Photoclubalpha

Two birds with one stone here - can the 17-35mm D hack it on the A900 (answer is a resounding YES!) and does DRO manual work well (answer - it is very powerful and not subtle, use with care).



This is an in-camera JPEG with DRO+3 and you can see the full 25.6 megapixel file:

http://www.pbase.com/image/103391090

To show the degree of effect, here's a pair (also shows the good straight-line geometry of this lens used for vertical architectural shots):



Again, a larger version is present, not full size as that would be very silly!

http://www.pbase.com/davidkilpatrick/image/103391270

David

I have a feeling that there will soon be a huge article on the A900, signed D. Kilpatrick.

Hello David,

thanks for sharing. I am starting to believe it was a good idea not to listen to my colleagues and sell the 17-35. I found I had no use for it since I got the Tamron 11-18, even if there is a gap between that one and the KM 28-75, I never missed that 10mm... Don't ask me why. Supposedly it was the feeling "Once you go wide, then really go wide...". So who knows, once I win the lottery I might get an a900 and find some use for the lens.

But I find it difficult to judge the level of vignetting in the image. Do you have any blue sky pictures that could show that bit? As expected, a lot of CA around the arcades, but otherwise I find it very satisfying.

Cheers

Jonathan

Thank you David,

I'm constantly finding myself in awe over the detail being picked up by the a900.... You can clearly see the Grouting texture between the stones on the floor!

Although I think that the DRO +3 might be a little TOO harsh in the shadows, but like you say, use with care.

Can I ask a really daft question please? Have you tried the 18-70 mm on the a900? I doubt the quality will be anywhere near as good as this shot.... but part of me really hopes it would perform reasonably well...

Ian C wrote:Thank you David,

I'm constantly finding myself in awe over the detail being picked up by the a900.... You can clearly see the Grouting texture between the stones on the floor!

Although I think that the DRO +3 might be a little TOO harsh in the shadows, but like you say, use with care.

Can I ask a really daft question please? Have you tried the 18-70 mm on the a900? I doubt the quality will be anywhere near as good as this shot.... but part of me really hopes it would perform reasonably well...

The 18-70mm is a DT lens, and the 18mm circle is small - and it auto crops, no matter what you do. You can NOT turn off APS-C cropping with DT lenses on the A900, so there is really point in using them. The exposure is haywire, as Sony warned, and you must remember to use the crop area in the finder, and you get a 10.6 megapixl image.

David

Jonathan K wrote: But I find it difficult to judge the level of vignetting in the image. Do you have any blue sky pictures that could show that bit? As expected, a lot of CA around the arcades, but otherwise I find it very satisfying.

It is almost unfair to post a full size JPEG from a DRO+3 image taken on a lens like the 17-35mm D which we all thought would not be that good on the A900. Here, to enable a ready comparsion, is an ACR 4.6 export from another 17mm view this time with CA corrected and some capture sharpening, but no NR, and no web sharpening. No vignetting correction is applied at all, the aperture is f/11. Some fill light and highlight recovery have been used, together with -0.4 exposure in ACR, to optimise the tonal range which as you can see included a large area of shadow.



The orginal size, if you visit pBase, has been exported to 11.2 megapixels size which is midway between the A100-300 series and the A700. This will enable you to compare the level of foliage detail (etc) and the quality of corner illumination and sharpness to APS-C.

http://www.pbase.com/davidkilpatrick/image/103395342

I have more to come, I'll keep posting new Alpha 900 pix from the walk around town - a rare bit of sunshine for once, timed perfectly!

David

Ohh Err!

Thanks for clearing that up

Ian.

David Kilpatrick wrote:

Ian C wrote:Thank you David,

I'm constantly finding myself in awe over the detail being picked up by the a900.... You can clearly see the Grouting texture between the stones on the floor!

Although I think that the DRO +3 might be a little TOO harsh in the shadows, but like you say, use with care.

Can I ask a really daft question please? Have you tried the 18-70 mm on the a900? I doubt the quality will be anywhere near as good as this shot.... but part of me really hopes it would perform reasonably well...

The 18-70mm is a DT lens, and the 18mm circle is small - and it auto crops, no matter what you do. You can NOT turn off APS-C cropping with DT lenses on the A900, so there is really point in using them. The exposure is haywire, as Sony warned, and you must remember to use the crop area in the finder, and you get a 10.6 megapixl image.

David

Hi David
The Sony rep told me to switch to centre-weighted exposure to solve the exposure with DT lenses. If you use the full area matrixing, you include areas beyond the view of the lens, which will of course create exposure issues. My CZ16-80 exposed perfectly on my test shots with centre metering on.

Mike-Photos wrote: The Sony rep told me to switch to centre-weighted exposure to solve the exposure with DT lenses. If you use the full area matrixing, you include areas beyond the view of the lens, which will of course create exposure issues. My CZ16-80 exposed perfectly on my test shots with centre metering on.

I am aware of that (and you can also use spot metering). I thought I might make some use of DT lenses on the A900 but it is clear I won't be doing so. The 10.6 megapixel crop is not that much use compared to shooting on the A700, it is a backward step.

David

David Kilpatrick wrote:

Mike-Photos wrote: The Sony rep told me to switch to centre-weighted exposure to solve the exposure with DT lenses. If you use the full area matrixing, you include areas beyond the view of the lens, which will of course create exposure issues. My CZ16-80 exposed perfectly on my test shots with centre metering on.

I am aware of that (and you can also use spot metering). I thought I might make some use of DT lenses on the A900 but it is clear I won't be doing so. The 10.6 megapixel crop is not that much use compared to shooting on the A700, it is a backward step.

David

OK, thanks for that, and that probably settles it for me for awhile, I guess. I really can't justify two cameras, and I want to continue using DT lenses for travel, etc., so I will stick with the A700 - unless the IQ on the A900 is a huge improvement, and I haven't heard you say that yet. More megapixels I'm not looking for.

The KM17-35 D is quite a nice lens on FF after all David, (I always thought the best place for a FF lens is actually on a FF camera), what I'm really waiting for is some people type shots using the KM28-75 D @ f5.6 and f8 (100 or 200 ISO) when you can find some victims that is.....and maybe a two shot pan of a scene with about 1/4 frame overlap with the 50 1.7 (or 1.4) @ f11 using a tripod.....then I'll be happy and leave you in peace.
Greg

David Kilpatrick wrote: No vignetting correction is applied at all, the aperture is f/11. Some fill light and highlight recovery have been used, together with -0.4 exposure in ACR, to optimise the tonal range which as you can see included a large area of shadow.
David

The lack of vignetting really strikes me... I remember the first pics of the Canon 5D with the 24-105 which were at the limit of being usable. Do you think it has to do with the sensor design or is it a plain and simple software correction which is applied in-camera?

Thanks,

Jonathan

Hi David,
Many thanks for posting these pictures. I am still a fairly happy 7D user, which at over 8000 photos to date hasn't yet let me down.
When I got the 7D, I also got a 17-35 D lens, and it was OK, but I wasn't over the moon about it. But these look fantastic and show what this lens is capable of.
I also have the 100-300 APO, and the 24-85 f 3.5-4.5 Minolta, althouth to be honest I've been using only the 18-250 Tamron since I bought it a year ago.
What would you expectation be about these other two Minolta lenses?
I am really excited by the A900, and the thought of re-using my older lenses, but perhaps now that V4 of the A700 is out and solves some outstanding issues, APS-C would be good enough, and given the timing,m wait for the A700 successor.

Jonathan K wrote: The lack of vignetting really strikes me... I remember the first pics of the Canon 5D with the 24-105 which were at the limit of being usable. Do you think it has to do with the sensor design or is it a plain and simple software correction which is applied in-camera?

It is not the sensor, it is a shading map - DRO+ results have proved that to me without doubt. It is fairly extreme. When you shoot a pic with a wide-angle like this, use ISO 100. That way the best quality is retained into the corners. Many DSLR users do not appreciate that even for standard lens uses, shading maps are in the firmware of all cameras, and mean that the gain applied pixel by pixel across the frame varies.

David

@david: in the first picture "roxburgheaisle17-35f11-17mmDRO+3.jpg" on the upper right corner there is a strong violet border between arc and sky. I assume this is not CA as it should then be visible in nearby areas as well. But what does cause this effect? Is it blooming from overloaded sensor pixels?

Regards - Markus