Reason For LetusHD100 at DVinfo.net

Jack Foster · December 2nd, 2006, 05:10 PM

Hi
This is going to seem like a dumb question, why use the Letus on the JVC HD100? If the answer is because you can get a sharper image then the stock lens that comes with the camera, I understand. But all the posts I've read indicate that the sharpness is similar to the stock lens. So is it just DOF?
thanks
Jack

Solomon Chase · December 2nd, 2006, 05:37 PM

Yes, the primary purpose of these adapters (letus, brevis, redrock m2, mini35, etc) is for shallower DOF.

Also you can use some very wide lenses like 20mm, 24mm, fisheyes, etc..

Bob Hart · December 2nd, 2006, 09:04 PM

The Letus35 or any other similar adaptor enables the wider field-of-view relative to lens focal length characterstic of the larger image area formats of motion picture film to be emulated.

It does this by enabling the camera to take a picture of a picture which is the lens image projected onto a groundglass screen.

This indirect or "non-coherent" route introduces one generation of resolution loss, so any adaptor will not be as sharp as imaging direct via the camera's own lens.

This loss of sharpness if kept within reasonable limits is offset by the improved aesthetic of the image which can contain areas of very soft background and sharpness on the selected subject.

The sharpness of the subject may be measurably inferior to the direct-to-camera image but the viewer sees it differently.

Two benefits are the creative effects given by the narrow depths of field available and perspective effects which can be achieved by ultrawide lenses.

Ultrawide fields of view can be had direct-to-camera with accessory lenses.

The Letus35 for the HD100 has its own relay lens. You could use another Letus35 which does not have its own relay lens and instead use the JVC standard lens with a close-up lens on front of it.

There is some argument for using the original JVC lens for relay as it is optimsed for HD but you end up with a very long and awkward combination.

The balance of convience comes down on the side of using a device which has its own relay lens built-in to replace the JVC standard lens entirely.

Michael Fossenkemper · December 4th, 2006, 10:52 PM

what about the newer JVC HD110 or HD200 that have a flip function built in? I would really like to get the JVC camera and use a 35MM adapter on it. but I would also like to go through as little as possible as far and prisms and such.
At this point, I don't mind flipping the image in post as long as I can see it on the camera properly like with the HD110. Would the Letus in this case not be the best adapter? i don't want to tag it on the end of the stock lens, just too long.

December 2nd, 2006, 05:10 PM	#1
Jack Foster Regular Crew Join Date: Mar 2004 Location: Los Angeles Posts: 41	Reason For LetusHD100 Hi This is going to seem like a dumb question, why use the Letus on the JVC HD100? If the answer is because you can get a sharper image then the stock lens that comes with the camera, I understand. But all the posts I've read indicate that the sharpness is similar to the stock lens. So is it just DOF? thanks Jack

December 2nd, 2006, 05:37 PM	#2
Solomon Chase Regular Crew Join Date: Jan 2006 Location: Woodstock, Georgia Posts: 154	Yes, the primary purpose of these adapters (letus, brevis, redrock m2, mini35, etc) is for shallower DOF. Also you can use some very wide lenses like 20mm, 24mm, fisheyes, etc..

December 2nd, 2006, 09:04 PM	#3
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	The Letus35 or any other similar adaptor enables the wider field-of-view relative to lens focal length characterstic of the larger image area formats of motion picture film to be emulated. It does this by enabling the camera to take a picture of a picture which is the lens image projected onto a groundglass screen. This indirect or "non-coherent" route introduces one generation of resolution loss, so any adaptor will not be as sharp as imaging direct via the camera's own lens. This loss of sharpness if kept within reasonable limits is offset by the improved aesthetic of the image which can contain areas of very soft background and sharpness on the selected subject. The sharpness of the subject may be measurably inferior to the direct-to-camera image but the viewer sees it differently. Two benefits are the creative effects given by the narrow depths of field available and perspective effects which can be achieved by ultrawide lenses. Ultrawide fields of view can be had direct-to-camera with accessory lenses. The Letus35 for the HD100 has its own relay lens. You could use another Letus35 which does not have its own relay lens and instead use the JVC standard lens with a close-up lens on front of it. There is some argument for using the original JVC lens for relay as it is optimsed for HD but you end up with a very long and awkward combination. The balance of convience comes down on the side of using a device which has its own relay lens built-in to replace the JVC standard lens entirely.

December 4th, 2006, 10:52 PM	#4
Michael Fossenkemper Major Player Join Date: Sep 2005 Location: NYC, weeee. Posts: 417	what about the newer JVC HD110 or HD200 that have a flip function built in? I would really like to get the JVC camera and use a 35MM adapter on it. but I would also like to go through as little as possible as far and prisms and such. At this point, I don't mind flipping the image in post as long as I can see it on the camera properly like with the HD110. Would the Letus in this case not be the best adapter? i don't want to tag it on the end of the stock lens, just too long.