Plano-Convex Lens

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RichardB
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Plano-Convex Lens

Post by RichardB »

Will one of these do the job for DIY telecine?

http://www.knightoptical.co.uk/acatalog ... etermm.htm

100mm diameter, and if so which focal length? Price isn't a particular issue, unless I can get the same thing brand new for less from another UK retailer (I don't want to have to wait for something to come up on ebay).
roger lauwens
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Re: Plano-Convex Lens

Post by roger lauwens »

I am considering to build the same set up. But I would consider a larger lens. Companies who sell the system use a 5 inch condenser lens. According to what i read in this forum a condenserlens is the same as a plano convex lens or a field lens.
Do not forget to change tha lamp in your projector for a led lamp.

If somebody could help us with the focal distance, I would be very happy.
roger lauwens
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Re: Plano-Convex Lens

Post by roger lauwens »

Somlething I want to add : Please see also on this forum :

Telecine condenser lens supplier

where you will find a lot of info
Chris-B
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Re: Plano-Convex Lens

Post by Chris-B »

I'm using a Mightex camera shown here-
http://www.mightexsystems.com/family_in ... ries_id=43

With a Pentax c mount 50mm c mount lens and I'm getting great results.
I have tried the condenser lens method and it is really tricky to set up, a total headache.
I found using a little video camera with extension tubes loads easier.

I've also experimented with flatbeds with some programe that splits the frames up, I forget what the software is call now. Also tried a close-up lens mounted to the camcorder which was ok but difficult to find the right lens, I used some elements from a dead zoom lens.

The condenser lens is a cheap option, but I would suggest a small c mount camera if you can afford one.

Good luck!
Chris.
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JhnZ33
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Re: Plano-Convex Lens

Post by JhnZ33 »

Chris-B wrote:I'm using a Mightex camera shown here-
http://www.mightexsystems.com/family_in ... ries_id=43

With a Pentax c mount 50mm c mount lens and I'm getting great results.
I have tried the condenser lens method and it is really tricky to set up, a total headache.
I found using a little video camera with extension tubes loads easier.
Be interested to see some of your results. Would also be curious as to which Pentax lens you're using.

JP
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gianni1
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Re: Plano-Convex Lens

Post by gianni1 »

Double Convex or Single Convex Lens? Will a "Double Convex Lens" work or do I go for a single convex lens?

I was checking out Edmund Optics (UK) yesterday for a few items to upgrade my converted projector. My system is a diy telecine, sort of moviestuff workprinter clone. I'm looking to replace the boot sale, dumpster diving, junk parts with some new components...

I'm pointing a Firewire Mini DV camcorder into the film gate, through a condenser lens, and reversing the image with a surface coated mirror, using a microswitch on the projector claw to advance the stop motion "Capturemate" program on my Apple Mac computer.



Gianni in Londinium
roger lauwens
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Re: Plano-Convex Lens

Post by roger lauwens »

In Europe is used what they call a magnifying lens + 3, in combination with the mirror.

Are we talking about the same kind of lens or is there a difference between the plano convex lens and a magnifying lens
granfer
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Re: Plano-Convex Lens

Post by granfer »

A plano convex lens is flat on one side and domed on the other. For the use proposed it does not matter if the lens is plano-convex or bi-convex (domed both sides) as long as it has a fairly short focal length.
The actual focal length is not important; it needs to be short enough not to be too far from the projector but not so short as to distort the image. Having said that, it needn't be expensive; a good quality glass or acrylic "magnifying glass" will work quite happily so long as it is free of blemishes.
And size is not terribly important; the larger it is the less obvious will be any slight blemish or dust on the surface. My webpage.....

http://hometown.aol.co.uk/granfer/myhom ... adget.html

deals with some of the criteria and problems associated with this approach. I don't pretend to be either an expert or authority on the subject, but what I have acheived so far brings out some of the problems.
Contact me if you wish.

Granfer
thepelell
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Re: Plano-Convex Lens

Post by thepelell »

Granfer, your story is very similar to mine. I'm using a 75mm lens from a 35mm slide projector as supplementary lens in front of my DV cam. I'm not getting vignetting, but i am experiencing blur and slight distortion at the corners of the image. At the moment i'm keeping this setup, as soon as cash will allow, i'll get myself one of those mega pixel cmos usb cams with c mount lens to get at least HD resolution frame grabs.
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Re: Plano-Convex Lens

Post by audadvnc »

The old Oxberry animation stands would use plano-convex lenses for generating virtual image planes from alternate image sources such as projectors.
Robert Hughes
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