Need condenser advice at DVinfo.net

Carl Jakobsson · June 1st, 2006, 10:58 AM

Hi!

Here's the deal, I'm refining my cd-spinner and need a condenser. I've disassembled various projectors in search of optics, but I haven't found anything that give me satisfying results yet. So my question to you expert is what exact condenser should I buy?

The lens is a fast Canon FD1.4 and the camcorder type that will be mostly used is the 3CCD Panasonic NV-series (37mm optics). Groundglass will be a transparent Nivea-coated cd-r.

I would really appreciate if you could point out specific condensers, preferably within the EU, but US shops are ok too. I guess glass condensers are the best.

Forrest Schultz · June 1st, 2006, 08:01 PM

if you are just going to coat a clear cd with nivea without grinding it first with a 200 or 300 grit i doubt you will get enought diffusion to avoid hotspot. in that case, you also wont get much of a shallow dof, if its too transparent.

but as for condensers, this one works alright:
http://www.surplusshed.com/pages/item/l3385.html

it was used in early versions of the Letus and Sg35

For me, i was lucky to snag a 35mm sized condesner out of an old SLR camera. it was coupled with the focus screen. I like to use that, and this may sound odd, but i found that if you put the condenser between your SLR lens and the GG. with the flat side facing your gg, place the condenser about say 20mm in front of your gg, and if you are using a 35mm condesner like i am, you will get a perfect 35mm sized image on the glass (slightly larger perhaps) but without any falloff, it is bright throught the frame until it ends and then its just dark like the cd. very cool and good for reference. It plays with the optics when you do this so back focus changes, but once you find backfocus again, it wont vary from slr lens to slr lens. it works really well.

Carl Jakobsson · June 1st, 2006, 08:29 PM

I forgot to mention the grinding. You're right, without any grinding I could as well skip the GG... :)

I disassembled an 8mm camera and used that "condenser" (or was it a condenser? - don't know) between the GG and SLR and it worked quite well, the image projected was a bit smaller though than without the "condenser".

Thanks for the advice and link to the condenser, exactly what I was looking for. Is that condenser some kind of "generic" condenser that works well with most adapters?

/Carl

Min Lee · June 1st, 2006, 08:55 PM

I think that condensor is sold out. I took a chance with this one instead. Waiting for it to arrive. http://www.surplusshed.com/pages/item/l3600.html

Carl Jakobsson · June 1st, 2006, 09:05 PM

Quote:

Originally Posted by Min Lee

I think that condensor is sold out. I took a chance with this one instead. Waiting for it to arrive. http://www.surplusshed.com/pages/item/l3600.html

Ok, would you please tell me if it worked when it's arrived?

Min Lee · June 1st, 2006, 09:58 PM

Will do. They seem to be a bit slow though. It's been two days and I still haven't been billed or receive any shipping info.

Wayne Kinney · June 2nd, 2006, 01:59 AM

Quote:

Originally Posted by Carl Jakobsson

I disassembled an 8mm camera and used that "condenser" (or was it a condenser? - don't know) between the GG and SLR and it worked quite well, the image projected was a bit smaller though than without the "condenser"

I recommend placing it between your GG and Camcorder with it very close to the GG:

SLR-----GG| |)-----cam

Carl Jakobsson · June 2nd, 2006, 04:56 AM

Quote:

Originally Posted by Wayne Kinney

I recommend placing it between your GG and Camcorder with it very close to the GG:

SLR-----GG| |)-----cam

That wasn't possible because the "condenser" was only around 18 mm in diameter :). I believe the placement you suggest is the best, but it requires the condenser to be in good condition, which is not the case with all my scratched optics.:( And that's a reason why I have to buy one!

Wayne Kinney · June 2nd, 2006, 05:12 AM

OK cool.

That one from surplus looks ok, just note that alot of lenses from there arrive scratched.

Min Lee · June 2nd, 2006, 08:19 PM

It arrived. I take back what i said about them being slow. Anyhow, it does what it is suppose to do but it might be too strong. The center of the lens is over 1/2 inch thick. There's quite a bit of distortion. I took a pic so you can see for yourself.

http://www.ocf.berkeley.edu/~mdlee/condenser.jpg

Carl Jakobsson · June 3rd, 2006, 07:15 AM

Quote:

Originally Posted by Min Lee

It arrived. I take back what i said about them being slow. Anyhow, it does what it is suppose to do but it might be too strong. The center of the lens is over 1/2 inch thick. There's quite a bit of distortion. I took a pic so you can see for yourself.

http://www.ocf.berkeley.edu/~mdlee/condenser.jpg

Yes, it does indeed look quite distorted. I have a condenser that is 2/3 of an inch, which is way too much. Have you tried filming with that condenser?

Min Lee · June 3rd, 2006, 09:23 AM

I'm actually still putting my adapter together so no, I haven't shot any footage. I still need a macro. The distortion is mainly around the edge and my camera has a 37mm lens so it doesn't really pick it up so much. I still get some vignetting but not nearly as bad as before. A new problem though is that the area in the center is a bit soft. I notice this everytime I move a object off center and when I tried to focus on a ruler. Any solutions to this?

Carl Jakobsson · June 5th, 2006, 09:25 AM

I've been looking in Surplussheds catalouge for a PCX that has similar specs as the suggested "L3385" (52MM X 44MM, 100MM FL).

What do you think about those?
STOCK#, TYPE, DIA, FL,COATED,$
L4336 PCX 52.5 80 Y $4.00
L6260 PCX 51.5 103 N $4.00
L8081 PCX 35.0 103 Y $4.00
L5705 PCX 38.0 101 Y $4.00

Unfortunately I can't find the product pages for those lenses.

What about achromats? Aren't those the same thing as a pcx, but with an extra lens cemented on that prevents chromatic aberration?

Does anyone know about some other supplier that has a pcx or achromat that has been tested to work?

/Carl

June 1st, 2006, 10:58 AM	#1
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	Need condenser advice Hi! Here's the deal, I'm refining my cd-spinner and need a condenser. I've disassembled various projectors in search of optics, but I haven't found anything that give me satisfying results yet. So my question to you expert is what exact condenser should I buy? The lens is a fast Canon FD1.4 and the camcorder type that will be mostly used is the 3CCD Panasonic NV-series (37mm optics). Groundglass will be a transparent Nivea-coated cd-r. I would really appreciate if you could point out specific condensers, preferably within the EU, but US shops are ok too. I guess glass condensers are the best. __________________ http://www.nattvard.com Last edited by Carl Jakobsson; June 1st, 2006 at 10:59 AM. Reason: spelling mistake

June 1st, 2006, 08:29 PM	#3
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	I forgot to mention the grinding. You're right, without any grinding I could as well skip the GG... :) I disassembled an 8mm camera and used that "condenser" (or was it a condenser? - don't know) between the GG and SLR and it worked quite well, the image projected was a bit smaller though than without the "condenser". Thanks for the advice and link to the condenser, exactly what I was looking for. Is that condenser some kind of "generic" condenser that works well with most adapters? /Carl __________________ http://www.nattvard.com

June 2nd, 2006, 05:12 AM	#9
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	OK cool. That one from surplus looks ok, just note that alot of lenses from there arrive scratched. __________________ Thanks, Wayne.

June 5th, 2006, 09:25 AM	#13
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	I've been looking in Surplussheds catalouge for a PCX that has similar specs as the suggested "L3385" (52MM X 44MM, 100MM FL). What do you think about those? STOCK#, TYPE, DIA, FL,COATED,$ L4336 PCX 52.5 80 Y $4.00 L6260 PCX 51.5 103 N $4.00 L8081 PCX 35.0 103 Y $4.00 L5705 PCX 38.0 101 Y $4.00 Unfortunately I can't find the product pages for those lenses. What about achromats? Aren't those the same thing as a pcx, but with an extra lens cemented on that prevents chromatic aberration? Does anyone know about some other supplier that has a pcx or achromat that has been tested to work? /Carl __________________ http://www.nattvard.com

June 1st, 2006, 08:01 PM	#2
Forrest Schultz Major Player Join Date: Mar 2005 Location: Atwater, CA Posts: 246	if you are just going to coat a clear cd with nivea without grinding it first with a 200 or 300 grit i doubt you will get enought diffusion to avoid hotspot. in that case, you also wont get much of a shallow dof, if its too transparent. but as for condensers, this one works alright: http://www.surplusshed.com/pages/item/l3385.html it was used in early versions of the Letus and Sg35 For me, i was lucky to snag a 35mm sized condesner out of an old SLR camera. it was coupled with the focus screen. I like to use that, and this may sound odd, but i found that if you put the condenser between your SLR lens and the GG. with the flat side facing your gg, place the condenser about say 20mm in front of your gg, and if you are using a 35mm condesner like i am, you will get a perfect 35mm sized image on the glass (slightly larger perhaps) but without any falloff, it is bright throught the frame until it ends and then its just dark like the cd. very cool and good for reference. It plays with the optics when you do this so back focus changes, but once you find backfocus again, it wont vary from slr lens to slr lens. it works really well.

June 1st, 2006, 08:55 PM	#4
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	I think that condensor is sold out. I took a chance with this one instead. Waiting for it to arrive. http://www.surplusshed.com/pages/item/l3600.html

June 1st, 2006, 09:58 PM	#6
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	Will do. They seem to be a bit slow though. It's been two days and I still haven't been billed or receive any shipping info.

June 2nd, 2006, 08:19 PM	#10
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	It arrived. I take back what i said about them being slow. Anyhow, it does what it is suppose to do but it might be too strong. The center of the lens is over 1/2 inch thick. There's quite a bit of distortion. I took a pic so you can see for yourself. http://www.ocf.berkeley.edu/~mdlee/condenser.jpg

June 3rd, 2006, 09:23 AM	#12
Min Lee Major Player Join Date: Sep 2005 Location: San Francisco, CA Posts: 200	I'm actually still putting my adapter together so no, I haven't shot any footage. I still need a macro. The distortion is mainly around the edge and my camera has a 37mm lens so it doesn't really pick it up so much. I still get some vignetting but not nearly as bad as before. A new problem though is that the area in the center is a bit soft. I notice this everytime I move a object off center and when I tried to focus on a ruler. Any solutions to this?