non vignetting teleconverter?? at DVinfo.net

John M. McCloskey · August 1st, 2007, 08:34 AM

I know there are many teleconverters for the Z1 but is there one out yet that does not vignette when pulled wide?? I am fairly sure there isnt, but would think since the camera has been out for a few years someone would try to tackle the issue of vignetting. Any suggestions under 3k would be welcomed, the 12X zoom just isnt getting it done. THX

Justin Carlson · August 1st, 2007, 03:16 PM

I'm not 100% sure but I don't think it's possible unless the glass inside the lens moves. Like a still camera SLR lens.

John M. McCloskey · August 1st, 2007, 03:49 PM

Quote:

Originally Posted by Justin Carlson

I'm not 100% sure but I don't think it's possible unless the glass inside the lens moves. Like a still camera SLR lens.

If this is the case Justin, Sounds like something Century Optics or some other lens manufacturer might need to look at. Thanks

Boyd Ostroff · August 1st, 2007, 08:02 PM

I don't think you will ever see something like this with a 72mm lens mount. In order to go full wide the conversion lens would have to be HUGE. I think the nature of teleconvertors is that they will always vignette when zoomed wide. If you have a camcorder with 37mm filter threads you might be able to put a big teleconvertor on it and zoom full wide. But I think the size (not to mention the cost) would be prohibitive for a camera like the Z1.

I have the Century optics 1.6x which is quite large and heavy, and it vignettes at about 50% zoom. I really don't see this as a limitation; if I need to do wider shots I just remove it - better not to add extra glass unless really needed.

Bob Hart · August 2nd, 2007, 03:55 AM

There is a workaround, though not ideal. It involves using a 35mm adaptor with groundglass removed and shooting the aerial image of a 35mm stills lens.

You end up shooting with the camcorder on full zoom to get inside the vignette of the relayed 35mm lens.

If it is a non-flip adaptor, then you have the issue of flipping the image in post or via Cineform capture.

This clip was shot with the Z1, home-made AGUS35 and Sigma 50mm - 500mm f4-6.3 zoom.

http://www.youtube.com/watch?v=G4rC5dVPq1s

There is a vignette evident in thid clip due to

1. operator error. - inadvertantly closed ther Sigma iris.

2. Poor build quality of my adaptor since fixed. The optical centre was off by 1.2mm which brought the left edge of the iris into the frame.

August 1st, 2007, 08:34 AM	#1
John M. McCloskey Major Player Join Date: Jun 2005 Location: West Point, MS Posts: 313	non vignetting teleconverter?? I know there are many teleconverters for the Z1 but is there one out yet that does not vignette when pulled wide?? I am fairly sure there isnt, but would think since the camera has been out for a few years someone would try to tackle the issue of vignetting. Any suggestions under 3k would be welcomed, the 12X zoom just isnt getting it done. THX

August 2nd, 2007, 03:55 AM	#5
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	There is a workaround, though not ideal. It involves using a 35mm adaptor with groundglass removed and shooting the aerial image of a 35mm stills lens. You end up shooting with the camcorder on full zoom to get inside the vignette of the relayed 35mm lens. If it is a non-flip adaptor, then you have the issue of flipping the image in post or via Cineform capture. This clip was shot with the Z1, home-made AGUS35 and Sigma 50mm - 500mm f4-6.3 zoom. http://www.youtube.com/watch?v=G4rC5dVPq1s There is a vignette evident in thid clip due to 1. operator error. - inadvertantly closed ther Sigma iris. 2. Poor build quality of my adaptor since fixed. The optical centre was off by 1.2mm which brought the left edge of the iris into the frame. Last edited by Bob Hart; August 2nd, 2007 at 04:12 AM. Reason: error

August 1st, 2007, 03:16 PM	#2
Justin Carlson Regular Crew Join Date: Oct 2006 Location: Vancouver, Canada Posts: 173	I'm not 100% sure but I don't think it's possible unless the glass inside the lens moves. Like a still camera SLR lens.

August 1st, 2007, 08:02 PM	#4
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,798	I don't think you will ever see something like this with a 72mm lens mount. In order to go full wide the conversion lens would have to be HUGE. I think the nature of teleconvertors is that they will always vignette when zoomed wide. If you have a camcorder with 37mm filter threads you might be able to put a big teleconvertor on it and zoom full wide. But I think the size (not to mention the cost) would be prohibitive for a camera like the Z1. I have the Century optics 1.6x which is quite large and heavy, and it vignettes at about 50% zoom. I really don't see this as a limitation; if I need to do wider shots I just remove it - better not to add extra glass unless really needed.