Sony A900 w/Zeiss vs ? - A Challenge

[jonoslack]

Hey guys, I certainly wasn't trying to set anyone up so if anyone feels upset I apologize. As I mentioned, I simply wanted to get unbiased results. If I'd gone in saying Lens A was the Tamron and B was the Zeiss what do you think the likely outcome would have been?

Well, I only took it as an interesting diversion, and although I guessed right, it was just that . . . a guess.

the idea that you can make definitive decisions about lenses (or cameras) from 2 images with crops on the internet is surely always going to be 'a bit of fun'.

Hardly a setup.

 

[toddbee]

interesting comparison. i would like to hear what you wind up keeping

 

[Greg Seitz]

Ok, finally got a chance to get out with a bit better lighting. Below are a few photos again comparing the Canon/Tamron with the Sony/Zeiss. This stuff was all hand held so none of them are completely precise but are generally in the ballpark. Other than exposure tweaks you are seeing default color renderings out of Lightroom for both cameras. Both were shot using daylight white balance. Without tweaking they rendered very similarly.

Once again a few observations. The Zeiss was significantly quicker to focus and generally felt more precise. For most focal lengths and apertures things felt really close with the exception of shooting at 28mm wide open at F/2.8 where the Zeiss was superior especially when shot at middle distances of 20-50 feet. Close up and infinity were generally pretty close in behavior.

In pretty much every case both cameras metered within 1/3 of a stop. A few cases had the Sony metering hotter and in a few more it was the opposite with the Canon metering a bit hotter but again they were almost always within 1/3 of a stop.

The bokeh of both was close most of the time but I did see a few cases of pretty drastic differences. The last shot in this series is followed by a crop that shows one case of that dramatic difference. I'd be interested in hearing your comments on that one since it's so different.


I've posted a bigger set of full sized images on pbase at:

In each case below it will be the Sony followed by the Canon...

28mm F/3.2

45mm F/5.6

70mm F/2.8

And now that crop I mentioned above. This is a crop of the above shot and it's clear both lenses are responding very differently to the specular highlights coming off of the water droplets. Sony and then the Canon.

 

[Greg Seitz]

Oh, and the link to the pbase album with more images at full size:

http://www.pbase.com/gseitz/a900-5dmkii&page=all

 

[toddbee]

I DL the raws and was surprised how close they were. That tamron looks pretty impressive.

 

[jonoslack]

With respect to the Tamron.
I bought one to go with my 900. In fact, I tested three in the shop before buying one. It looked fine, but the corners were impossibly bad at most focal lengths (by impossible I really mean it, and large swathes of corner too!).

Now, of course, I hadn't sent it back to Tamron for recalibration, but the centre was sharp, and it wasn't decentered either. The edges were okay as well.

So, maybe I had a bad one, maybe you have a good one Greg, or maybe we haven't seen the corners!

Of course, here we are looking at hand held shots using different cameras (shrug). So, although I can see the fun in the first post and question, I'm really not sure that these can do anything except to tell you that, in the centre and mid edges, the tamron 28-75 can look pretty good.

 

[Greg Seitz]

With respect to the Tamron.
I bought one to go with my 900. In fact, I tested three in the shop before buying one. It looked fine, but the corners were impossibly bad at most focal lengths (by impossible I really mean it, and large swathes of corner too!).

Now, of course, I hadn't sent it back to Tamron for recalibration, but the centre was sharp, and it wasn't decentered either. The edges were okay as well.

So, maybe I had a bad one, maybe you have a good one Greg, or maybe we haven't seen the corners!

Of course, here we are looking at hand held shots using different cameras (shrug). So, although I can see the fun in the first post and question, I'm really not sure that these can do anything except to tell you that, in the centre and mid edges, the tamron 28-75 can look pretty good.

Maybe we have different definitions of impossible but these don't look so bad to me. It may be a curvature of field thing as my gut tells me the Zeiss curves inward at the edges and the Tamron seems to curve outward. Haven't tried the verify it but the in focus area of the Zeiss tends to typically look better at distances closer to the camera near the edges.

Extreme top and bottom right corners at what is arguably the lenses weakest focal length of 28mm. Shot at F/8. Sure as you open up they get progressively worse. Definitely the Zeiss has better corners at wider apertures but the lens is anything but unusable.

 

[Greg Seitz]

Oh, and if you want to see truly bad corners try a copy of the Tamron 17-35 some time at 17mm. It's scary bad.

 

[Shelby Lewis]

A couple of things...

The tamron, on my old 5D was the most reliably sharp and contrasty of all my lenses. That's not to say it was always pleasant, but sharp (and well focussed) was the norm. A true bargain performer.

I wonder, though, how it holds up to 24mp. Need to look at more tests, I guess, lol.

The latest samples above, to my eye, show the zeiss to have more dimension and "roundness" to "bodies". I think the canon files do, indeed, look VERY nice and I would be hard pressed to tell them apart without serious consideration... and the ever so slightly less contrast does make the first canon image a bit easier to mentally process (doesn't appear so busy to me)... but as far as sharpness and "3D" factor, the zeiss is a winner in my book.

Not sure if it was the shooting or the camera, but i do NOT like the highlight roll-off in the canon files, especially on the pink roses.

All that said, the guy I shoot weddings with just picked up a 5dII and an 85/1.2 and I have to admit his images from this weekend's wedding were stunning.

It's a great time to be a photographer!

 

[Greg Seitz]

Shelby,

Thanks for the comments. I'm finding both of these cameras capable of producing amazing results and wholeheartedly agree with your sentiment about it being a great time to be a photographer! Funny thing is, the camera I enjoy shooting from a pure fun point of view isn't either of these, it's the little Nikon D5000 - go figure. But, I sure do love the files the Sony and Canon deliver.

Thanks,

Greg

 

[edwardkaraa]

It may be a curvature of field thing as my gut tells me the Zeiss curves inward at the edges and the Tamron seems to curve outward.

Nope, the Zeiss curvature is outwards as well.

 

[Braeside]

My first Sony CZ24-70mm was very poor at 70mm f/2.8, obviously sharper at one side of the frame. I rejected it and the replacement is fantastic. So it appears that many lens manufacturers have their quality problems and it can be a bit of a lottery.

I now try to purchase from places that will let you return a lens if you think it is poor.

 

[Braeside]

For some reason the first half of my last post was accidentally removed, so here it is again.

My Tamron experience has been mixed.

1. KM28-75mm on APS-C - returned for autofocus fix - better but still soft at 2.8

2. Tamron 28-75mm on A900 - OK at f/4, but again 2.8 mushy.

3. Tamron 17-35mm on A900 OK well stopped down, corners never perfect.

Greg, you got a good one!