Is this inconsistency acceptable? Sigma 85 1.4 question.

[csoller]

Hello folks, I'm curious what do you think about my new Sigma 85 1.4.

Overall I'm impressed by the corner to corner sharpness of this lens even wide open, but I suspect some minor decenteredness here. Contrast shifting (or coma as you will) seems to be a non issue in the upper left corner, but i'ts a rather big one in the lover right corner. The other two corners seem to be similar. I have 8 more lenses in my inventory and I haven't noticed this with my other lenses. I'd be glad if you could comment on this, especially the ones who own this piece of glass. They were taken with a 5D2, the second one is contrast enhanced, otherwise they are unmodified.

https://dl.dropbox.com/u/19423458/s85_1401.jpg
https://dl.dropbox.com/u/19423458/s85_1402.jpg
https://dl.dropbox.com/u/19423458/s85_1403.jpg

 

[agierke]

whats it look like when you take pictures of people?

i really don't see the concern here.

 

[RS2021]

Taking these pictures and the pixel peeping itself suggests you are going to have a tough time being happy with most any lens. It looks ok to me...

Go take real photographs, something other than brick walls and granite counters.

 

[liberace]

I'm not sure I would be happy with it. Even to the untrained eye you can easily see the bottom right corner is much less sharp than the top left and less sharp than the other two.

 

[csoller]

Thanks for the anxious looks, but you don't need to worry about me, this topic is about this specific lens.

Regarding the comment about my future happiness: I also have the Sigma 35 1.4, Canon 16-35 II, 70-200 2.8 IS II, 100 L IS Macro, TS 90 2.8, TS 24 3.5 II, and the 50 1.4, and I have never had a complaint. This is the first time.

I still await your impressions about this copy of this lens.
Thanks.

 

[RS2021]

I'm not sure I would be happy with it. Even to the untrained eye you can easily see the bottom right corner is much less sharp than the top left and less sharp than the other two.

I dont' see the exif info, perhaps I am downloading the processed picture...but if these shots were made any where close to wide open, DOF is bound to be razor thin.

Some of this could even be due to positioning or angling of the camera or the shot by just an inch if they were made at close quaters (looking at the pictures, clearly these were very close shots)...in this case a slight tilt in the camera will render one or the other edge/border of the printed page out of sharp focus depending on where the focus point is.

His 5D2 has no leveling feature unlike 5D3...and even then...unless these shots are made very carefully under controlled conditions on tripods and with leveling, pixel peeping is rather fruitless at such close quaters on a tele lens wide open.

 

[distant.star]

.
Nothing personal, but I see so many of these first posts about some non-Canon product. There's just something fishy about them to me. I no longer take them seriously.

If you have a lens that is not working correctly, send it in for repairs. As Roger at LensRentals just pointed out, lenses sometimes get out of whack (and they can come that way from a factory):

http://www.lensrentals.com/blog/2013/02/optical-tune-ups

Worth a read, I think.

 

[csoller]

Im in Hungary at the moment, and returning a product here is not as easy as it is in the US. You have to argue with a teenager for minutes in the shop to be considered serious about returning it. Thats the reason I would like to be sure. I only have one sample of this lens, I need your input to decide if I'm happy with it.

Back to the topic again.

The first image is what really matters here, the second one is for inspecting vignetting, the third one is for distortion. The second and third looks normal to me.

All were taken at 1.4. I am aware of the difficulties small DOF creates, but I've been using this lens for a week, and all my photos return the same result: inconsistent lower right corner.

 

[Mt Spokane Photography]

If its not acceptable to you, thats the only thing that counts! Return it!

 

[RMC33]

Im in Hungary at the moment, and returning a product here is not as easy as it is in the US. You have to argue with a teenager for minutes in the shop to be considered serious about returning it. Thats the reason I would like to be sure. I only have one sample of this lens, I need your input to decide if I'm happy with it.

Back to the topic again.

The first image is what really matters here, the second one is for inspecting vignetting, the third one is for distortion. The second and third looks normal to me.

All were taken at 1.4. I am aware of the difficulties small DOF creates, but I've been using this lens for a week, and all my photos return the same result: inconsistent lower right corner.

Frame your shots so you can either crop that softness out or it gets lost in the bokeh. Just be aware of it when you go landscape to portrait and you will be fine. There is nothing wrong with your lens. The article from lens rentals Distant.star recommended is spot on.

 

[RS2021]

If its not acceptable to you, thats the only thing that counts! Return it!

+1
Ultimately, if you have the impression that it is off in one corner or the other, enough of an impression to put it in writing with example pictures, as you have done here, that's what matters...you will always have that view whatever is said here...return it.

 

[picturesbyme]

first: try this or another test to be sure
http://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover
then you can make a decision...

Sok Szerencset!

 

[AudioGlenn]

If its not acceptable to you, thats the only thing that counts! Return it!

+1
Ultimately, if you have the impression that it is off in one corner or the other, enough of an impression to put it in writing with example pictures, as you have done here, that's what matters...you will always have that view whatever is said here...return it.

+1

 

[agierke]

are you going to be shooting Architecture or Landscapes with this lens? or do you intend shooting people with the lens? if you do plan on shooting people, will you be placing anything in the composition thats worth looking at in the bottom corner near the edge?

again...i am having trouble understanding the thought process here. this level of criticism under these circumstances seems inane.

for an 85mm 1.4 lens shot wide open, what difference does corner sharpness make? what photographic purpose are you trying to achieve that you feel this lens wont be able to cover?

 

[RS2021]

are you going to be shooting Architecture or Landscapes with this lens? or do you intend shooting people with the lens? if you do plan on shooting people, will you be placing anything in the composition thats worth looking at in the bottom corner near the edge?

again...i am having trouble understanding the thought process here. this level of criticism under these circumstances seems inane.

for an 85mm 1.4 lens shot wide open, what difference does corner sharpness make? what photographic purpose are you trying to achieve that you feel this lens wont be able to cover?

Please stop feeding this post, I think several satisfactory answers have been given, and the OP seems to know what matters to him...feeding this post will just drag it out more.

As one of the posters said above...

.
Nothing personal, but I see so many of these first posts about some non-Canon product. There's just something fishy about them to me. I no longer take them seriously.

If you have a lens that is not working correctly, send it in for repairs....

 

[csoller]

Thank for you who helped, got it replaced, new one works as I would expect a lens of this caliber to work.