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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

For Historical technical Interest - Groundlgass Adaptors.

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Robert Hart

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Way back when Noah was a pup, I along with a good many others initially built and used alternative storebought 35mm groundglass adaptors primarily evolved for 1/3" camera-recorders. They were further adapted for the 1/2" and 2/3" camera-recorders.

Here is a very short clip for curiosity and interest sake, shot with what is probably the final evolution of the 35mm groundglass adaptor, Dennis Wood's Cinevate Brevis with prototype Cinveate Varifocal relay lens into a SI2K digital cinema camera.

http://www.youtube.com/watch?v=FOBhF1kjqsw
 
Good to see you here Rob. They were the days, some terrific images.

You remember that alternative I proposed, there are a number of 4k suitable speed booster/format convertors that work the same way coming to the market now. WWW.43rumors.com often reports on them.

I was proposing to use just a triplet macro as
 
Hello again Wayne. If I recall correctly there might have been discussion that JVC had done something similar in principle with the the subsequent Super16mm optical adaptor for the GY-HD*** 1/3" camera family.

It was an interesting confluence, dvinfo.net, Agus Casse and groundglass adaptors. One should also not forget P+S Technik, who kicked the thing off with the contradiction in terms of an impeccably engineered adaptor that worked fine but cost up to 210% more than the companion camcorder.

I guess Chris Hurd had no idea just how many fires would be lit in people's bellies and just how many little revolutions would be started when dvinfo.net was launched.

I wonder if Agus Casse ever bought himself a Scarlet or Epic. If not, maybe the venerable Jim should give him one. That $20 adaptor made out of CD parts was muchly the genesis of the 35mm digital cinema "movement" which Red Digital Cinema tapped into and evolved from.

It is all in the land of specialists now. The appeal of the adaptors was that anyone who could swing a pair of pliers and screwdriver could do high science on the kitchen table. I concede that last statement is a bit of an over-reach.

I wonder if a newer generation of visitors to reduser has any clue what this last post has been on about.
 
Don't forget that the Angenieux/Zeiss CLA adapter preceded the Pro35 by several years. It was basically the 35-to-2/3" version of what JVC did in S16-to-1/3", and what is now in the Speed Booster. Of course Paul Duclos beat them all with his 707 adapter back in the 70s, which was a Full Frame 35-to-Academy 35 Speed Booster.

As for pliers & screwdrivers on the kitchen table, let us remember that a guy using the clear plastic disk spacers that went between CD-Rs eventually turned into the RedRockMicro company.
 
Robert. I remember Marla the movie, one of my favorite shirt films of all time. The quality of that wobbling spinning disc really shined alongside the snappiness of the film. Was dine by a European crew for $100 or $400eu I think.
 
I've been looking at a new combined lens and adaptor technology to adapt a 70mm format to 1/2-1/4 inch sensor cheaply with high latitude filtering and 3d . Still more to go in this industry.
 
The "Coatwolf" camera, which used an early prototype SI2K head, has already done the 70mm plus thing in 2D. It is the roughest looking device you ever saw. It is actually larger format than 70mm. 70mm would translate to the RED camera platform quite well I think but as I don't have a RED I won't trouble myself at this stage. The Blackmagic pocket cam is an absolute sitter for doing this with. It is self-contained and would integrate tidily on the back of a larger assembly. Groundglass adaptors confer a little more "apparent" dynamic range. If ever you go further, the Le brother's oscillating groundglass arrangement with a larger motor and added vibrational mass would work fine. For the larger screen you would need added, a small countermass on the opposite side of the motor to the mass of the groundglass screen and its supports. Why? - to maintain the excursion equally across the whole larger groundglass for 3D. My personal preference would be to chase a larger movement but in reality an excursion as small as 50 microns would be adequate at normal frame-rates and shutter speeds and probably preferable as to noise and rolling shutter artfacts which were not a problem for us in groundglass adaptor days when CCD sensors ruled.


http://www.fastcodesign.com/1664622/the-secret-sauce-behind-bellflower-a-buzzy-indie-film-handmade-cameras

Le brothers, Wayne Kinney, Redrock, Dennis Woods, JAG and of course P+S Technik themselves, originally groundglass adaptor manufacturers, diversified and focussed upon the affordable accessory products they originally made to accompany their adaptor products.

Oscar Spier who I think posts here sometimes, if I recall correctly, was somewhat of a mentor on optics and wax diffusers (Boss Screens) but my memory may be a bit fallable now.

I tried wax laminate disks but could never beat the variable density problem that only a synchronous motor and frame-rate tracking controller could have solved - all way out of my league. It was the sweetest groundglass. It probably would have resolved 2K easily in a Letus/Brevis arrangement with fullframe lenses of the f1.2/1.4 class and a 4+ dioptre for a 45mm relay. That is about what I think they all shook down to in the end when using a 1/2" sensor.
 
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Sounds nice. I once wanted to relay down a large format lens for ultimate "speed" boosting. I had some neat latitude boosting techniques I wanted to use to be first to film the moon and stars in the middle of the day with scenery in exposure (and I think maybe the sun too), but multislope technology was available. and now thus trick is too common. Those were the days, simple.

But my newest design work is a replacement of lens technology, handheld 70mm. Cameras would never be the same again. I might still turn to do it.

Thanks Robert, for the memories
 
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I love that P+S Technik have been promoting a kit to convert old Pro35 adapters into director's finders using a freakin' iPhone mounted on the back. I know someone is going to actually shoot a movie with this nutty thing. More power to 'em; I bet it has a "look," for better or worse.
 
Oh man, I had the first SG35 (later SGPRO, then SGBlade)... That was the Land where indie men were made. None of this play school dslrs or even red. We had to kick lights ass with optics and wax oscillating surfaces to get cinematic images.... :) you know the good old days,
 
He, he, got a link Mitch?
 
I remember that at the studio I had a lovely Fries VistaVision camera and at home I had my little Brevis35, which led to nights of aggressive frustration.

Oddly, I refuse to sell the Brevis. It is a trophy celebrating a time that I hope won't ever need to exist again.
 
QUOTE: " I know someone is going to actually shoot a movie with this nutty thing. More power to 'em; I bet it has a "look," for better or worse." END OF QUOTE. Somebody will and it won't be as bad as people might like to imagine, so long as they make sure the iphone is properly centered. Please don't call it "nutty". You will make me all traumatised and render me unto a gibbering mess. For I was one "nut-case" among likely quite a few others who put them up to it to enable people who own the adaptors some new lease of life from the investment, a reprise of the original purpose for the moving groundglass, a better previsualisation tool for directors. Sadly the mod did not extend to the Mini35-400 but nothing is impossible. -- Phil. Don't deny yourself. Get out the Sony Hi-band Video8. Bung it on the back with a FX1/Z1 adaptor via stepdowns and transport yourself back into the sublime bliss of what could have been before modern tech came along and made it all too perfect. You know you want to. Maybe a GoPro doesn't even need a relay dioptre on a non-flip Brevis if you can get it close enough to the groundglass. It will have the wickedest barrel distortion in the entire universe.
 
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I've done a bit of work in the pocket video camera industry, but usually they are locked to p30/50i/p60 which is terribly noisy, grainy or flickery under 50hz lighting. However I found one for $69 that does fullhd p25, and bought it to encourage them. It is tempting to put an adapter on it, it is higher performance than most prosumer HD cameras ten years ago. It is closer to 24mbs; at p25 it is easily convertible to p24; and I think it has high latitude mode and probably a 1/3rd inch sensor. If I studied the circuit I could block auto gain and shutter. But I'm waiting for cheap aswell as pro 4k cameras and have a 4/3rds.
 
Robert Hart said:
QUOTE: " I know someone is going to actually shoot a movie with this nutty thing. More power to 'em; I bet it has a "look," for better or worse." END OF QUOTE. Somebody will and it won't be as bad as people might like to imagine, so long as they make sure the iphone is properly centered. Please don't call it "nutty". You will make me all traumatised and render me unto a gibbering mess. For I was one "nut-case" among likely quite a few others who put them up to it to enable people who own the adaptors some new lease of life from the investment, a reprise of the original purpose for the moving groundglass, a better previsualisation tool for directors. Sadly the mod did not extend to the Mini35-400 but nothing is impossible. -- Phil. Don't deny yourself. Get out the Sony Hi-band Video8. Bung it on the back with a FX1/Z1 adaptor via stepdowns and transport yourself back into the sublime bliss of what could have been before modern tech came along and made it all too perfect. You know you want to. Maybe a GoPro doesn't even need a relay dioptre on a non-flip Brevis if you can get it close enough to the groundglass. It will have the wickedest barrel distortion in the entire universe.
Click to expand...
If you want to use it as a director's finder then fine, although I think I'd prefer something like a S-35 sensor point & shoot with a lens mount adapter. But be my guest to lose a couple of stops of light, heft around a big chunk of mechanics and optics plus a battery to power that spinning GG's motor.

Wayne, here's the link:
http://www.pstechnik.de/en/digitalfilm-pro35-smart.php
 
I had a lot of fun using a Brevis on an HVX200 and Canon FD lenses. I filmed a lot of paying gigs as well as a couple short films. You could get a really great look with that thing. I tried to spark it up recently but I think the motor is dead. What a fun time the 35mm adapter period was. I'm of course much happier using the Epic. But yeah, what a hoot!
 
Man i used to have a set of Canon FD primes to die for. Hand picked over the course of 10 years. ( iused to shoot stills on a AE1 program)

17mm SSC F4
20mm F4 SSC
24mm F1.4 SSC
35mm F2.0 SSC
50mm F1.4 SSC
55mm F1.2 SSC
85mm F1.2 L FD mount
135mm F2.0 SSC
200mm F2.8 SSC ( The best lens EVER)

Sold them all to buy a stupid fucking 5DmkII. Worst money i ever spent, as soon as the 5DmkII was in the mix, i spent 5,000 in accesories to make it work, and NOONE wanted to pay for it as a rental. I lost 8500 on that camera.
 
Mitch Gross said:
Wayne, here's the link:
http://www.pstechnik.de/en/digitalfilm-pro35-smart.php
Click to expand...

Thanks Mitch, good to see the device. I think I'd prefer to use a straight triplet macro setup as described before on a phone, for size. The new 8 core arm chip (only 4 high end and four low end cores) is said to be over 1.43* as fast as the snap dragon 800 on the Galaxy note 3 4k camera phone, so maybe we will see 4kp50 phone useful for something like this that can handle some modest level encoding for some fun.
 
Wayne Morellini said:
Thanks Mitch, good to see the device. I think I'd prefer to use a straight triplet macro setup as described before on a phone, for size. The new 8 core arm chip (only 4 high end and four low end cores) is said to be over 1.43* as fast as the snap dragon 800 on the Galaxy note 3 4k camera phone, so maybe we will see 4kp50 phone useful for something like this that can handle some modest level encoding for some fun.
Click to expand...

Wayne, just realize that by using a triplet instead of rephotographing an arial image you will get the field of view of the lenses in S-35 but will not get the shallow depth of field. The triplet works like the Angenieux/Zeiss CLA-55 adapter or the JVC adapter, but if you want the depth of field effect you need to rephotograph.

But I would agree with you. For the cleanest and brightest image I would go with a triplet, especially if the point was as a lightweight director's finder type unit.
 
I thought it increased the relative aperture size and decreased the dof as it relayed down the areal image that normally is projected on the ground surface?
 
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