Brochure denies AF possible with A-mount lenses

[David Kilpatrick]

The neat colour printed accessory brochure packed with current NEX deliveries has a chart showing lens compatibility and functions.

Despite statements by various Sony staff that the E-to-A adaptor was meant to provide AF with some Alpha mount lenses, and was still being worked on, this brochure firmly and completely denies any AF function when using the adaptor, with ANY of the lenses - SSM, SAM or conventional screw focus.

There is no footnote or rider to suggest this may be changed. It is unusual for a company to print thousands of booklets and deliberately include a leaflet (20 pages) devoting one entire spread to lens compatibility and functions, with three 'green for go' entries (the NEX E-series lenses) and 33 orange 'caution' entries (all the Sony lenses).

There are no new unknown Sony lenses included in the list (always worth looking!) and I note that the teleconverters, when used on the NEX, offer neither auto exposure nor manual focus - this may be an error or interpretation though.

David

[Greg Beetham]

Ah! now I get it, when you buy a NEX and the A-mount adaptor after reading the official wording at a Sony website such as here http://www.sony.com.au/product/la-ea1, you get a disclaimer in the box contradicting the previous information garnished from the website, neat.
You hoo ACCC, are you watching and listening.
I guess there is a defense though, using modern logic you could interpret the word 'use' in a couple of ways. If the customer interprets this too mean that an A-mount lens has full functionallity on a NEX camera via the e-mount adaptor (reasonable assumtion at first glance) Sony could always say that is just wishful thinking in his part, when in fact all Sony meant was you could connect the A-mount lens onto the camera, (ie. use it on the camera), Sony made no claim about the LEVEL of functionality and therfore has no control over others thought processes.
And besides it's all clearly laid out in the compatibility chart....where's the problem.

Sorry Sony not acceptable, the level of functionality it has should be laid out at the Sony website right where the adaptor is listed, not on a disclaimer/brochure in the box after you have bought the camera and adaptor.
Greg

[Javelin]

This is what the Canadian print brocure and web site says.

"The LA-EA1 Mount Adaptor lets you use SLR system A-mount lenses with your NEX-5 or NEX-3 camera.* If manual focusing is required, don't worry - the cameras' MF Assist function makes it easy"

[David Kilpatrick]

MF enlarged view - MF confirm (green light on the focus screen without magnifying) is disabled with the adaptor at present. They intended to have this function working, but say it can not be made to. I have no idea why.

David

[Javelin]

so even the magnified MF assist doesn't work with the adaptor?

[OneGuyKs]

MF confirm (green light on the focus screen without magnifying) is disabled with the adaptor at present. They intended to have this function working, but say it can not be made to. I have no idea why.

David

Contrast detect AF system can't do MF confirm. There's no way the camera can know whether the lens is in focus when it's set to MF. It can't determine what the maximum contrast of the scene should be from first principles.

Now, why can't the camera track changes in real time of focus & contrast as the user moves the lens towards or away from the optimum focus point? The answer is even slight changes in light levels can result in contrast changes and misleading readings.

A good sharp screen with easily accessible magnification works well in practice.

[David Kilpatrick]

The camera can do MF confirmation with E-mount lenses, and was supposed to be able to do it with A-mount. This was confirmed to me in Croatia. For some reason, because they were not able to get the adaptor to work correctly with all SSM and SAM lenses, they have disabled all the functions including MF 'green dot' confirmation. Manual enlarged focus assist was never supposed to offer green light confirmation, it works normally, by visual checking.

David

[agorabasta]

OK, everybody! Physicist is here declaring the fate of your delusions...

That funky 'contrast detect' AF really can be made as good or better than any imaginable PD AF.
It may be done with as small a sample as 9x9 pixels or, better yet, 18/18 sensels. All that the focussing proc has to do, is to analyse the spectral energy density of the signal spatial spectrum components at half the pixel/sensel number period as compared to the 3x or 6x that density (that would be 3 or 6 pixels/sensels linear diameter sample).
Upon that, knowing the lens particulars, focus corrections may be calculated for both directions either to front- or back- focussing corrections. So the only downside is that there's a guess as to which direction to choose.

Guess why nobody ever cared to employ the FFT analysis for the focussing samples? The answer is simply boring: it was close to impossible with former (just about 4 year old) tech; and now it's just pure inertia perpetuated by neverending corporate quarrels.

[Javelin]

But would things like the lens coatngs and the colour the light is affect what the camera sees as sharp contrast? I know coatings have a lot to do with what we see through it in terms of contrast with our eyes. couldn't the age and type of coatings affect this? and make some lenses miss focus?

[agorabasta]

But would things like the lens coatngs and the colour the light is affect what the camera sees as sharp contrast? I know coatings have a lot to do with what we see through it in terms of contrast with our eyes. couldn't the age and type of coatings affect this? and make some lenses miss focus?

Use the 'green' array only. (That's why I mentioned the 18x18 'sensel' array.)

[David Kilpatrick]

I think the main problem is that while the NEX can identify a moving contrast target from the 16mm (short focal length) or from its OSS lenses (the image is pretty accurately stabilised), the designers have hit a problem with unstabilised Alpha lenses, especially longer ones.

I guess they designed the adaptor to allow AF and MF with confirmation (I was hoping for a 'beep' sound, neat quick way to get focus) and only when they tried unstabilised lenses did they realise it was not going to work. You only need to turn OSS off on the 18-55mm, set it to 55mm, turn on the magnified MF and the problem is obvious - without a tripod, you have no chance of focusing and the sensor would be trying to 'contrast detect' from a hopelessly volatile blur of image!

The Micro 4/3rds format has either got many more OS lenses, or sensor-based stabilisation, which partly compensate by keeping the image more or less in one place.

David

[alphaomega]

Reference David Kilpatrick's comments above re contrast detect focus on A lenses without stabilisation, so what about Sigma and/or Tamron designing an adapter that can make the NEX AF with one of their stabilised lenses? Or one of the third party makers doing just that? There seems no limit to what a NEX can be made to do if there is a will and demand. Let's get some of these adapter and an EVF and somebody providing an adapter that will T&S with manual prime lenses etc. etc. etc. and a more sophisticated NEX7 with inbuilt EVF.
Having cancelled my A550 purchase due quality problems I could be tempted with a NEX if the usage possibilities increased beyond what they have now.

[David Kilpatrick]

As soon as I get the E to A adaptor, I will let you know if the Sigma 18-250mm and 70-300mm OS lenses have working stabilisation. Paul Genge immediately said 'no' when I asked him if OS or VC third party lenses would stabilise on the adaptor. But I think this was a formula response and he does not actually know. He was unable to let me try the Croatia sample adaptor with the 70-300mm OS I had taken along.

David

[redsim74]

I would imagine it would be somewhat embarrassing if third party, stabilised a-mount lenses worked better on the NEX than Sony's own a-mount lenses.

[redsim74]

As soon as I get the E to A adaptor, I will let you know if the Sigma 18-250mm and 70-300mm OS lenses have working stabilisation.
David

A user on Dyxum claims to have tried the Sigma 18-250 OS... and stabilisation worked.