1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

The camera construction thread

Discussion in 'General Equipment Chat & Advice' started by Benchista, Jul 5, 2013.

  1. El_Sid

    El_Sid Well-Known Member


    But then fluorite isn't a glass either - it's a crystalline mineral... However some of the special anomalous dispersion glasses (often referred to by various OEMs as ED, UD, SLD etc) are known to be less hard than more normal glass.
     
  2. Benchista

    Benchista Which Tyler

  3. Roger Hicks

    Roger Hicks Well-Known Member

    A point not yet addressed is tolerances. I was doing a little idle consulting work once, to do with the location of interchangeable digital backs. The manufacturer gulped when I pointed out a few truths about how accurately they need to be located. He said, "Working to tolerances like that would double the cost!"

    Interestingly, the company that does the same thing, best, charges -- guess what? -- nearly twice as much for a similar looking camera.

    Addendum: of course, working to REALLY TIGHT tolerances with moulded components is quite hard. It's often easier to machine the final tolerances -- which tends to be easier with metal.

    Cheers,

    R.
     
    Last edited: Jan 7, 2014
  4. Roger Hicks

    Roger Hicks Well-Known Member

    Dear Roger,

    Incidentally, GPS is available for the M typ 240 -- but it requires an add-on grip, either because there's no room or because it would add too much to the already high price.

    Cheers,

    R.
     
  5. Benchista

    Benchista Which Tyler

    What reference to glass being hard? I can't find one anywhere in this thread!
     
  6. Benchista

    Benchista Which Tyler

    The conclusion Bob Newman came to in his article in the mag was that for the tolerances required for camera bodies, moulding plastics produces them far more easily, effectively and cheaply than moulding or machining metal, which I would agree with. Once you get to the tightest of tolerances, I agree with you.
     
  7. Roger Hicks

    Roger Hicks Well-Known Member

    Dear Nick,

    I was talking only about the tightest, namely, "medium format" interchangeable backs. Hence my use of capitals.

    Also, of course, "moulding" and "plastics" both cover a very wide range.

    Cheers,

    R.
     
  8. Footloose

    Footloose Well-Known Member

    I remember well the ruckus that occurred when Kodak brought out their 126 Instamatic cameras on which the rear body casing and back cover, was one moulded/cast piece. The hinge itself looked as if it was barely thicker than a couple of sheets of A4 paper, and yet, I don't think I ever saw, or heard of any of these 'hinges' breaking, though there were rumours circulating for about 6 months after this camera's appearance of a very small number of people saying they 'knew someone, who knew someone' who had one of these cameras where this had happened. From that point in time, this method of construction was perceived by the public as being better than a separate, metal hinge. A slightly similar thing occurred when Fluorite was first usd in lenses, though this was more about the material being too fragile and soft.

    On the other hand, Carbon fibre, which may well be defined as many as a 'plastic', has never been subjected to the same criticism but that is probably because it's perceived as a woven, rather than a solid material.
     
  9. ascu75

    ascu75 Well-Known Member

    having read this thread I have always wanted one of those Italian Cameras made out of what looks to be Aluminium I cant think of the name it was a fifties sixties piece of to me of iconic design. If I remember the name I will put it on here but reading this has reignited the fire to have one

    Just been on ebay and it is a
    Bencini Comet
     
    Last edited: Jun 19, 2016
  10. hotwenxynt

    hotwenxynt In the Stop Bath

    Perhaps thinking of a hybrid construction where a strong metal interior holding most of the 'interesting bits' suitbly shock protected are cocooned in a lightweight plastic shell which can be moulded quite cheaply and if it it became damaged, easily and equally cheaply replaced may be what could become the 'norm'.

    I know from my long association with thing photographic, (over 55 years) I appreciated the very well designed and constructed lenses from the likes of Nikon, Canon and a few other makes which inspired confidence in their pedigree of excellence. The later AF versions of similar lenses always seemed to be, well.....not so well constructed although they worked adequately enough.

    I remember the advert for the screw thread Pentax models such as the S1a, SV and then the Spotmatics etc. and the wording read....Just hold a Pentax. They were right...errrr.... spot on!. Not a scrap of moulded plastic to be seen, (except perhaps the eyepiece surround and the lever wind), not too heavy and perfectly balanced. The same could be said of their lenses. Just a perfect combination.
     
    Last edited: Sep 7, 2016
  11. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    Glass and ceramics are used to make jet turbine blades, they are extremely difficult to form. but have incredible strength.
    I have never heard of them used in cameras. But perhaps one day.
     
  12. 0lybacker

    0lybacker In the Stop Bath

    Did not a camera maker incorporate a ceramic pressure plate into a film SLR? Contax? Sounds like the sort of thing they'd do. Cheers, Oly
     
  13. Benchista

    Benchista Which Tyler

    Correct and correct. And correct. ;) It was paired with a vacuum system to suck the film on to the plate and thus hold it completely flat.
     
  14. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    Almost all aspheric lens elements are moulded. As are all smart phone lenses.
    Moulding is the obvious option when either the volume is high or the shape difficult to form.
    The accuracy can be far more cosistant than machining.
     
  15. Footloose

    Footloose Well-Known Member

    The metal moulds used for materials made of plastic, over a period of time (sometimes not that long) suffer from wear due to the abrasive nature of some plastics, but on the other hand, some (exotic) plastics suffer less than metal from expansion/contraction due to the hot or cold conditions they are used in. Some plastics are just plain 'weird' ... One grade of Teflon I have encountered and machined can be 'cooked' in an oven until it literally melts, but when allowed to cool down, re-forms back into its original shape to such an extent that it is dimensionally identical (within +/- 0.1mm) to the item before it was 'melted'.
     
    Last edited: Jul 31, 2017
  16. Footloose

    Footloose Well-Known Member

    Just a couple of things which may be useful to others around here constructing things. ... I'm in the process of devising a lightweight L/hand grip and some brackets for holding some LED lighting units. For these, I am going to be using carbon fibre rods, epoxy resin and aluminium for a rig to be used on my E-M1. It's still in the design stage using SketchUp though I already have most of the materials and tools, including 1/4" UNC/Whitworth taps and dies I bought when I used to be a machinist.

    However, I found buying 1/4" UNC bolts, nuts and threaded bar locally, a real pain. Quite why, photo gear in general, still uses this thread when they could have gone over to a 6mm thread decades ago, baffles me. Maybe one of these days someone will come up with a 12-15mm long Allen grub-screw which has a 1/4" UNC on one end and 6mm on the other, so people can switch between these two threads.

    For anyone seeking out small bolts with Hex heads or the Allen headed versions, here's some useful advice ... It might well be worth spending a bit more on the high-tensile versions because a lot of the cheap Allen bolts which can be bought are prone to shearing or 'cheesing' if too much leverage is applied to them even with a normal length key! - This is however, much less of an issue with Hex bolts. I personally prefer Allen bolts because 'aesthetically', (when what you are making is attached to 'modern' equipment, the finished item looks a lot tidier/better.

    For those seeking stuff like this down, I can highly recommend the supplier below for their fast delivery, reasonable prices and excellent quality.

    http://www.namrick.co.uk/acatalog/B.S.W_Socket_Cap_Screws.html

    In fact, I have even suggested that they consider placing an ad in the AP magazine ...
     
  17. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    The alternative is to buy them from the USA where the unc bolts, screws, and studding, are still the norm.
    I recently mandged to get a pack of four American 1/4 20 unc thread inserts on ebay. Of the type ued on wooden cameras
     

Share This Page