Homemade 35mm Adapter

Isaiah Kraus · February 5th, 2004, 10:35 AM

I took my mini50 (project-box design) out a few days ago and I have some images of it and the shoot, but no hosting. I've emailed Chris, but for some reason I haven't haven't recieved a reply. If any one has some hosting solutions/suggestions, I'd like to put them up.

Thanks

Taylor Moore · February 5th, 2004, 01:48 PM

Isaiah's Mini 50 Pix
www.moorefilms.com/isaiah.htm

Isaiah Kraus · February 5th, 2004, 02:41 PM

Thanks to Taylor for hosting my images.

Some info on my setup for the curious...
GL2
10x B+W Macro filter
Maxell frosted CD (with some nasty scratches near the center)
Minolta 1.7f 50mm MD 35mm lens on the front (open to 1.7 for the whole shoot)

There was a lot of light, Cam settings were:
autofocus on(dvcam was not manually focused on CD)
manual exposure
60i
f3.2 or there abouts
no gain

The images were deinterlaced using Jim Lafferty's "manual deinterlace" method in FCP 4.1.1, exported as an uncompressed, deinterlaced tif from FCP, and flipped h+v and saved as jpegs (with quality 100) in photoshop. Other than that, I did not manipulate these images in FCP or photoshop in any way.

About the video itself: all handheld, rather shaky and full of a lot of me fumbling with focus and shooting upside down and backward. Its not pretty, but if you really think it'd be informative, I'll put some of it up.

This is the first time I really got out and used my mini50 (Agus50?), so a lot of improvement is needed. Getting alignment/proper positioning of camera to cd-plane is critical to avoid vignetting/distortion. My rig is adjustable in this regard, but I failed to spend enough time beforehand so there is noticable vignetting, esp. in bright shots. Also my plastic CD is just not flat enough, and I think every time I use it it just gets worse. But I'm not looking for/don't need perfection (thankfully). Thanks to Agus and Daniel and everyone for their inspiration and ideas.

-Isaiah

Seth Richter · February 5th, 2004, 03:18 PM

Is it possible to use the formula agus35 to make two, for even more focal length?

camera|agus35|agus35

I know that the light loss would be significant, but, it would be interesting to see just how shallow we could get it.

Taylor Moore · February 5th, 2004, 03:26 PM

Is it possible to use the formula agus35 to make two, for even more focal length?

camera|agus35|agus35

I know that the light loss would be significant, but, it would be interesting to see just how shallow we could get it.

Why not just use ND filters.

Kevin Burnfield · February 5th, 2004, 05:36 PM

Thanks Taylor for hosting the pics.

Really interesting stuff here--- seems like you are getting a good focal plane area and not a super shallow DOF.

Taylor Moore · February 5th, 2004, 08:28 PM

Here is the video, looks good.

http://www.moorefilms.com/isaiahvid.htm

Brett Erskine · February 5th, 2004, 11:16 PM

Isaiah-
Great looking footage. Real sharp in the middle. You can make your corners as sharp too if you switch to a ACHROMAT screw on macro of the same power. (Did someone hear a echo...? ;-)

What kind of camera are you using?

What was your target gate size?

John Gaspain · February 6th, 2004, 01:11 AM

Looks Great taylor!

A bit of darkness in the corners but overall Im impressed, great clarity.

what camera did you use?
what size UV filter?
what grit did you use on the GG?

Bob Hart · February 6th, 2004, 03:11 AM

Isiah. - Two cheap and mean methods of shooting with the Agus35. I'm assuming you are using a VX2000 or PD150 from your mention of DVCAM.

If not using the tripod turn the whole camcorder and Agus35 upside-down. The camera will tolerate this with one caveat. - Make sure the tape cassette enclosure is scrupulously clean so that the debris of projects past does not fall from dark bottom corners of the camcorder onto your tape and the moving guts of the camcorder.

About the only way to operate the whole assembly by this method is to use it a waist height like an olde box brownie using the LCD. Holding at eye height and using the eyepiece will have you shivering with fatigue in seconds. There is just too much outboard weight.

Another cheap method is to mount to the tripod as normal. Work the camcorder with your back to the subject, the lens and Agus assembly at your left under your shoulder and look at your LCD screen from this position. I have the advantage of being left-handed. (All cameras should be made that way.) By adjusting the LCD screen to face foward, it should be possible to have the image appear the right way up. As for the (CORRECTION) "rightway up method on tripod", waist to mid-chest height for the tripod is the most practical as higher means the LCD screen switches to inverted when you tilt it too far forward. It's a bit tricky to begin with but gets easier with practice. - Likewise with the camera controls.

However with both methods, people who stop and observe develop a confirmed belief that the camera operator is an idiot.

Experiments in a camera shop with erecting prisms for telescopes, both schmidt and roof type have not yielded anything so far. A Meade schmidt mated up to a 55mm prime lens projected the required image area but the cumulative optical path through the prism exceeded the focal length of the 55mm lenses onto the groundglass and was too narrow for the stage from groundglass to camcorder without extreme vignetting.

Seth. - There's nothing to stop you from trying but two generations of definition loss ??? Offtopic, they apparently did do this with early generation night vision, stacked the tubes to get more light amplification.

Brett Erskine · February 6th, 2004, 04:25 AM

The image needs to be both flipped (U-D) AND mirrored (L-R) to appear correct to the operator. Heres a thread that has links to LCD's that can do just.

http://www.dvinfo.net/conf/showthrea...threadid=20754

Isaiah Kraus · February 6th, 2004, 11:22 AM

I'm using a GL2, sorry about about the dvcam reference.

I could have flipped the rack focus video h+v in post, but I haven't figured out a way to do it without slightly softening the image. As it is, I captured the footage, color corrected it, and exported it with quicktime conversion. If I want to flip it, I have to flip it, then deinterlace it to fix the fields, and color correct it, then export. This softens it up just a touch. So I thought I'd give you guys the sharper one. Using FCP4.1.1. I wish there was just a "reverse fields" option. The only such option I've found in FCP is tied to changing the clips speed.

As to my setup for this shot, its the same as last time. See my last post. Of note, I guess, is no fresnel. I took a lot of care to get the spinnning CD exactly the right distance from the 50mm lens. That distance is critical and you need to adjust the board while the CD is spinning (sp?), and eyeball the results on a big TV or at least the camera LCD to get it right

I'm confidant I can get rid of that vignetting by more carefully adjusting the camera to the exact center of the projection. The GL2 is so close to the CD (almost in the box), which I think is why I'm getting such good coverage from the 50mm. I'm stuck with the blurry edge/corner distortion until I shell out for an achromat.

I will get back to you on the gate dimensions.

Thanks for your advice and comments, and thanks again to Taylor for hosting my stuff.

Seth Richter · February 6th, 2004, 11:51 AM

Even when you add the cost of making 2 agus' and the purchase of lighting equip. it would still be cheeper than trying to achieve this with ND filters. Unless anyone knows where to get a x16+ ND for under 200?

Brett Erskine · February 6th, 2004, 01:04 PM

Seth you seemed to be throughing out and combining alot of terms here that dont have anything to do with each other. There is no such thing as a x16+ ND it you might be throwing alot of people off wth this information. Let me clarifty.

1)ND dont have power scale ratings like this

2)NDs alone will never give you even close to the DOF your looking for

3)+16 refers to the magnification rating for a screw on macro lens

4)x16 would be a much more powerful magnification rating than +16 because a +16 is closer to around 4x or 5x.

Seth Richter · February 6th, 2004, 03:38 PM

I'm sorry Brett, you misunderstood..

When I was referring to X16+, I was just trying to say a "times 16 or greater" and that was probably my mistake.

I agree with your statement on "NDs alone will never give you even close to the DOF your looking for".

When I posted, I was just trying to make others understand that it wasn’t even an option, AT ANY LEVEL, for how much it costs. I didn’t even desire to debate on that topic of ND usefulness, but thank you nonetheless for understanding what I want to do.

February 5th, 2004, 01:48 PM	#902
Taylor Moore Regular Crew Join Date: Dec 2003 Location: Canada Posts: 94	Isaiah's Mini 50 Pix Isaiah's Mini 50 Pix www.moorefilms.com/isaiah.htm

February 5th, 2004, 03:18 PM	#904
Seth Richter New Boot Join Date: Dec 2003 Location: Jacksonville, Florida Posts: 23	Super crazy something Is it possible to use the formula agus35 to make two, for even more focal length? camera\|agus35\|agus35 I know that the light loss would be significant, but, it would be interesting to see just how shallow we could get it. __________________ Solutions for a small planet.

February 5th, 2004, 08:28 PM	#907
Taylor Moore Regular Crew Join Date: Dec 2003 Location: Canada Posts: 94	isaiah video Mini50 Here is the video, looks good. http://www.moorefilms.com/isaiahvid.htm

February 6th, 2004, 01:11 AM	#909
John Gaspain Major Player Join Date: Oct 2003 Location: WA-USA Posts: 371	Looks Great taylor! A bit of darkness in the corners but overall Im impressed, great clarity. what camera did you use? what size UV filter? what grit did you use on the GG? __________________ The glory of the World passes by.

February 6th, 2004, 11:51 AM	#913
Seth Richter New Boot Join Date: Dec 2003 Location: Jacksonville, Florida Posts: 23	ND filters Even when you add the cost of making 2 agus' and the purchase of lighting equip. it would still be cheeper than trying to achieve this with ND filters. Unless anyone knows where to get a x16+ ND for under 200? __________________ Solutions for a small planet.

February 5th, 2004, 10:35 AM	#901
Isaiah Kraus New Boot Join Date: May 2003 Location: Columbus, Ohio Posts: 7	I took my mini50 (project-box design) out a few days ago and I have some images of it and the shoot, but no hosting. I've emailed Chris, but for some reason I haven't haven't recieved a reply. If any one has some hosting solutions/suggestions, I'd like to put them up. Thanks

February 5th, 2004, 02:41 PM	#903
Isaiah Kraus New Boot Join Date: May 2003 Location: Columbus, Ohio Posts: 7	Thanks to Taylor for hosting my images. Some info on my setup for the curious... GL2 10x B+W Macro filter Maxell frosted CD (with some nasty scratches near the center) Minolta 1.7f 50mm MD 35mm lens on the front (open to 1.7 for the whole shoot) There was a lot of light, Cam settings were: autofocus on(dvcam was not manually focused on CD) manual exposure 60i f3.2 or there abouts no gain The images were deinterlaced using Jim Lafferty's "manual deinterlace" method in FCP 4.1.1, exported as an uncompressed, deinterlaced tif from FCP, and flipped h+v and saved as jpegs (with quality 100) in photoshop. Other than that, I did not manipulate these images in FCP or photoshop in any way. About the video itself: all handheld, rather shaky and full of a lot of me fumbling with focus and shooting upside down and backward. Its not pretty, but if you really think it'd be informative, I'll put some of it up. This is the first time I really got out and used my mini50 (Agus50?), so a lot of improvement is needed. Getting alignment/proper positioning of camera to cd-plane is critical to avoid vignetting/distortion. My rig is adjustable in this regard, but I failed to spend enough time beforehand so there is noticable vignetting, esp. in bright shots. Also my plastic CD is just not flat enough, and I think every time I use it it just gets worse. But I'm not looking for/don't need perfection (thankfully). Thanks to Agus and Daniel and everyone for their inspiration and ideas. -Isaiah

February 5th, 2004, 03:26 PM	#905
Taylor Moore Regular Crew Join Date: Dec 2003 Location: Canada Posts: 94	Is it possible to use the formula agus35 to make two, for even more focal length? camera\|agus35\|agus35 I know that the light loss would be significant, but, it would be interesting to see just how shallow we could get it. Why not just use ND filters.

February 5th, 2004, 05:36 PM	#906
Kevin Burnfield Major Player Join Date: Dec 2002 Location: Princeton, NJ Posts: 363	Thanks Taylor for hosting the pics. Really interesting stuff here--- seems like you are getting a good focal plane area and not a super shallow DOF.

February 5th, 2004, 11:16 PM	#908
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Isaiah- Great looking footage. Real sharp in the middle. You can make your corners as sharp too if you switch to a ACHROMAT screw on macro of the same power. (Did someone hear a echo...? ;-) What kind of camera are you using? What was your target gate size?

February 6th, 2004, 03:11 AM	#910
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Isiah. - Two cheap and mean methods of shooting with the Agus35. I'm assuming you are using a VX2000 or PD150 from your mention of DVCAM. If not using the tripod turn the whole camcorder and Agus35 upside-down. The camera will tolerate this with one caveat. - Make sure the tape cassette enclosure is scrupulously clean so that the debris of projects past does not fall from dark bottom corners of the camcorder onto your tape and the moving guts of the camcorder. About the only way to operate the whole assembly by this method is to use it a waist height like an olde box brownie using the LCD. Holding at eye height and using the eyepiece will have you shivering with fatigue in seconds. There is just too much outboard weight. Another cheap method is to mount to the tripod as normal. Work the camcorder with your back to the subject, the lens and Agus assembly at your left under your shoulder and look at your LCD screen from this position. I have the advantage of being left-handed. (All cameras should be made that way.) By adjusting the LCD screen to face foward, it should be possible to have the image appear the right way up. As for the (CORRECTION) "rightway up method on tripod", waist to mid-chest height for the tripod is the most practical as higher means the LCD screen switches to inverted when you tilt it too far forward. It's a bit tricky to begin with but gets easier with practice. - Likewise with the camera controls. However with both methods, people who stop and observe develop a confirmed belief that the camera operator is an idiot. Experiments in a camera shop with erecting prisms for telescopes, both schmidt and roof type have not yielded anything so far. A Meade schmidt mated up to a 55mm prime lens projected the required image area but the cumulative optical path through the prism exceeded the focal length of the 55mm lenses onto the groundglass and was too narrow for the stage from groundglass to camcorder without extreme vignetting. Seth. - There's nothing to stop you from trying but two generations of definition loss ??? Offtopic, they apparently did do this with early generation night vision, stacked the tubes to get more light amplification.

February 6th, 2004, 04:25 AM	#911
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	The image needs to be both flipped (U-D) AND mirrored (L-R) to appear correct to the operator. Heres a thread that has links to LCD's that can do just. http://www.dvinfo.net/conf/showthrea...threadid=20754

February 6th, 2004, 11:22 AM	#912
Isaiah Kraus New Boot Join Date: May 2003 Location: Columbus, Ohio Posts: 7	I'm using a GL2, sorry about about the dvcam reference. I could have flipped the rack focus video h+v in post, but I haven't figured out a way to do it without slightly softening the image. As it is, I captured the footage, color corrected it, and exported it with quicktime conversion. If I want to flip it, I have to flip it, then deinterlace it to fix the fields, and color correct it, then export. This softens it up just a touch. So I thought I'd give you guys the sharper one. Using FCP4.1.1. I wish there was just a "reverse fields" option. The only such option I've found in FCP is tied to changing the clips speed. As to my setup for this shot, its the same as last time. See my last post. Of note, I guess, is no fresnel. I took a lot of care to get the spinnning CD exactly the right distance from the 50mm lens. That distance is critical and you need to adjust the board while the CD is spinning (sp?), and eyeball the results on a big TV or at least the camera LCD to get it right I'm confidant I can get rid of that vignetting by more carefully adjusting the camera to the exact center of the projection. The GL2 is so close to the CD (almost in the box), which I think is why I'm getting such good coverage from the 50mm. I'm stuck with the blurry edge/corner distortion until I shell out for an achromat. I will get back to you on the gate dimensions. Thanks for your advice and comments, and thanks again to Taylor for hosting my stuff.

February 6th, 2004, 01:04 PM	#914
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Seth you seemed to be throughing out and combining alot of terms here that dont have anything to do with each other. There is no such thing as a x16+ ND it you might be throwing alot of people off wth this information. Let me clarifty. 1)ND dont have power scale ratings like this 2)NDs alone will never give you even close to the DOF your looking for 3)+16 refers to the magnification rating for a screw on macro lens 4)x16 would be a much more powerful magnification rating than +16 because a +16 is closer to around 4x or 5x.

February 6th, 2004, 03:38 PM	#915
Seth Richter New Boot Join Date: Dec 2003 Location: Jacksonville, Florida Posts: 23	ND missunderstanding I'm sorry Brett, you misunderstood.. When I was referring to X16+, I was just trying to say a "times 16 or greater" and that was probably my mistake. I agree with your statement on "NDs alone will never give you even close to the DOF your looking for". When I posted, I was just trying to make others understand that it wasn’t even an option, AT ANY LEVEL, for how much it costs. I didn’t even desire to debate on that topic of ND usefulness, but thank you nonetheless for understanding what I want to do. __________________ Solutions for a small planet.