[MF3D.FORUM:1177] Re: Camera design

["Bill Glickman" <bglick@xxxxxxxx>]

Brian

> I agree with Bill that your best bet would be to start with a 4x5
> camera.

     My lone supporter, thanks!

You should be able to find a used 4x5 camera with a Graflok
> (or International) back for not too much money.  You want a camera
> with a square bellows, so that will probably mean a monorail view
> camera.  Flat bed (often called field) cameras tend to have a taperd
> bellows so that they can fold smaller.  You can probably use a camera
> with a short rail since MF lenses are shorter focal length than LF
> lenses.

       Yes, very short rail...the benefit is, you can just lift it up on
tripod and view... do not have to unfold, mount lens, etc..

> Just yesterday I saw a (somewhat rough) Omega View 45E at Wall Street
> Photo for $389 (before haggling), and NYC is not really the place to
> find low cost used cameras.  A new Toyo 45CX is listed for $629 at
> Calumet's weg page <URL:http://www.calumetphoto.com/>.  Based on a
> note on the page, the price is probably lower.  (Toyo won't let them
> advertise a lower price.)  Either of these cameras will give you all
> the movements you could possibly want.

     Even cheaper in the UK at Robert White...

> If you are using movements you will have the camera on a tripod, so
> ground glass focusing and composition shouldn't be a problem.  Remove
> the ground glass panel when you are ready to shoot and use a roll film
> back to hold the film.

      many film holders are slide mount like a film holder...so you do have
to remove the gg back.  That would be the ultimate RFH.


 If you want both movements (on a tripod) and
> handheld shooting you can get a press camera with a linked rangefinder
> and a viewfinder (and perhaps a sports finder) like a Graflex or
> Linhof.  You can also mark the focusing rail for scale focusing.

       That sure would be interesting....but I doubt any of those handheld
cameas have a front lens board that can accomodate two lenses...most all of
them are less than 110mm square.

> Horseman makes a 6x12 roll film back that will attach to a 4x5 Graflok
> back.  Personally (given the cost) I wouldn't cut up a smaller back.

       The only reason I mentioned hacking up a smaller back is that a
Horseman 6x12 measures about 10.5 cm.  so you can not get two 6x6 shots out
of one frame.  Linhof makes the only 12cm back, and it costs $1200 in the
UK.  Here its way more... but if you hacked up a 6x7 back and opened the
image area up to 12.5cm, which is the max. opening of most view camera
backs, then you would just get your two 6x6 shots with a tad space for a
divider.  The beauty is, you would not have to change the gearing in the
winder, just wind twice for each shot.    You can buy the 6x7 backs in slide
in style, so you would not have to remove the gg.  The only trick would be
to increase the size of the metal film backing from 7cm to 12.5cm.   A
machinist can do this by replacing the existing backing with a larger one.
This can all be done for way less than the cost of a Linhoff back.  The
Horseman backs cost about $350.

>
> As far as lens synchronization goes I see two solutions.  First, you
> could mount two lenses in separate shutters on a single lensboard and
> use either a linkage between the shutter releases or a dual cable
> release.  The biggest problem is that LF shutters are pretty big and
> you might not get the separation that you want.  If you use two of the
> Mamiya TLRs lenses this probably wouldn't be a problem.
>
> Second you could mount the elements from two lenes on a custom board
> (or use two lenses "in barrel") with a single Packard
> <URL:http://www.hubphoto.com/> shutter behind the lenses.  The Packard
> shutter is meant for this application (lenses in shutter, not stereo)
> and is available in very wide openings (up to 8 inches).  Packard
> shutters are pneumatic (operated via a squeeze bulb).  The number 6
> shutter has both instantaneous (1/25 sec.)  and time (T) speeds.
> Since there is an electronic version of the shutter (with not much
> mention as to what exactly the electronics do) I assume something
> could be rigged up to provide other speeds.  The biggest problem would
> be making sure the shutter wasn't too big for the front of the camera.

    Great lead...I never thought of that!

> I just had an idea.  You could build a camera from a 4x5 camera with a
> square bellows, a pair of Mamiya TLR lenses, a Horseman 6x12 roll film
> back for their SW612 camera and a custom ground glass panel (perhaps
> also from the Horseman SW612).  The lenses would be mounted (with
> their viewing lenses) on a single lens board at the front of the
> camera.  The bellows would be interally divided into four sections.
> The back of the camera would have a single panel with the roll film
> back on bottom and the ground glass panel on top.  This would allow
> you to compose and focus without having to fidle with the groundglass
> panel in the field.

       Great idea, but I think it would be much harder to maintain exact gg
/ film alignment.  That is the beauty of staying with standard backs,
everything will be perfectly aligned with no tinkering.

>
> If you want to build a camera with movements I suggest looking at a
> lot of 4x5 cameras because whatever you come up with is likely to be
> about the same size.  Jon Grepstad <URL:http://home.online.no/~gjon/>
> has a great site on building LF cameras with pointers to other sites
> (including people who have built rollfilm holders).  Jon has also
> written a good book (with full size drawings) on building LF 4x5
> cameras.

      At the prices these rail cameras have come down to, I bet it would be
hard to match their ability to make movements and hold the standards where
you want them.    You would have to spend a lot of time and match this...
but it sure would be interesting!

     One of the issues is the lenses.  I thought of doing this myself, or
doing the same with two 4x5 cameras with a roll film back... however, I was
planning on using Schneiders new Super Symar XL 80mm lens...it will be
released in two weeks at Photokina.   I own the 110mm and  the  150mm now,
and can honestly say these lenses rival any MF lenses, which is a first for
LF lenses.  In the past, LF outperformed MF due to image size, not lens
resolving power.  But this has all changed with the XL's.   BUT, things are
never easy.... although the 80XL would be a perfect stereo lens, 200 mm
image circle, excellent contrast, etc.... if the MTF curves on this lens
come out looking like the MTF's like the other XL lenses, they will be very
poor if shot at f 11 or wider.... so all the movements such as rise and tilt
would enable you to shoot at faster ss and wider apt...but this would be
negated by the poor MTF curve at these apt.   So, I guess the ultimate would
be using two MF lenses instead, possibly the ones you suggested.... but the
key is to find a 80mm lens with a large image circle at wide apt.  I am sure
some exist... at www.photodo.com  you will find some great lens data...

      To me, the ultimate would be .... two small box type cameras, home
made, similar to David Lees homemade 4x5's  (incredible ingeunity Dave) with
1.5" of front rise and 5 deg of front tilt, MF lenses to cover these
movements with linked shutters and 6x7 roll film holders /  gg.   Then the
real kicker would be to have these two cameras have the ability to get
really close to each other on the slide bar...like 80 to 90 mm inter ocular
distance.    Any builders out there?  I would love to buy a stereo system
like this!  But don't have the time or the patience to build one...

Bill G




>
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> Brian Reynolds                  | "Dee Dee!  Don't touch that button!"
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