Homemade 35mm -- Edited Copy for Reading

Peter Sciretta · December 21st, 2003, 03:20 PM

agus - I think people would be satisfied in a commercial version if you could find either:

A. an output from the cameras RCA's that will flip the image normal for an external monitor/lcd

B. If you include an LCD that will flip everything.

I like the idea of the prism but I think it will cause too many problems plus it will just be one more thing the light must go through and will bring the light levels down yet again.

I don't think most people have a problem with flipping in post... the problem is to see everything as it is (right side up) while filming.

Don Berube · December 21st, 2003, 03:27 PM

Agus, are those your sons or your nephews? They seem like good kids. You should name your device after them to reward them for tolerating your chasing them around with your device, which I am sure looks a little scary to them. hehe

Just curious if you could find a way to control the exposure more - so that you are not so overexposed in the white areas of the frame? It would be cool to see a nice flat, balanced exposure.

Is that sound I hear being made by your device? Is there a way you could deaden that sound? Reminds me of an old class at MIT, where the engineering students were given a Braun coffee bean grinder and the goal was to see who could figure out the best way to make the grinder perform as silently as possible. One solution was to deaden the walls of the coffee bean grinder with neoprene and to use a motor which was slightly over-rated for the task of grinding coffee beans. They lowered the voltage to that motor, so that it ran at only the torque needed to grind the beans and it was indeed a bit quieter. I would say that plastic shell of your device is resonating and somewhat amplifying the sound of the motor. Perhaps gluing a thin piece of neoprene inside the walls of your device (or around the motor?) would help mask the sound.

- don

Agus Casse · December 21st, 2003, 03:40 PM

yeah those are my newphies they are twins. :)

The problem really is that the mic of the TRV is less than 3 inches from the motor, so it is silent but the mic is too close. it can be solve using an external mic with no trouble. about the exposure, my bad i was so excited using the device that i didnt set it manually. but well :) i am so haappy that the optics are working well, and the image is not deformed like my first versions, and also there is no vigneting.

Don what do you think about a commercial version ? is flipping the image critical ?

Stewart McDonald · December 21st, 2003, 03:52 PM

Are you using a fresnel lens or macro between your GG and the camera Agus?

Agus Casse · December 21st, 2003, 04:01 PM

Yeah, a magnifying glass actually it is very powerfull i took it off froma wide conversion lens (VCL-0630 S)

Agus Casse · December 21st, 2003, 04:03 PM

Peter i still havent test using Glass, i am sure i will loose lest light with it than with a plastic cd, also the pentaprism or dove prism should be high quality to work...

Louis Feng · December 21st, 2003, 04:57 PM

I have figured out a static (no moving parts) solution. The test is very promising. I'm still waiting for parts to complete the whole thing. Once complete, I'll have an adapter which:

1. produce upright image
2. smaller (6x10 cm)
3. higher image quality and brighter.

The downside is that the complete cost to produce such adapter will cost a few hundred, might cost more depending on the quality of the coating and glass.

http://f2.pg.photos.yahoo.com/ph/lou....dnm=model.jpg

Filip Kovcin · December 21st, 2003, 06:14 PM

<<<-- Originally posted by Peter Sciretta : I think, and I could be the minority but I wouldn't think I am... if it is a loss of quality or light steps flipping the image is not needed if you could somehow see the image right side up while you are shooting (ie flipped on a monitor or lcd).

I would rather that then lose quality. -->>>

peter,
(and others, of course)

i think that there is a place where you can put a prism for inverting!
if the small prism (DOVE PRISM) is mounted as kind of EXPANDER of normal viewfinder (between your eye and a viewfinder) - you will NOT change a picture (quality) at all, you will se everything in a proper way - but you will of course need to flip recorded image after the shooting.
considering small monitor already with the cameras - i think that VERY simple device can be added to commercial version of agus35 - small mirror laying down on one side of "LCD chimney" - so if you are turning your camera monitor bit down - you will look at that mirror which turns everything upside down. so the image foer the viewer will be again proper one.
does this make a sense?

Peter Sciretta · December 21st, 2003, 06:30 PM

For people who don't use the viewfinder as much as a lcd or crt monitor this viewfinder idea is not good. If you're going to do any handheld work we'll need to see an lcd right side up.

As for the mirror LCD idea, I implimented this with my unit weeks ago... this still has the BIG problem that everything is still flipped horrizontally.

Louis Feng · December 21st, 2003, 07:38 PM

The limiting factor of the current method (mini35) is the requirement of moving the GG. P+S was able to create something fairly small because they probably machined the parts as small as possible. The sole purpose of the rotating/vibrating GG is to reduce the artifacts produced by the coarseness of the GG.

I have been testing a number of solutions, ground glass and other kind of materials to produce a diffusing surface that is very fine, so fine that it appears to be white to the camera. With such surface, you can project image on to it and there won't be any noticeable artifacts. The result is pretty close, but not yet there. I'll let you guys know how it goes.

Louis Feng · December 21st, 2003, 10:00 PM

This is a very rough test of the my static solution. I am still looking for method to improve the quality. Especially in terms of transmitting more light and to be able to "distribute" more light to the corners. Maybe a frensel lens would help.

http://f2.pg.briefcase.yahoo.com/bc/...=/35mm+adapter

Corey Smith · December 21st, 2003, 11:18 PM

Hey, I tried to post this yesterday, but I may have found a way to not have to use a spinning CD. I had to scrap the spinning CD because of the size of my camcorder (which made it virtually impossible for me to have a spinning cd). The non moving method has no scratches, dust, etc. The image is bright too.

I used very thin, slightly diffused plastic and if i triple the layers it becomes diffused enough to create the projection. Worked for me. I was using other still pieces and the scratches from the sandpaper were just too noticeable. I knew there had to be an alternative. I'm not sure how it compares to the spinning CD, but it works for me.

J. Clayton Stansberry · December 21st, 2003, 11:19 PM

Yeah, you need to zoom or magnify it. If you are zoomed in as far as possible, then you need to magnify it before you capture it. I have had problems with the vignetting, but that was due to my holes being off and not totally centered. I was able to zoom in a little more and that fixed the problem...this is just with the lens going straight into the camera without the frosted glass. Haven't got my hands on the sandpaper yet. Hope it works!

Louis Feng · December 22nd, 2003, 03:07 AM

Don, that's a good one. Actually I think Agus's last video looks really good. However, it's an outdoor shooting, lighting is much more abundant in that case. I have yet to see anyone that can handle in door lighting well.

It should be noted that the video I shoot was shooting directly from the GG without any cover and was not modified or color corrected in anyway. I'm sure it will look brighter when everything is in a blackbox. But I'm not expecting dramatic improvement from this type of GG (hint, hint).

In fact I am wondering how good the mini35 is, considering there really isn't that much light passing through the lens. I don't believe there is any magic that somehow they can "squeeze" more light from how much there actually is. Again, it probably works well outdoor with bright sun light. I haven't seen any "bright" indoor shots on their web site (most are dark and smoky).

Having played with different kinds of real ground glass, I can tell you that the best/finest ground glass can only produce ok results in a static solution. However, there are other materials can do much better job, both transmitting more light and produce clearer image, but also cost a lot more. Let science do the magic, that's what I'm going to test next. I might even impress myself.

Louis Feng · December 22nd, 2003, 03:23 AM

Regarding using ground glass/plastic/consumer products

All the materials above will work fine with a rotating/vibrating solution. The downside is they scatter too much light in every direction. They are not specially made for this video recording.

A static solution is even harder. Ground glass won't work, plastic CD won't work, any short of consumer product won't work. They all produce uneven illumination or visible noise.

I am only considering a static solution for myself, because it would be much more cumbersome to produce an upright image with the rotating/vibrating solution. The missing part right now is to find the best material for the projection. I might have found what I need. I'll know in a few days.

December 21st, 2003, 03:27 PM	#287
Don Berube Moderator Join Date: Mar 2002 Location: Boston, MA (travel frequently) Posts: 837	Agus, are those your sons or your nephews? They seem like good kids. You should name your device after them to reward them for tolerating your chasing them around with your device, which I am sure looks a little scary to them. hehe Just curious if you could find a way to control the exposure more - so that you are not so overexposed in the white areas of the frame? It would be cool to see a nice flat, balanced exposure. Is that sound I hear being made by your device? Is there a way you could deaden that sound? Reminds me of an old class at MIT, where the engineering students were given a Braun coffee bean grinder and the goal was to see who could figure out the best way to make the grinder perform as silently as possible. One solution was to deaden the walls of the coffee bean grinder with neoprene and to use a motor which was slightly over-rated for the task of grinding coffee beans. They lowered the voltage to that motor, so that it ran at only the torque needed to grind the beans and it was indeed a bit quieter. I would say that plastic shell of your device is resonating and somewhat amplifying the sound of the motor. Perhaps gluing a thin piece of neoprene inside the walls of your device (or around the motor?) would help mask the sound. - don __________________ DONALD BERUBE - noisybrain. Productions, LLC Director Of Photography/ Producer/ Consultant http://noisybrain.com/donbio.html CREATE and NETWORK with http://www.bosfcpug.org and also http://fcpugnetwork.org

December 21st, 2003, 03:40 PM	#288
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	yeah those are my newphies they are twins. :) The problem really is that the mic of the TRV is less than 3 inches from the motor, so it is silent but the mic is too close. it can be solve using an external mic with no trouble. about the exposure, my bad i was so excited using the device that i didnt set it manually. but well :) i am so haappy that the optics are working well, and the image is not deformed like my first versions, and also there is no vigneting. Don what do you think about a commercial version ? is flipping the image critical ? __________________ Agus35 - the ultimate tool for indie DV filmakers -

December 21st, 2003, 04:01 PM	#290
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	Yeah, a magnifying glass actually it is very powerfull i took it off froma wide conversion lens (VCL-0630 S) __________________ Agus35 - the ultimate tool for indie DV filmakers -

December 21st, 2003, 04:03 PM	#291
Agus Casse Major Player Join Date: Jul 2003 Location: Guatemala Posts: 322	Peter i still havent test using Glass, i am sure i will loose lest light with it than with a plastic cd, also the pentaprism or dove prism should be high quality to work... __________________ Agus35 - the ultimate tool for indie DV filmakers -

December 21st, 2003, 06:14 PM	#293
Filip Kovcin Major Player Join Date: Dec 2003 Location: warsaw, poland Posts: 440	inverting ideas <<<-- Originally posted by Peter Sciretta : I think, and I could be the minority but I wouldn't think I am... if it is a loss of quality or light steps flipping the image is not needed if you could somehow see the image right side up while you are shooting (ie flipped on a monitor or lcd). I would rather that then lose quality. -->>> peter, (and others, of course) i think that there is a place where you can put a prism for inverting! if the small prism (DOVE PRISM) is mounted as kind of EXPANDER of normal viewfinder (between your eye and a viewfinder) - you will NOT change a picture (quality) at all, you will se everything in a proper way - but you will of course need to flip recorded image after the shooting. considering small monitor already with the cameras - i think that VERY simple device can be added to commercial version of agus35 - small mirror laying down on one side of "LCD chimney" - so if you are turning your camera monitor bit down - you will look at that mirror which turns everything upside down. so the image foer the viewer will be again proper one. does this make a sense?

December 21st, 2003, 03:20 PM	#286
Peter Sciretta Regular Crew Join Date: Nov 2003 Posts: 72	agus - I think people would be satisfied in a commercial version if you could find either: A. an output from the cameras RCA's that will flip the image normal for an external monitor/lcd B. If you include an LCD that will flip everything. I like the idea of the prism but I think it will cause too many problems plus it will just be one more thing the light must go through and will bring the light levels down yet again. I don't think most people have a problem with flipping in post... the problem is to see everything as it is (right side up) while filming.

December 21st, 2003, 03:52 PM	#289
Stewart McDonald Regular Crew Join Date: Feb 2003 Location: UK Posts: 130	Are you using a fresnel lens or macro between your GG and the camera Agus?

December 21st, 2003, 04:57 PM	#292
Louis Feng Vendible Book Join Date: Dec 2003 Posts: 59	I have figured out a static (no moving parts) solution. The test is very promising. I'm still waiting for parts to complete the whole thing. Once complete, I'll have an adapter which: 1. produce upright image 2. smaller (6x10 cm) 3. higher image quality and brighter. The downside is that the complete cost to produce such adapter will cost a few hundred, might cost more depending on the quality of the coating and glass. http://f2.pg.photos.yahoo.com/ph/lou....dnm=model.jpg

December 21st, 2003, 06:30 PM	#294
Peter Sciretta Regular Crew Join Date: Nov 2003 Posts: 72	For people who don't use the viewfinder as much as a lcd or crt monitor this viewfinder idea is not good. If you're going to do any handheld work we'll need to see an lcd right side up. As for the mirror LCD idea, I implimented this with my unit weeks ago... this still has the BIG problem that everything is still flipped horrizontally.

December 21st, 2003, 07:38 PM	#295
Louis Feng Vendible Book Join Date: Dec 2003 Posts: 59	The limiting factor of the current method (mini35) is the requirement of moving the GG. P+S was able to create something fairly small because they probably machined the parts as small as possible. The sole purpose of the rotating/vibrating GG is to reduce the artifacts produced by the coarseness of the GG. I have been testing a number of solutions, ground glass and other kind of materials to produce a diffusing surface that is very fine, so fine that it appears to be white to the camera. With such surface, you can project image on to it and there won't be any noticeable artifacts. The result is pretty close, but not yet there. I'll let you guys know how it goes.

December 21st, 2003, 10:00 PM	#296
Louis Feng Vendible Book Join Date: Dec 2003 Posts: 59	This is a very rough test of the my static solution. I am still looking for method to improve the quality. Especially in terms of transmitting more light and to be able to "distribute" more light to the corners. Maybe a frensel lens would help. http://f2.pg.briefcase.yahoo.com/bc/...=/35mm+adapter

December 21st, 2003, 11:18 PM	#297
Corey Smith Regular Crew Join Date: Dec 2003 Location: Hot Springs, AR Posts: 31	No Moving Parts Hey, I tried to post this yesterday, but I may have found a way to not have to use a spinning CD. I had to scrap the spinning CD because of the size of my camcorder (which made it virtually impossible for me to have a spinning cd). The non moving method has no scratches, dust, etc. The image is bright too. I used very thin, slightly diffused plastic and if i triple the layers it becomes diffused enough to create the projection. Worked for me. I was using other still pieces and the scratches from the sandpaper were just too noticeable. I knew there had to be an alternative. I'm not sure how it compares to the spinning CD, but it works for me.

December 21st, 2003, 11:19 PM	#298
J. Clayton Stansberry Major Player Join Date: Sep 2003 Location: Colorado Posts: 316	Yeah, you need to zoom or magnify it. If you are zoomed in as far as possible, then you need to magnify it before you capture it. I have had problems with the vignetting, but that was due to my holes being off and not totally centered. I was able to zoom in a little more and that fixed the problem...this is just with the lens going straight into the camera without the frosted glass. Haven't got my hands on the sandpaper yet. Hope it works! __________________ I understand everything about nothing.

December 22nd, 2003, 03:07 AM	#299
Louis Feng Vendible Book Join Date: Dec 2003 Posts: 59	Don, that's a good one. Actually I think Agus's last video looks really good. However, it's an outdoor shooting, lighting is much more abundant in that case. I have yet to see anyone that can handle in door lighting well. It should be noted that the video I shoot was shooting directly from the GG without any cover and was not modified or color corrected in anyway. I'm sure it will look brighter when everything is in a blackbox. But I'm not expecting dramatic improvement from this type of GG (hint, hint). In fact I am wondering how good the mini35 is, considering there really isn't that much light passing through the lens. I don't believe there is any magic that somehow they can "squeeze" more light from how much there actually is. Again, it probably works well outdoor with bright sun light. I haven't seen any "bright" indoor shots on their web site (most are dark and smoky). Having played with different kinds of real ground glass, I can tell you that the best/finest ground glass can only produce ok results in a static solution. However, there are other materials can do much better job, both transmitting more light and produce clearer image, but also cost a lot more. Let science do the magic, that's what I'm going to test next. I might even impress myself.

December 22nd, 2003, 03:23 AM	#300
Louis Feng Vendible Book Join Date: Dec 2003 Posts: 59	Regarding using ground glass/plastic/consumer products All the materials above will work fine with a rotating/vibrating solution. The downside is they scatter too much light in every direction. They are not specially made for this video recording. A static solution is even harder. Ground glass won't work, plastic CD won't work, any short of consumer product won't work. They all produce uneven illumination or visible noise. I am only considering a static solution for myself, because it would be much more cumbersome to produce an upright image with the rotating/vibrating solution. The missing part right now is to find the best material for the projection. I might have found what I need. I'll know in a few days.