View Full Version : Newbie with a GS200
Steve Wardale November 3rd, 2004, 03:03 PM This is probably asking the impossible, but is it at all possible to construct a mini35 system for a VERY modest Panasonic GS200? Like others, I've been confused with the designs for these adaptors, but I did read that a german cameraman setup something for a panasonic camera, and subsequently someone else did with a prosumer SonyDV (not sure which model). I've been researching here an awful lot (as you can see, in all the time I've been here, I've only really searched and never ask since most of it has already been done for me).
I wouldn't normally either, but I think I'm getting the wrong end of the stick, and would love some advice as where to start. If it is possible to be made with such a low-budget cam as mine, I'd like to know where to start!
Thanks ever so much,
S.
Jim Lafferty November 4th, 2004, 01:05 PM That cam has a 37mm lens, correct? If so, your only obstacles will be:
Finding an achromatic diopter/macro lens that will fit 37mm (look on eBay, and places like bhphotovideo.com)
Determining whether or not you need to pair the achromat with condensor(s) -- I'm really not able to help here
Build a lens tube to house your GG, whether using ThorLabs stuff (stepping up to their 50mm parts), or something using PVC piping and coupling from Home Depot
Acquire the appropriate step-up ring to fit the tubing to your lens (37mm-52mm)
Acquire a ground glass of the appropriate diameter -- made from a ground 37mm UV filter
Mount your film lens to the front with the ppropriate mount, and adjust flange focal length
- jim
Steve Wardale November 5th, 2004, 04:19 AM Thanks very much for the help, this have certainly got me started since I had no idea what to do before! Can I ask what type of adaptor this is, since there are a few (the Agus35, Aldu35 and a few others) and will the GS120 be able to cope with the lack of light since it's aboninable for low light (my old JVC VHSC cam could at least tape SOMETHING at nighttime!)
Thanks again,
s.
Jim Lafferty November 5th, 2004, 08:44 AM Ah, my advice is in regards to a static adapter. I don't know about light loss and whatnot with your cam -- that's something of an area where you'll have to experiment and see.
- jim
Steve Wardale November 5th, 2004, 11:43 AM I've managed to locate some of the items you've mentioned and will go ahead and see if I can construct something with it (if it works, I'll be sure to post a clip here).
Out of interest, could a spinning version of this be done using the same equpiment you mentioned?
Jim Lafferty November 5th, 2004, 01:45 PM Well... yes and no.
The spinner involves a larger housing so that you can place the line of sight of the lenses off-center. Then there's thge motor and power supply. Finally, a support system. So, some of the parts would still be needed/advised for a spinner -- the achromat, maybe parts of the housing -- while others would need to be modified or changed out entirely (i.e. you'd need larger glass...)
- jim
Steve Wardale November 5th, 2004, 05:09 PM Yeah, that's what I thought you might say! I'll give the static design a go first, then try the motorized version afterwards if all goes to plan.
BTW, how sucessful have 37mm > 52mm adaptors been with other people? I'd have thought the quality would be pretty awful compaired to an XL1S or even a GL1/2.
s.
Richard Mellor November 6th, 2004, 09:49 AM this is the parts list I used for my final version of the static adapter .
http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=213&Product_ID=1481
(2) http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=848&Product_ID=1483
http://www.thorlabs.com/ProductDetail.cfm?&DID=6&ObjectGroup_ID=112&Product_ID=11280
http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=1132&Product_ID=36117
all the parts for my static version . will be used in the ocillating version .
Steve Wardale November 6th, 2004, 10:05 AM Richard, do you happen to have any examples of images/video taken with your adaptor, since I haven't been able to find many static clips, only rotating ground glass clips.
Thanks for the links!
Richard Mellor November 6th, 2004, 10:30 AM this is a still. from a lens tube version of the static adapter
the camera is a 1 chipper the lens is a cannon 50mm1.4
the ground glass used is optmosigma 1500 grit . the plcx has a focal length of 60
the adapter could not be precisly focused because of the filter rings. in the filter ring version
and I could not get the plcx flush with the ground glass. the shallow depth of field is created.I broke the optmosigma glass and on monday I will be reciving the throlabs glass . I already have the tube system. this is the way to go. focus will be perfect.
to my surprise the threads are the same in the tube system as 52mm camera .so you just have to get stepdown or stepup riing to fit your camera
http://www.dvinfo.net/media/mellor/PDVD_540.BMP
Richard Mellor November 6th, 2004, 11:08 AM sounds like steve when finished you will have for less than a thousand dollars. a 3ccd camera with slr lens attachments
a $26,000 adapter clone creating shallow depth of field.
and ability to use great 35mm glass.
Steve Wardale November 7th, 2004, 03:59 AM Haha, yeah I just hope it will be able to handle the low light! I found the miniDV Aldu35 static lens system diagram for piecing together the parts, is this of any use for this one?
Richard Mellor November 7th, 2004, 06:18 AM you just have to figure out which brand of 35mm camera lenses you want to use . you want fast lenses I bought on ebay a cannon 1.2 for about $90. nikons are claimed a little better,but more money . then buy a c-mount for that brand. once you buy the parts listed above from thorlabs you just have screw them all together. any camera shop would have all the things you needed to get this fitted to your camera:c-mount/stepdown ring . for the thorlabs tube system just insert adjustable ring about 1.3 inches from c-mount insert ground glass next adjust threaded ring untill you get a sharp image on the ground glass . next insert plcx flat end on top of the ground glass . then thread retaing ring on top of plcx . tighten down with thumbnail . attach to camera . I think you need 37 to 52 step ring.
when we perfect the microcrystiline wax method, we will just swap out the ground glass http://www.dvinfo.net/media/mellor/aldu-test-44.jpg
Jim Lafferty November 8th, 2004, 12:15 AM Just to be clear -- Nikon lenses use an F mount.
Steve Wardale November 8th, 2004, 12:25 PM Thanks for those Richard, it's useful to see many setups for the Aldu, so if doesn't work I can fall back on a different design. Hopefully the Pentax KA fit 52mm lenses I have should work with it, and give a sharp enough image to work with.
Richard Mellor November 8th, 2004, 03:33 PM steve I just got in the new groundglass from thorlabs.
started testing it and it looks as good as the optmo sigma . and it,s only $14
and I am getting sharp focus now with the tube system
it looks beautiful. I am sure you will quite happy when you put this on your camera.
Steve Wardale November 8th, 2004, 03:48 PM Richard, is this the ground glass - http://www.thorlabs.com/ProductDetail.cfm?DID=6&ObjectGroup_ID=1132&Product_ID=36117
If so, this would certainly be alot easier than grounding down a UV filter with AO. Unless you still have to ground it?
Steve Wardale November 25th, 2004, 10:20 AM Well, since I couldn't get my hands on any AO locally, I went with Silicon Carbide, but unfortunatly it seems to be too fine to get a good frosting on it... by the looks of the Aldu, his is completely opaque, whereas all I can get is a semi-transparant covering. Furthermore, I tried it out with the macro, and it looked like a spider's web down there... nothing but harsh grain, even after I went up to 400 (eventually I can go to 600).
Does anyone have any Silicon Carbide advice, or should I just try it with AO?
Bob Hart November 26th, 2004, 08:06 AM There was a reference to another site related to optical groundglass awhile back on one of the posts.
The grade you are using is a little too coarse. I think the grade in silicon carbide should be 1200 grit. I understand this equates with 5 micron in aluminium oxide.
Silicon Carbide is apparently inferior to aluminium oxide because for the same grade or size of particles, it had a tendency to drag long chips out of the glass rather than punch pits into it.
If you want to determine if your cam has the light performance to work with AGUS/ALDU appliances, see if you can get some 1x f-stop neutral density filter material as used for making gel filters to put in Bolex or CP16 motion picture cams. These have little frames you put the gel filter material into. The material comes in a folder and looks like very thin plastic sheet and cuts with scissors.
The AGUS/ALDU appliances seem mostly to lose between three and four f-stops of light so test with as many layers of gel in front of the lens until your camcorder says enough.
The SLR lens on front has some bearing on it as well. For best results use f1.8 of better lenses.
Steve Wardale November 28th, 2004, 01:44 PM I've uploaded a shot of what I've gotten so far with the grade 600 sodium carbide, a spacer tube of cardboard and the lens at the appropriate distance...
http://www.keanufan.co.uk/camtest.jpg
This is obviously far from acceptable, but what I can't yet understand is how to stop it looking like a 1920's zoetrope... the vignetting is unbearable!! The scratches are also horrible (like you said Bob, cause of the SO) which leads me question weather or not it is possible to remove a clean focusing screen from an old camera, and using that instead of grinding a filter lens?
Bob Hart November 28th, 2004, 09:28 PM Steve.
From what I see, your camcorder has adequate light performance to deal with the AGUS/ALDU. Your groundglass is very opaque which cuts light transmission down.
The vignette is another matter.
I was unable to determine if it is from the close-up lens/macro, insufficient zoom-in available on your camcorder, or the Pentax lens on the front, being of insufficient wide aperture. Judging by the scale of the scratches relative to the circular image, I suspect your camcorder needs to be zoomed in closer through the vignette. The close-up/macro lens on front of the camcorder may have to be a larger diameter with step-up ring to enable mounting.
What close-up lens are you using?
If you are using no close-up lens at all and relying on the camcorder's own macro/zoom facility to get to the groundglass image, you may be running out of camcorder zoom range which would mean you are looking at an area on the groundglass larger than the projected image.
To test for this, draw a 24mm x 18mm rectangle and see if your camcorder/close-up combination will frame tightly on it. If it remains a small rectangle in center of your image, you will need a stronger close-up lens to bring the gg image closer to the camcorder.
Then you may need to add a close-up/macro lens to bring the groundglass object closer. Going out to the end of camcorder zoom, drops the light level as well with most products.
All input to the AGUS/ALDU ideally is with the SLR lens at its widest aperture, ideally an f1.8 if you can get it.
Don't take too much notice of my comments as they are largely guesswork.
Danny Hatzi November 29th, 2004, 01:05 AM <<<-- Originally posted by Bob Hart
All input to the AGUS/ALDU ideally is with the SLR lens at its widest aperture, ideally an f1.8 if you can get it. -->>>
Sorry for the ultra newbie question,but isn't it going to be better with an f1.2 or f1.4? (besides the higher price of cource)
Danny
Aaron Shaw November 29th, 2004, 09:07 AM Yes, but they don't come cheap. I think that was Bob's point.
Danny Hatzi November 29th, 2004, 12:37 PM got it!
thanks
Steve Wardale November 29th, 2004, 01:42 PM http://www.keanufan.co.uk/camtest2.jpg
http://www.keanufan.co.uk/camtest3.jpg
These are the two newest photos that I've taken an f2.8 macro lens, so it gave me a better aperature to focus through. The problem is it looks like I've zoomed in, which I have, but I can't seem to find a way of getting a wideangle image. I'd have blamed the Macro lens, but the other one looked the same!
Aaron Shaw November 29th, 2004, 04:28 PM For a wide angle image you need a wide angle lens ;)
What is the focal length of your current lens?
Steve Wardale November 30th, 2004, 12:20 PM The focal length is 90mm, but I also tried the 50mm and both gave a rather telephoto image. What is the ideal focal length to use?
Also, could the ground glass diffuser that Richard linked to be useful with my setup? Cause it seems alot handier than having to use a UV filter, if it would work.
Edit -
I discovered a UK place that sells GG Diffusers: http://www.knightoptical.co.uk/acatalog/DiffusersGroundGlassDiffuser207.htm
Would any of these be useful, since $60 for shipping to the UK from Thorlabs is a little expensive!
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