New moving ground glass mechanism

Jesse Rosten · February 8th, 2005, 01:10 PM

I was under the impression that the action of oscilation would somehow negate the fresnel's light gathering properties.

I guess this test proves that theory wrong? So you have no condenser lens in your current set up? Just a moving fresnel screen? I am very excited about the possibility of not needing a condenser lens. I've had nothing but bad luck with those things.

Another question: at what shutter speed does the grain become visible? In other words can you shoot at higher shutter speeds without seeing grain?

thanks
jesse

Dan Diaconu · February 8th, 2005, 02:05 PM

Yes,... just a moving Fresnel.....
I did not try higher shutter speeds since 1/60 is the nearest (I have available ) to the soooo worshiped 24 pee.
I will try it and post the results on my site.
I can foresee each individual "sample screen" showing grain but in the end, looking like a "motion blend" as real film does.(IF you can see the grain which is subject to camcorder setting and available light)
In other words, a "grainy film look" . If the movement speed is NOT in sink with the 30fps (as recorded by the camcorder), each frame will "sample" the GG in a DIFFERENT position and, (depending on the shutter speed) the sampling will look more grainy at 1/500 than it would at 1/100 or 1/60. Grain movement amount/time sampled (basic freeze motion photography)
One more word about 24 P. (a full can of.....)
In theatre, the brightness dif between TOTAL DARKNESS and FRAME is HUGE. The persistence of vision "fills" the gap.
Not the same when watching TV. Not to mention that you are watching 30fps interaced. The 24P I saw on all camcorders does not resemble at all the way I see the same thing in theatre.
Maybe is just me......
BTW:
What good does it do to you 24P when you have "talking heads" in sharp focus and a "strobing soft BG" in the picture?????? Will that ADD value or "sell" the film look better? Or is just one more thing to avoid; panning too fast or you get strobing? There is soo much more and different that can help "sell" the film look. (IMHO) Actually , that was not at all on the topic. Just curious....

Jesse Rosten · February 8th, 2005, 02:24 PM

Yeah the 24p thing has been discussed to death on the board so best not to get it started here.

Good job on eliminating the condenser lens. This seems like the best way to prevent image distortion and abberation. I'm guessing that a macro will be needed as well to get the adapter to work on the DVX.

Keep us posted on you progress. Great work Dan.

-jes

Brett Erskine · February 8th, 2005, 03:40 PM

Let me clarify the situation with using only a fresnel lens/focusing screen in a oscillation or rotating adapter. You will get the best results if you are osillating it NOT rotating it. If you rotate it like a CD your likely to see the effects of the ribbed fresnel lens in the picture. Oscillating it wont have this problem BUT you have to be careful how wide your oscillation is. If your oscillation it in a circle wider than a couple of mm your likely to see a issue of light fall off showing up again (ie hot spot). This isnt because the fresnel lens isnt strong enough but its because a fresnel lens (which serves the same purpose of a condensor lens) is trying to focus its image to one central point (the CCD). When you oscillate the fresnel you are also oscillating that central point to and from its target (the CCD). When the motor comes to speed the effect will be a darkening of the edges. This effect can be reduced to a point that its not noticeable by using a oscillating movement thats tighter than a couple of mm's. Dans and my design do this so thats why the image is clear and bright from corner to corner. I hope that made sense.

Jesse Rosten · February 8th, 2005, 04:25 PM

Yes Brett that does make sense.

How's your design coming along by the way?

Brett Erskine · February 8th, 2005, 05:10 PM

I'm getting some parts computer machined that would be impossible to make by traditional means. I would say I'm 60% done with my final design. I have the design finished and bought the focusing screen, bearings, lens and mounts I plan on using. The rest is going to be machined.

Dan Diaconu · February 8th, 2005, 05:43 PM

Sounds good Brett,
post some pics/clips when ready.

Steev Dinkins · February 8th, 2005, 07:29 PM

Looks awesome. I'm looking forward to it's release. :)

Filip Kovcin · February 9th, 2005, 03:25 PM

i am wondering if it's possible to compare somehow TWO adapters - Brett's and Dan's?

like - both of you can shoot the same picture - i do not know what, but i.e. same newspaper - to see resolution in different light conditions... or something similar wchich can be done by both of you. maybe you can prepare same table setup with same same articles which everyone can buy (soda can, chocolate, box of sweets, bottle of mineral water etc). and use same amount of light and shoot...

just a thought...

filip

Dan Diaconu · February 9th, 2005, 04:33 PM

I might do a rez and color chart. Stills of the GG with a Nikon Coolpix 8.0-MEGAPIXEL Digital. Just for the rez. Color is subject to WB and camcorder sensitivity. I'll take notes of the exposure time and aperture, but that is dif from CCD to CCD as well (and no 3 CCD on Nikon either) as well as light used and... oh well , distance and so on....
Had some fun today with the P+S Mini35 (latest) helping a local rental house to set it up and get it going. It was fun.
Please, do not ask me for an opinion. I am biased. But some local DP's will look at them side by side and post their reviews independently of what I think or like to hear.
Did some tests on mine while there. Works with all PD170 DVX100 and Z1.
A "relay lens" of +4 is needed on all except PD170 . That's all.
XL1 will have to wait... (chinese new year)

Brett Erskine · February 10th, 2005, 12:37 AM

Fillip-
I don’t want to make this a competition between designs because Dan is selling his and I'm not going down that road. I'm just trying to make the best one I can for myself and share what I find with others. I would glad to post pictures of the res chart when mine is done but it won’t be a fair comparison. I'm shooting on a progressive mode camera and my design doesnt require to look thru a close up/diopter lens. When its all done and tested I'll post the working design for you guys but it still has a little time to go. I would recommend you consider buying Dan's device because it looks like a quality product and it’s already finished.

Les Dit · February 10th, 2005, 01:58 AM

My device has come a long way also. It's like the other 'mini 35' type designs, with the GG moving in an orbital
motion. I have posted HDV video of my results so far. Absolutely no image shake or grain.
I still have some optical tuning to do, to remove the hot spot. The hard part is
making that GG move right, as I'm sure Brett can attest to! ;) Dan and I are the only ones to post
sample video with such a device. I'm the only one to post high bit rate HDV video.
Yep, I'm planing on selling mine too, for under $500. I CNC the main parts, and if I get a
few orders I'll drop the cost even more. ;)
See the other thread for the HD demo video, or email me.
I'll shoot a res chart in a couple of days.
-Les

Dan Diaconu · February 10th, 2005, 02:00 AM

Brett,
This is a fair statement, about rez comparison, capturing CCD and format as well as lens used, etc. Too many differences.
As for the rest, I do not know how soon I will finish with all the "bells and w" needed (adjustable support, rods for a MB and follow focus.....etc)
It will not take for ever, but still, they have to be there to get footage that will bring paying customers. As for selling the device... will also take some time. The road to heaven goes through hell (if it is going to make it that far! lol) I want to see its shape coming back after a few rental days, see what's left of it (lol)
Anyway, thank you for your interest and moral support guys and check the website for updates.

PS. I wonder how come I did not received an email about your new post????????...........hmmmmm???.......

Dan Diaconu · February 10th, 2005, 02:23 AM

Les,
For that price, I am out of the race (with you)and wish you well and a lot of customers. Honestly.
I am planning a shooting this weekend on Z1 as well.
Too bad I do not have "the technology" to edit the footage :(
....will see....
However, do not forget who's clips explicitly describing this kind of movement you saw first! BTW: orbital movement was a test I did in July 2004 (for fun) I did not lke the turning points (uneaven) That is why I went for circle:-)<
(I still have the clip, since I took the trouble to document my work in video. I might post it on my site along with other designs, obsolete now)
I still did not bult the charger (and keeps going...and...)

Steev Dinkins · February 10th, 2005, 02:28 AM

I echo that. I don't know how any of these adapters with R&D, materials, and time can add up to $500 with a significant profit margin. I'd hate to manufacture these things on such slim profit. However, profit quality is in the eye of the beholder. From $10,000 down to $500. Hmmm.

February 9th, 2005, 03:25 PM	#159
Filip Kovcin Major Player Join Date: Dec 2003 Location: warsaw, poland Posts: 440	i am wondering if it's possible to compare somehow TWO adapters - Brett's and Dan's? like - both of you can shoot the same picture - i do not know what, but i.e. same newspaper - to see resolution in different light conditions... or something similar wchich can be done by both of you. maybe you can prepare same table setup with same same articles which everyone can buy (soda can, chocolate, box of sweets, bottle of mineral water etc). and use same amount of light and shoot... just a thought... filip __________________ in kino (sic!) veritas

February 8th, 2005, 01:10 PM	#151
Jesse Rosten Regular Crew Join Date: Mar 2004 Location: Redding, California Posts: 114	I was under the impression that the action of oscilation would somehow negate the fresnel's light gathering properties. I guess this test proves that theory wrong? So you have no condenser lens in your current set up? Just a moving fresnel screen? I am very excited about the possibility of not needing a condenser lens. I've had nothing but bad luck with those things. Another question: at what shutter speed does the grain become visible? In other words can you shoot at higher shutter speeds without seeing grain? thanks jesse

February 8th, 2005, 02:05 PM	#152
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	Yes,... just a moving Fresnel..... I did not try higher shutter speeds since 1/60 is the nearest (I have available ) to the soooo worshiped 24 pee. I will try it and post the results on my site. I can foresee each individual "sample screen" showing grain but in the end, looking like a "motion blend" as real film does.(IF you can see the grain which is subject to camcorder setting and available light) In other words, a "grainy film look" . If the movement speed is NOT in sink with the 30fps (as recorded by the camcorder), each frame will "sample" the GG in a DIFFERENT position and, (depending on the shutter speed) the sampling will look more grainy at 1/500 than it would at 1/100 or 1/60. Grain movement amount/time sampled (basic freeze motion photography) One more word about 24 P. (a full can of.....) In theatre, the brightness dif between TOTAL DARKNESS and FRAME is HUGE. The persistence of vision "fills" the gap. Not the same when watching TV. Not to mention that you are watching 30fps interaced. The 24P I saw on all camcorders does not resemble at all the way I see the same thing in theatre. Maybe is just me...... BTW: What good does it do to you 24P when you have "talking heads" in sharp focus and a "strobing soft BG" in the picture?????? Will that ADD value or "sell" the film look better? Or is just one more thing to avoid; panning too fast or you get strobing? There is soo much more and different that can help "sell" the film look. (IMHO) Actually , that was not at all on the topic. Just curious....

February 8th, 2005, 02:24 PM	#153
Jesse Rosten Regular Crew Join Date: Mar 2004 Location: Redding, California Posts: 114	Yeah the 24p thing has been discussed to death on the board so best not to get it started here. Good job on eliminating the condenser lens. This seems like the best way to prevent image distortion and abberation. I'm guessing that a macro will be needed as well to get the adapter to work on the DVX. Keep us posted on you progress. Great work Dan. -jes

February 8th, 2005, 03:40 PM	#154
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Let me clarify the situation with using only a fresnel lens/focusing screen in a oscillation or rotating adapter. You will get the best results if you are osillating it NOT rotating it. If you rotate it like a CD your likely to see the effects of the ribbed fresnel lens in the picture. Oscillating it wont have this problem BUT you have to be careful how wide your oscillation is. If your oscillation it in a circle wider than a couple of mm your likely to see a issue of light fall off showing up again (ie hot spot). This isnt because the fresnel lens isnt strong enough but its because a fresnel lens (which serves the same purpose of a condensor lens) is trying to focus its image to one central point (the CCD). When you oscillate the fresnel you are also oscillating that central point to and from its target (the CCD). When the motor comes to speed the effect will be a darkening of the edges. This effect can be reduced to a point that its not noticeable by using a oscillating movement thats tighter than a couple of mm's. Dans and my design do this so thats why the image is clear and bright from corner to corner. I hope that made sense.

February 8th, 2005, 04:25 PM	#155
Jesse Rosten Regular Crew Join Date: Mar 2004 Location: Redding, California Posts: 114	Yes Brett that does make sense. How's your design coming along by the way?

February 8th, 2005, 05:10 PM	#156
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	I'm getting some parts computer machined that would be impossible to make by traditional means. I would say I'm 60% done with my final design. I have the design finished and bought the focusing screen, bearings, lens and mounts I plan on using. The rest is going to be machined.

February 8th, 2005, 05:43 PM	#157
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	Sounds good Brett, post some pics/clips when ready.

February 8th, 2005, 07:29 PM	#158
Steev Dinkins Major Player Join Date: Nov 2004 Location: San Francisco, CA Posts: 613	Looks awesome. I'm looking forward to it's release. :)

February 9th, 2005, 04:33 PM	#160
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	I might do a rez and color chart. Stills of the GG with a Nikon Coolpix 8.0-MEGAPIXEL Digital. Just for the rez. Color is subject to WB and camcorder sensitivity. I'll take notes of the exposure time and aperture, but that is dif from CCD to CCD as well (and no 3 CCD on Nikon either) as well as light used and... oh well , distance and so on.... Had some fun today with the P+S Mini35 (latest) helping a local rental house to set it up and get it going. It was fun. Please, do not ask me for an opinion. I am biased. But some local DP's will look at them side by side and post their reviews independently of what I think or like to hear. Did some tests on mine while there. Works with all PD170 DVX100 and Z1. A "relay lens" of +4 is needed on all except PD170 . That's all. XL1 will have to wait... (chinese new year)

February 10th, 2005, 12:37 AM	#161
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Fillip- I don’t want to make this a competition between designs because Dan is selling his and I'm not going down that road. I'm just trying to make the best one I can for myself and share what I find with others. I would glad to post pictures of the res chart when mine is done but it won’t be a fair comparison. I'm shooting on a progressive mode camera and my design doesnt require to look thru a close up/diopter lens. When its all done and tested I'll post the working design for you guys but it still has a little time to go. I would recommend you consider buying Dan's device because it looks like a quality product and it’s already finished.

February 10th, 2005, 01:58 AM	#162
Les Dit Major Player Join Date: Oct 2003 Location: Southern Cal-ee-for-Ni-ya Posts: 608	My device has come a long way also. It's like the other 'mini 35' type designs, with the GG moving in an orbital motion. I have posted HDV video of my results so far. Absolutely no image shake or grain. I still have some optical tuning to do, to remove the hot spot. The hard part is making that GG move right, as I'm sure Brett can attest to! ;) Dan and I are the only ones to post sample video with such a device. I'm the only one to post high bit rate HDV video. Yep, I'm planing on selling mine too, for under $500. I CNC the main parts, and if I get a few orders I'll drop the cost even more. ;) See the other thread for the HD demo video, or email me. I'll shoot a res chart in a couple of days. -Les

February 10th, 2005, 02:00 AM	#163
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	Brett, This is a fair statement, about rez comparison, capturing CCD and format as well as lens used, etc. Too many differences. As for the rest, I do not know how soon I will finish with all the "bells and w" needed (adjustable support, rods for a MB and follow focus.....etc) It will not take for ever, but still, they have to be there to get footage that will bring paying customers. As for selling the device... will also take some time. The road to heaven goes through hell (if it is going to make it that far! lol) I want to see its shape coming back after a few rental days, see what's left of it (lol) Anyway, thank you for your interest and moral support guys and check the website for updates. PS. I wonder how come I did not received an email about your new post????????...........hmmmmm???.......

February 10th, 2005, 02:23 AM	#164
Dan Diaconu Major Player Join Date: Dec 2004 Location: Vancouver, Canada Posts: 804	Les, For that price, I am out of the race (with you)and wish you well and a lot of customers. Honestly. I am planning a shooting this weekend on Z1 as well. Too bad I do not have "the technology" to edit the footage :( ....will see.... However, do not forget who's clips explicitly describing this kind of movement you saw first! BTW: orbital movement was a test I did in July 2004 (for fun) I did not lke the turning points (uneaven) That is why I went for circle:-)< (I still have the clip, since I took the trouble to document my work in video. I might post it on my site along with other designs, obsolete now) I still did not bult the charger (and keeps going...and...)

February 10th, 2005, 02:28 AM	#165
Steev Dinkins Major Player Join Date: Nov 2004 Location: San Francisco, CA Posts: 613	I echo that. I don't know how any of these adapters with R&D, materials, and time can add up to $500 with a significant profit margin. I'd hate to manufacture these things on such slim profit. However, profit quality is in the eye of the beholder. From $10,000 down to $500. Hmmm.