ByThom with Love

[David Kilpatrick]

Plastic mounts are more common than you think. The Samyang 85mm f/1.4 which feels nice and solid is almost all plastic, and the Sigma 70-200mm f/2.8 II HSM may have a metal lens mount, but it is screwed into engineering plastic. Richard found out the hard way, he dropped a Nikon D3 with the lens fitted, and it 'broke off' leaving the mount on the camera. Zero damage to the camera, and £70 to replace a plastic component and the metal mount on the Sigma.

The NEX lenses look metal but actually it's a super-thin skin over normal plastic.

David

[Dusty]

The term 'plastic' has been greatly expanded over the years, while our general perception of it has not.

Today's polycarbonate and polyamide plastics are a long way from Bakelite, and even carbon-fiber reinforced epoxies are often called plastics today. It's not the fact that it's plastic, it's the type of plastic that matters.

It might impress some of you to know that 'plastic' connecting rods have been used in racing engines pushing 14,000+ RPMs. I'm not worried if they make lens bodies or mounts out of something like that.]

Dusty

[InTheSky]

The term 'plastic' has been greatly expanded over the years, while our general perception of it has not.

Today's polycarbonate and polyamide plastics are a long way from Bakelite, and even carbon-fiber reinforced epoxies are often called plastics today. It's not the fact that it's plastic, it's the type of plastic that matters.

It might impress some of you to know that 'plastic' connecting rods have been used in racing engines pushing 14,000+ RPMs. I'm not worried if they make lens bodies or mounts out of something like that.]

Dusty

Ok ... I know I'm completely out of the subject but this is the Engineer in me that want to give the information. Probably because of the Iron Man , people always think that metal is stronger and better, this is a example of impressive other material :

http://machinedesign.com/article/wood-y ... rings-0520

We have an Old Hydro-Electric power plant in Saguenay, Quebec, Canada that use Woods bearing in the mechanism since ~1930.

Regards,

Frank

[Vidgamer]

Racing programs aren't profitable for car manufacturers either, but they sell cars.

Or, to use another example, a Corvette really isn't profitable, but it helps the brand and to get people into the dealership, where people typically buy something else, like a Camaro.

When Sony came out with the A900, my thought then was that it was like the 'Vette. It's there to prove that they can do whatever they want. I was kind of surprised to see the affordable A850.

I don't know if I believe Thom or not. I don't think FF is really necessary for the vast, vast majority of photographers, so I can definitely see where a company could make the decision to avoid/drop it for beancounting reasons.

[bfitzgerald]

Nothing wrong with plastic on it's own. However after trying the 50mm f1.8 sam I'm convinced Sony sources out the cheapest nastiest feeling plastics they could find and used them. There is good quality plastic and horrible stuff. Regardless IMO a mistake to have a plastic mount cheap build 85mm prime lens..also a serious error to have an f2.8 one.

They're just not paying attention to the real world I'm afraid.

[dynax800si]

Something interesting for the SONY 85/2.8. The press release says this for the lens - "Sonnar-type optical design".

Here is the Carl Zeiss Sonnar T* 2.8/85 Contax/Yashica mount.


The two lenses have design with 5 elements in 4 groups (The Zeiss specs in PDF).

[David Kilpatrick]

Most lenses of this type are Sonnar-type design. It does not mean anything more than called a Helios 53mm f/2.8 a Tessar-type design. Every development in lens design has resulted in a new type; you could call a Zeiss Novar a Cooke triplet, for example, because that's basically what it is - one step behind a Tessar in historical development.

Now if the 85mm lens had been called a Petzval-type design, we should have been worried

David

[peterottaway]

I think someone must have been joshing poor old Thom.

If you go to the latest posting on NikonRumors they have

1. Nikon D3100 being announced in the middle of August with a 14 MP CMOS sensor, 11-12 AF points, HD video, AVCHD video codec, no swivel display and 3 fps. If you take a look at the predictions for the A 500 replacement then what you have is the the Sony internals with a Nikon skin and the F lens mount.

2. Nikon D95 to be announced mid September with a 16M MP CMOS sensor, HD video, 6 - 8 fps, improved ISO (not sure if improved high end ISO or speed for speed ISO) and 39 AF points. Is this the A700 replacement as well ?

3. A Nikon 200mm/ 2.8 AFS lens ?

Are we also looking to a Nikon D 700 and Sony A850 co-replacement let alone a Nikon D4 and Sony A900 replacement ? This may be going a bridge too far as someone out there may smell a rat.

Just another silly Saturday in pre Photokina season.

[KevinBarrett]

Nikon D3100 being announced in the middle of August with a 14 MP CMOS sensor, 11-12 AF points

Hmmm, where to put that even AF sensor...

[peterottaway]

A three way centre sensor ? Perhaps a crossed x with a horizontal or vertical placed sensor.

At least Uncle Thom has conceded that the " almost official " D3100 will have the Sony 14 MP CMOS sensor. So a few more billion Yen to Sonys bottom line over the next couple of years, whether or not several people we know buy a Sony camera or no.