Some basic questions about 35mm Adaptors for HV20 at DVinfo.net

Anton Marini · February 22nd, 2008, 02:18 AM

Hi. I hope this is the right forum.

Im building (have mostly built/finished) a DIY 35mm lens adaptor for my HV20. By building I mean putting together pieces kindly provided by Daniel Schweinert. Im a video tech nerd/hobby diy person and not a real cinematographer or have much real photographic/production knowledge, so bear with me as a stumble horrendously on basic concepts :)

I noticed a few things that .. trouble me.

Ive built Daniels basic 35mm lens adaptor following his guidelines posted : http://www.jetsetmodels.info/pics/vh57x_tut.pdf

My lens for now is a 35mm Nikon swapped from an older FM10 SLR. Its a 35-70, 3.5 aperture at its fastest. pretty basic, and probably a bit on the slow side for video (right?)

Some questions:

If I zoom my HV20 all the way out (this is the cameras built in zoom), I can see the edge of the ground glass and my spectacularly bad gluing job of the focusing screen to the adaptor. If I zoom in on the camera, I can get rid of it, but since the stupid LCD preview display is not full raster, I cant really know if its out of the image or not. How are people dealing with this? Is that 'wrong'? Am I loosing light if I zoom in via the camera?

Shooting cine mode is MUCH darker. I am assuming my lens is not fast enough. What speed lenses are recommended for the HV20 to shoot 24p? Im assuming just faster = better due to more light. Do folks have any suggestions re lenses?

Also, focusing: should I let the AF do its thing while I use the manual focus on the lenses, if not, how do I get a 'default' manual focus that is correct for the lens? And whats the deal with the focus assist not working when in record mode? That is somewhat annoying and makes focusing that much harder.

Are there any good resources/writeups specific to the HV20 and 35mm adaptors? Do folks mount their cameras upsidedown to deal with the flip? So many questions!!

Thanks in advance for any answers.

Paul Nixon · February 23rd, 2008, 08:59 PM

Use an external monitor that shows the full view. I bought a dual DVD/LCD headrest DVD system for my car from Walmart for, what $70, and as it turns out the LCD's show the full view when connected to my Sony HC1 HDV cam. Otherwise I know exactly what you're talking about - why did they make the view on the LCD smaller than the actual view? Were they really trying to make us get the boom mic in the shot?

As for the focus, I'm not sure, but I think you should set the camera to manual - the camera is focusing on the "screen" in front of it, not the objects in the distance. Thus focus should not change from the camera's POV.

Hope this helps.

Chris Barcellos · February 24th, 2008, 02:08 AM

Most consumer cameras have overscan issues.

As far as zooming in, just test where the zoom indicator has to be.

Worse case, you may have to crop some edges... it happens...

I tend to think a 3.5 is not bad. If you shot everything at f1.4, you would have no forgiveness with the focus, and 3.5 to 5.6 seems ideal. You will have to light certain scenes as a result.

Anton Marini · February 28th, 2008, 12:52 AM

Thanks for the info. I did some research and found out that the screen I had purchased, the Canon EE-S, is a darker screen meant for faster lenses, which may explain my darker results. Im going to swap out for an EE-A and report back.

Thanks for the info.

Anton Marini · March 16th, 2008, 12:52 PM

I figured id post just for the record incase anyone was curious what the result was, but I finally got my hands on an EE-A stock screen and it has made quite a bit of difference. The HV20 is getting a lot more light, and im much happier with the adaptor.

Scott Harris · March 17th, 2008, 09:19 AM

Quote:

Originally Posted by Anton Marini

I figured id post just for the record incase anyone was curious what the result was, but I finally got my hands on an EE-A stock screen and it has made quite a bit of difference. The HV20 is getting a lot more light, and im much happier with the adaptor.

Where did you get the EE-A screen? I can't find one anywhere :( Please PM me if you think they have more stock!

Anton Marini · March 22nd, 2008, 06:36 PM

Quote:

Originally Posted by Scott Harris

Where did you get the EE-A screen? I can't find one anywhere :( Please PM me if you think they have more stock!

I also had a very hard time finding them. From what I've gathered Cannon has run out of back stock. Im in NYC, and tried B&H, Adorama, Willobys (? know I spelt that wrong :P) and Calumet, but K&M photo had them. Not sure what / where to look online however. :(

Bob Hart · March 22nd, 2008, 07:57 PM

Another method I carried out earlier in the peace before I became intuitive with the adaptor on the PD150 was to set it up with the computer and firewire and display the image live to the computer where it appears as an underscanned image.

This was in the days of Premiere 6 in its capture function so things may have changed since.

I recorded notes relating to one lens which I used as my calibrating lens, the one most likely to be around for all outings.

This was the 50mm f1.8 I then had.

I set it up to frame fully a test chart, which was then the EIA 1957 TV chart which I had printed on an A4 sheet.

I then placed it about 1.2 metres (I think) from the adaptor focal plane, where the edge to edge framing was about right with the zoom set to biggest GG area for best res without vignetting on the version of my adaptor I then had.

I then observed the LCD screen and marked in dots on the test chart, the edges of the viewed area and drew them in with a thick texta pen (you call'em sharpies).

From that point on, away from home, the test chart, with the same lens, the same distance from the focal plane and a tape measure became my reference for setting up. I would frame on the marks with the LCD until as I say I become more intuitive, started to rely on the little zoom logo in the LCD and of course started making more mistakes.

My intuitive method might be otherwise described as unthoroughness and expediency.

Scott Harris · March 24th, 2008, 07:01 AM

Quote:

Originally Posted by Anton Marini

I also had a very hard time finding them. From what I've gathered Cannon has run out of back stock. Im in NYC, and tried B&H, Adorama, Willobys (? know I spelt that wrong :P) and Calumet, but K&M photo had them. Not sure what / where to look online however. :(

B&H had them a few days ago so I ended up receiving one... :)

Chris Barcellos · March 24th, 2008, 09:59 AM

1. I have checked my overscan issues by using my computer and HDVSplit, and enabling the preview mode with camera switched on. It will eventually crash HDVSplit, but I can get an idea before it does.

2. I bought Daniel's vibrating screen, and promptly popped the springs at two places. It is an awful fragile affair, so take care. Because of that, I have converted his vibrating holder into a vibrating Letus type holder with three post constructed of stirring straws that you get from Cost by the thousands. If you haven't seen one of Daniels vibrating screens, he appears to C&C them from a single plastic disc by cutting out out the rectangular screen mount area, and then cutting spirals and curves outside of the screen mount area. The result is a floating central screen mount. He does warn in the material he sends after purchase about potential for breakage and the need to even limit your voltage to prevent the springs from breakage.

It certainly is a lot more delicate than the Letus set up.

Toenis Liivamaegi · March 24th, 2008, 06:30 PM

Oh well, before Daniel "stole" our Cinedof leaf spring oscillation principle we worked for one whole year to get absolutely non breakable homopolymer solution and almost silent vibration. Even when distorted really badly it worked on, in minus 20 to plus 90 Celsius. Those were the times...
I still plan to give our recipe to Lee brothers for quite a bit more effective manufacturing process and silent vertical tilt operation.

Cheers,
T

February 22nd, 2008, 02:18 AM	#1
Anton Marini New Boot Join Date: Dec 2007 Location: Manhattan Posts: 15	Some basic questions about 35mm Adaptors for HV20 Hi. I hope this is the right forum. Im building (have mostly built/finished) a DIY 35mm lens adaptor for my HV20. By building I mean putting together pieces kindly provided by Daniel Schweinert. Im a video tech nerd/hobby diy person and not a real cinematographer or have much real photographic/production knowledge, so bear with me as a stumble horrendously on basic concepts :) I noticed a few things that .. trouble me. Ive built Daniels basic 35mm lens adaptor following his guidelines posted : http://www.jetsetmodels.info/pics/vh57x_tut.pdf My lens for now is a 35mm Nikon swapped from an older FM10 SLR. Its a 35-70, 3.5 aperture at its fastest. pretty basic, and probably a bit on the slow side for video (right?) Some questions: If I zoom my HV20 all the way out (this is the cameras built in zoom), I can see the edge of the ground glass and my spectacularly bad gluing job of the focusing screen to the adaptor. If I zoom in on the camera, I can get rid of it, but since the stupid LCD preview display is not full raster, I cant really know if its out of the image or not. How are people dealing with this? Is that 'wrong'? Am I loosing light if I zoom in via the camera? Shooting cine mode is MUCH darker. I am assuming my lens is not fast enough. What speed lenses are recommended for the HV20 to shoot 24p? Im assuming just faster = better due to more light. Do folks have any suggestions re lenses? Also, focusing: should I let the AF do its thing while I use the manual focus on the lenses, if not, how do I get a 'default' manual focus that is correct for the lens? And whats the deal with the focus assist not working when in record mode? That is somewhat annoying and makes focusing that much harder. Are there any good resources/writeups specific to the HV20 and 35mm adaptors? Do folks mount their cameras upsidedown to deal with the flip? So many questions!! Thanks in advance for any answers. __________________ http://abstrakt.vade.info http://yatesparks.com

February 24th, 2008, 02:08 AM	#3
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	Most consumer cameras have overscan issues. As far as zooming in, just test where the zoom indicator has to be. Worse case, you may have to crop some edges... it happens... I tend to think a 3.5 is not bad. If you shot everything at f1.4, you would have no forgiveness with the focus, and 3.5 to 5.6 seems ideal. You will have to light certain scenes as a result. __________________ Chris J. Barcellos

February 28th, 2008, 12:52 AM	#4
Anton Marini New Boot Join Date: Dec 2007 Location: Manhattan Posts: 15	Thanks for the info. I did some research and found out that the screen I had purchased, the Canon EE-S, is a darker screen meant for faster lenses, which may explain my darker results. Im going to swap out for an EE-A and report back. Thanks for the info. __________________ http://abstrakt.vade.info http://yatesparks.com

March 16th, 2008, 12:52 PM	#5
Anton Marini New Boot Join Date: Dec 2007 Location: Manhattan Posts: 15	I figured id post just for the record incase anyone was curious what the result was, but I finally got my hands on an EE-A stock screen and it has made quite a bit of difference. The HV20 is getting a lot more light, and im much happier with the adaptor. __________________ http://abstrakt.vade.info http://yatesparks.com

March 22nd, 2008, 07:57 PM	#8
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	Another method I carried out earlier in the peace before I became intuitive with the adaptor on the PD150 was to set it up with the computer and firewire and display the image live to the computer where it appears as an underscanned image. This was in the days of Premiere 6 in its capture function so things may have changed since. I recorded notes relating to one lens which I used as my calibrating lens, the one most likely to be around for all outings. This was the 50mm f1.8 I then had. I set it up to frame fully a test chart, which was then the EIA 1957 TV chart which I had printed on an A4 sheet. I then placed it about 1.2 metres (I think) from the adaptor focal plane, where the edge to edge framing was about right with the zoom set to biggest GG area for best res without vignetting on the version of my adaptor I then had. I then observed the LCD screen and marked in dots on the test chart, the edges of the viewed area and drew them in with a thick texta pen (you call'em sharpies). From that point on, away from home, the test chart, with the same lens, the same distance from the focal plane and a tape measure became my reference for setting up. I would frame on the marks with the LCD until as I say I become more intuitive, started to rely on the little zoom logo in the LCD and of course started making more mistakes. My intuitive method might be otherwise described as unthoroughness and expediency. Last edited by Bob Hart; March 22nd, 2008 at 08:01 PM. Reason: can't spell - just practicing my illiteracy skills

February 23rd, 2008, 08:59 PM	#2
Paul Nixon Regular Crew Join Date: Feb 2007 Location: Mesa, AZ Posts: 141	Use an external monitor that shows the full view. I bought a dual DVD/LCD headrest DVD system for my car from Walmart for, what $70, and as it turns out the LCD's show the full view when connected to my Sony HC1 HDV cam. Otherwise I know exactly what you're talking about - why did they make the view on the LCD smaller than the actual view? Were they really trying to make us get the boom mic in the shot? As for the focus, I'm not sure, but I think you should set the camera to manual - the camera is focusing on the "screen" in front of it, not the objects in the distance. Thus focus should not change from the camera's POV. Hope this helps.

March 24th, 2008, 09:59 AM	#10
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	1. I have checked my overscan issues by using my computer and HDVSplit, and enabling the preview mode with camera switched on. It will eventually crash HDVSplit, but I can get an idea before it does. 2. I bought Daniel's vibrating screen, and promptly popped the springs at two places. It is an awful fragile affair, so take care. Because of that, I have converted his vibrating holder into a vibrating Letus type holder with three post constructed of stirring straws that you get from Cost by the thousands. If you haven't seen one of Daniels vibrating screens, he appears to C&C them from a single plastic disc by cutting out out the rectangular screen mount area, and then cutting spirals and curves outside of the screen mount area. The result is a floating central screen mount. He does warn in the material he sends after purchase about potential for breakage and the need to even limit your voltage to prevent the springs from breakage. It certainly is a lot more delicate than the Letus set up. __________________ Chris J. Barcellos

March 24th, 2008, 06:30 PM	#11
Toenis Liivamaegi Major Player Join Date: Nov 2005 Location: Tartu, Estonia Posts: 579	Oh well, before Daniel "stole" our Cinedof leaf spring oscillation principle we worked for one whole year to get absolutely non breakable homopolymer solution and almost silent vibration. Even when distorted really badly it worked on, in minus 20 to plus 90 Celsius. Those were the times... I still plan to give our recipe to Lee brothers for quite a bit more effective manufacturing process and silent vertical tilt operation. Cheers, T