My first adapter test (gg advice needed)

[Jeff Tyler]

Okay so today I decided to go to Home Depot to see if I could find some pvc parts that I might be able to fit my lens and some filters in nicely. I really want to make a static adapter that can be screwed onto my camera (Panasonic PV-GS150) via step up ring. I have a UV filter but I really dont know how to go about grinding it since I cant find any Aluminum Oxide anywhere. I was thinking and decided to cut out a circle piece the size of a 50mm circle using a Report Cover. Its just thin clear plastic. I then took sandpaper to it. I couldnt get it even put I did it enough for my testing purposes. I saw that I could focus my camera on the GG with my adapter. Here I have some pics showing some test frame grabs (yes they are horrible but they're there) and my adapter so far.

Frame1
Frame2
Frame3
Frame4
Frame5
Frame6


Adapter
Lens
Makeshift GG
GG Texture

As you can see I am getting a focused image but I really need to know what you guys think the best ground glass would be, and if you can tell me where I can get it, or link me to a place that shows me how to make it.
I really want to be able to fit the ground glass in there so it should be about the size of a 52mm filter. If you think a ground 52mm uv filter would work than if you could please provide a link on how to grind it I would greatly appreciate it.

Thanks

Sincerely,
Jeff Tyler

[Quyen Le]

Not bad for a first test.
I think this link will have infos that you are looking for
http://ideaspora.net/oldskool/
Thanks.

Quyen

[Wayne Kinney]

Hi Jeff,
You have put together something that shows you the idea works and you can now improve.

You have a few options I see as far as ground glass in concerned, But the static route will not give you the quality of a moving ground glass setup.

Firstly, to make your own ground glass you have mai9nly 2 options, grinding glass with Aluminium Oxide (a UV filter can be the glass) or get into the micro wax thing)

for aluminium oxide look here:
http://ideaspora.net/oldskool/alain35-2.html

I have not done this yet but am waiting for some 1000 grit AO to arrive to give it a try.

Secondly the wax option here:
http://members.chello.nl/a.schultzev...g/wax/wax2.htm


I have tried the wax method with varied results.

You could also buy a premade ground like like the one from here:
http://www.optosigma.com/miva/mercha...uct_Code=pg211

I have tried the 1500 grit ground glass but found it does not diffuse enough.

Hope this helps,
Wayne.

[Jeff Tyler]

Thank you Quyen that link is very helpful. The footage doesnt look too bad with that route.

Wayne I think that looking at results of static adapters, you are right that they aren't that good. Although I have seen some very good ones, I think maybe trying one that moves or oscillates might work although I really am thinking that might be very difficult for me. Most designs with moving gg have required work using things like drill presses and dremels. Both of which I do not have. Do you know of any designs that I could make not requiring to much machinery? I want to get the best possible quality and I know it will take awhile but I cant afford to buy expensive machinery. Another thing is I thought about using the cd spinning method thing but that would be too bulky for me anyway. Especially since im using one of the smallest minidv cams known to man (slight exaggeration). If you know of any good moving ground glass techniques please feel free to share them with me, I would greatly appreciate it.

Thanks again

Sincerely,
Jeff Tyler

[Quyen Le]

Tyler,

http://www.dvinfo.net/conf/showthread.php?t=48267
This design doesn't require as much tools. I have heard some use hand drill for it. Hope this helps.

Quyen

[Wayne Kinney]

Jeff,
I think you have to decide between simplle and bulky or compact and more complex to build.

If you decide to follow Quyen's design and are in the UK (you dont state your location), i have some of the parts like syringees and 2 pager motors that i could sent to you to get you stated.

Im using the CD method, using 2 plano convex lenses with great results. Its bulkier and I also have a tiny camcorder, but ill make a small mounting rod/rail to join the adapter better to the cam.

Wayne.

[Jeff Tyler]

Hmm Wayne well I am not in the UK. But I heard previously that the cd design was bad, although I would more like to try that approach as I understand it and have/can get all the parts used in that design. Does your cd design work well? I have heard that design lowers the light a considerable amount. Is this true?

[Wayne Kinney]

Originally Posted by Jeff Tyler

But I heard previously that the cd design was bad, although I would more like to try that approach as I understand it and have/can get all the parts used in that design. Does your cd design work well? I have heard that design lowers the light a considerable amount. Is this true?

It all depends how you 'treat' the clear cd to make it your ground glass. I think the trick is getting the cd diffused enough just to the point where you cant 'see through it' and pick up details, so everything is blurred, then you loose as little light as possible. 1 trick i read on here and used was to rub the scratched surface after sanding the disk with vaseline and a soft cloth to give it a perminant 'wet look'. This both improves light loss and increases image contrast.

I do however want to try rotating a real cd shaped peice of glass ground with aluminum oxide.

Either way, I could only get good results with using a condensor lens which both brightens up the image more plus gets rid of the vignetting/hotspot. Im using 2 50mm diameter 63mm FL plano convex lenses in this arrangment:
GG|)---(|dvcam

This distance between the two lenses is crucial as not to get barrell distortion.

I do recommend trying the cd spinning idea first. then maybe improve the design from there.

here is a link to get you started: http://www.mediachance.com/dvdlab/dof/index.htm

Hope that helps,
Wayne.

[Jeff Tyler]

Thanks wayne. I think thats the first route Ill go from here and see if that works out and try to keep improving.
Now that I think about it there is this stuff I have taht is supposed to make scratches on glasses "go away" so maybe if I grind the cd, then put that on it might work better. I guess I will just experement. Thanks for the help!

Jeff

[Jim Lafferty]

Wayne -- the 1000 grit A-Ox you're waiting on will not be fine enough. Check the very first page of my tutorial for more info -- http://ideaspora.net/oldskool

3 micron (1200 grit) is where it begins to become truly rewarding. I'm waiting on 1.4 micron (1500 grit) A-Ox as I type this. I have .3 and .05 micron grit, but neither actually produce a consistent slurry -- in fact, in all my efforts, they did not even scratch the glass.

Sorry I have not had the time to update that tutorial, and this is why I'm trying to be vigilant about people quoting it -- it's about a year and a half old.

- jim

[Ben Winter]

Here's footage that's hot off the export function from my GL2 camera using Optosigma 1500 grit glass. Personally I don't think the grain is terribly noticable unless you're one of those nitpicky types. And if you are, yes, I know I have some dirt on the glass. Boo hoo.

http://www.astronautradiomusic.com/dofpracsmall.wmv
I'm not sure what that weird diagonal artifact is in the left corner to the middle (if you see it, it may be a computer-related issue), but take my word for it when I say it must be the encoding process creating that, and is not in the original footage.

Some frame grabs:

http://www.astronautradiomusic.com/Test1.jpg
http://www.astronautradiomusic.com/Test2.jpg

[Wayne Kinney]

Originally Posted by Jim Lafferty

Wayne -- the 1000 grit A-Ox you're waiting on will not be fine enough.

But im planning on using it on a spinning glass setup, so with grain not being a problem, would the 1000 grit be OK otherwise?

Cheer,
Wayne

[Jim Lafferty]

Yeah. Sorry I'd missed that. You should be alright then.

[Leo Mandy]

Wayne,

You said the distances between the two lens is crucial for not getting barrel distortion - can you elaborate? Have you tried different distances? IS a short or longer distance betteR?

[Ben Winter]

Yeh, that is perculiar--I was getting distortion before but then changed the distance of the GG. I'm also interested on what the effects are of moving it either way.