PDA

View Full Version : 35mm Adapter



J46les
04-20-2006, 01:48 AM
I'm looking to get a 35mm adapter for my DVX100a. I saw the reference post down the page however I have a few question. From what I've read I see things about the image being flipped, vibrating vs static, batteries being needed.

Can someone please take some time to educate an ignorant fellow on how these exactly work and the pros and cons of certain features. Or a link to where I can read about this sort of thing. I don't want to buy and item without really understanding it.

thanks in advance.

Kaegan
04-20-2006, 02:18 AM
I could use some help with this matter as well.

FilmMakerr
04-20-2006, 03:01 AM
I'm looking to get a 35mm adapter for my DVX100a. I saw the reference post down the page however I have a few question. From what I've read I see things about the image being flipped, vibrating vs static, batteries being needed.

Can someone please take some time to educate an ignorant fellow on how these exactly work and the pros and cons of certain features. Or a link to where I can read about this sort of thing. I don't want to buy and item without really understanding it.

thanks in advance.


Hmm, I may be wrong, but from what I've read, this is what I know.

Image being flipped means that the image you record is upside down, which you will have you flip over in post, which is why people buy external monitors.

Batteries aren't a big deal, just use regular batteries that you're television remote control uses, two most of the time.

The rest, I don't know about.

J46les
04-20-2006, 03:33 AM
I'm trying to understand why the image is flipped. What are the mechanics at work and what requires batteries? I'm looking for a overall explanation of these products.

Wayne Kinney
04-20-2006, 03:37 AM
This might explain it best:

http://www.mediachance.com/dvdlab/dof/index.htm


Upside down issue.
One biggest trouble with this setup is that the image projected on the ground glass is upside down. Of course, every photo or video lens project the image upside down, just the electronics in the camera will make it flip. But now we have 2 lenses - the 35 mm and the camera lens so the image is also recorded upside down. And because we are capturing the projection from back, it is also horizontally reversed. Well, we can't have everything these days. You can either tun the camera upside down and the image will be just horizontally flipped (and you may even make a few friends using the camera like that) or simply swallow it and turn everything the right way in post-production.
To turn the image the right way optically before the camera captures it would be troublesome You need to use a mirror to turn flip it vertically and then pentaprism or pentamirror to flip it horizontally. This is out of the reach of most home-improvement guys. Especially that these things are not easy to find in VAL-MART or Home Depot.

So for our design we will simply make it flip at post-production. The easiest way is in fact to forget the flipping right now and add a small hood and a mirror to the LCD screen of the camera so we see the image correctly during shooting.

craigbowman
04-20-2006, 03:53 AM
35mm dof adaptors 101

The lens from the camera is focused on a spinning ground glass (gg) in the case of the M2. The batteries power a small motor that spins the ground glass. The image is flipped because the lens in front of the adapter which also focuses on the gg naturally flips the image, just like the lens on a view camera. SLR cameras have a mirror which flip the image back again when using those same lenses. The mirror flips out of the way when the shutter is pressed. So put those SLR lenses in front of a gg in these adaptors, and you get a flipped image.

Certain monitors are able to flip their picture which when used with the adaptor let you see the image again right side up. There is also a technique where a small magnet can be placed at a certain spot on the camera's lcd display which will cause the lcd to flip the image as well.

So the images are actually recorded to tape flipped. You flip them back in post, (yawn).

The gg has a grain to it. The grain makes the gg semi-transparent so there is something to focus the lenses on. By spinning or vibrating the gg the grain is moved fast enough so it doesn't leave a tell tale pattern on the image. If the gg is too coarse then it will soften the image. The goal has been to make a gg with the finest of grain so there will be minimal effect on the image.

craigbowman
04-20-2006, 03:54 AM
Whoa, you slid in there as I was posting.