Converting a 4x5 view camera to a......

[Gordon Moat]

Hello GPS,

Consider wooden view cameras that allow the front and rear standards to swing or tilt. Many have detents for zero position, yet some do not on all positions; for example the swing on my Shen-Hao is not detented to zero. In other words, there are probably less parallel than something that is machined to fit.

An assumption would be that a donor rear standard would be somewhat precise. Making a box that is parallel (or super close) would not be that tough to accomplish. The distance measurement data would start with published lens data from Nikon, Rodenstock, Fuji, and Schneider. Then it would be measuring tools, starting with a dial caliper, though perhaps some might want to use a depth micrometer. Anyone attempting this would likely need to have these measuring tools; I still have many from when I was making custom parts for roadracing motorcycles.

The other aspect is the desire to mostly use shorter lenses. Considering that guess focusing, or even a helical with numbers on it, is just not that precise anyway, then error needs to be within the DoF for the desired lens. In practice, I use an uncoupled rangefinder for my old folder cameras (6x4.5 to 6x9) and the numbers on the front cells. With my old folder camera shots, it has been rare for me to get out of focus images, even wide open at f4.5 with fairly normal (not wide angle) lenses. My folder cameras were calibrated with an old 35mm Nikon screen taped onto the open back (very crud, but these were cheap cameras), then set for a distance of 3m for accuracy. Just to use an example, a 90mm f5.6 large format lens has about 0.5m DoF at near 2m distance, and DoF only increases with camera to subject distance.

Probably obvious that such a system might not be that great an idea for selling to others. Those slight differences between lens manufacturers for flange to focal distance would mean several slightly different spacer boxes . . . definitely not a practical solution beyond a few more common lenses. Restricting to one lens manufacturer's measurements would be even tougher on potential sales. Therefore, this type of soluton would better suit someone who only wanted to make one or two of these cameras.

Ciao!

Gordon Moat
A G Studio

[GPS]

Yes Gordon, the view cameras sometimes don't have zero detentes etc. But you focus them with a Lupe and you see the bad focus (at least you try). A handheld camera has the imprecision inbuilt once for ever - and there is no easy way to correct a slightly nonparallel cone, or its placement etc. once in its place. For the shorter focal lengths the problems come also with the small depth of focus - the plan parallelism is then much more important. Some kind of problems (parts precision and the precise assembly) must be solved with a clever construction rather than trying to imitate professional manufacturing methods. All in all, a good camera building is possible but certainly not easy.

[Gordon Moat]

Not to come across as picky, but handholding a camera while guess focusing, no matter how good it was made, simply cannot be as accurate as most cameras on a tripod focused using a loupe on the ground glass. However, the point of a handheld 4x5 is to escape the tripod and ground glass focus. Regardless of manufacturing accuracy, luck will be involved in getting precise focus and absolute best results.

On the subject of precision, a mock-up could be made to test the validity of a concept. When basic ideas prove possible, then precision could be handled by any competent machine shop. Maybe I am lucky in that San Diego has tons of these places, mostly left over from the collapse of the local defense industry in the 1990s. Provide any of these places accurate measurements, and they can build your design, often for quite low cost. Want to make the cost even lower, create a basic shape, then have them fine tune it to parallel, probably cutting an hour off labour.

Okay, so let's say you live in the suburbs, don't have a machine shop anywhere close, and lack some precise meauring tools. Then I don't think something like this should be attempted. Just buying measuring tools and a few metal working tools could run a few hundred dollars (or more). Then there is the matter of someone not having experience using such tools, or figuring out how to design proper parts to make everything work. In such a situation, those individuals should find a solution they can purchase, either Gaoersi or Fotoman should provide much nicer solutions. Those who want something cheaper should get something like a Crown Graphic.

I don't want people to be misled into thinking this would be easy when some basic knowledge is needed to accomplish the task. Just like anyone could buy tools and workshop manuals, without some basic mechanical knowledge and ability, the average person will not be able to set Desmo valvetrain clearances, nor rebuild an engine . . . so building a camera is not much simpler than working those things. I already am capable of working on complex things, already have most of the necessary tools, so this is why I think it is not that tough; for some others it very well might be quite difficult.

Ciao!

Gordon Moat
A G Studio

[Paul Droluk]

[QUOTE=Bob Salomon - HP Marketing;232466]

Fotoman makes two (2) different Helical Focus Mounts. One short (HFM-S, same extension as the Rodenstock) and one long (HFM-LT) with an additional 10mm of extension. Both accept #00, #0, or #1 shutters, and have calibrated distance and DOF scales.

Paul, Rodestock helicoids, off the shelf, are the correct length for the focal length lens they are designed for and have the proper focusing and DOF scales for the lens that they are made for. These are not universal helicoids. They are specific to the focal length. Therefore they always focus accurately.

The focus mount and scales on the one for the 28mm Apo Sironar Digital HR is quite a different length then the ones for the 35mm, 45mm, 55mm, 65mm, 75mm, 90mm, 100mm, 120mm, 105mm, 135mm and 150mm lenses.

Schneider also has helicoids similar to Rodenstock's.

Fotoman HFM's are precisely calibrated and marked for a given focal length as well. Of course you still have to match the FFD of the lens with the lens flange to film plane distance, and then calibrate the HFM to the finished assembly. To make this easier, we incorporated a FULL +/- 1mm of adjustment capability into our HFM, rather than the =/- .5mm of the ROD or SCH.

[Paul Droluk]

Adjustable shift would be tougher. This would require a machine shop. The only lower cost option I can imagine would be an offset lens mount, much like ALPA offer as an option; the downside being a fixed amount of shift built into the mount.

Ciao!

Gordon Moat
A G Studio

This idea works quite well. We recently made two custom off-set Cones for a clients 617 camera. No Reason it couldn't be done for 4x5 Cones as well, and the off-set could be any amount you would desire.

Earlier it was mentioned that Cones are expensive. Everything is relative of course, but our Cone for a 90mm lens, for example, is just over 100 dollars. Depending on the combined depth of both standards it's likely that a shorter Cone would actually be chosen, which would be considerably cheaper.

[GPS]

Not to come across as picky, but handholding a camera while guess focusing, no matter how good it was made, simply cannot be as accurate as most cameras on a tripod focused using a loupe on the ground glass. However, the point of a handheld 4x5 is to escape the tripod and ground glass focus. Regardless of manufacturing accuracy, luck will be involved in getting precise focus and absolute best results.

On the subject of precision, a mock-up could be made to test the validity of a concept. When basic ideas prove possible, then precision could be handled by any competent machine shop. ...Ciao!
Gordon Moat
A G Studio

An Alpa can be much more accurate than a view camera. When you take a picture at infinity (to make the example simple) the Alpa will win because of the precise parallelism of its parts and the precise flange focal length. But if you build such a camera yourself it can be much less precise than the view camera - because of the bad parallelism and the incorrect FFL. And surely you can have the parts built with high precision - still the result can be miserable because of the differences in the measured - designed - and the actual dimensions needed. It's nice to think that your Nikon 90mm demands 87.5mm flange focal distance and that your parts are made to 0.005mm precision when in fact the FFL was taken from a brochure and the real specimen is 0.3mm different! Unless you have put it at the right distance from the film you won't see it! And how to measure the right distance from the film plane, once you have the lens at the right distance? Put a caliper against the film - it won't hold there... Those are real problems whose solution you have to know before you get your parts - made with 0.005mm precision - home. You can regulate the view camera - the hand held one is regulated just in your plans before you get the parts done.
I don't think you cannot build cameras (I did) but that you must have enough knowledge with the practical manufacturing and design problems. Which you probably know...

[GPS]

[QUOTE=Paul Droluk;232584]

Fotoman HFM's are precisely calibrated and marked for a given focal length as well. Of course you still have to match the FFD of the lens with the lens flange to film plane distance, and then calibrate the HFM to the finished assembly. To make this easier, we incorporated a FULL +/- 1mm of adjustment capability into our HFM, rather than the =/- .5mm of the ROD or SCH.

That's exactly what I meant - the +/- 1mm adjustment is necessary because the FFL values are not as precise as declared. The adjustment is the design necessary to overcome the differences between the actual and the designed measures.

[Gordon Moat]

So rather than stating why something is too difficult, provide a solution to get within that 1.0mm range. That is also quite different than having something made within 0.025mm tolerances (which is fairly easy in machining operations). How I would accomplish that is having something be too long, then removing the excess material to get the matching flange to focal distance. The first construction would be adding to the published specifications, then the material removal would be a many step process to reach a solution distance allowing helical calibration (which is another step). Obviously none of this is quick and easy, but I am not so negative to think it is impossible to accomplish (and I don't consider myself an optimist).

Using my 6x9 crude technology folding camera as an example, I do have lens mounting shims with all the parts I have for these. Some similar shim material could be used on a project camera, depending upon how a mounting system is devised. The trouble with focus error is more an issue at close focus, than at infinity. As the camera to subject distance increases, so does DoF. It would be more likely to guess focus incorrect at close distances, and get a soft looking result, than anything that might happen at infinity focus (or approaching that distance).

It still needs to be pointed out that there is a huge difference between building one camera, and creating something that could go into regular limited production. Most people wanting hand held 4x5 cameras would be better off starting with a Gaoersi or Fotoman, or buying a used Crown Graphic, than they would with attempting to make their own. Though consider how cool it would be to build your own, and that might be the draw for attempting it.

All this discussion is great, and hopefully gives the OP (and others) some ideas of what they would need to do to accomplish this. What has yet to be discussed is cost. Paul of Fotoman mentioned their cone prices, and I think those could be near (or less than) the cost of having a custom made part. Buying a helical is certainly an option, as would be buying a finder of some sort. The other parts, like a donor camera or rear standard parts, could be found used. I would still guess a project cost near $300 to $600, not including a lens. Add to that the cost of measuring tools, or tools to do adjustments, though unless someone already owns that I stuff, I question the wisdom of attempting to construct a camera.

Ciao!

Gordon Moat
A G Studio

[Paul Droluk]

To anyone who want's to try building their own personalized 4x5 Point & Shoot...

we have a fair amount of expertise in this regard, and would happily assist anyone who would like to give it a try. With the correct forethought, it wouldn't be terribly difficult. Using the approach that's being discussed, all we would need to know would be the distance from lens board to the film plane, and the specific lens that was to be mounted. With that information, we could provide a simple list of required components to put it together with enough precision so that the HFM could provide the final FFD adjustment.

Buy the components from us, or do-it-yourself, it really doesn't matter. The important thing is that P&S 4x5 shooting is fun and makes a lot of sense in many situations. Think about it... every great pic ever taken without the benefit of movements would likely have been more useable (maybe even better) if it had been captured on larger film, regardless of format.

[GPS]

So rather than stating why something is too difficult, provide a solution to get within that 1.0mm range. That is also quite different than having something made within 0.025mm tolerances (which is fairly easy in machining operations). How I would accomplish that is having something be too long, then removing the excess material to get the matching flange to focal distance. The first construction would be adding to the published specifications, then the material removal would be a many step process to reach a solution distance allowing helical calibration (which is another step). Obviously none of this is quick and easy, but I am not so negative to think it is impossible to accomplish (and I don't consider myself an optimist).
...
Ciao!

Gordon Moat
A G Studio

Gordon,
first of all, in case you haven't noticed, I'm not under you commands. Therefore I won't present you "solutions" so that you could just simply do what others have find with their effort. Sorry for that. Secondly - if you read more carefully my post you can see that nowhere did I say - "it is too difficult" (quite the contrary - I said I have built cameras!) - those are your words. If you want to discuss in an honest way then don't put in the other's mouth words they don't say.
Thirdly, as to your "solution" of making a body and shaving it after to the right dimension - this is the least pleasing method from the practical point of view. In no moment will you know how much exactly would you need to shave off. And at the end, not having this knowledge, if you shave off too much - will you start the building all over again with the same method to come, perhaps, to the same result?
There are better solutions to it. One of them is the adjusting method Paul Droluk uses in his cameras. Still, the amateur camera builder faces other problems he doesn't not...