Discussion of all digital SLR cameras under the Minolta and Konica Minolta brands
Forum rules
No more than three images or three external links allowed in any post or reply. Please trim quotations and do not include images in quotes unless essential.
Greg Beetham wrote:The bayonet flanges don’t seem to be the usual machined bright metal finish, i.e. they don’t look like the flanges on my three cameras that were machined out of solid.
What they do look like is a fish plate stamping that is separate to the mounting slip surface and located in position by the mount screws passing through both plates and clamping them together against the mirror box.
Sony A700, A580, Nex-5t, KM D7D & VC-7D, M Dynax 500si
KM 17-35 F2.8-4 D, M 50 F1.7 RS, M 135 F2.8, M 28-100 F3.5-5.6 D, M 100-200 F4.5, T 70-300 F4-5.6 Di USD, S 18-55 F3.5-5.6 SAM, S 18-70 F3.5-5.6
Sony hvl-f42s, Minolta 3600 HS D
Sony Z1C & Z2
The plastic behind the main metal mount is the same as the 5d's I have, and A200 I used to have, and film 5's and 60's. But NOT the film 7 which is all metal. If I remember rightly the A700 is all metal as well.
Now if it is the case it's part plastic, it might not be a huge deal as I've yet to encounter an problem with this my other bodies. But it's worth pointing out the only camera I've seen other than KM/Sony to use a partial plastic mount is Canon on the EOS 1000d but not the newer EOS 1100d, nor have I see it on budget Pentax or Nikon bodies.
Actually Barry now that I stopped operating from memory and pulled cameras out of bags and removed lenses and had a close look at them all you are correct I think. The KM5D is the same as the A100 and the Dynax60, they all have a separate bayonet plate behind the actual mounting slip surface that appears to be some kind of plastic but I’m not sure if it is actually plastic.
The service manual for the A100 doesn’t state what the material is for that item, and the A700 mount is all one piece.
Greg
A100 mirror-box
A100-mirror-box-unit-2.jpg (93.31 KiB) Viewed 3954 times
A700 mirror-box
A700-Mirror-box-section-sub.jpg (156.8 KiB) Viewed 3954 times
The material seems quite hard plastic I don't want to use the term "Bakelite" because it's likely not that, but I might not be a million miles away either. It does not look to me like a bog standard type of common plastic. Must be some sort of resin type plastic. There are lots of types of plastic and I'm no expert in them either I just found it slightly interesting looking at this one it's unusually hardened for a plastic but I would expect it to be brittle as well.
I think the hard plastic of the actual lens mounting flange is there for a purpose, it’s designed to be a sacrificial replaceable item in case the camera is accidentally dropped with enough force to separate the lens from the camera.
If the lens and mount both are machined metal and the same thing happens (a large impact) then the next weakest link is going too fail instead, most likely the mirror box itself which would entail a major repair. Probably in that case the cost of the repair would exceed the value of the camera; also if the machined flanges on the lens are damaged or deformed at the same time there would be a major repair for it also instead of just replacing the broken plastic flange ring.
Greg
Ps. No it won't be the original 'bakelite' that was made from tree sap in a mould, usually reinforced with a fibre of some kind then baked in an oven until hard.
Now that I have been shooting both the a77 and a850 I must say I love them both but prefer the a850. The a77 certainly keeps up in the noise department but the a850 seems to have a little more dynamic range and color depth. I have been using the Konica Minolta 17-35mm which is a great lens as long as it is stopped down. I prefer the a850 because of its simplicity. Also I prefer the traditional OVF. I hope the a950 will have a OVF.
