View Full Version : New method for spinning real Ground Glass
Wayne Kinney September 17th, 2005, 07:13 AM Hi,
I am going to offer an introductory price of £125-£150. Still finalising the price.
One thing to keep in mind is it wont come with macro/acromat. It will come with 58mm thread size, so the buyer will provide his/her own macro, then screw the adpater onto his/her own macro. The case will be the black ABS plastic project box. Would people perfer a glossy or matte finish?
I see this as a better option anyway, as it gives the buyer the freedom to choose the macro/acromat that best suits their camcorder and personal preference. I will provide exact distance between filter thread and GG so potential buyers test if they need a macro or not by trying to frame and focus on a 36x24mm frame from that distance.
Im currectly finalising the design, more info to follow.
Thanks,
Wayne.
Glen Hurd September 17th, 2005, 11:15 PM Great job, Wayne! Looks real good.
Doesn't look like you have any vignetting problems either. Did you use a PCX lens with that, or straight from GG to video cam?
You've been pretty focused on getting to this point, and it looks like you're outta the woods. (By the way, what's it like? :)
G
Wayne Kinney September 18th, 2005, 04:08 AM Thanks Glen,
There is a bit vignetting in the far corners, you can see that mostly in the last 3 shots, but i know why it is and have adjusted it all now. Yes i was using a pcx lens as in my other thread http://www.dvinfo.net/conf/showthread.php?t=50884
Yes Glen, it feels good that i have got there, and the results are better then i could have hoped for, both in terms of picture quality, and how robust the glass mechanism is.
Give me a couple of weeks, and the commercial version will hopfully be available.
Thanks,
Wayne.
Kurt August September 18th, 2005, 05:06 AM The footage looks very nice. Is it perhaps possible to post a full frame of the last shot, the one with the pepper? Just curious how sharp it really.is.
Wayne Kinney September 18th, 2005, 05:38 AM Hi Kurt, thanks.
Here are 2 full frames from the pepper shot.
http://homepage.ntlworld.com/wayne.kinney/fullframe01.jpg
http://homepage.ntlworld.com/wayne.kinney/fullframe02.jpg
Please remember that it was shot with a cheap 1 chip/ccd panny, an nvds30 like here: http://www.skala.nl/usr_img/webshop/19/PA-NVDS30.jpg
You can see the slight vignetting i was talking about, which is now resolved.
I'll try and get some more footage up soon, but i have ran out of webspace. I only have 55mb;)
Thanks,
Wayne
Bill Porter September 18th, 2005, 08:48 AM Wayne,
I have a massive amount of space available if you want a host. It's a very fast server. I host files for a couple of other dvinfo folks and my ISP never complains. So far it's been typically hundreds of views of 50-ish meg files with no problems (!)
Wayne Kinney September 18th, 2005, 08:52 AM Bill, that is very very helpful of you. Yes i would love it if you could host my video files for me. Could you please host the video i have already posted and give me the new link, if you would be so kind?
Is it possible for me to upload video's to your server directly, maybe via ftp?
Please let me know my friend, and thanks again!!!
Wayne.
Bill Porter September 18th, 2005, 09:00 AM Happy to help.
http://tinyurl.com/cgazu
I don't know how to make other accounts so just let me know if you need more files uploaded and we'll figure something out.
Wayne Kinney September 18th, 2005, 09:12 AM Thanks Bill,
I'll send you an email when i get my next video ready for upload:D..Thanks again!!!
Wayne.
Bill Porter September 18th, 2005, 09:27 AM You're welcome. Glad to help another member, of a community that has helped me a lot.
Kurt August September 18th, 2005, 09:42 AM Thanks for posting the full frames. Quite sharp! I've saved it as a reference file...
Which lens did you use? Do you have a whole bunch of them to test?
Very nice work indeed!
Wayne Kinney September 18th, 2005, 10:23 AM Thanks Kurt,
Im using a Nikon Nikkor -S 50mm F1.4 lens, its the only lens i have right now, planning on gotting more soon.
Wayne.
Bill Porter September 18th, 2005, 10:56 AM Don't know why I didn't think of this earlier, but, Wayne, will you do a test movie and close up the aperture? Maybe in steps? I'm very curious to see what happens when the aperture is stopped down.
Thanks!
Wayne Kinney September 18th, 2005, 11:08 AM Bill,
Good idea, thats the real test, huh?:D Hehe, ill get to it.
Wayne.
Kurt August September 18th, 2005, 11:14 AM "Im using a Nikon Nikkor -S 50mm F1.4 lens"
Does it always have so much barrel distorition? Or is that the camera?
Secretly, I hope it's the camera, since I've just ordered the same lens... Having a fast lens is nice and I can hardly image a 50mm lens so distorted.
Leo Mandy September 18th, 2005, 11:20 AM Looks good Wayne - I was thinking about moving to glass as well because of the abberation I am getting from plastic. I daresay you will see micro35 probably moving that way shortly as well! What kind of glass did you end up using? Museum?
Wayne Kinney September 18th, 2005, 11:36 AM Yeah glass is way better optically then plastic. Not sure if the micro35 will make the move or not....Oh, its a 1.5mm glass, not sure of the type.
Thanks,
Wayne.
Bill Porter September 18th, 2005, 04:13 PM Oh it's not even so much the real test (your footage seems to be quite terrific), so much as satisfying my own curiosity. I am a static GG kind of guy so I'm so curious to see what on earth does happen when you shut the 35mm lens' aperture with a spinning one!
Wayne Kinney September 18th, 2005, 05:36 PM Bill,
Yeah, well thats 'suppose' to be 1 advantage of a spinner, so we'll see tomorrow.
Kurt, its not the SLR or the camera creating the distortion, its the condensor lens, its because the distance from GG was not properly set. All is fine now, shell prove tomorrow.
Thanks,
Wayne.
Wayne Kinney September 19th, 2005, 08:45 AM Ok guys, got some new test footage up, so the old footage is now here (kindly hosted by Bill Porter):
http://tinyurl.com/cgazu (right click and save as)
The New footage is here:
http://homepage.ntlworld.com/wayne.kinney/adaptertest02.mov (Bill Porter, would you be so kind as to upload this clip to your webspace aslo?)
Tested both different aperture settings on the SLR and different shutter speeds on the cam. As you can see, as the aperture is closed, it starts to vignette slightly around the edges. Again, this is due to setting up the proper distance between the elements. I have setup the condensor the correct distance from the GG, so no more barrel distortion, but there is a sweet spot with distance from condensor to camcorder as to get no vignetting. Is the vignetting acceptable? NOT AT ALL. It needs to be perfect, quality is top of the list, so this is my next adujstment.
I set the shutter speed in increasements from 1/50th to 1/8000th, even at 1/8000th you can only slightly start to see the glass spinning in the window.
My aim it to take every artifact and limitation of these adapters like grain, vignetting, distortion, light loss, limited aperture use, limited shutter speed use, and get past them one by one. I think I have nearly passed all except light loss, which is around 1 - 2 stops light loss.
Anyhow, let me know what you think of the footage. Also, please let me know what tests I can do next for you all to see, lets test this baby;)
Thanks,
Wayne.
Bill Porter September 19th, 2005, 09:16 AM Here ya go, my friend:
http://tinyurl.com/aqpaf
Now that is a neat test. Thanks for doing that; I was the only one who asked to see it with the aperture closed, but I know literally hundreds of people are going to download it. My server stats prove it! :)
Your results are ridiculously impressive. You make it look easy!
Keep it up!
P.S. some of the folks around here (thankfully not me) are on slow connections. Will your file size be smaller if you delete all audio? Some people might want that. Even though Simon and the boys have still got it!
Wayne Kinney September 19th, 2005, 09:34 AM Bill,
Thanks, im getting there dont you think?:D
No, the audio is compressed so much it only takes like 200K of the file. I lowered the video frame rate as much as i could as not to get compression artifacts. Maybe i'll try a little lower next time.
Thanks for hosting man, im just getting some really tight close ups now, with EXTREME DOF, by adjusting the flange focal length further away fromt he GG to experiement, makes some pretty neat shots, ill show you in about 30 minutes:D
Wayne.
Wayne Kinney September 19th, 2005, 10:46 AM OK,
Here are the new links for the 2 footage files:
First: http://tinyurl.com/cgazu
Second: http://tinyurl.com/aqpaf
Ok, I have done some extreme close up extreme DOF shots. These were done buy moving the GG distance away from the lens, thereby allowing you to focus on objust just MM away from the lens, with extremly shallow DOF. It was just for fun to see what the results would be, all shot through my adapter.
http://homepage.ntlworld.com/wayne.kinney/closeup02.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup03.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup04.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup05.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup06.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup07.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup08.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup09.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup10.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup11.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup12.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup13.jpg
http://homepage.ntlworld.com/wayne.kinney/closeup14.jpg
And I also did a test to try and get the cam to see the grain spinning. Its not untill I shut the SLR aperture all the way to F16 and put shutter speed to 1/2000th that you started to notice the spinning glass. BTW, it looks as though the glass is spinning very slowly, but that just an illusion, kinda the same thing as a car wheel look like its turning backwards when you look at it at a certain speed.
http://homepage.ntlworld.com/wayne.kinney/GG Grain.mov
Again remember these are shot with my cheap 1 chip/ccd panasonic. Let me know what you all think,
Wayne.
Bill Porter September 19th, 2005, 12:20 PM Bill,
Thanks, im getting there dont you think?:D
I'd say you're there, in fact, you're more there than Daves Spi, from what I've seen from both of you guys (ok, there are two Daves, who shared one name). Your footage sure looks sharp with no fuzziness or fresnel-like marks.
Super nice job!
Wayne Kinney September 19th, 2005, 12:47 PM Thanks bill,
I think my adapters performance come from 2 main factors, 1: I treat my ground glass with my 'secret ingredient';), which improves light transmittance and gives much more contrast and richness to the image, without effecting diffusion properties. Also, proper/accurate setup of condensor lens.
I have now made a new thread announcing my commercial unit thats going to be available buy the end of this month. IM asking £150 including 15mm rod support, but no macro.
Thanks,
Wayne.
Craig Bellaire September 19th, 2005, 12:57 PM Just wondered how you attached the Glass to the motor. In the Guide you say to use 3 screws... BUT in the picture you seem to have a different attachment Method...
Wayne Kinney September 19th, 2005, 12:59 PM Craig.
Always 3 screws, but with thick rubber washers so the screws will not 'crush' the glass.
Thanks,
Wayne.
Michael Maier September 19th, 2005, 06:03 PM What's gyroeffect?
Wayne Kinney September 19th, 2005, 06:08 PM Now this is a hard one to explain:D
Its a force that acts on a spinning object. With my spinning glass, there is a resistance to any rotational movement around its own axis, but only around 2 axis, the other two axis other then the one the glass is spinning around
Im not very clear about it, but see here for a more detailed explaination.
http://www.sheldonbrown.com/brandt/gyro.html
Or if your a mathmatician, go here;)
http://print.google.co.uk/print?id=53H9ojcBeTcC&pg=PA63&lpg=PA63&dq=what+is+gyroscopic+force&prev=http://print.google.co.uk/print%3Fq%3Dwhat%2Bis%2Bgyroscopic%2Bforce%26oi%3Dprint&sig=lr4jId4G8Rry2kuPE0inm4xA-NY
Thanks,
Wayne.
Michael Maier September 19th, 2005, 06:12 PM Ok, but How does it affect performance or use in the real world?
Michael Maier September 19th, 2005, 06:20 PM How loud is the adapter by the way?
Wayne Kinney September 19th, 2005, 06:21 PM OK,
Basically there is a theoretical resistance against panning and tilting movement. Have I noticed any resistance when using the unit? NONE AT ALL.
My only real concern when first coming up with the design a while back was if the gyroeffect was going to be so strong as to shatter the glass. I now know that this is not the case with my design.
I think the main difference was the macro with the tests with the dvx100? Not sure.
I have a potential buyer wanted to use onto a dvx100a. He would post results with my unit. I dont have access to that kind of equipment, sorry.
Wayne.
Michael Maier September 19th, 2005, 06:24 PM Thanks.
Also, I wonder if the results wouldn't be worse with a higher resolution camera like a DVX100 and XL2. I think that happened to the Letus35 is another thread. Somebody said it looked better with a cheaper camera than with a DVX100. Do you have the possibility of testing it with a better camera?
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