Homemaking a 35 mm adapter at DVinfo.net

Matt Katsaros · December 17th, 2005, 04:14 PM

Hey all, first post here. I'm making a 35 mm adapter for my GL2, and I have got stuck a little bit. I've been using the tutorials from http://www.tedramasola.9k.com/photo.html and also http://www.mediachance.com/dvdlab/dof/index.htm. My first problem is that from the first one, it says instead of a macro lens you can use a magnifying glass. 1. Does this actually work and 2. What power should it be? My second problem is, on page 3 in the second tutorial it tells you how to find the right distance between the ground glass and the lens by puting the lens on infinity, pointing the device to far away trees, then looking from the backside of the ground glass and move it closer or further until the image is focused. Does he mean to attatch the whole thing to my GL2 and make it focus; look through the macro, ground, glass, and 35 mm and make it focus; or just look through the ground glass and 35 mm and make it focus. As you can guess I don't really know how any of this works so any help is needed.

Wayne Kinney · December 17th, 2005, 04:20 PM

Hello,
The magnifying glass will probably give you chroma seperation, where (mainly towards the edge of the frame) your colours, especially white highlights, start to give a blue or red fringe. An achromatic lens will give better results.

Regarding finding the right distance between GG and SLR, you can start to do this by eyeballing it, adjusting and eyeballing, without the camcorder or macro (magnifying glass) connected. Depending on the manufacture of SLR lens used, there is a set distance.

Matt Katsaros · December 17th, 2005, 04:53 PM

i still dont really get how to find the distance between the gg and slr. since my gg is just a spinning, clear cd, what would i see different when the cd is there or not? when i look through the lens through the cd all i see is like a tiny little upside tree and it doesnt seem to change whether i bring the cd forward or back. am i missing somehting or what?

Carl Jakobsson · December 17th, 2005, 04:59 PM

I would suggest you wait with the magnifying glass/macro. On some cameras with good zooms you can avoid the magnifying glass. But you will notice as soon as you've got the other stuff working.

Setting the distance between the gg and the lens is not hard. As you stated, put the lens at infinity and point the adapter at some trees far away (more than 15 meters). Then adjust the distance between the lens and the ground glass (the cd) until you see a sharp picture on the ground glass. Now that distance is correctly set. You can verify it by setting the lens' focus on 0.5 meter and then taking a ruler and measure up 0.5 m from the lens to some object (a can of coke or whatever that has details like text on it). If the object is sharp and the lens is set at 0.5m you have verified that the distance is correctly set.

Carl Jakobsson · December 17th, 2005, 05:01 PM

Quote:

Originally Posted by Matt Katsaros

i still dont really get how to find the distance between the gg and slr. since my gg is just a spinning, clear cd, what would i see different when the cd is there or not? when i look through the lens through the cd all i see is like a tiny little upside tree and it doesnt seem to change whether i bring the cd forward or back. am i missing somehting or what?

You must sandpaper the cd so it's not clear any more. Do it only on one side of the cd. The sandpapered side should face the lens. Then you'll se what we're talking about.

Wayne Kinney · December 17th, 2005, 05:08 PM

Yes,
A clear cd will do nothing. the cd needs to be etched/fosted like in the tutorial to diffuse the light. It's this that gives you the DOF effect

Matt Katsaros · December 17th, 2005, 07:35 PM

wow that completely fixed it i had no idea. thanks so much

Matt Katsaros · December 17th, 2005, 08:42 PM

Ok new problem. So i had this coffe mug set up so that at one end were some filters without the glass (so i can attatch it to the GL2) and about 6 or 7 cm down was my magnifying glass. I was doing some testing and it didnt seem to be working and i realized that the magnifying glass probably had to be right up against the GL2 to work (if this is wrong tell me). So i took it out and sortof held it up against my camera then did some tests and it worked a little bit but to get rid of the vingetting i had to zoom almost all the way in. Then i took this other big magnifying glass that was more powerful and held it up and tried again and it worked a tiny better, i had to still zoom in almost 3/4 of the way. any help, ideas, comments would be very helpful.

Matt Katsaros · December 17th, 2005, 08:57 PM

and yet another question, i dont think its possible, but could one use one of those magnifying sheets instead of the glass, im guessing no but i may be wrong

Carl Jakobsson · December 18th, 2005, 07:41 AM

It's better to get rid of the vignetting than zooming too far. Zooming too far will give you a very narrow view, like you're filming with zoom on. I suggest you get a condenser or maybe a better lens - or both.

What lens do you use? F-value?

Matt Katsaros · December 18th, 2005, 11:17 AM

The one i tried it with is a Canon EF-S 18-55 f/3.5-4.5, i do have a Canon EF 75-300 F/4-5.6 too

Matt Katsaros · December 18th, 2005, 04:39 PM

I know this may seem stupid but what is a condesner lens. ive seen it mentioned on many of the threads like this one and i googled it and i havent found it, what is it?

Ben Winter · December 18th, 2005, 04:42 PM

A 'condenser' is actually two plano-convex lenses used in conjunction with each other, sandwiching the ground glass/focusing screen. It's used to eliminate vignetting. What you want is just a single plano-convex lens (plano = flat side; convex = outwardly round side, so it's a lens in the shape of a glass pebble), which can be found at any optical store online. I got mine for my static adapter at www.optosigma.com. Check the "35mm adapter parts list" thread on this forum for the exact one used in a 52mm setup.

Matt Katsaros · December 18th, 2005, 09:35 PM

ok i gave up and decided that i am just going to buy a macro instead of trying this magnifying glass stuff its too difficult. any suggestions? how powerful should it be? i bought something (http://www.ebuyer.com/customer/produ...137744&_LOC=US) at fry's to test with the intention of returning it. i dont even know if its a macro. im gonna go to the good camera store tomorrow but what do u guys suggest?

December 17th, 2005, 04:14 PM	#1
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	Homemaking a 35 mm adapter Hey all, first post here. I'm making a 35 mm adapter for my GL2, and I have got stuck a little bit. I've been using the tutorials from http://www.tedramasola.9k.com/photo.html and also http://www.mediachance.com/dvdlab/dof/index.htm. My first problem is that from the first one, it says instead of a macro lens you can use a magnifying glass. 1. Does this actually work and 2. What power should it be? My second problem is, on page 3 in the second tutorial it tells you how to find the right distance between the ground glass and the lens by puting the lens on infinity, pointing the device to far away trees, then looking from the backside of the ground glass and move it closer or further until the image is focused. Does he mean to attatch the whole thing to my GL2 and make it focus; look through the macro, ground, glass, and 35 mm and make it focus; or just look through the ground glass and 35 mm and make it focus. As you can guess I don't really know how any of this works so any help is needed.

December 17th, 2005, 04:20 PM	#2
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	Hello, The magnifying glass will probably give you chroma seperation, where (mainly towards the edge of the frame) your colours, especially white highlights, start to give a blue or red fringe. An achromatic lens will give better results. Regarding finding the right distance between GG and SLR, you can start to do this by eyeballing it, adjusting and eyeballing, without the camcorder or macro (magnifying glass) connected. Depending on the manufacture of SLR lens used, there is a set distance. __________________ Thanks, Wayne.

December 17th, 2005, 05:08 PM	#6
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	Yes, A clear cd will do nothing. the cd needs to be etched/fosted like in the tutorial to diffuse the light. It's this that gives you the DOF effect __________________ Thanks, Wayne.

December 18th, 2005, 04:42 PM	#13
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	A 'condenser' is actually two plano-convex lenses used in conjunction with each other, sandwiching the ground glass/focusing screen. It's used to eliminate vignetting. What you want is just a single plano-convex lens (plano = flat side; convex = outwardly round side, so it's a lens in the shape of a glass pebble), which can be found at any optical store online. I got mine for my static adapter at www.optosigma.com. Check the "35mm adapter parts list" thread on this forum for the exact one used in a 52mm setup. __________________ BenWinter.com

December 17th, 2005, 04:53 PM	#3
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	i still dont really get how to find the distance between the gg and slr. since my gg is just a spinning, clear cd, what would i see different when the cd is there or not? when i look through the lens through the cd all i see is like a tiny little upside tree and it doesnt seem to change whether i bring the cd forward or back. am i missing somehting or what?

December 17th, 2005, 04:59 PM	#4
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	I would suggest you wait with the magnifying glass/macro. On some cameras with good zooms you can avoid the magnifying glass. But you will notice as soon as you've got the other stuff working. Setting the distance between the gg and the lens is not hard. As you stated, put the lens at infinity and point the adapter at some trees far away (more than 15 meters). Then adjust the distance between the lens and the ground glass (the cd) until you see a sharp picture on the ground glass. Now that distance is correctly set. You can verify it by setting the lens' focus on 0.5 meter and then taking a ruler and measure up 0.5 m from the lens to some object (a can of coke or whatever that has details like text on it). If the object is sharp and the lens is set at 0.5m you have verified that the distance is correctly set.

December 17th, 2005, 07:35 PM	#7
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	wow that completely fixed it i had no idea. thanks so much

December 17th, 2005, 08:42 PM	#8
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	Ok new problem. So i had this coffe mug set up so that at one end were some filters without the glass (so i can attatch it to the GL2) and about 6 or 7 cm down was my magnifying glass. I was doing some testing and it didnt seem to be working and i realized that the magnifying glass probably had to be right up against the GL2 to work (if this is wrong tell me). So i took it out and sortof held it up against my camera then did some tests and it worked a little bit but to get rid of the vingetting i had to zoom almost all the way in. Then i took this other big magnifying glass that was more powerful and held it up and tried again and it worked a tiny better, i had to still zoom in almost 3/4 of the way. any help, ideas, comments would be very helpful.

December 17th, 2005, 08:57 PM	#9
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	and yet another question, i dont think its possible, but could one use one of those magnifying sheets instead of the glass, im guessing no but i may be wrong

December 18th, 2005, 07:41 AM	#10
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	It's better to get rid of the vignetting than zooming too far. Zooming too far will give you a very narrow view, like you're filming with zoom on. I suggest you get a condenser or maybe a better lens - or both. What lens do you use? F-value?

December 18th, 2005, 11:17 AM	#11
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	The one i tried it with is a Canon EF-S 18-55 f/3.5-4.5, i do have a Canon EF 75-300 F/4-5.6 too

December 18th, 2005, 04:39 PM	#12
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	I know this may seem stupid but what is a condesner lens. ive seen it mentioned on many of the threads like this one and i googled it and i havent found it, what is it?

December 18th, 2005, 09:35 PM	#14
Matt Katsaros New Boot Join Date: Dec 2005 Posts: 11	ok i gave up and decided that i am just going to buy a macro instead of trying this magnifying glass stuff its too difficult. any suggestions? how powerful should it be? i bought something (http://www.ebuyer.com/customer/produ...137744&_LOC=US) at fry's to test with the intention of returning it. i dont even know if its a macro. im gonna go to the good camera store tomorrow but what do u guys suggest?