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-   -   35mm adaptors and jvc hd200/250 (https://www.dvinfo.net/forum/alternative-imaging-methods/85754-35mm-adaptors-jvc-hd200-250-a.html)

Phil Bloom February 5th, 2007 04:36 PM

35mm adaptors and jvc hd200/250
 
anyone tried this combo yet, with the built in flip it could be the perfect camera for the adaptors.

Toenis Liivamaegi February 6th, 2007 02:27 AM

The HD200 has even vignette compensation in addition to the built in image flip.
But there are no full frame relay lens for the HD200 and the like to use it with the great adaptors like SGpro and Brevis. I really wanted to get a HD200 for my productions but due the fact that there are no alternative than the Mini35 and Letus for it I went for another camcorder because using an adaptor in front of the stock HD200 lens really screws up the great ergonomics.

I have wondered if maybe mega pixel C-mount lens can be used in macro configuration as relay lens but there aren`t much information available on that.

Cheers,
T

Jon Wolding February 6th, 2007 12:56 PM

Quote:

Originally Posted by Toenis Liivamaegi
The HD200 has even vignette compensation in addition to the built in image flip.

That's pretty cool. I didn't know that.

Phil Bloom February 6th, 2007 01:34 PM

whoops...bought one

Phil Bloom February 6th, 2007 05:12 PM

I will do some tests over the next week with the 201 and the Brevis and M2 and post my findings on my web site.

This camera, if it does what it says on the tin could be the best camera for DOF adaptors. If Redrock, Dennis or Wayne come out with a relay for their adaptors for this camera with the built in flip you will have a mini 35 killer. Better image quality with way less light loss. What more could a DOP want?!

Bob Hart February 6th, 2007 09:22 PM

Phil.

In the UK there is an engineer, Les Bosher.

He makes a Nikon Mount to JVC HD100 adaptor mount which I presume may be the same as the HD200. He is apparently amenable to custom work and has the knowings of calculating lens focus etc..

He may even have a rig good enough for testing field-of-view from 24mm wide to 8mm diameter (corner-to-corner) at the CCD as he has re-engineered Bolex H16RX5 film cameras for Super16 with whole new front re-centered lens mounts (including PL mount, I have been told hearsay).

It may be possible to make the Nikon adaptor with an adjustable space between the two flange faces so that the Nikon lens can be offset forwards for closer focus to eliminate need for an added acromatic dioptre.

Without the achromat, the combination may a bit long. If the Brevis has its own existing achromat, then the Nikon lens might not even need to be offset forward.

The standard Les Bosher adaptor may be sufficient and you then retain the utility of all available Nikon glass on front of a HD200, a worthwhile adaptor in its own right.

You will still need to make a simple tube bridge from the Nikon to the Brevis to keep things centred and on axis.

The options for the Brevis might then shake down to a 50mm f1.8 or 50mm f1.4 Nikon for an approximate 24mm wide image off the groundglass or a 35mm f2 Nikon for a larger area. You can get a Nikon 35mm f1.4.

These lenses come new as an autofocus with manual option or as manual-only lenses. The f1.4 lenses will likely be quite expensive which might make their use with a budget adaptor a bit of an over-capitalisation.

Secondhand the 50m f1.8 Nikon is fairly common but the others seem harder to get. The 50mm f1.8 Nikon I have is not so outstanding for sharpness so you might need to hand-pick from several if you source one secondhand.

Modern lenses are plastic bodies so I am not sure I would want to make them part of the loadbearing structural path as the Letus35 does with the Minolta which is good metal.

However the Nikon lenses are internal focus which means the actual focus mechanism itself does not carry any structural loads. Whatever, I would be inclined to have a structural bridge across the Nikon, the obvious contender being a bridgeplate and support rods.

(An enclosing loadbearing tube incorporating JVC mount would be ideal. However cut-outs for focus and aperture access or mechanical relay to these adjustments would be needed.

It would be an entirely new design from JVC flange to Brevis rear, expensive, operator unfriendly and not cost-effective except for robust portability.)

I think Les Bosher is findable at www.lesbosher.co.uk but I am guessing here.

(PYSER SGI (night-vision) also in the UK have a C-mount relay for 1/3" CCD CCTV cams made up for their PNP-HG monocular IR scopes.

I understand there is one also for 2/3". this relay however optically adapts the existing eyepiece optic.

The human 2020 model eyeball is not the same as a camera lens so the optics would be all wrong but the supplier may have other buyable options available.)

The quickest and dirtiest test I guess would be to offer the BREVIS up to a digital Nikon SLR with the selected lenses and see if you can get a sharp relay.

Then calculate a scale 1/3" CCC frame relative to the digital SLR frame size, shoot a resoluton chart tight within this "safe-area", then crop it in Photoshop and see if you have satisfactory resolution and distortion performance.

Just a few thoughts.

Phil Bloom February 11th, 2007 04:01 PM

i have a test video on my websote now with this camera and the brevis. It worked well. 35mm shorts 2 and under the shootout section

Danny Natovich February 16th, 2007 04:40 PM

Hi Phil, I just realized what where the rods for.

Phil Bloom February 16th, 2007 05:32 PM

Hi Danny

Your rods came yesterday so the are now on the JVC thanks! Best value and most solid rods i have used.

Phil

Charles Hurley February 17th, 2007 07:55 PM

f1.8 or f1.4 relay lenses are silly. They're as slow or slower than the stock lens. The P&S relay is about 1000 bucks and it is made for 1/3"chips and is f1.0. This could probably be modified for other adapters much easier than trying to reinvent the whole relay process. Is 1&1/? stops worth a grand? Probably. Is it worth a grand for 1&1/? stops and 8 inches? Definitely. Good Luck, Chuck.

Phil Bloom February 18th, 2007 11:15 AM

what sort of connector is at the other end of the p&s relay. How difficult would it be adapt it for an m2 or brevis?

Sam Jankis February 18th, 2007 04:32 PM

Quote:

Originally Posted by Phil Bloom
what sort of connector is at the other end of the p&s relay. How difficult would it be adapt it for an m2 or brevis?

You should try calling some retailers or rental houses. I've been surprised at how much information I can pick up.

Eric Ramahatra April 30th, 2008 04:58 AM

did someone succeed on trying a p+s relay lens on another mini35 adapter ?

Bob Hart April 30th, 2008 10:56 AM

Phil.

The front-end of the P+S Technik relay for all types has a lens bayonet style fitting and key pin like the PL mount. There is also another compression collar and screws which enable fine adjustment of the angle the camera attaches around the camera optical centre axis.

There is no adjustment for deviation off-axis in the mount itself. Given the precision of the appliance there would be no need for it under normal circumstances.

This can be achieved with a adjustable mirror within the flip path of the Mini35 itself in an exceptional circumstance.

It may be possible to fit the P+S relay but would be a complex machining job to make up the bridgepiece with threaded collar and female splines or lugs to fit on back of the Letus to accept the bayonet end of the P+S lens.

With the Sony Z1, the P+S relay seems to be about a 4+. It presents the same sized image as the Century 4+ from my AGUS35 which I adapted to fit with about the same zoom setting. Groundglass to front of relay lens on my AGUS35 was about 8 inches fotr a 4+ relay.

Hunter Richards April 30th, 2008 12:34 PM

Just wanted to say that the P+S technik relay found on the mini35, is not F1.0! The markings on the P+S lens do not correspond to the appropriate F-stop. After taking the P+S relay apart (and the entire adapter), we found that the P+S relay for the mini35 is a rehoused Schnider optics lens with a maximum aperture of around f2-2.2.


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