Aspheric Lens as a Condenser? at DVinfo.net

Akira Ando · July 5th, 2005, 04:13 PM

I have been asking an optic company about the static GG adapter lens set up for DVX100A. I was intending to use the 75mm Diameter Achromat doublet (200mm Focal Length = +5 Diopter Power), and with this Acromat lens, I need more dipter power to fill the 36x24mm image plane without having too much zoom (Less zoom = less light loss). I need extra +2 to +5 dipter power. And I was thinking of using PCX as magnifier / condenser

Then the optic company chap suggested me that the best image quality will be acquired by hacking DVX and remove its lens, and attach the 35mm lens directly to DVX. But this way, I think it affects the FOV / DOF. Can anyone confirm this? Or am I wrong?

And also what the optic chap suggested was, if I don't want to hack DVX, then use 75mm Dia. Aspheric Condenser Lens (50mm FL = +20 Diopter Power) contacting the Achromat lens. Which means Stick the two lenses together, and no space in between. It acts as one lens.
To magnify GG image I am thinking about having space between GG and condenser.
[35mm lens] > [GG]>[some space]>[Aspheric:D][Achromat:()]>]DVX100A]

Since Acromat costs quite much. I haven't got these lenses with me now. I am talking about assumption before I buy these lenses.
So, if anyone has experience with Aspheric Condenser, please give me some feedback.
Much appreciated you suggestion.

cheers

Akira

Quyen Le · July 5th, 2005, 05:01 PM

By taking out the DVX lens and use 35mm lens instead, you can only use the center portion of the 36mmX24mm. It depends on the size of the CCD of the camera. With 1/3 inch CCD, any 35mm lens will be multiplied by 7.2 the focal length and any lens will become telephoto lens (unless you have some kind of lens to correct the image to 1/3 inch instead of 36x24) . DOF is the DOF of the 35mm and image quality will be better than using the adapter (I am talking about no gg involve because the image of the 35mm lens will get on the CCDs). Light lost is significant. I am talking about 4 stops light lost. So this way is only good for outdoor and indoor with good lighting.
The picture below was captured using a really cheap lens on the XL1 using the 35mm lens to demonstrate DOF.
http://www.nuocsong.com/nhatho/adapter/07.JPG
Hope this info will help, thanks.

Quyen

Akira Ando · July 5th, 2005, 06:08 PM

Thanks Quyen,

That's what I thought. Removing DVX lens and attach SLR lens, makes 7.2 tuimes telephoto, this doesn't match my need. So I should stick to the static GG (perhaps wax) adapter.

Then again, Aspheric Condensor. It seems Aspheric is good at condensing light but with 50mm Focal Length, I'm a bit worried about barrel distortion or other abberations.

Any thoughts?

cheers

Akira

Leo Mandy · July 6th, 2005, 11:48 AM

Didn't the 'andromedia' do the same thing?

July 5th, 2005, 04:13 PM	#1
Akira Ando New Boot Join Date: Jul 2005 Posts: 7	Aspheric Lens as a Condenser? I have been asking an optic company about the static GG adapter lens set up for DVX100A. I was intending to use the 75mm Diameter Achromat doublet (200mm Focal Length = +5 Diopter Power), and with this Acromat lens, I need more dipter power to fill the 36x24mm image plane without having too much zoom (Less zoom = less light loss). I need extra +2 to +5 dipter power. And I was thinking of using PCX as magnifier / condenser Then the optic company chap suggested me that the best image quality will be acquired by hacking DVX and remove its lens, and attach the 35mm lens directly to DVX. But this way, I think it affects the FOV / DOF. Can anyone confirm this? Or am I wrong? And also what the optic chap suggested was, if I don't want to hack DVX, then use 75mm Dia. Aspheric Condenser Lens (50mm FL = +20 Diopter Power) contacting the Achromat lens. Which means Stick the two lenses together, and no space in between. It acts as one lens. To magnify GG image I am thinking about having space between GG and condenser. [35mm lens] > [GG]>[some space]>[Aspheric:D][Achromat:()]>]DVX100A] Since Acromat costs quite much. I haven't got these lenses with me now. I am talking about assumption before I buy these lenses. So, if anyone has experience with Aspheric Condenser, please give me some feedback. Much appreciated you suggestion. cheers Akira

July 5th, 2005, 05:01 PM	#2
Quyen Le Major Player Join Date: Jun 2005 Posts: 356	By taking out the DVX lens and use 35mm lens instead, you can only use the center portion of the 36mmX24mm. It depends on the size of the CCD of the camera. With 1/3 inch CCD, any 35mm lens will be multiplied by 7.2 the focal length and any lens will become telephoto lens (unless you have some kind of lens to correct the image to 1/3 inch instead of 36x24) . DOF is the DOF of the 35mm and image quality will be better than using the adapter (I am talking about no gg involve because the image of the 35mm lens will get on the CCDs). Light lost is significant. I am talking about 4 stops light lost. So this way is only good for outdoor and indoor with good lighting. The picture below was captured using a really cheap lens on the XL1 using the 35mm lens to demonstrate DOF. http://www.nuocsong.com/nhatho/adapter/07.JPG Hope this info will help, thanks. Quyen

July 5th, 2005, 06:08 PM	#3
Akira Ando New Boot Join Date: Jul 2005 Posts: 7	Thanks Quyen, That's what I thought. Removing DVX lens and attach SLR lens, makes 7.2 tuimes telephoto, this doesn't match my need. So I should stick to the static GG (perhaps wax) adapter. Then again, Aspheric Condensor. It seems Aspheric is good at condensing light but with 50mm Focal Length, I'm a bit worried about barrel distortion or other abberations. Any thoughts? cheers Akira

July 6th, 2005, 11:48 AM	#4
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	Didn't the 'andromedia' do the same thing?