Homemade 35mm Adapter

[Bob Hart]

Alex.

In my haste to answer your questions, I did not realise you had quoted a previous post of mine in grey highlight so my replies have probably looked like the ramblings of a madman.

I'll try again.


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So you are saying for flipped adaptor, it is only limited to a few camcorders in the market and not all even with different diopters magnification strength in the market?

--------- If the camcorder is 1/3" CCD, can zoom in to at least 54mm, the +7 dioptre will get you inside the 24mm wide movie frame where hotspots and other complications are a lesser problem.

The FX1/Z1P with a 7+ and about 120mm from lens to GG will give usable GG images from about 32mm zoom-in to 54mm zoom-in which is its maximum.


An easy way i guess to test if a camcorder can zoom in to see if it will frame a 24mm wide GG is to have the camcorder positioned at the correct distance away from the GG, i.e if the adaptor has a light path of 120mm say. Then place a GG size rectangle on a white sheet of cardboard and zoom in using different diopter strength. What do you think?

--------- Your method is the same that I used. - As close to the groundglass as the structure of the adaptor and the power of your close-up lens (dioptre) will let you and keep sharp focus is best, yet still correctly frame the image area you want off the groundglass.



When you build, you need to keep the camera position rearwards about 2mm from the closest position to the GG where the camera-dioptre combination will permit sharp focus, to allow for construction errors and still have camcorder focus adjustment to enable final sharp focus on the GG.

Do all your setup tests with the camcorder aperture on a wide setting, as this will help reduce any mistakes in positioning the camera which might not be apparent with the deep depth of field a small (high f-number) aperture setting will provide.

[Bob Hart]

A short clip of aerial image relay imaging of the Red Bull Air Race final 2006 in Perth is here at Youtube ( poor res images )

Lensing was via Peleng 8mm and Sigma 50mm - 500mm zoom. Relay via AGUS35, Camera HVRZ1P.


http://www.youtube.com/watch?v=RnfnlMt_7FE

and here at Filefactory (34Mb .mpg manual download only)

http://www.filefactory.com/file/6c2ce7/

A still-image of the camera/adaptor combination configured for ground-to-air aviation videography is here (plus my scruffy overweight profile) :-

http://www.filefactory.com/file/9428f5/

All other filefactory clips referred to in my previous posts have now timed out.

[Bob Hart]

Another "Kill Devil Hills" live performance music clip "Nasty Business" is here :-

http://www.youtube.com/watch?v=TWg2AW91D9w

Origination was as for "Boneyard Rider", Two Sony FX1 HDV cams, one fixed as master, the second fixed as backstage, the third a PD150 with AGUS35 and Nikon 85mm f1.4 lens as the roving cam.

The assembly/edit is rather rough. In an attempt to preserve apparent resolution under minimal lighting conditions - the band prefers to perform in subdued lighting, - the 4:3 and 16:9 frames have been letterboxed.

[Bob Hart]

A music clip shot direct-to-camera with Sony HVR-Z1P, Canon XL1 and via Canon XL2/ LETUS35XL can be found here.

http://www.youtube.com/watch?v=NXyJZHPYPP0

I also shot footage on an AGUS35 but did not use it in this clip except the very first shot through the window of the booth with the blue mike in frame.

[Bob Hart]

I had my greasy hands on the JVC HD100 and Mini35 combination again today. It was on the set of a Vietnam war era movie project which is being shot on Super16. The Mini35 footage was being shot by an industry professional to compare later with super16mm footage.

Their AD has worked on Star Wars so knows what he is doing.

Slightly off-topic, this Mini35 was bought into the country by the owner in part because of exposure to my own home-made adaptor with which I had demonstrated the groundglass relay principle.

The operator was not able to remain on the shoot due to other committments so despite my own deficits as an operator I was give the opp to drive the machinery.

Firstly I was impressed with the optional "handlebars" on the front. These can be arranged in a wide variety of positions.

The one I found most useful for handheld was right grip in about the position of a CP16 film camera although the grip is actually furthur forward.The left bar and grip were arranged downwards to make contact with the barely distinguishable boundary between my upper chest and ample gut.

In this arrangement it was very easy to keep the camera steady when standing upright. I didn't do so well when trying more awkard shots, most likely due to my age and lack of exercise in these working postures.

The arms also allow improvised fixed camera setups in lieu of a tripod. At the end of it all I did not feel like I had been run over by one of the army jeeps my own gadget would make me feel like.

The JVC is greedy for battery power. Conveniently, the Mini35 is less demanding on the JVC battery so when the camera battery itself drops dead, it can be switched to the Mini35 and the Mini35 battery will power the JVC for long enough to get a few more shots until the replacement batteries can be fetched or recharged.

I also shot some footage with the FX1 and Agus35 with the same prime lenses so will be interesting to see comparisons although the setups were not identical. I continued on shooting shadow footage with the Agus35 after the JVC batteries ran down as we only had the one pair.

Some observations - The Mini35 is superficially similar to the home made Agus35 to set up but there are some significant differences in behaviour. The groundglass has a nicer white.

In bright lighting conditions where with my device on the FX1, I might choose ND1 and a very tight relay aperture, this practice will provoke a moire artifact in the JVC when the GG motor is not running (when setting up relay focus).

With the motor running some indistinct GG artifact can be seen but this is only under very hostile aperture settings. ND2 and wider relay aperture works best. This suggests the low light performance of the Mini35 is going to be better than my own project.

There is available the choice of a common run button for both the Mini35 and JVC camera. Due to my unfamiliarity with the JVC, I chose to switch them separately like I do with my own adaptor. This brought me undone once or twice when I forgot to turn on the Mini35.

I get the impression P+S have been conservative in their advice of how to use the Mini35 to keep people operating within a safe and reliable performance envelope. I shot f11 on the prime lens by error with it and didn't pick up any bads in the image.

The location of the shoot was a set which is a recreation of a Vietnam War army firebase. They had all manner of military hardware vehicles and things like genuine Wisconsin 24v power plants and radio comms equipment. They also had lots of extras moving about.

It was a great experience to shoot the shadow stuff against those backdrops and see people who know what they are doing at work and play. (I also blotted my copybook by stepping into a shot so like a bloke on another project long ago who loaded 7240 into mags back to front, I'll probably get a DCM.)

I did not have exact prime lens equivalents to the focal lengths chosen by their cinematographer for the comparable fields of view, so I chose the closest I could find and erred on the wide side.

I shall not disclose any details as the project has its own promotional program which I do not want to cause any problems with. The morale and committment I observed was remarkable. I am looking forward to seeing this one when it is released.

[Bob Hart]

Furthur to above, I have consent from the production entity of "The Eleventh Soldier" to post some of my AGUS35 shadow footage. I have yet to capture and assemble the little I shot with the Agus. Most of the shadow footage I shot was on the JVC HD100/Mini35 combination.

After having a play with that, my own gadget seemed decidedly secondhand.

I shot it on my original prototype as the current one has the GG removed for ground-to-air videography of aircraft. There is a fault with my images. The groundglass alignment on the prototype had gone off.

I dropped it, fortunately the groundglass didn't break but the jolt chipped the front prism, luckily only a corner, out of shot. The upper and and lower backfocus adjustments where knocked out and the lower portion of the image was off the focal plane though it looked okay in the viewfinder at the time.

In meantime, to see some on-set still images of this remarkable movie project, go to www.fotograf.com.au (homepage) , Click on "your photographs", then on the menu that page offers, click on "Eleventh Soldier 10th" which is the day I was there.

The website of the project is here :-

http://www.cinemascorestudios.com/th...dier/index.htm

My own images, when I upload them should not be regarded as representative of the production camera footage as my own camera positions were different and my own images are inferior.

[Bob Hart]

Here's the images I promised at this address :-


http://www.youtube.com/watch?v=S69rcLasmpY

They look good on the computer and on DVD-Video but by the time mp4 compression has had its way with them they look dreadful.

If anyone has any clues to offer on how to get from Cineform lossless HD to Youtube with some vestiges of clarity intact, I would greatly appreciate your advice.

I have tried to export to a .flv file and Youtube's system rejected it.

[Bob Hart]

I called by the director of The Eleventh Soldier to drop off a disk of my assembled shadow footage which I had already posted.

While there, I saw a 30 second action sequence with a full sound mix and music underscore, assembled from the recording of the video tap. It was shown in a small preview theatre with a full-on sound system.

The film is still being processed. Even with the safe area markers from the viewfinder in the vision it, was still a wild event and that sequence will not disappoint viewers.

There was also some standard definition MiniDV footage with the Mini35 which had some regrading done to it. On the big display screen it looks quite good so the JVC HD100 progressive footage should look even better.

It is remarkable how good standard definition MiniDV can be made to look and sound, so am looking forward to seeing the actual film vision when they get it back and done.

[Bob Hart]

On YouTube at this address,

http://www.youtube.com/watch?v=RGM0GBiwEA0

I have posted an indifferent quality SD originated clip from my home-made AGUS35 APVE into a Sony PD150. It was a demo scene from a screenplay. It was shot in the flourescent equivalent of about 400 watts of light, set up as best I could manage it in condined space in a traditional key-fill layout.

[Bob Hart]

On Youtube at this address,

http://www.youtube.com/watch?v=7RTupPYGThE

I have re-posted the 4+ achromatic dioptre long setback clip which was originally at the filefactory in higher resolution but has since timed out.

The resolution at Youtube is as expected but illustrates the corner falloff issues well enough.

[Bob Hart]

I have just dragged this thread back upstairs for an enquirer from YouTube to look at. I have referred him to the Redrock DIY page which is found at http://www.redrockmicro.com/diy_guide.html

[Bob Hart]

Furthur bump for some other researchers.

Andrew or Poppy. This is the thread which tells much of the story. If you go to page 1, there is a post by Chris Hurd which links to a condensed version of this thread.

[Bob Hart]

Some info for idle interest sake.

Of late I have been repairing and servicing a CP16R 16mm motion picture camera for use by a media student. It had been in storage for nine years and had deteriorated. That adventure is another story best left untold.

After resetting the viewfinder screen backfocus to match the film plane idle curiosity led me to grab the Agus35, put the Nikon adaptor and a lens on the CP plus the 7+ dioptre and shove the Agus35 handheld on front.

It would seems that one of these things could work on front of a 16mm film camera. What the resolution would be like at the end of it all is another matter.

[Chris Barcellos]

Originally Posted by Chris Barcellos

Bob:

We talked about achromats in another thread I started. I'm still awaiting delivery of my 72mm achromat from Cinavete... hoping that will improve the footage I get on the FX1 Micro35 DIY project I built. Will advise you what kind of luck that has brought. Hope to get where you have gotten already, at a minimum.

Updating:

I am using the Cinevate 72mm achromat on my DIY adapter, which was loosely based on the Redrock DIY plans. I am having to use an extension tube of about 5 inches from the front of achromat mount on FX1 to ground glass. I can then zoom from about 30 to 50 on the FX1 without vignetting.

[Bob Hart]

I have managed to enveigle my way into a music video shoot going on here in the West. It is being shot on the new JVC HD250 and a Mini35.

I assembled my own gadget onto a Z1P and compared the two images. I don't have a direct-to-camera comparison between the JVC and Sony safe area frame markers.

Assuming both are the same, the Mini35 for a 14mm lens is yielding a wider field of view than my own device with better apparent resolution. To get the same field-of-view, I have to use the 12mm-24mm on wide.

The DOP/videographer is an industry professional and is using a real steadycam.

He is apparently doing some beta testing for JVC and he has this black box with a small LCD display on front which attaches to the camera body and records to a hard drive of some kind.

It appears I shall have to revisit using the 4+ dioptre and the longer setback on my design until I can get round to redesigning for the odd sized prism pair.

The 14mm lens is being used for motion moves down a dark and dingy corridor. The advancing or retreating motion is accentuated by the corner stretch of this type of lens which is designed to render straight edges all the way across the frame. Looks good.

I shall try to shoot some comparison footage if I can do so without causing disruptions or getting run down.