results with homebuilt 35 adapter at DVinfo.net

Jonas Gramming · December 18th, 2005, 11:32 AM

Well, i just finnished my 35 mm adapter and did a test shoot
with my old camera (Canon XM1). if anyones interested
you can watch it here, i think it looks really good!

http://w1.325.telia.com/~u32512721/DOF.wmv

Wayne Kinney · December 18th, 2005, 11:42 AM

I think its a good start, Jonas.

The most obvious fault is the vignetting. Could you go into detail about your setup so we can help?

DJ Lewis · December 18th, 2005, 11:44 AM

Part list?

Carl Jakobsson · December 18th, 2005, 01:04 PM

Sounds like cd-spinner. What lens do you use? I guess you haven't any kind of condensor. Have you tried to zoom in more?

Fin hund.

Jonas Gramming · December 18th, 2005, 03:04 PM

Well, I agree there is a problem with vignetting, I use the macro from a fisheyelens, I cant zoom in anymore or i´ll loose focus. any ideas on what to do. Ive built it with help from http://www.mediachance.com/dvdlab/dof/index5.htm

(like many others i guess) I use a CD wich I just softend with sandpaper,
are there any better alternatives to this?
I use a f1.8 40mm lens. What is recomended?

Thanks for your help everyone!

Ben Winter · December 18th, 2005, 03:14 PM

You need a condenser setup. Or at least a Plano-convex lens on one side. Check out optosigma.com for a PCXL in whatever diameter lens your camera uses/whatever diameter opening your adapter has. That essentially magnifies the usable area of the GG to the point where you can avoid all vignetting. I don't think there's a single adapter out there that doesn't use one.

You're also suffering from a curious amount of distortion. A macro from a fisheye lens? I think even a Hoya or Tiffen macro off ebay might serve you better.

Wayne Kinney · December 18th, 2005, 03:23 PM

Quote:

Originally Posted by Ben Winter

That essentially magnifies the usable area of the GG to the point where you can avoid all vignetting.

Well not quite. You should still be framing on the same 36x24mm frame area of the ground glass with or without a PCX (plano convex) lens, but the job of the PCX is not to magnify but to change the angle the camcorder looks at the ground glass , so that it is at the best angle for any given point on the ground glass.

Just to understand the above, hold a 35mm lens and ground glass in front of you, looking at the ground glass dead on the optical axis (with one eye). You see the edges of the image are darker. Now, keeping your eye on the darker edge, move your head off axis about 45 degrees to the side your looking at. Now that dark area becomes bright. This is essentially what the PCX lens is doing,varying the angle of view across the frame.

Carl Jakobsson · December 18th, 2005, 03:53 PM

You'll definitively need a condersor. I got mine from an 8mm filmcamera with zoom, but I would recommend buying a real condenser.

I personally have used F1.9 lenses but isn't satisfied. Therefore I've bought a Canon F1.4 that hopefully will help me on my quest of getting a vignetting free image.

Using a spinning cd as a groundglass has been discussed a lot of times here, but I personally think it's the best affordable solution. It may look stupid filming with a box in public, but it works. i recommend you to spend your money on a condenser and a fast lens (low F-value like 1.4).

Jonas Gramming · December 19th, 2005, 03:03 AM

so okey, let me get this straight. I need, instead of my macro lens, to get a plano convex lens?
And what exactly is a condensor?

I am a little confused with all the terms here...

Thank you everyone for replying so fast, and for helping me out!

Wayne Kinney · December 19th, 2005, 04:56 AM

You will still probably need the macro as well as the plano convex lens, as they do 2 seperate jobs. The PCX is to prevent hotspot, and the macro to allow the camcorder to focus while zoomed in.

Jonas Gramming · December 19th, 2005, 06:10 AM

My dad is an optician, and he can probably get me a lens, his question is what dioptri to use?

Leo Mandy · December 23rd, 2005, 10:24 AM

Jonas : I am selling my Tiffen MAcro 7+ 10+ if you are interested.

Wayne & Ben : I was wondering about the size of the condenser myself. If you had a really big condenser - like one from an old overhead projector - I wonder if this serves the purpose better because there is less chance of vignetting because the light is spread out on a large surface. But then I also wondered if it would scatter the light less evenly because there is more surface area to cover...

Comments?

Carl Jakobsson · December 24th, 2005, 04:48 PM

The condenser spreads the light. If you don't have a condenser, you will porbably get a hotspot and dark edges (vignetting).

The macro helps your camcorder to zoom in farther on the ground glass. Only needed if your camcorder has bad zooming capabilities.

So, they are two totally different things with totally different purposes
Condenser - spread the light from the SLR-lens evenly on the ground glass
Macro - help the camcorder to zoom in closer on the ground glass

December 18th, 2005, 11:32 AM	#1
Jonas Gramming New Boot Join Date: Dec 2005 Posts: 12	results with homebuilt 35 adapter Well, i just finnished my 35 mm adapter and did a test shoot with my old camera (Canon XM1). if anyones interested you can watch it here, i think it looks really good! http://w1.325.telia.com/~u32512721/DOF.wmv

December 18th, 2005, 11:42 AM	#2
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	I think its a good start, Jonas. The most obvious fault is the vignetting. Could you go into detail about your setup so we can help? __________________ Thanks, Wayne.

December 18th, 2005, 11:44 AM	#3
DJ Lewis Regular Crew Join Date: Dec 2005 Posts: 97	Looks nice... Part list?

December 18th, 2005, 03:14 PM	#6
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	You need a condenser setup. Or at least a Plano-convex lens on one side. Check out optosigma.com for a PCXL in whatever diameter lens your camera uses/whatever diameter opening your adapter has. That essentially magnifies the usable area of the GG to the point where you can avoid all vignetting. I don't think there's a single adapter out there that doesn't use one. You're also suffering from a curious amount of distortion. A macro from a fisheye lens? I think even a Hoya or Tiffen macro off ebay might serve you better. __________________ BenWinter.com

December 19th, 2005, 04:56 AM	#10
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	You will still probably need the macro as well as the plano convex lens, as they do 2 seperate jobs. The PCX is to prevent hotspot, and the macro to allow the camcorder to focus while zoomed in. __________________ Thanks, Wayne.

December 18th, 2005, 01:04 PM	#4
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	Sounds like cd-spinner. What lens do you use? I guess you haven't any kind of condensor. Have you tried to zoom in more? Fin hund.

December 18th, 2005, 03:04 PM	#5
Jonas Gramming New Boot Join Date: Dec 2005 Posts: 12	Well, I agree there is a problem with vignetting, I use the macro from a fisheyelens, I cant zoom in anymore or i´ll loose focus. any ideas on what to do. Ive built it with help from http://www.mediachance.com/dvdlab/dof/index5.htm (like many others i guess) I use a CD wich I just softend with sandpaper, are there any better alternatives to this? I use a f1.8 40mm lens. What is recomended? Thanks for your help everyone!

December 18th, 2005, 03:53 PM	#8
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	You'll definitively need a condersor. I got mine from an 8mm filmcamera with zoom, but I would recommend buying a real condenser. I personally have used F1.9 lenses but isn't satisfied. Therefore I've bought a Canon F1.4 that hopefully will help me on my quest of getting a vignetting free image. Using a spinning cd as a groundglass has been discussed a lot of times here, but I personally think it's the best affordable solution. It may look stupid filming with a box in public, but it works. i recommend you to spend your money on a condenser and a fast lens (low F-value like 1.4).

December 19th, 2005, 03:03 AM	#9
Jonas Gramming New Boot Join Date: Dec 2005 Posts: 12	so okey, let me get this straight. I need, instead of my macro lens, to get a plano convex lens? And what exactly is a condensor? I am a little confused with all the terms here... Thank you everyone for replying so fast, and for helping me out!

December 19th, 2005, 06:10 AM	#11
Jonas Gramming New Boot Join Date: Dec 2005 Posts: 12	My dad is an optician, and he can probably get me a lens, his question is what dioptri to use?

December 23rd, 2005, 10:24 AM	#12
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	Jonas : I am selling my Tiffen MAcro 7+ 10+ if you are interested. Wayne & Ben : I was wondering about the size of the condenser myself. If you had a really big condenser - like one from an old overhead projector - I wonder if this serves the purpose better because there is less chance of vignetting because the light is spread out on a large surface. But then I also wondered if it would scatter the light less evenly because there is more surface area to cover... Comments?

December 24th, 2005, 04:48 PM	#13
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	The condenser spreads the light. If you don't have a condenser, you will porbably get a hotspot and dark edges (vignetting). The macro helps your camcorder to zoom in farther on the ground glass. Only needed if your camcorder has bad zooming capabilities. So, they are two totally different things with totally different purposes Condenser - spread the light from the SLR-lens evenly on the ground glass Macro - help the camcorder to zoom in closer on the ground glass