David & all

[calpon]

Without looking at Exif....

Can you guess at what lens this is at f/2.8. (wide open for this lens)

This is a 100% crop centered at Niacin 20% (the bold one). Tripod with a remote release.(both without and with SSS looked the same).

Do you think this lens has usable images at 2.8.

I ask David to look at this because of his experience with lenses and when it is revealed what lens it is I would like to see him comment on it.

[David Kilpatrick]

That looks like the 70-200mm SSM used close up wide open - massive field curvature. I don't know any other lens as bad as the 70-200mm for this type of shot, so my money is on that. It's simply a non-use for a lens which is wonderful at greater distances.

David

[calpon]

That looks like the 70-200mm SSM used close up wide open - massive field curvature. I don't know any other lens as bad as the 70-200mm for this type of shot, so my money is on that. It's simply a non-use for a lens which is wonderful at greater distances.

David

Wow....That was quick....and correct!

Here is a comparison from 10-12 feet away
f/2.8

f/4


I still find wide open lacking for such an expensive lens. I had someone from Sony service look at these 2 images and they felt like it should be a little sharper at 2.8. They offered to send me a new copy, but I have yet to decide if I should take them up on it.

I know this lens is not going to be as sharp at 2.8 as at 4, but shouldn't it be better? I had rented one before I bought this one and I got very decent bird pics with the rented one, but my copy will not give me ANY usable bird images at 2.8.

[David Kilpatrick]

The 'can't get any bird shots sharp' doesn't sound right. It simply lacks flatness of field at close distances, but it should be extremely sharp if you photograph a bowl
The Nikon 70-200mm f2.8 is exactly the same and both of them get even worse when used full frame. I recently used the Canon and it seemed better in this respect.

If you think a 1.5X digital crop shows severe field curvature, wait for the Alpha 900.
However, no-one is likely to believe me on this score - some owners will deny there is any issue no matter what their eyes say.

I am perfectly happy with my 70-200mm Minolta SSM (same issues exactly) because its real job is not to shoot the ground at my feet at full aperture.

It is important to get the subject centered, and use the centre focus sensor with the 70-200mm f2.8. If you use any of the offset AF sensors, you may get the centre totally unfocused at closer distances.

David

[calpon]

The 'can't get any bird shots sharp' doesn't sound right. It simply lacks flatness of field at close distances, but it should be extremely sharp if you photograph a bowl
The Nikon 70-200mm f2.8 is exactly the same and both of them get even worse when used full frame. I recently used the Canon and it seemed better in this respect.

If you think a 1.5X digital crop shows severe field curvature, wait for the Alpha 900.
However, no-one is likely to believe me on this score - some owners will deny there is any issue no matter what their eyes say.

I am perfectly happy with my 70-200mm Minolta SSM (same issues exactly) because its real job is not to shoot the ground at my feet at full aperture.

It is important to get the subject centered, and use the centre focus sensor with the 70-200mm f2.8. If you use any of the offset AF sensors, you may get the centre totally unfocused at closer distances.

David

You don't come out and say it, but it sounds like you think at 2.8 it should be sharper than what I am showing and seeing. If this is true, than I should go ahead and send this one back and get another one.

Thanks for the replies:)

[Javelin]

I think there is another propblem. the peanut thats sticking out of the cage on the right looks like it has some CA around it but I don't see why it would with the way the scene is lit

[calpon]

Ouuch...that may look worse than my Tokina 80-200 ATX-Pro at 2.8...Wow. Photodo says the M80-200 is pretty good wide open, and I knew the 70-200 was not as good wide open, but I never knew it looked quite that bad. What ranges other than "close" does it do not so hot on? How does it look at 3.2? I can usually live with my Tokina at 3.2.

-Sonolta

I think I have a lemon.....My rented lens (thanks Matt), was better than this copy at 2.8.

With this copy, it doesn't get to great until f/4. F/3.2 still wasn't great, but at f/3.5 I am happy. I expected my f/3.5 to be what f/2.8 should be.

[calpon]

I think there is another propblem. the peanut thats sticking out of the cage on the right looks like it has some CA around it but I don't see why it would with the way the scene is lit

I'll have to go back to the unprocessed RAW image to see if it was something in the PP as these were done awhile back.(If I have not deleted it)

[David Kilpatrick]

I would agree that it looks as if you have a badly centred lens, in addition to the normal performance issues around minimum focus and wide aperture. I would expect the 20% to have been perfectly sharp, but not much else.

Examples just shot on my Minolta copy:


My wallpaper, which makes a very good low contrast target, at 70mm and closest focus, wide open on the A700. It's not bad at 70mm.

http://www.pbase.com/davidkilpatrick/image/102255571 to view the full size file


At 200mm under the same conditions - you will see that the fall off is dramatic and even the centre is not exactly sharp.

http://www.pbase.com/davidkilpatrick/image/102255576 link to the full size file, view ORIGINAL to see it.

My lens is a typical sample, with good performance at greater distances - you only need to be 2m away instead of 1.2m and the field curvature corrects itself.

David