belly. How long do you think the trip would take if I do that?

Mitch

Post by **Mitch Perkins** » Tue Feb 07, 2006 11:57 pm

skahde wrote:
Mitch Perkins wrote:the right tool is needed.

How about a large enough stepup ring and some epoxy?
Just a thought...

Stefan

Good idea, though better to expose some threads; reduced chance of failure.

Use contact cement instead of epoxy; it's less rigid/prone to cracking/failure. Epoxy is great for "liquid rivets".

Apply small amount of cement to step-up/down ring, not wide attachment. Place ring face down and lower wide attachment carefully onto it. this reduces the chance of spilling cement onto lens. With epoxy, you're screwed if you get it on the lens, but since C8 is glass, unlike the plastic Nizo wide lens, contact cement can be allowed to tack up and rubbed off with finger.

Mitch