35mm Adapter Static Aldu35

Eric Ohman · July 12th, 2004, 03:03 PM

Hi, I've been following and reading all threads (even the agus35 ones)

Just need to know...
What does a condensor and a fresnel lens do?

-----------------
Eric Öhman
www.de-interlaced.net

Brett Erskine · July 12th, 2004, 05:07 PM

Rather than re-write the whole book try the search feature on this web site and plug in "condenser", "fresnel". Also www.Google.com is a good source for techincal info. You should find everything you need.

Eric Ohman · July 15th, 2004, 11:02 AM

i've done a few tests with different magnifiers... this is what i'm using:

Cam(vx1000)->magnifier->frosted rotating cd->50mm f/2.0 minolta lens

when i change the focus on the minolta lens, like when i blur the picture.. everything gets distorted, especially in corners. why is this? please help. i'm pretty close an 35mm adapter now :)

and by the way, would it be better to use medium format lenses? do you think i would be able to skip the magnifier lens then?

THANKS IN ADVANCE
ERIC
www.de-interlaced.net

Jim Lafferty · July 15th, 2004, 01:09 PM

Still no response on the acid-etching? Is everyone distracted by all these Build Your Own HD threads?! Is it the XL2?

:)

- jim

Brett Erskine · July 15th, 2004, 01:36 PM

Eric-
Thats real odd that you would get distortion from simply changing focus. Describe what kind of "distortion" your seeing and maybe I can help. The only thing that MIGHT be going on is that your not framing up the right size on the GG. Your video camera should be looking at roughly 36mm wide by 24mm tall section of the GG. Perhaps your looking at a much wider section of the GG and the outer edges are revealing some type of distortion that wouldnt normally be seen. Check it and let me know.

As far as using a medium format lens question - the answer is no you generally wont need any type of magnifier. I say generally because every model of video camera is different. Draw a 2 1/4 inch square (basically the smallest medium format size) and find out if you can focus sharply from the center all the way out to the edge and without any barrel distortion. Generally a good distance to try is about 2 inches. Read all of the other pros and cons of using medium format lenses in some of my recent post in the "oscillating ground glass" thread.

-Brett Erskine
www.CinematographerReels.com

Eric Ohman · July 15th, 2004, 07:35 PM

-> Brett

I just found the reason for the distortion. It was simply my ground glass wich had some mm convex bending...

Yeah, I frame about 36x24 but I haven't find any good magnifier lenses to use yet. Do those HOYA(for example) close up filters work? This will surely be different because of what camcorder you use and the vx1000 is pretty big (52mm thread so pretty big front lens) so the I really need some magnifier lens that will take away the hot spotting (I'm at f/2.0 on my 50mm minolta md lens.)

Any help is appreciated.
ERIC
www.de-interlaced.net

Bob Hart · July 16th, 2004, 12:45 AM

Eric.

Some of my early Agus35 experimental images were with a PD150 and a stack of 1+,2+,4+,Hoya lenses to get up to 7+.

This meant my GG had to be about 4 inches from the front of the close-up lens.

Some of these are at www.dvinfo.net/media/hart and will be among the earlier files by date which is on the right side of the list.

I subsequently used a SW5042 lens set which is the optics out of an unbranded 50mm 2" telescope eyepiece sold in Australia for for Tasco telescopes.

This enabled me to close couple to about 18mm from the groundglass but introduced difficulties with edge softness. The arrangment works adequately but not brilliantly with the 4:3 motion picture frame of 24mm x 18mm ( see Brett Erskine's test chart ) but fails miserably on the larger still-camera frame.

Whilst the PD150 has a 58mm front filter mount, the front element is 52mm.

You may find that if you build to precision along the centerline of your lens, cropping/vignetting, may first occur on the left side of your image as viewed. This happens with the PD150. It may or may not be the case with the VX1000.

I don't know about the VX1000 but with the VX2000/PD150, the lens center axis does not fall in the center of the 3xCCD array, but partly to the right as viewed on the LCD screen.

I have not gone with condensers or fresnels as yet as I am still trying to get the raw resolution on the groundglass up to scratch beforehand. Look for Brett's posts through the Agus and Aldu threads or run a search as he suggests above.

The latest images on www.dvinfo.net/media/hart were shot off a spinning wax composite disk (home made boss-screen). The image is subjectively about the same resolution as a spinning 5 micron groundglass but it is very difficult for a home-builder to achieve a consistant grading of the crystal texture in the wax layer around the disk.

On my specimen, the variable density amounted to over 2 f-stops which introduces unacceptable flicker.

The wax composite disk image seems marginally better but the two glass disks require more precision on the wax faces than I can achieve on my home figuring/polishing setup.

So far, on a test pattern, the glass disk with 5 micron dressing and the SW5042 lens set achieves the 530 lines horizontal resolution which is the spec of the PD150.

Brett Erskine · July 16th, 2004, 02:58 AM

Eric-
Yeah that explains it.

The +1,+2,+4 close up kits you see out there are pretty much all single element diopter. You dont want to use these because of color "abberation" problems. You need to get a two or three element diopter. These are called achromatic diopters. More expensive but well worth it. Basically the best deal out there is the Hoya +10. Its the strongest power to diameter ratio diopter out there in photography. The largest they make them is 55mm. Anything larger and its a single element diopter. Its real hard to tell which one your buying any other way than by price. A single element will go for about $25 and a double element will be around $70. I found though that while the two element Hoyas much better than any other diopter in its price range - it still has a slight amount of chroma abberation. Century Optics pride themselves on great optics but are pricey and their achromats arent as powerful as the Hoyas.

-Brett Erskine

Eric Ohman · July 16th, 2004, 04:25 AM

-Brett and Bob
Thanks for your comments.

-Bob, is there any place to buy that SW5042 pretty cheap? I did a search but couldn't find too much

-----------------------------------------------------------

I dismounted a reversal projector and find this lens wich is flat on one side and curved on the other. The focal length is around 9-10mm but I'm curious if there is any way to check what the x-factor is?

I think I will go for that HOYA x10 filter and test it even if this lens from the reversal projector seems to be working fine.... I always find it better to work with filters cause then I can just order the 52mm one that will fit directly to my vx1000.

I'm going to post some pictures soon. Too bad I've short circuit'ed my vx1000 firewire port (this happens when you accidentically put the 6-pin plug upside down in the computer's firewire port).

-All the best.
ERIC

Eric Ohman · July 18th, 2004, 11:34 AM

www.de-interlaced.net/mini35/mini35.mpg

i was having my vx1000 on a tripod but i held the cd and the 135mm lens (@ f/2.8) that's why it is so shaky and often out of focus... but what do you think except that?

Patrick Wright · July 18th, 2004, 09:45 PM

This adapter consists of a canon 1.2 50mm FD mount lens and adapter on a Radioshack 4.5x6.5inch project box. the GG is a Linhof 4x6inch micrograin obtained from B&H. Next step is to make a platform for the whole setup to rest on. Perhaps a mattebox & support rod setup. I used the stock 16x auto lens and the Macro is a 5x single element. when money and time permit I'll replace it with an Achromat, perhaps more powerful although with a little more tweaking I think 5x should be enough to fully eliminate the vinetting.

the clip is about 1mb and is a fairly low bitrate so pardon the compression artifacts. It doesnt like to stream so download before viewing.

www.quicktel.com/users/archamian/candletest.wmv

Bob Hart · July 18th, 2004, 09:48 PM

The +10 may be the best way for you to go. It should be more controllable than the SW5042 set because you would have to have access to a lathe and some flo-cast bronze stock and the skills to to turn up the adaptor and cut an internal 0.70mm thread. The assembly order of the SW5042 glass elements also has to be reversed for best resolution.

The SW5042 seems to be a generic product out of mainland China. Retailers who carry telescope parts should be able to track them down.

Josh Johnson · July 19th, 2004, 06:53 PM

Hi everyone. I have posted here once before about my ALDU35 type adapter. Anyway, I just made a little movie for my kids, starring my kids, and tested my adapter on it. Here are some of the results.

http://www.kidventures.net/mydownloads/other/scene1.jpg

http://www.kidventures.net/mydownloads/other/scene4.jpg

http://www.kidventures.net/mydownloads/other/scene7.jpg

Thanks,
Josh

Jim Lafferty · July 20th, 2004, 12:12 AM

Nice images! What cam are you using?

- jim

Josh Johnson · July 20th, 2004, 01:11 AM

Hi,

I am using a Panasonic PV-GS70. I bought the camera at a circuit city for like $650 or so...

Oh and you can watch the actual movie if you like. It is at http://www.jayfor.com/jnjosh/ and click on the image for the movie, 'Not Fair'. It was the first movie I have ever made... So I was happy with my new adapter...

Thanks,
Josh

July 12th, 2004, 03:03 PM	#961
Eric Ohman New Boot Join Date: Nov 2002 Location: Skellefteå, Västerbotten, Sverige (Sweden) Posts: 23	Condensor, fresnel? Hi, I've been following and reading all threads (even the agus35 ones) Just need to know... What does a condensor and a fresnel lens do? ----------------- Eric Öhman www.de-interlaced.net

July 15th, 2004, 11:02 AM	#963
Eric Ohman New Boot Join Date: Nov 2002 Location: Skellefteå, Västerbotten, Sverige (Sweden) Posts: 23	blur focus looks distorted! i've done a few tests with different magnifiers... this is what i'm using: Cam(vx1000)->magnifier->frosted rotating cd->50mm f/2.0 minolta lens when i change the focus on the minolta lens, like when i blur the picture.. everything gets distorted, especially in corners. why is this? please help. i'm pretty close an 35mm adapter now :) and by the way, would it be better to use medium format lenses? do you think i would be able to skip the magnifier lens then? THANKS IN ADVANCE ERIC www.de-interlaced.net

July 15th, 2004, 01:09 PM	#964
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	Still no response on the acid-etching? Is everyone distracted by all these Build Your Own HD threads?! Is it the XL2? :) - jim __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

July 18th, 2004, 09:45 PM	#971
Patrick Wright New Boot Join Date: Jan 2004 Location: Bellingham, Wa. U.S.A Posts: 7	XL1 Static Adapter This adapter consists of a canon 1.2 50mm FD mount lens and adapter on a Radioshack 4.5x6.5inch project box. the GG is a Linhof 4x6inch micrograin obtained from B&H. Next step is to make a platform for the whole setup to rest on. Perhaps a mattebox & support rod setup. I used the stock 16x auto lens and the Macro is a 5x single element. when money and time permit I'll replace it with an Achromat, perhaps more powerful although with a little more tweaking I think 5x should be enough to fully eliminate the vinetting. the clip is about 1mb and is a fairly low bitrate so pardon the compression artifacts. It doesnt like to stream so download before viewing. www.quicktel.com/users/archamian/candletest.wmv

July 19th, 2004, 06:53 PM	#973
Josh Johnson Regular Crew Join Date: Mar 2004 Location: Raleigh, NC, USA Posts: 53	My attempt Hi everyone. I have posted here once before about my ALDU35 type adapter. Anyway, I just made a little movie for my kids, starring my kids, and tested my adapter on it. Here are some of the results. http://www.kidventures.net/mydownloads/other/scene1.jpg http://www.kidventures.net/mydownloads/other/scene4.jpg http://www.kidventures.net/mydownloads/other/scene7.jpg Thanks, Josh

July 12th, 2004, 05:07 PM	#962
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Rather than re-write the whole book try the search feature on this web site and plug in "condenser", "fresnel". Also www.Google.com is a good source for techincal info. You should find everything you need.

July 15th, 2004, 01:36 PM	#965
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Eric- Thats real odd that you would get distortion from simply changing focus. Describe what kind of "distortion" your seeing and maybe I can help. The only thing that MIGHT be going on is that your not framing up the right size on the GG. Your video camera should be looking at roughly 36mm wide by 24mm tall section of the GG. Perhaps your looking at a much wider section of the GG and the outer edges are revealing some type of distortion that wouldnt normally be seen. Check it and let me know. As far as using a medium format lens question - the answer is no you generally wont need any type of magnifier. I say generally because every model of video camera is different. Draw a 2 1/4 inch square (basically the smallest medium format size) and find out if you can focus sharply from the center all the way out to the edge and without any barrel distortion. Generally a good distance to try is about 2 inches. Read all of the other pros and cons of using medium format lenses in some of my recent post in the "oscillating ground glass" thread. -Brett Erskine www.CinematographerReels.com

July 15th, 2004, 07:35 PM	#966
Eric Ohman New Boot Join Date: Nov 2002 Location: Skellefteå, Västerbotten, Sverige (Sweden) Posts: 23	-> Brett I just found the reason for the distortion. It was simply my ground glass wich had some mm convex bending... Yeah, I frame about 36x24 but I haven't find any good magnifier lenses to use yet. Do those HOYA(for example) close up filters work? This will surely be different because of what camcorder you use and the vx1000 is pretty big (52mm thread so pretty big front lens) so the I really need some magnifier lens that will take away the hot spotting (I'm at f/2.0 on my 50mm minolta md lens.) Any help is appreciated. ERIC www.de-interlaced.net

July 16th, 2004, 12:45 AM	#967
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	Eric. Some of my early Agus35 experimental images were with a PD150 and a stack of 1+,2+,4+,Hoya lenses to get up to 7+. This meant my GG had to be about 4 inches from the front of the close-up lens. Some of these are at www.dvinfo.net/media/hart and will be among the earlier files by date which is on the right side of the list. I subsequently used a SW5042 lens set which is the optics out of an unbranded 50mm 2" telescope eyepiece sold in Australia for for Tasco telescopes. This enabled me to close couple to about 18mm from the groundglass but introduced difficulties with edge softness. The arrangment works adequately but not brilliantly with the 4:3 motion picture frame of 24mm x 18mm ( see Brett Erskine's test chart ) but fails miserably on the larger still-camera frame. Whilst the PD150 has a 58mm front filter mount, the front element is 52mm. You may find that if you build to precision along the centerline of your lens, cropping/vignetting, may first occur on the left side of your image as viewed. This happens with the PD150. It may or may not be the case with the VX1000. I don't know about the VX1000 but with the VX2000/PD150, the lens center axis does not fall in the center of the 3xCCD array, but partly to the right as viewed on the LCD screen. I have not gone with condensers or fresnels as yet as I am still trying to get the raw resolution on the groundglass up to scratch beforehand. Look for Brett's posts through the Agus and Aldu threads or run a search as he suggests above. The latest images on www.dvinfo.net/media/hart were shot off a spinning wax composite disk (home made boss-screen). The image is subjectively about the same resolution as a spinning 5 micron groundglass but it is very difficult for a home-builder to achieve a consistant grading of the crystal texture in the wax layer around the disk. On my specimen, the variable density amounted to over 2 f-stops which introduces unacceptable flicker. The wax composite disk image seems marginally better but the two glass disks require more precision on the wax faces than I can achieve on my home figuring/polishing setup. So far, on a test pattern, the glass disk with 5 micron dressing and the SW5042 lens set achieves the 530 lines horizontal resolution which is the spec of the PD150.

July 16th, 2004, 02:58 AM	#968
Brett Erskine Major Player Join Date: Dec 2003 Location: Anaheim, CA Posts: 445	Eric- Yeah that explains it. The +1,+2,+4 close up kits you see out there are pretty much all single element diopter. You dont want to use these because of color "abberation" problems. You need to get a two or three element diopter. These are called achromatic diopters. More expensive but well worth it. Basically the best deal out there is the Hoya +10. Its the strongest power to diameter ratio diopter out there in photography. The largest they make them is 55mm. Anything larger and its a single element diopter. Its real hard to tell which one your buying any other way than by price. A single element will go for about $25 and a double element will be around $70. I found though that while the two element Hoyas much better than any other diopter in its price range - it still has a slight amount of chroma abberation. Century Optics pride themselves on great optics but are pricey and their achromats arent as powerful as the Hoyas. -Brett Erskine

July 16th, 2004, 04:25 AM	#969
Eric Ohman New Boot Join Date: Nov 2002 Location: Skellefteå, Västerbotten, Sverige (Sweden) Posts: 23	-Brett and Bob Thanks for your comments. -Bob, is there any place to buy that SW5042 pretty cheap? I did a search but couldn't find too much ----------------------------------------------------------- I dismounted a reversal projector and find this lens wich is flat on one side and curved on the other. The focal length is around 9-10mm but I'm curious if there is any way to check what the x-factor is? I think I will go for that HOYA x10 filter and test it even if this lens from the reversal projector seems to be working fine.... I always find it better to work with filters cause then I can just order the 52mm one that will fit directly to my vx1000. I'm going to post some pictures soon. Too bad I've short circuit'ed my vx1000 firewire port (this happens when you accidentically put the 6-pin plug upside down in the computer's firewire port). -All the best. ERIC

July 18th, 2004, 11:34 AM	#970
Eric Ohman New Boot Join Date: Nov 2002 Location: Skellefteå, Västerbotten, Sverige (Sweden) Posts: 23	www.de-interlaced.net/mini35/mini35.mpg i was having my vx1000 on a tripod but i held the cd and the 135mm lens (@ f/2.8) that's why it is so shaky and often out of focus... but what do you think except that?

July 18th, 2004, 09:48 PM	#972
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,476	The +10 may be the best way for you to go. It should be more controllable than the SW5042 set because you would have to have access to a lathe and some flo-cast bronze stock and the skills to to turn up the adaptor and cut an internal 0.70mm thread. The assembly order of the SW5042 glass elements also has to be reversed for best resolution. The SW5042 seems to be a generic product out of mainland China. Retailers who carry telescope parts should be able to track them down.

July 20th, 2004, 12:12 AM	#974
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	Nice images! What cam are you using? - jim __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

July 20th, 2004, 01:11 AM	#975
Josh Johnson Regular Crew Join Date: Mar 2004 Location: Raleigh, NC, USA Posts: 53	Hi, I am using a Panasonic PV-GS70. I bought the camera at a circuit city for like $650 or so... Oh and you can watch the actual movie if you like. It is at http://www.jayfor.com/jnjosh/ and click on the image for the movie, 'Not Fair'. It was the first movie I have ever made... So I was happy with my new adapter... Thanks, Josh