Photoclubalpha

Hello to all,

I have posted some samples of a test I done with the A900 and beercan.

I have tested the beercan on a sturdy tripod with a massive ball head. This gem of telezoom lens seems to reach a peak in sharpness at f/8: at this aperture the picture is very crisp, but the whole frame remains very detailed even at /22.

I have developed the raw file with Lightroom 2.2 boosting the sharpening.

I have found is better to use the mirror lock up mode drive, instead of the 2 second delay self timer, WITH STEADY SHOT OFF. The photographer must be very careful, because wind blowing or mirror vibration effects are very visible in the final picture, affecting the sharpness. the best way is to raise the mirror, wait 5-6 second or more, no wind, then open the shutter (with the release cable of course).

The location is the outskirts of a little town, near to where I live, built along the side of a valley. I have photographed from the opposite side of the valley, from a distance of 500-1000 meters around, so there wasn't any depth of field issue.

The sun had gone away already, the low contrast light was diffused by sky alone.

Those are the links
Whole frame: http://www.pbase.com/aformaphoto/image/107396332
Center crop: http://www.pbase.com/aformaphoto/image/107395916
Corner crop: http://www.pbase.com/aformaphoto/image/107396151
Regards
Antonio

Antonio, good demonstration but you have used so much sharpening it is impossible to tell how the lens performs.

Here's a sample from the Alpha 200, which has slightly less pixel density than the A900:

http://www.pbase.com/davidkilpatrick/image/92723805

It is at ISO 400 which is not ideal, but you can still get a better idea of the lens's real sharpness by looking at the seated fisherman's face. No sharpening is used. Pictures without any sharpening show lens sharpness better, because the fine detail is not erased. When you sharpen a lot in Lightroom, a printed picture may look better but 100 per cent screen view will have less detail - it will be obscured by the sharpening effects.

David

David,
thank you very much for your comment.
I have seen your very clean picture and I would ask you what setting of AMOUNT, DETAIL, RADIUS, MASKING are better to check sharpness? So I will develop again the picture and then re-upload!
Regards

David Kilpatrick wrote:Antonio, good demonstration but you have used so much sharpening it is impossible to tell how the lens performs.

Here's a sample from the Alpha 200, which has slightly less pixel density than the A900:

http://www.pbase.com/davidkilpatrick/image/92723805

It is at ISO 400 which is not ideal, but you can still get a better idea of the lens's real sharpness by looking at the seated fisherman's face. No sharpening is used. Pictures without any sharpening show lens sharpness better, because the fine detail is not erased. When you sharpen a lot in Lightroom, a printed picture may look better but 100 per cent screen view will have less detail - it will be obscured by the sharpening effects.

David

Thanks to this kindly suggestion I have uploaded again the samples, after the same picture was developed with Lightroom at default setting and no sharpening.

Those are the new links:

whole frame: http://www.pbase.com/aformaphoto/image/107396332

center crop: http://www.pbase.com/aformaphoto/image/107399368

corner crop: http://www.pbase.com/aformaphoto/image/107399371

Regards
Antonio

That's a much better illustration! Lightroom could do with a CA control, looks like about -10 to -15 Red/Green with Defringe highlight edges turned on to remove the slight visible colour fringes towards the edge of the frame. Sometimes, just using +50 Chroma NR is enough to remove these fringes when they are fine and sharply defined. These look soft.

David

OK David, I will try those settings. Many thanks.

We are all a kinda of perfectionist here, but the A900 has really some great potentialities and it takes me some time to know the camera and the programs well.

Regards and Merry Christmas to you, to your family and to all the people.
Antonio

Antonio, thanks for the links and the test.
Wish you all the best and Merry Christmas.
And, by the way, I was just admiring all the details at the corner photo. Just look at the branches of the trees... thumbs up