Building a Sinar Handy from non-Sinar parts

[Frank Petronio]

I've always been intrigued by the idea of assembling a helical focus wide angle camera like a Sinar Handy from off the shelf parts. I know the right thing to do is to find a vintage used lens already in a Handy cone and focusing mount, which would simply fit onto the front of a 4x5 format frame and you'd be good to go except for a tripod mount and a shoe for the viewfinder.

So... how would you add a shoe mount and a proper tripod hole to a Sinar format frame? What is the slickest way?

Short of finding an OEM Sinar Handy Cone/Helical/Lens, has anyone used those new cheap Chineses focusing helicals they are selling on eBay? I would like to avoid messing around and hoping for the best with regards to focal flanges distances and vignetting, so are there any lens combinations that you know would work with a flat lenboard (no cone) and not vignette too badly? (It seems like you could stick a 65mm onto one of those, stick it on a Sinar board and be ready to go, but I don't wannabe to be the first to try it...)

[David A. Goldfarb]

Now I know I've seen that shoe mount for an accessory finder (that looked very much like the finder on a Graphic) in some old Sinar catalogue. It may have even used the keyhole slot.

[Paul Droluk]

Frank... we can supply you with both the high quality Helical Focus Mount and Viewfinder for your project, as well as the accessory shoe to mount the viewfinder if you need. We could also make you a custom lensboard and any spacers you might require for that matter... http://www.fotomancamera.com

[GPS]

I've always been intrigued by the idea of assembling a helical focus wide angle camera like a Sinar Handy from off the shelf parts. I know the right thing to do is to find a vintage used lens already in a Handy cone and focusing mount, which would simply fit onto the front of a 4x5 format frame and you'd be good to go except for a tripod mount and a shoe for the viewfinder.


If I understand you well - and I'm not sure of it - the biggest hurdle you face is to make sure your lens with the helical mount is plan parallel to the film. Not easy and of uttermost importance with wide angles.

[Frank Petronio]

I would expect the helicals to be relatively parallel if everything is mounted properly. I think the big problem is to get the right distance between the lens and the film so that it doesn't vignette and so that the focus throw is appropriate (infinity to 3 feet or so) with the helical mount. That's why I am looking for people who have already done this and know which lens works with which mount.

The Fotoman option is pretty appealling actually, in fact maybe there is a new product for them in this (a ready to go camera using people's existing Sinar, Toyo, Linhof, or Arca -- any 'system" camera -- frames and backs?)

I mean I'd drop a couple of hundred on a mount and Sinar sized lensboard knowing that a 90/6.8 Grandagon (or whatever) will drop in and be good to go...

[GPS]

It's not that the helical mount would wobble - it's rather a question of how you want to make the whole lens board with the helical mount to get an to maintain the precise plan parallel position.

[Uli Mayer]

There should be somebody who could tell you the minimal length and the inner diameter of a Pentax 6x7 helicoid extension tube. I'd be surprised if the rear lens of the shorter and slower Grandagon and Super Angulon types couldn't be moved within the tube while focusing - and without getting the picture vignetted.
Building my own 4 x5 wide angle camera is still a project. But since I have already built two smaller cameras with helical tubes, I don't think it should be too difficult. One of them is based on an Ercona body and provides both 6x8/ 6x6; the other one is a 24x72 "panoramic" camera for which I used a Meopta copying body ("Reprokassette" in German). The lens is a Koni Omega 58mm which got a Minolta bayonet so that I can use it with either camera. (One helical tubes served as a telescope focouser before; the other one I hacked from a Vivitar tele converter.

Uli

[Paul Droluk]

Determining the correct distance at which the lens should be placed, and maintaining perfect parrallelism are the keys to building any camera. Using the 90/6.8 Grandagon example, the distance between the face of the HFM to the film must be exactly 94mm. Subtracting the thickness of the HFM and both standards as well as the set back from the rear standard to the film plane will determine the remaining distance needed to be "filled" with a spacer that would connect the two standards... essentially a rigid bellows. The viewfinder and tripod mounts would be added to the spacer itself. Vignetting should not be a problem at all, assuming you select a lens that covers 4x5. Neeedless to say, the spacer would have to mate to the standards in such a manner that prevents light leakage, which would likely require machining of the standards to provide a method of affixing the spacer.

My Toyo 4x5 has standards that are around 12mm in thickness plus another 6mm or so back to the film plane (not measured). Using the Fotoman HFM at 17.4mm in thickness would result in the need for a spacer 46.6mm thick... 94 -(12+12+6+17.4).

Aternatively, the required spacer length could be added between the helical and the front standard. This is how the Sinar Handy and Fotoman 45PS cameras are designed, and the "spacer" becomes a "cone". It needn't be conical however, thought additional weight will be incurred by a flat design.

Another way to look at it would be to calculate the stacked thickness first and then try to find a lens with a FFD that matches. This would eliminate the need for any spacer mechanism. Using the prior 90 Grandagon-Toyo Standards example the stack dimension is 47.4mm. In this example you could use a 47XL on a 12mm recessed lensboard (59.1 FFD -47.4). The final .3mm being adjusted within the HFM itself when calibrating focus for infinity.

[Uli Mayer]

Calculation of camera depth may wisely be based on the fact that effective focal length (and consequently flange focal distance) of lenses can vary by +/- 1% , as older data sheets state. Thus one should't start with a FFD of 94mm ( by taking the example given above) but with a FFD of ca. 93mm. This is to make sure that the final camera body will not get too deep for reaching "infinity"-focus.

I don't see much advantage in using a helical mount with an already given "infinity"-position and a marked distance scale. Instead of "harmonizing" everything - by resorting to spacers - so that the scale can be used, one can easily take a plain mount and mark positions after the whole apparatus has been assembled. "Infinity" may then be with the focuser one or more millimeters drawn but that's much better than having to start all over again. It happened!

[GPS]

I don't see much advantage in using a helical mount with an already given "infinity"-position and a marked distance scale. Instead of "harmonizing" everything - by resorting to spacers - so that the scale can be used, one can easily take a plain mount and mark positions after the whole apparatus has been assembled. "Infinity" may then be with the focuser one or more millimeters drawn but that's much better than having to start all over again. It happened!

The great disadvantage of your later metod is that you cannot focus at infinity automatically, just turning the HFM to its end position - you must look at your infinity mark first. "Harmonizing everything" - that's where you come to my original question - how do you want to put "everything" in the exact distance and the plan parallel position? Unless you have a clear answer to this question you cannot build anything precise.

[Paul Droluk]

Uli - currently, both Schneider and Rodenstock build to a tolerance of +/- 0.5mm for the FFD specified. I have no data for Nikon or Fuji. In any case, the Fotoman HFM provides +/- 1mm of internal adjustment capability (Schneider & Rodenstock HFM's provide +/- 0.5mm) to compensate for the allowable manufacturing tolerance. From our experience calibrating MANY lenses, all of the makers most usually deviate on the longer (+) side of the stated FFD... probably due to stack-up. Regarding the use of a pre-marked or un-marked HFM, a pre-marked mount includes an accurate DOF scale for the focal length being mounted... a distinct asset.

GPS - HFM's from every maker are accurate (out of the box) for infinity focus with a given lens ONLY on a pot-luck basis... maybe 10% of the time. The reason is that every lens is different... even within a single production run. For this reason you must always find or verify infinity focus anyway. Assuming the components have been manufactured within tolerance, the final "calibration" of the HFM becomes the last fine tuning step in the "Harmonizing" effort.

Determining the exact length for each component of the assembly is not that difficult as long as you have precise measurements (see my earlier posting). Maintaining Parallelism across muliple components on the other hand is more difficult. However assuming one uses quality machine tools and proper machining practice, acceptable parrallelism is quite acheivable.

[GPS]

GPS - HFM's from every maker are accurate (out of the box) for infinity focus with a given lens ONLY on a pot-luck basis... maybe 10% of the time. The reason is that every lens is different... even within a single production run. For this reason you must always find or verify infinity focus anyway. Assuming the components have been manufactured within tolerance, the final "calibration" of the HFM becomes the last fine tuning step in the "Harmonizing" effort. ...


Yes, I know it. That's why I use a construction that allows me to fine tune the lens both on distance and the parallelism. In imagination it's always just "I put this there and that's it" but the devil is in details...

[Uli Mayer]

IMO, neither knowledge of focal length tolerances (+/-1% in the past or +/- 0.5mm today) nor statistical trends are of much help here. My rule is simple: If one does not know the lens' exact f.l. or its precise FFD ( within fractions of a millimeter) one should build for the shortest f.l. or FFD tolerated by the manufacturer - and accept that "infinity" might finally not coincide with the helical mount's zero-position. Better some draw than filing! You may call this approach less than perfect but at least it's "error-friendly".
Having the "infinity" mark at the mount's end position would certainly complicate calculation and actual building (and make the doubtful use of shims and spacers almost obligatory).

My approach does not rule out adding a home-made DOF scale or a pair of DOF marks for the most frequently used stop. But as I stick to the rules published by Harold Merklinger, I can do without.

[GPS]

Better some draw than filling? Even better is - adjusting! And no, shims or spacers are not obligatory for adjusting...

[Uli Mayer]

GPS,
you wrote: "I use a construction that allows me to fine tune the lens both on distance and the parallelism."

Could you be a bit more specific about this construction or do you want to keep it as a secret?

[Ed K.]

Hi Frank!

You could make a wooden body spacer and then sand or, better yet, mill it down.

I have made many wooden box cameras, and I have a 65mm Angulon version that works great with FIXED focus and F22. The only trouble though is that hand-held shots are seldom practical once the center filter is added. That said, using DR5 processed HP5 is one way to get enough speed to make it practical. I use a shim washer for closeup range of 6-50 ft., and no shim for 25 ft to infinity. The results are quite sharp and nice. You could make a wooden body to accept your sinar parts in a jiffy. The flange to film plane distance stated by Schneider is .75mm different than Schneider specs for my particular Technica 65mm. Best to start with the recommended distance and then check it somehow first.

As to the Chinese helicals, I have one made for 90mm, which is not a Fotoman. Unfortunately, it won't fit my 90mm 5.6 Fujinon because the rear element is too large. I bought it from a non-Fotoman supplier. Be sure to watch out - make sure that they have one that will fit your particular lens!

At the moment, I have a Fotoman 90mm mount on order, one that is supposed to fit my Fujinon SWD 90 / 5.6. My plan is to use it in combo with my Gowland architectural/scenic/aerial so that I have Grafloc back, rise and fall, aerial handles, and the Fotoman helical all in one package, and of course, f 5.6 in a pinch. I can let you know how it came out if you like - the parts should be here soon.

Cost-wise, and time-wise, the Fotoman camera itself looks just right if you don't care about Grafloc items such as the Horseman 6x12 back, or if you don't care about rise and fall. By combining the Gowland and the Fotoman parts, I get what I need, but the price starts to climb pretty fast.

One good thing about building some wooden box cameras is that it lets you find out how you like the idea. I ended up loving it - so I'm getting the rest of it done.

Good luck on your projects!!!

[GPS]

GPS,
you wrote: "I use a construction that allows me to fine tune the lens both on distance and the parallelism."

Could you be a bit more specific about this construction or do you want to keep it as a secret?

This specific construction is indeed my secret ;-) ... but as a consolation I can tell you that there are many other different ways of adjusting the lens board correctly. One of them is even known to all of us, I dare to say... (now it starts to be interesting, doesn't it?) And it doesn't need any filling or shims or a spacer either! If you don't know at least this method... uhm, then take out your view camera and look at it. No shims, no spacer, no filling, yet - adjusting. And not the only way of adjusting, as I said... ;-)

[Uli Mayer]

GPS,
with or without your kind permission I'll answer in my mothertongue in order to prevent further misunderstandings:

Du kannst dir deine Arroganz - "as a consolation I can tell you" .."If you don't know at least ..." - dahin stecken, wo du das Geheimnis ( das Sekret ) deiner Konstruktion bewahrst.

[Daniel Unkefer]

https://farm5.staticflickr.com/4636/27468791959_0d875031aa_b.jpg (https://flic.kr/p/HRjJRn)Norma Sinar Handy Final Version (https://flic.kr/p/HRjJRn) by Nokton48 (https://www.flickr.com/photos/18134483@N04/), on Flickr

Made from Sinar and Non-Sinar parts :)