Letus35A on the HV20 at DVinfo.net

Chris Barcellos · April 10th, 2007, 09:50 PM

Here is my first attempt at footage with the Letus35A adapter. Bought the Handyman special, cleaned it up, but missed a couple things in my haste to beat the light. I posted this in HV20 section on a thread there, but didn't get into details of Letus application.

Here is download at Megaupload. It is a Windows media file:

http://www.megaupload.com/?d=4UCEHLIF

I had bought adapter rings from BH to step up to the 72mm size. You do need the achromat, but you will be able to zoom enough that you won't need a spacer or extender tube.

Mike Dulay · April 15th, 2007, 07:11 PM

Chris,

Which achromat are you using and what distance do you have from focus screen to achromat and achromat to HV20 lens? It appears to me that the zoom can only go as far as a little over 1/2 zoom to maintain focus. I had to adjust the distance with various spacers using trial and error but the picture still seems fuzzy.

Chris Barcellos · April 22nd, 2007, 01:44 AM

Hey Mike. Missed this post somehow.

I am using the 72mm achromat that came with the Letus35. I am using no spacers. I think the Letus achromat is very close to the Cinevate achromat because I took it the Letus one off, and did some experimenting with the Cinevate. I zoom actually less than 1/2 at max, but in that set up, and with my Nikon 50mm F1.4 lens on the front end, I seem to be able to zoom/focus well enought to get within any vignetting. That is not true of 24mm Canon I got, thought the vignetting is basically a fall off in brightness, and not a sharp demarcation.... I just got a Nikon Series E 100mm on recommendation of Steven Dempsy, and it appears I can fill the whole screen with that. Here is a megaupload file showing that. Its my mug, and thus I couldn't focus, but I was just testing it out:

http://www.megaupload.com/?d=GGQM8XY3

When you are zooming in, have the zoom set at low speed, so you can adjust it finely....

David Delaney · April 22nd, 2007, 09:05 AM

I wouldn't mind Dennis chiming in here about the similarities or difference in the achromat.

April 10th, 2007, 09:50 PM	#1
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	Letus35A on the HV20 Here is my first attempt at footage with the Letus35A adapter. Bought the Handyman special, cleaned it up, but missed a couple things in my haste to beat the light. I posted this in HV20 section on a thread there, but didn't get into details of Letus application. Here is download at Megaupload. It is a Windows media file: http://www.megaupload.com/?d=4UCEHLIF I had bought adapter rings from BH to step up to the 72mm size. You do need the achromat, but you will be able to zoom enough that you won't need a spacer or extender tube. __________________ Chris J. Barcellos

April 15th, 2007, 07:11 PM	#2
Mike Dulay Major Player Join Date: Mar 2007 Location: Somerville, NJ Posts: 304	How far is the achromat to focus screen and macro? Chris, Which achromat are you using and what distance do you have from focus screen to achromat and achromat to HV20 lens? It appears to me that the zoom can only go as far as a little over 1/2 zoom to maintain focus. I had to adjust the distance with various spacers using trial and error but the picture still seems fuzzy. __________________ DIY, 35mm, HV20: http://www.primitivebuteffective.net

April 22nd, 2007, 01:44 AM	#3
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	Hey Mike. Missed this post somehow. I am using the 72mm achromat that came with the Letus35. I am using no spacers. I think the Letus achromat is very close to the Cinevate achromat because I took it the Letus one off, and did some experimenting with the Cinevate. I zoom actually less than 1/2 at max, but in that set up, and with my Nikon 50mm F1.4 lens on the front end, I seem to be able to zoom/focus well enought to get within any vignetting. That is not true of 24mm Canon I got, thought the vignetting is basically a fall off in brightness, and not a sharp demarcation.... I just got a Nikon Series E 100mm on recommendation of Steven Dempsy, and it appears I can fill the whole screen with that. Here is a megaupload file showing that. Its my mug, and thus I couldn't focus, but I was just testing it out: http://www.megaupload.com/?d=GGQM8XY3 When you are zooming in, have the zoom set at low speed, so you can adjust it finely.... __________________ Chris J. Barcellos

April 22nd, 2007, 09:05 AM	#4
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	I wouldn't mind Dennis chiming in here about the similarities or difference in the achromat.