Photoclubalpha

I came across an interesting contribution by Phixel on DPReview. Here is an excerpt:

I have talked to the manager of the local SonyStyle store several times over the last six months about the a700 replacement and he has been consistent in his assertion that the FF a900 is the upgraded a700. He told me that the a900 was designed as an APS-C camera that would take full frame lenses, not a FF camera that would take APS-C lenses . He pointed out that the focus sensor array for the a900 is not for a full frame camera, but for an APS-C lens mounted on a FF camera. Even the sensor for the a900 is an APS-C sensor that was scaled up rather than say a 16 MP full frame sensor that would have satisfied the needs of more potential customers than the 24 MP one with better high ISO image quality and still stellar IQ for landscapers.

I am totally unable to judge the quality of this statement, but it soulds plausible, particularly if an APS-C replacement for the A700 is not forthcoming.
The question (particularly for DK, but also any other A900 owner with APS-C lenses) is how many effective MPs can actually be used (before vignetting) fitting various Sigma and Tamron APS-C lenses on the A900? I understand that a Sony APS-C lens will automatically restrict you to 10.7 Mp. I am about to order another A700 as I have no further confidence in Sony's current policy of releasing cameras with reduced functionality and little if any improvement so the A900 might be considered if my current APS-C lenses such as Sigma 10-20 and Tamron 18-250 would yield more than 10.7 Mp. Ideally I would like at least usable 12 Mp.

The statement is nonsense, really, the camera was designed around a supersized shutter and all sorts of other aspects which make it primarily a superb full-frame model with an APS-C facility.

It depends entirely on the lens. The new Sigma 18-250mm for example projects a cut off circle all the way to about 230mm and then suddenly almost fills the frame. The 11-18mm Tamron, in contrast, will shoot full frame when set to about 14mm - rather wider than 11mm on APS-C, with some need to stop down.

But it is hardly ever worth considering using APS-C lenses this way.

David

Yes, nonsense---that was the first word crossing my mind when reading your inquiry.

-- Olaf

FF sensor is 35.9 x 24mm, while APS-C is 23.5 x 15.6mm.

Without making any exposures on my Maxxum 5 film body, I am confident that most APS-C lenses can yield a decent square crop from the center of a 35mm frame.

Some lenses have an image circle that grows with the focal length (Sony 18-70 DT), and some lenses have an image circle that remains relatively constant (Tamron 17-50/2.8). I've tried out my two APS-C lenses on a Maxxum 5 film body (which has just 90% viewfinder coverage), to verify this. Of note: the Sony 18-70 covers the frame from somewhere between 24mm and 28mm, all the way out to 70mm. The Tamron 17-50 shows sharper fall-off at the wide end and more gradual but intrusive fall-off at the long end. A square crop at 17mm from the middle of a 35mm frame should be usable.

"Actually the A900 is the A100 replacement. The A7000 will be 240 megapixels and will be 6x6 format and will be 1 frame per month. Also it will do video at 800fps with a 300 gigs per second wifi transfer rate!"
Word to the wise... dont believe all the rubbish on the internet. Just ask yourself this... why would Sony create a system where you go from 12.5 megapixels (a700 for $1400 - canon 40d territory) then the next version be 24.6 megapixels and cost $3,000.00 (Nikon D2 price range!!)? This would be sales suicide.

All thats happening is this... just like big Auto makers... they release the most expensive stuff first so all you see is that and some buy. Then they release the next level (mid level) down and the mid levelers buy because they couldnt wait for the price to drop on the first or they didnt need all of what it offered. Then they release the bottom level (entry level) for the masses and it serves as a jumpstone for you to go from the bottom to the mid level.

Square crops and panoramic crops are both practical with some lenses - but it is a lottery. You won't know whether an APS-C lens provided a useful square image at a shorter enough focal length to be interesting, until you have tried it. I find the Sigma 12-24mm far more useful for square crops, with the camera used vertical and only the top of the shot used - trimming off 24 x 12mm from the bottom. This is like a rising front on a square crop. You get the same as a Hasselblad SWC but with 'movement'.

David

Thanks for the replies. What I am afraid of is that the Sony rep. was engaged in "marketing speak" and the real message was "Sorry pal, but you have to wait an awful long time for a direct A700 replacement" The rumoured A500/550 would indicate some kind of downgrade from A700 in functionality although the software side may be improved such as has happened in the new A2/300 series DSLRs. I agree with DK and O1af that there are no new APS-C sensors in the pipeline so almost certainly the 500 series will have the Exmor in the A700 probably improved to D300s type performance. As I do not need video I will stand by my decision to purchase a new A700 as soon as the expected A500/550 specs have been released. If Sony comes up with something that maintains A700 functionality and a much improved sensor then I may re-consider. I am not too hopeful. The A700 at just over £500 is a real bargain.

alphaomega wrote:I agree with DK and O1af that there are no new APS-C sensors in the pipeline ...

Huh!? You agree with me on something I never said?

As a matter of fact, I am absolutely sure there are new sensors (Exmor R for APS-C and 35-mm full-frame, probably with video capability) in the pipeline right now. I just don't expect them to emerge in actual shelf products before, say, Spring 2010. Of course, I could be wrong ... I have no insider information.

-- Olaf

Ref O1af's post above:

alphaomega wrote:
I agree with DK and O1af that there are no new APS-C sensors in the pipeline ...

Huh!? You agree with me on something I never said?

As a matter of fact, I am absolutely sure there are new sensors (Exmor R for APS-C and 35-mm full-frame, probably with video capability) in the pipeline right now. I just don't expect them to emerge in actual shelf products before, say, Spring 2010. Of course, I could be wrong ... I have no insider information.

-- Olaf

I am sorry if I I wrongly attributed a statement to you. I actually referred to a previous statement made by DK and my apologies to both if I got it wrong. I actually meant that since there has been no recent commercialisation of a new Sony Exmor sensor, the A500/550 will have a version of the current 12 Mp Exmor. That is assuming that there will be such DSLRs. That is not to prevent Sony from commercialising a new Exmor R at some stage and release new APS-C and/or FF DSLRs in 2010 or later. I was solely concerned about DSLRs to be released this year as I need to purchase a replacement for my A700, which is going to my son. So if the A500/550s are getting the same "treatment" as the A230/330/380 I am on for a new A700.

alphaomega wrote:Thanks for the replies. What I am afraid of is that the Sony rep. was engaged in "marketing speak" and the real message was "Sorry pal, but you have to wait an awful long time for a direct A700 replacement".

Do you think the manager of a Sony Style store (original post) is well placed to comment on Sony thinking and future product plans?
I'm not so sure.

Harvey