Hey,
So basically, this is my problem:
My Sigma lens has suffered from the problem where the far left side of the image is horrendously blur and soft. Then, approx. 3 weeks back, I accidentally knocked the camera+lens and the lens became tremendously better ( Whoa, I know). However, I did not realise that yet and sent the lens to Sigma service centre to repair the soft left side issue. At the centre, they tested the lens on my body, and their 5d ii, and came to the conclusion that apart from back focusing, the lens was perfectly alright and they had fixed the backfocusing. Furthermore, they said that there could have been something wrong with my body.
The way they tested the lens was just a "sophisticated and dedicated measuring tape like sheet of paper used to test for front-back/ left-right focusing'. However, this paper only covered a vertical strip in the centre of the image and not the far left or right.
After getting back my lens, I decided to do a couple more tests, and found something VERY peculiar.
The below is the image which had this funny thing:
EXIF of the Original Image can be found via Flickr.
Original Image ( except for resizing) [Focus point right in the middle]
100% Crop of roughly centre:
100% Crop of far left:
100% Crop of far right:
As you can see from the images, IQ decreases significantly at the far left of the image as compared to the far right.
However, the top of the car in the far left image still stays relatively sharp as compared to the background in the distance, which is really perplexing.
I'm not to sure if there is something wrong with the lens alignment, or the sensor alignment.
Can any masters here please help?
This is really quite urgent and thanks for reading through this long text!
Please feel free to ask for any information which I've not stated here.
