Sony A58 "plastic lens mount"

[Greg Beetham]

There’s a couple of things about replacing the metal mounting flange with plastic, the metal mounting flange acts as a stiffener for the body shell whereas plastic might not offer that degree of additional structural strength also I’m not sure what they would have done with the compression leaf spring on the back of the mount, that’s one thing you can’t replace with plastic, it’s the main wear item in a mount not the front slip face so much, the front slip face’s main duty is to index the c-line of the lens perpendicular to the sensor.
Sony must be very confident that the action of tightening the attaching screws isn’t going to warp the plastic face of the mount.
The last remaining metal ring item that is visible is the f-stop actuator, it’s free floating on rollers and driven by a stepper motor to the exact position required to produce the desired f-stop in a given lens, there is an engaging lug on it that engages the f-stop pin on the back of the lens, I can’t imagine them ever changing that to plastic.
I can’t really see Sony discontinuing the A-mount when there is so much investment by them in A-mount lenses, it’s not as big as Nikon or Canon but considerable just the same. It also doesn’t make a lot of sense to continue to make A-mount lenses for an E-mount camera either, so it will be interesting to see how things develop.
Greg

[bfitzgerald]

I can see them dropping A Mount it's just a matter of "when" might be a few years down the road but that's my take.
Why? I think the Sony execs will sit in an office and crunch the numbers and say "NEX is doing better" or they have better margins on that product range (as per DK's less controls prediction years ago) Can Sony afford to run 2 mounts?

There is no suggestion of an updated A65 to appeal to current A3/5 series users (as a real update) this is apparently the only entry model Sony will have. And it's hard to see how that is going to compete with it's main rivals (A57 had a hard enough time and this is going to be seen as a step backwards) Sony might update the A77 but the gaps is too big between that an the A58. I'm not surprised they are doing only one entry model, but I am surprised they downgraded it so much. Sensor/output might be interesting, but with the cut down body it's taken any charm away that might have had.

I would not panic there is no need, but I think 2013 will be a year where Sony will really struggle with SLT, there are no signs of any attempt to counter Canikon's aggressive full frame pricing with the A99 (it's still around £2100) and I think that's where the market is moving full frame is going to tempt a lot of users. And I have to say bar having some nice FF Minolta glass I can't think of a single reason why potential FF buyers should look at Sony over others. As for APS-C again I can't see how this A58 can offer any kind of competition against the price falling Canon 650d. (which will likely get updated again this year)

[David Kilpatrick]

I may accidentally have broken an embargo on Nikon D7100 specs, because I did not know there was one - the conference was on Wednesday, and I received reports to go into a magazine, so I forgot it might have a few days secrecy (until Feb 25 maybe).

Let's just say that the D7100 while costing a great deal more will offer all the things which Sony seems to be letting go - the heritage of the A700, for example.

My feeling at the moment is that if I am going to use an EVF camera, it might as well be mirrorless not SLT; and if I am going to use an SLR-type camera, it might as well have a choice of optical viewing and electronic viewing (finder and LCD) rather than two variants of electronic viewing. But I've seen future EVF development samples, and that view might change.

This week I bought a KM A2 cheaply on eBay for several reasons, one of which turned out to be a mistake - the intervalometer function does not go down one frame every few seconds, which I need, 30 seconds between frames is the minimum.

I was impressed to see that this camera has a simple function I have forgotten, to over-ride the EVF exppsure simulation when you switch to manual. No need to take any other action. This one function would make the Sony EVF range useful for me (as opposed to having to set the function via a menu and not have it auto-set when using manual).

David

[Heidfirst]

You won't be able to use a wired remote with a flash in the shot shoe either (another dumb move), the LCD is smaller and half the res of the A57, the shooting rate is half the A57 too. Not much of an update is it really?

the remote/flash etc. potential issue I had realised very quickly but it's possible that there will be some kind of multiplier available. & I see it as being of more concern further up the range.
It's not a direct update, it's a reposition.
(btw watch all the Nikonians screaming when they realise that the D7100 may signify no D400... )

I As for APS-C again I can't see how this A58 can offer any kind of competition against the price falling Canon 650d. (which will likely get updated again this year)

perhaps it's not designed to? the srp of the 650d is ~£750, street price after a year is ~£550 - the A58 is supposedly £450 on launch (so perhaps ~£300 when it's a year old?).
& if it does what you need & gives a better image (to be seen) ata cheaper price ...
People like us on forums such as these represent a tiny subset of the market & our thinking is not the same as the mass market.

[bfitzgerald]

I read the D7100 previews and can't say I find it that compelling overall. It gets a few updates, but very much expected stuff like 24mp and the 51 point AF (one would hope that it's better than the last one!) not sure about the AA filter removal if that's a good idea. Apart from some minor updates it's not a dramatic step over the D7000, and criminally does not address the small buffer that the D7k had. D7100 won't even take the D7000 vertical grip (another cash cow)

Don't get me wrong now had I NOT had issues with the AF on the D7k it was overall a very good camera and nothing wrong in an updated one. I'm just seeing a watershed point here where some users will simply say "yawn to APS-C" and let's just go full frame. I wouldn't pay £1100 for a D7100 looks more like an £800 camera (like the K-5II price is nowhere near as high as it used to be) I can't see dedicated action shooters being too happy with such a tiny buffer on the D7100 either.

I know Canon have yet to respond but I'm seeing a new phase of cameras where most of the interesting stuff is going on full frame. Why bother paying £1100 for a crop sensor body if you can add a few hundred more and go full frame.?

[agorabasta]

...not sure about the AA filter removal if that's a good idea.

Appears to be very good from that particular sample - http://chsvimg.nikon.com/lineup/dslr/d7 ... g_05_l.jpg.

Although the regular birefringent LPF may be not there, in doesn't mean that some lowpass filtering is not happening at all. E.g. making the microlens array slightly thicker could bring that very small amount of crosstalk blurring that high-density sensor only needs to kill most aliasing; or there could be further changes exactly to the microlens array that could work out even better.

And Nikon are very good at sensor toppings design - they normally get far less PF and false colour edges while using the same Sony sensors.

[bfitzgerald]

We shall have to see. That sample does not have repeating patterns so that is one area where it could cause a problem.
Also for video shooting it could cause even more issues we will have to wait and see how that pans out.

I can't see D300s users being overly impressed though they have specific action needs and the buffer depth is just too small (in reality the buffer has not increased since the D90 though obviously it is moving larger files around) I'm not much of an action shooter but even I hit the buffer on the D7000 at times it's just too small for higher fps shooting. A mere 9 shots for a 12bit raw compressed D300s users won't be impressed (try double the buffer size)

[mikeriach]

I realise that the plastic mount is a step backwards however if you consider the type of buyers of "entry level" bodies, will the majority ever notice? In the aviation crowd, there are at least 2 types of photographer, the enthusiast who probably used film in the past and has a good grasp of photographic terminology and theory and then there are people who buy an entry level camera with twin lens kit.

The former is like most on this forum. The latter has mastered the charging of the battery but simply switches the camera on, adjusts absolutely nothing and presses the button thing on the top, subsequently downloading images we'd cringe at and thinking "how great is this". Remember they may have shot film and had appauling prints from the cheap chain processor.

I think the latter will not even notice the mount material (or any other material come to that). they certainly won't be hanging large, heavy G lenses off the mount.

I'm sure we'd all agree with Barry that this is a backward step but in the big picture (pardon the pun) this may not be seen by many as a big issue.

It does make me worry what the A78 will be like but at the moment I don't see that as an option for me unless it is significantly better (I'm not going into details but buffer, dual card slots, noise, fps options, rear SSS switch, etc) and costs no more than the A77 costs now.

[agorabasta]

Sure, Barry is completely right about the plastic mount. And I know it completely well from personal experience with a55 that was less plastic. And the total amateur crowd is also well exposed to heavier lenses, the older Sigma 18-250 OS HSM being one example. I actually think that any fully extended superzoom must be a problem.

When I got my a55 in early 2010 (edit: sorry that was late 2010), it worked very well with that Sigma 18-250. But my Tamron 28-75 had problems often losing communication with body. So a year later the heavy Sigma also started to lose the body. Then after two years of use even a native SAL 18-250 started to lose communication intermittently.
So I discovered that the mount got a bit loose and tightened the screws till Tamron and Sony stopped losing contact with the body which means that I tightened the mount more than it was tight originally. But then the Sigma stopped working correctly as its aperture lever started getting jammed after every few shots which is a typical problem with some Sigma's on SLT bodies.

So my educated guess is that a plastic mount is a no-no at all costs, if anything but plastic-mount SAM's attach to that.

[bfitzgerald]

The issue with a plastic mount is one of price. The last time it made an appearance on a budget 35mm SLR was way back in 204 with the Dynax 40, before that the 3L and Dynax 4 (but not the 5 which was metal)

The A58 is not nearly as cheap as those bodies, not even close. It's on pre-order for £499 with a kit lens (basically right now the same price as the A57 is) I'm sure that will drop to £399 but I doubt it will end up at £299 (even if it did the A200 had that price point and didn't have a plastic mount either)

There are 2 issues, one is durability and I don't have a lot of confidence in a fully plastic mount (I've argued the current metal mount and plastic tabs should be upgraded to fully metal in line with ALL other makers) the other problem is one of customer perception. I can imagine more than a few folks who buy this model won't know it has a plastic mount, and won't be overly impressed when they see it. Sony just come off as "cheaping out" and in a big way. I mean how much can they save with the plastic mount? Probably pence it's so trivial as to not be worth doing.

I think for 2013 the A58 will struggle badly in the market despite the should be decent sensor they've downgraded it in too many ways plastic mount, lower res smaller LCD which can't be turned around on itself to protect it, the full res fps is half that of the A57 too. These things will matter more to potential buyers than a few gimmicks such as auto object framing. Sony have also made the serious error of producing a model that to most will be seen as a step back from the A57, thus ignoring the lucrative "upgrade market" that Canon has done so well with it's EOS 350-650D range. There is a clear progression on these models over the years, and I know many people who upgraded in that model line up.

So I can't see this as a positive move in any way, rather the death throws of Sony's SLT range. Unless an A65 update turns up (which I doubt) then Sony just don't have enough models to have any impact in the market. A77 is getting on a bit now, due for an update too. When a new one is released it will likely be £1000 odd leaving a huge gap between entry Alpha and nothing in the mid range (which is what a 5 series body should be) A very serious error from Sony and IMO one that will only hurt their market position.

[OneGuyKs]

So I can't see this as a positive move in any way, rather the death throws of Sony's SLT range. .

You have a tendency to offer wrong predictions. Sony just released 70-400 II and 50mm Zeiss lenses. They have a lot invested in the A-mount. It's not going anywhere any time soon.

Here is what I think is happening:

A58 has the same launch price as A37. What that means is that Sony is bringing the entire APSC line down due to cheaper full-frame cameras squeezing APSC cameras from the top.

So A3s line is killed.
A5s price range comes down to the discontinued A3s price range.
A6s line will replace the previous A5s spot (price wise).

That will mean a new A7s camera that would be 100 to 300 dollars cheaper than A77 launch price.

And that would mean they will have breathing room for a 1500 - 2000 dollars full-frame in an year or two.

A58 is the first step in that process.

[classiccameras]

Just to put things in to perspective and I also have similar thoughts to the last post, there has been too much investment in A mount lenses for Sony to throw the towel in just yet. Since the introduction of the SLT system, their sales have improved. They know they will never be able to compete with Canikon, so they will make a product that will be supposedly superior at a similar price point to the competition. They have already done that with NEX.

World sales of DSLR cameras by the 3 main manufacturers plus Pentax.
Canon: 47%
Nikon: 33%
Sony: 6.2%
Pentax around 2.5%
I have left out Olympus because they no longer make DSLR's

Pete

[dynax800si]

Some Q/A about the plastic mount:

Is the camera inferior in terms of performance and durability in comparison to the metallic mount?
We have verified that there are no issues in general use.

Are there lenses that cannot be used? Does the camera have less strength?
All lenses can be used. When using heavy lenses, however, we recommend that you handle the camera in ways that do not apply loads, such as to support the lens as was done with metallic mount cameras.

What is the mount made of?
High strength engineering plastic.

Why did you choose a plastic mount?
We have been using plastic mounts to downsize and lessen weight since the α57.

[classiccameras]

I think their answer to why they used a plastic mount is a cop out. Truth is, it was to save money, which they would never admit to.
Pete

[agorabasta]

Why did you choose a plastic mount?
We have been using plastic mounts to downsize and lessen weight since the α57.

That's not true. They have been using plastic mounts since a55/33.

Here I'd guess the rest of their 'answers' are of the same informative quality, a.k.a. plain garbage.