New moving ground glass mechanism

Brett Erskine · April 29th, 2005, 06:52 PM

Quote:

Originally Posted by Oscar Spier

Never really seen anything like this (I mean the organic DOF effect, not the girl)
It would be terrific on DV. Incredible, especially on B/W I think, now I reconsider to shoot B/W (not with such a lens though >3K)

Perhaps for rental?

Sarena Valilis · April 30th, 2005, 12:48 AM

Hey Dan,

is it just the lens,

or does the "Unsharp Mask applied in Corel PhotoPaint v5"
mean that a large part of the effect was in post??

Dan Diaconu · April 30th, 2005, 01:04 AM

<<<Perhaps for rental?>>>

to be honest Brett, when I will get one of those (for my soul) I will accompany it out each time (with insurance in place)
Let's get real here.. in the DV and lately HDV world, the production budgets are minuscule. Some camcorders sell for less than that lens alone... need I go on?...

<<<<<is it just the lens,?>>>>

....sadly ....yes....is just the lens.... sigh.......

Bill Porter · April 30th, 2005, 08:25 PM

Quote:

Originally Posted by Brett Erskine

A second reason why I went with MF is that for MY particular video camera I wasnt able to zoom in and focus on a 35mm sized piece of GG without the aid of some type of close up lens.

Quote:

Originally Posted by Mandy Leo

I cannot get near the GG without it going out of focus

These are just two samples of all the multitudes of writing I have seen about people saying they need a diopter/macro to be able to focus on the GG.

I disagree. What they mean to say is "I need a diopter/macro to be able to focus on the GG *if I put the GG close to my camera*"

I have been doing a lot of tests on my adapter and I've found that you can go one of two ways: You can use a diopter, or you can simply use a really long extension tube between your camcorder and your GG. The longer the tube, the more you can/must zoom in... and the more you zoom in, the smaller your camera's field of view, and therefore, less vignetting.

This second method seems to be what the Guerilla35 guys are doing too. Take a look at how long their adapter is. I ended up building basically the same thing by trial and error.

The biggest advantages to using more distance between camcorder and GG are 1) you don't need pay for diopters, and 2) you eliminate vignetting.

The biggest disadvantage to using more distance between camcorder and GG is that you have a really long adapter.

Thoughts, anyone?

Leo Mandy · April 30th, 2005, 11:01 PM

I think that you are right on the money, but the obtrusiveness of a long tube is going to be problematic - but I am going to try it anyway. If I can save $200 by including a long tube, I am going for it and seeing what happens. I will post results tomorrow.

Also, I checked out the Guerilla35.com guys and they have no pictures of the unit, how did you know they did the tube thing?

Dan Diaconu · April 30th, 2005, 11:02 PM

second that!

Oscar Spierenburg · May 1st, 2005, 08:18 AM

Using one mirror will also increase the distance and put your camera in an angle which is less clumsy to shoot with.
The mirror could even be placed after the GG, like a still camera.
I wrote this somewhere else too:
If you have a LCD screen that can be flipped and closed to the camera, you can look it when the camera is at 90 deg. I'm not sure, but maybe the image will be correct (in stead of mirrored.)

I made a drawing:
http://s01.picshome.com/c7e/setup.jpg

I think if the mirror is put after the GG (unlike the drawing) the distance to the camera will be increased, but dust on the mirror will be a bigger problem.

Bill Porter · May 1st, 2005, 08:56 AM

There are pictures of the Guerilla35 device, but you have to go into their forum to see them. Here are the shortcuts:

http://www.guerilla35.com/talk/viewtopic.php?t=8

http://www.guerilla35.com/talk/viewtopic.php?t=9

It looks to be a 52mm tube, with an SLR-format GG at the end. Looks like no condenser, either! Which if true, further backs up the notion that zooming in will get rid of vignetting.

I find my long tube a bit funny looking, sure, but if you are filming a movie, that doesn't matter at all. A steadicam-style body-mounted stabilizer is pretty darn ridiculous looking, and so it's not like a prosumer camera is small in the first place, especially when it's equipped with a huge lens hood or matte box, a big mic, an eyepiece extender, follow focus, rails, etc!

For documentary or interview work, some might think the long tube is obtrusive, but in reality, your subjects are going to react more to the fact that you have a giant camera pointed at them. The extra 2" of tube are the least of their concerns!

Thanks for the input, Dan. I'm always interested to see what you've built next.

Dan Diaconu · May 1st, 2005, 10:02 AM

funny, but... you asked for it:
yesterday I had to build a replica to this:

http://www.knightsedge.com/medieval-...apult-4804.jpg

(my younger son's school project) It does not look like much, (even now when I look at it) and it seems like one hour project but keeped us busy for 8 hours.... we are one "knight sword" away from completion.... (to everyone's luck, we are roughly 500 years away from mass distruction weapons..lol) I will keep you updated with the progress if you wish...

Leo Mandy · May 1st, 2005, 12:53 PM

Well, using my camera, to get in focus, zoom in as far as I can go - the object needs to be...wait for it...30+ inches away ( that's right, about 2.5 feet). Much too far indeed. I can't work with the tube. Oh well, had to test to be sure.

Leo Mandy · May 1st, 2005, 01:45 PM

It's also interesting that I don't see the artifacts from a static GG in the Guerilla35 footage. I wonder how they accomplished that?

Les Dit · May 1st, 2005, 02:04 PM

Mandy, most demo footage is compressed with a low bit rate to make file sizes small. ( and to hide grain !!!! ) It so happens that the first thing the compression 'throws away' is the grain. Stills are obviously useless in evaluating these adapters because you can't see fixed pattern grain in a still image.

When I post my demos I use 8 or 9 megabit data rate in Media9 to avoid this 'feature' .

Quote:

Originally Posted by Mandy Leo

It's also interesting that I don't see the artifacts from a static GG in the Guerilla35 footage. I wonder how they accomplished that?

Leo Mandy · May 1st, 2005, 02:26 PM

Ok, that sounds reasonable, but from reading the forum some other people have seen the footage first hand and they say it looks great. I guess it will be wait and see.
I wonder how they are dealing with interchangeable lenses - the focal length will have to be changed each time - unless it only works with one lens type only.

Sarena Valilis · May 1st, 2005, 07:51 PM

i dont think they are the same.... unless i am missing something...

Bill Porter · May 2nd, 2005, 12:52 PM

Quote:

Originally Posted by Mandy Leo

Well, using my camera, to get in focus, zoom in as far as I can go - the object needs to be...wait for it...30+ inches away ( that's right, about 2.5 feet). Much too far indeed. I can't work with the tube. Oh well, had to test to be sure.

Mandy,

I do not mean to zoom in as far as you can go. No way! I am talking about using SOME zoom.

For example, I put mine just at 3X zoom, then bottom out the focus and go up 15 clicks from there. That is perfect for a tube which is about 1.25" long as I recall (it's not in front of me to measure, and I have built several versions).

There is no reason to zoom in as far as you can go.

April 30th, 2005, 12:48 AM	#362
Sarena Valilis Regular Crew Join Date: Aug 2003 Location: hollywood , ca USA Posts: 38	Unsharp Mask applied in Corel PhotoPaint v5 Hey Dan, is it just the lens, or does the "Unsharp Mask applied in Corel PhotoPaint v5" mean that a large part of the effect was in post??

May 1st, 2005, 07:51 PM	#374
Sarena Valilis Regular Crew Join Date: Aug 2003 Location: hollywood , ca USA Posts: 38	back focus vs/ focal length i dont think they are the same.... unless i am missing something...

April 30th, 2005, 01:04 AM	#363
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	<<<Perhaps for rental?>>> to be honest Brett, when I will get one of those (for my soul) I will accompany it out each time (with insurance in place) Let's get real here.. in the DV and lately HDV world, the production budgets are minuscule. Some camcorders sell for less than that lens alone... need I go on?... <<<<<is it just the lens,?>>>> ....sadly ....yes....is just the lens.... sigh.......

April 30th, 2005, 11:01 PM	#365
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	I think that you are right on the money, but the obtrusiveness of a long tube is going to be problematic - but I am going to try it anyway. If I can save $200 by including a long tube, I am going for it and seeing what happens. I will post results tomorrow. Also, I checked out the Guerilla35.com guys and they have no pictures of the unit, how did you know they did the tube thing?

April 30th, 2005, 11:02 PM	#366
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	second that!

May 1st, 2005, 08:18 AM	#367
Oscar Spierenburg Major Player Join Date: Jan 2005 Location: (The Netherlands - Belgium) Posts: 735	Using one mirror will also increase the distance and put your camera in an angle which is less clumsy to shoot with. The mirror could even be placed after the GG, like a still camera. I wrote this somewhere else too: If you have a LCD screen that can be flipped and closed to the camera, you can look it when the camera is at 90 deg. I'm not sure, but maybe the image will be correct (in stead of mirrored.) I made a drawing: http://s01.picshome.com/c7e/setup.jpg I think if the mirror is put after the GG (unlike the drawing) the distance to the camera will be increased, but dust on the mirror will be a bigger problem.

May 1st, 2005, 08:56 AM	#368
Bill Porter Major Player Join Date: Mar 2005 Location: Ventura, California, USA Posts: 751	There are pictures of the Guerilla35 device, but you have to go into their forum to see them. Here are the shortcuts: http://www.guerilla35.com/talk/viewtopic.php?t=8 http://www.guerilla35.com/talk/viewtopic.php?t=9 It looks to be a 52mm tube, with an SLR-format GG at the end. Looks like no condenser, either! Which if true, further backs up the notion that zooming in will get rid of vignetting. I find my long tube a bit funny looking, sure, but if you are filming a movie, that doesn't matter at all. A steadicam-style body-mounted stabilizer is pretty darn ridiculous looking, and so it's not like a prosumer camera is small in the first place, especially when it's equipped with a huge lens hood or matte box, a big mic, an eyepiece extender, follow focus, rails, etc! For documentary or interview work, some might think the long tube is obtrusive, but in reality, your subjects are going to react more to the fact that you have a giant camera pointed at them. The extra 2" of tube are the least of their concerns! Thanks for the input, Dan. I'm always interested to see what you've built next.

May 1st, 2005, 10:02 AM	#369
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	funny, but... you asked for it: yesterday I had to build a replica to this: http://www.knightsedge.com/medieval-...apult-4804.jpg (my younger son's school project) It does not look like much, (even now when I look at it) and it seems like one hour project but keeped us busy for 8 hours.... we are one "knight sword" away from completion.... (to everyone's luck, we are roughly 500 years away from mass distruction weapons..lol) I will keep you updated with the progress if you wish...

May 1st, 2005, 12:53 PM	#370
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	Well, using my camera, to get in focus, zoom in as far as I can go - the object needs to be...wait for it...30+ inches away ( that's right, about 2.5 feet). Much too far indeed. I can't work with the tube. Oh well, had to test to be sure.

May 1st, 2005, 01:45 PM	#371
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	It's also interesting that I don't see the artifacts from a static GG in the Guerilla35 footage. I wonder how they accomplished that?

May 1st, 2005, 02:26 PM	#373
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	Ok, that sounds reasonable, but from reading the forum some other people have seen the footage first hand and they say it looks great. I guess it will be wait and see. I wonder how they are dealing with interchangeable lenses - the focal length will have to be changed each time - unless it only works with one lens type only.