I played with an A900 today

[Dr. Harout]

I expect that there will be a A700v4-like upgrade for the A900.

Jonathan

I expect that too.

[Jardyn39]

Just to add to the comments on the APS-C capture function on the A900 (Firmware 1.0):

With “APS-C Capt.” Set to ON, the picture saved is cropped to the APS-C size irrespective of the lens.

However, the behaviour of the OFF setting seems to be different depending upon whether or not the lens is detected as FF or not.

I’ve a Tamron 18-200 mm and the Sony 18-70 mm. At 18 mm and with “APS-C Capt.” set to OFF, the Tamron capture shows heavy vignetting in 6048 x 4032 pixels. Whereas, with the Sony attached the camera automatically crops the file down to 3984 x 2656.

I don’t have another APS-C Sony lens to compare, so I’m not sure if this applies to all non-Sony APS-C lenses or just the Tamron and Sigma examples I have.

To my eyes the viewfinder crop guides are not particularly clear in low light, so I much prefer to have the vignetting with the option to crop manually later on.

[Philip]

This possibly has something to do with the way in which 3rd party manufacturers 'chip' their lenses. My understanding (I think it was a Phototraveller thread) is that Tamron/Sigma reverse engineer mounts and chip their lenses with a lens chip that they know works (my 12-24 Siggy id's itself as a 28-80mm f3.5-5.6), so if the chip is a FF chip, then the A900 would not know to automatically crop for APSC. Good news for some lens owners

Philip

[Rincewind]

Hi Philip

Isn't your Sigma 12-24mm a full frame lens?
Why would it activate APS-C crop on the A900?

Regards.
Den.

[Dr. Harout]

Hi Philip

Isn't your Sigma 12-24mm a full frame lens?
Why would it activate APS-C crop on the A900?

Regards.
Den.

First post Den. Welcome.

[Rincewind]

Thank you for the welcome

I've lurked for a while, but have been meaning to register.
It's a good forum, well worth supporting, so if anyone else is doing what I was, maybe it's time to join

Regards.
Den.

[KevinBarrett]

Thank you for the welcome

I've lurked for a while, but have been meaning to register.
It's a good forum, well worth supporting, so if anyone else is doing what I was, maybe it's time to join

Regards.
Den.

Welcome, and thank you for the encouragement! All you other lurkers sign up and claim a user name! Post some pictures and converse!

[Greg Beetham]

Reading what Philip was saying, again...it looks like he's saying, that if Sigma can put a 28-85 chip in a 12-24 (just so it has a chip of some sort and can then assume an identity, even if it's not ideal), there might be a possibility that the have/will put an APS-C lens chip in a FF lens...not realizing the consequences with this new camera, which apparently will limit the sensor to only recording on the APS-C frame....(while there were only APS-C cameras around there wasn't the auto vignetting cancelling feature too contend with, as is on the A900), the lens would still work to some extent, except ADI flash, exposure calculation, DOF etc. would probably be out of whack if it was a variable f:ratio zoom.
Myself, I have doubts that Sigma would put an APS-C chip in a FF lens....
Greg

[Javelin]

In the past Sigma has rechipped lenses that weren't functioning properly for free. if this is what they did then they might start re-chippin gthe lenses again.

Myself, I have doubts that Sigma would put an APS-C chip in a FF lens....
Greg

[Philip]

Sorry for any misunderstanding of what I wrote. What I was saying is not that my 12-24 shows as an ASPC DT lens (it shows as a 28-80 in the exif, although the correct focal length used when a picture is taken is displayed), but that 3rd party DT lenses could well have FF chips in them enabling a FF view on the A900, thus circumventing the auto crop feature that prevents a FF view with DT lenses, allowing manaul cropping later. This is possibly why Jardyn39's Tamron 18-200 mm doesn't auto crop in the same way his Sony 18-80 does.

Philip

[Rincewind]

Sorry about my confusion Philip, yes that makes perfect sense to me now! lol
I assume older Sigma lenses (before APS-C) should be ok, unless the A900 point blank refuses to recognise the old Sigma chips that is!

To Kevin: Thanks for the welcome

Regards.
Den.