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Old December 24th, 2005, 12:11 PM   #1
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35 Adapter Question.

I plan on making one for my vx2100 which has 58mm threads.
So what exactly do I need to make one?

I already know I need a +10 macro, uv filters and what not, but how would I go about making this like whats the order of parts that go in order to build it and what would be the first thing that would be attached to the front of my camera?

I'm new to this so please help me out.
Garrett Goerl is offline   Reply With Quote
Old December 24th, 2005, 12:45 PM   #2
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There are different designs that are posted around this thread but the basic order of the adapter should be:

(camera side) macro lens --> ground glass --> SLR lens mount (Lens side)

In order to eliminate darkening of the edges and improve light spread, we add a plano-convex lens, also known as a condenser:

(camera side) macro lens --> *PXCL* --> ground glass --> SLR lens mount (Lens side)

UV filters are just used to put distance between these parts. In fact it's recommended that you remove the glass from the UV filter rings--the less glass needed between the camera and the image, the better.

The first thing that should be connected to your camera is the macro lens.

I'm still giving my vote to a sticky on this forum outlining the basics of a 35mm adapter...
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Old December 24th, 2005, 12:55 PM   #3
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You have my vote for the sticky.
Thanks for the help.

And the connection of all this stuff it just all goes together or is there something else involved like pvc? Also where would I find the plano-convex lens I tried ebay but it was oddly shaped like rectangle and as for the gg whats good to use?
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Old December 24th, 2005, 12:58 PM   #4
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A sticky on this has been mentioned before and is a great idea. I am willing to contribute and go into detail on how to create a spinning GG disk, if such a sticky were to come about.
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Old December 25th, 2005, 06:27 AM   #5
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This combination should work adequately for you but it is not a list of store bought parts. My personal preference is not for the stacked filter ring arrangements but for the project box designs or in my case, PVC sewer pipe and plastic caps. There is more hassle in building them but there is more flexibility in changing the design including using a moving groundglass should you decide to.

So here goes :-

SLR lens of choice, preferably f1.8 aperture >> 46.5mm (for Nikon lenses ) from flange face of lens mount to rough face of groundglass >> +7 power Century Optics achromatic dioptre with 58mm threaded mount >> camcorder. This is not an erecting version. The 7+ achromatic dioptre allows you to sit off far enough from the groundglass to add a prism pair if you want to later alter your adaptor to erect the image. (A stronger dioptre, say 10+ will deny you this later option and you will then have to buy in a +7.)

With this combination, you have to use about 70% zoom which just brings you into the performance fall-off of the Sony optics, which introduces a slight light loss and also a slight darkening in the corners under certain lighting conditions. You will find this characteristic inherent in the camera at this zoom setting and it is not the fault of the device. Shoot a test against a plain featureless white or grey panel and you will see it there, slightly offset to the right in a frame grab outside of the TV 4:3 safe area.

With a +7 dioptre, the distance from groundglass to front of dioptre attached to camera is about 5 inches or about 125mm. This will yield an area of about 24mm x 18mm usable off the groundglass.

The appliance will be a bit long.

When you set up your centres bear in mind that this family of camcorders has the centre of the CCD array offset relative to the lens centre-axis. To demonstrate lock your cam off on a tripod aimed at a target which when cam is zoomed right in is centre in the viewfinder.

Retreat zoom to wide and you will see the target move off-centre. So if setting up your centres through the camera viewfinder you will have the optical centres off-axis relative to each other and whilst you will seem to have a centred image, the res will be slightly inferior. The fixed gg devices using stacked filter rings automatically assure centricity and parallel alignment.

There are better designs than my combination which does not use condensers etc..

People have been using contrivances from other appliances in place of the achromatic dioptre, some more successfully than others, also cheaper lenses in the still-camera zoom class which generally seem to sit around f3.5 or thereabouts. The groundglass does lose resolution so you need the best image onto it you can get. f1.8 or even wider-aperture primes rule. Small plastic zooms do not. Digital SLR lenses are designed to cover a smaller image area and will not work adequately. Be carerful when you read the lens specs. Sometimes they can be confusing.

Time and money spent in the bargain hunting wilderness may come to naught if you are forced to go to the achromatic dioptre and good f1.8 primes eventually. So in the long run, money and effort may well be wasted in the form of bits of odd glass in the shed waiting for the next garage sale whilst you run around with the good lens on your camera at last getting the results you want.

Last edited by Bob Hart; December 25th, 2005 at 06:58 AM.
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