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View Full Version : Any ideas regarding this 4x5 SLR?



Dean Jones
18-May-2007, 03:44
I have long had a dream of building a 4x5 SLR.....If anyone has ideas regarding this project I'd love to hear from you....The camera will be tested the moment the rain stops......:)

http://homepages.ihug.com.au/~razzle/4x5_SLR/4x5_slr.html

Walter Calahan
18-May-2007, 05:22
Pretty cool

Me, I'm too lazy, so I simply use two RB Graflex 4x5s, one Graflex 5x7, and one Graflex 3 1/4 x 4 1/4 extended bellows model for 6x9 roll film backs.

Plus I can put many different lenses on my Graflex cameras by simply making custom lens boards.

Greg Lockrey
18-May-2007, 05:33
Way too cool.:cool: Is there going to be wideangle version? You guys "Down Under" do come up with some unique camera builds. I seen a Stereo 4x5 built by an Aussie a couple of years ago. It had to have weighed a "ton" also.

David A. Goldfarb
18-May-2007, 05:53
Is that made out of a Leitz-Linhof reflex viewer designed for use on copy stands?

When you trip the shutter, does the mirror move out of the way automatically, or do you have to do it manually? I guess an interesting way to do that would be to put in a cable release fitting so that when the mirror goes up, the shutter releases.

Dan Fromm
18-May-2007, 05:58
Way too cool.:cool: Is there going to be wideangle version? You guys "Down Under" do come up with some unique camera builds. I seen a Stereo 4x5 built by an Aussie a couple of years ago. It had to have weighed a "ton" also.Um, Greg, there are few, if any, retrofocus lenses that cover 4x5. And SLRs need lenses with long enough back focus to clear the mirror. For lenses shorter than normal, this usually means retrofocus.

There is, though what I think is the ancient Bronica solution. Falling, not rising, mirror, but that requires another shutter to block light entering from the viewing screen while the exposure is taken.

Dean, does your prototype's mirror rise or fall?

Cheers,

Dan

Greg Lockrey
18-May-2007, 06:02
Of course, what was I thinking?:o You'd have to go with a twin lens set up.

Bill_1856
18-May-2007, 06:03
Nice!
But it's hard to beat my old 4x5 Super D Graflex with semi-automatic diaphragm. It's only real drawbacks are that it weighs a ton and no retro-wideangle lenses had been invented when it was made. The 3x4 model is actually a lot more usable.

Frank Petronio
18-May-2007, 06:26
Brilliant Dean.... Patent It!

Dean Jones
18-May-2007, 06:49
Dean, does your prototype's mirror rise or fall?

Cheers,

Dan

The mirror is raised to shut out light from the viewing screen....The body of this camera was actually manufactured by Zeiss and originally designed as a microscope camera, but I saw the potential for use as a normal reflex.
Hopefully it will serve as a basis on which to experiment further.;)

J Peterson
18-May-2007, 07:24
Dean, it looks great! I'll be watching this one for sure.

Frank Petronio
18-May-2007, 08:54
You didn't realize that Litty already patented the mirror and reflected light did you? It's next to his patent for geared wheels.

cyrus
18-May-2007, 09:02
Hey what's the resolution on that? Is it a Hasselhoff?

Paul Ewins
18-May-2007, 18:32
Nice job Dean! I've already got a Graflex RB Auto in 4x5, so my thoughts have been running in other directions. I've got a broken 3x4 SLR that I've been thinking about widening into a 4x10 SLR and a broken 4x5 RB that may end up as poor man's Gowlandflex TLR.

andy bessette
18-May-2007, 23:51
I have long had a dream of building a 4x5 SLR.....If anyone has ideas regarding this project I'd love to hear from you....The camera will be tested the moment the rain stops......:)

http://homepages.ihug.com.au/~razzle/4x5_SLR/4x5_slr.html

Yo Dean,

TOTALLY COOL! Looks very professionally done. I like it.

best, andy

THERE'S MORE TO OPTICS THAN MEETS THE EYE

Wimpler
19-May-2007, 02:50
I've been thinking abot doing teh same thing. I hope I can giev some usefull suggestions:

1. To make such a large camera handholdable you need a big handgrip. Haven't found another way to hold such a thing comfortably.
2. When you are using 4x5 with regular 4x5 holders you need to change everytime, pull the darkslide etc etc, and a waistlevel viewfinder, you are essentially using a viewcamera, you just put a mirror betwheen the ground glass and the lens, needlessly complicating the process.
- Use a 6x9 rollfilm back
- Don't use a darkslide but let the mirror block the light
- Use 2 extra mirrors to create a mirror prism (pentaprism would be to heavy this big)
- Design camera in landscape orientation so that the minimum film-lens distance is just a bit more then 6cm
- Wide angle is very possible but needs a dedicated camera with an undersized mirror, which is used for focussing, and a seperate wireframe finder.
- Create a focussing mechanism yourself instead of the focussing helical which may not give enough extension etc etc, for example, sliding boxes focussing might be possible.
- Made a focal plane shutter and universal lens mount to be able to use ANY lens.
- Another idea I have been playing with was using a semi silvered mirror, which could be held in place during the exposure. This results in a dimmer image in the viewfinder, and a need for longer exposures. To read more search for info on the canon pellix.


These are just the ideas I had on my own project. Your camera is looking absolutely beautiful. I hadn't even considered helical focussing, so seeing your camera certainly was intersting. Good work!

Dean Jones
19-May-2007, 03:07
Ok so let's consider the mirror aspect...this baby utilises a mirror that's coated on the upside, same as all SLR's. These things are mighty expensive, so what compensation do I make when using a cheaper mirror that is coated on the underside like the one on your bathroom wall?
Say it's 2mm thick, does that mean I must space the film plane 2mm farther back than normal, or as it's on a 45 degree angle is that 1mm?
If I decide to make another camera of this type, obviously my prime consideration would be keeping the price to a minimum and the mirror is probably the most expensive part.
Has anyone gone down this road before? :confused:

JW Dewdney
19-May-2007, 03:32
What's the size of the mirror?? Seems as though you should be able to get away with using a 2x2 size mirror, closer to the lens, right? I don't think there's any hard and fast rule that says it has to be near the film plane... curious as to your thoughts on that.

JW Dewdney
19-May-2007, 03:35
Hey what's the resolution on that? Is it a Hasselhoff?

no no, man... THIS is a hasselhoff...

http://www.youtube.com/watch?v=oYj6TceYio0

Wimpler
19-May-2007, 04:06
Dean Jones, the problem is not the fact that there is a position difference between teh coating on top or on the bottom, the problem is that with a regular mirror, not only the silver will reflect, but also the glass! These reflection will both fall onto the ground glass, but in slightly different locations (for example 2mm apart), so you see a double image! Also, a part of the light reflected on the silver will reflect onto the glass just above it, back onto teh silver, then to the ground glass, resulting in yet another image. Ofcourse these images get fainter and fainter, but this will result in a less clear view on the ground glass.

It is entirely possible to use a regular mirror if you can live with the fact you see everything kidn of double. Focussing will still be possible but it is harder! In some plastic toy TLR cameras with a focus free lens, a regular mirror was used in the viewfinder.

Wimpler
19-May-2007, 04:09
JW Dewdney: Positioning the mirror as close to the film as possible is usefull to keep camera dimensions minimal. If you move the mirror closer to the lens, you will need to place the ground glass higher to compensate (keep distance between lens and film equal to distance lens to groundglass).

JW Dewdney
19-May-2007, 04:29
maybe (it seems it all depends on what the design actually IS - perhaps you could have a fold out prism that captures an aerial image, for example... that way you wouldn't need any sort of 'chimney') - but at least you could have an actual, functioning mirror that way (perhaps).

Dean Jones
26-May-2007, 15:54
I finally managed to get out and shoot a frame or two with the SLR. Lens I used was the 210 Sironar N f5.6......film was Delta 100, quite bright early morning sun, (hence the shadow from a light pole) and an exposure of f16 @ 1/60th.

I was mainly concerned about the focusing and this shot proves a couple of points. I used one of my slip in ground glass screens (made from a double dark holder) to ascertain the placing of the camera's own viewing screen. This had to be moved from inside the camera body to the outside, then I shimmed out the Razzlok by 0.4mm to get the two screens to coincide.

Obviously I thought the slip in screen was accurate, but I wanted confirmation.
Secondly, I cannot work out how the camera ever functioned with its screen originally placed inside the camera body, as the Razzlok adds only 2.6mm (plus 0.4mm) between the camera body and the film plane......

Certainly no denying the sharpness of the Sironar! :)

Dean Jones
26-May-2007, 17:13
Here's the neg from the other side of the holder.....Focusing has never been so easy and I can view it the right way up!

Cheers. :)

Kevin M Bourque
27-May-2007, 06:08
Nice work on your Obsession 6x17, too!

Ash
27-May-2007, 06:42
Dean you got mail. ;)

dazedgonebye
5-Jun-2007, 21:00
Dean,
I suppose you've seen one of these before? I hadn't.

Modern Mentor (http://cgi.ebay.com/Modern-Mentor-4x5-Reflex-Camera-Better-then-Graflex_W0QQitemZ200116890328QQihZ010QQcategoryZ15247QQrdZ1QQcmdZViewItem)

Don O'Neil
21-Jul-2007, 17:19
Peter Gowland built and sold the 4 X 5 Glowlandflex camera but I think it was a twin lens reflex. He used one of his cameras for years for glamour photography. I just googled it and he still sells his cameras. You may get some ideas from this site: http://www.petergowland.com/camera/.

Don

Rob_5419
21-Jul-2007, 17:47
I have long had dreams of building a 4x5 SLR......so this prototype is currently under review. The advantages are finally the image is right side up, so I no longer have to stand on my head..... I don't have to worry about any parallax issues so I get perfect framing without fear of any cropping......and interchangable lenses are no problem. It has bellows so awesome macro is also permissible.

Fascinating seeing your work Dean - hope the project goes well.... I'm wondering if there is another rationale for building a 4x5" SLR which you have not mentioned in your site?

A Silvestri H camera:

http://www.silvestricamera.it/eng/prodotti_eng/mod_h_h25_eng/mod_h_h25_eng.htm

does everything you mention without being an SLR.

It gives a right-way up image, with every lens from 38mm to 180mm on 4x5" (exc. coverage of the widest 38mm fals short). For those photographers who like to stand images on their head, ground glass viewing enables simultaneous upside-down viewing.

Parallax is avoided by using the groundglass screen focussing, as is cropping - so perfect framing is inevitable.

The laterally reversed images of the SLR design is a draw back if the up-right image is an advantage over the inverted image. Somehow, the weight and bulk introduced by the mirror reflex system does not seem to weigh in favour of a 5x4" camera for me ,as it cannot benefit from the use of roll film as in 120 roll film SLRs for a 5x4" format.

Bellows focussing enabling macro is a strong point: with Silvestri's rear bellow-focussing unit, macro is also possible - with a huge range of interchangeable lenses.

The most striking thing about the Silvestri Mod. H is that it comes all in a neat lightweight package which is handholdable and strap transportable without the issues of a heavy large format camera. With Quickloads and a back, it's a fantastic system.

Still, your project is great - it has "I love designing things" written all over it ;)



I still your ideas though

Ed K.
21-Jul-2007, 22:56
As to Peter Gowland, you may note that he created a 4x5 Single Lens Reflex quite a long time ago. Look midway down the camera history page to see it:

http://www.petergowland.com/camera/history/

Who knows, he might even have parts for one still!

Wayne Crider
22-Jul-2007, 10:21
Somehow I remember seeing that camera page before and not recently. Has it been raining all this time?:p

I shoot an old Graflex that cost me under $50. Only downside is finding good holders for it.

Saulius
22-Jul-2007, 10:41
Is it a Hasselhoff?
:D
Nice job. Does taking an image, from set up to the click of the shutter go any faster with this design from a traditional view camera or is it about the same?