Feeling frustrated

nickjohnwatson

nickjohnwatson

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Nick
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So I bought a Sigma 70-200 2.8 EX DC HSM off gumtree a few days ago, spoke to the guy on the phone he seemed genuine and showed me both of his websites etc and provided me with all contact details his address etc, and sent over a few test shots al all seemed good. So i sent over the money (BT) and awaited the lens. It arrived on monday and I had a chance to go out and use it yesterday, long story short its VERY soft at f2.8 and even stopped down to f11 its not sharp. I've spoke to the bloke and he reckons that i should try the micro adjustment in the 6D to see if that resolves it but surely the micro adjustment only does front/back focussing? It looks to me as if the lens elements may have been knocked out of aligment or something as it looks like there's ghosting (almost like if you look at something a bit cross eyed)

He sent me some full res files on email and they were fine so I'm thinking it must have been dropped in transit by parcelforce but how i'm going to prove that i dont know.

anyways im just having a rant as im feeling rather frustrated and a bit gutted to be honest.

f2.8 // tripod mounted // iso100 // 1/400th


f2.8 cant remember shutter speeds etc


f4


f8 i think


Nick
 
the f8 shot looks pretty sharp compared to the other images

have you had a look on flickr for the same lens and compared? as far as parcelforce, if its had a knocking and they're insured, i'd claim. You could get a brand new one for it or at least get it paid for to be repaired?
 
Have you tried a focus test to make sure the focus point is where you expect it? Use a ruler if nothing else is at hand.

If you really need best in class wide open then you can pay double and get the Canon/Nikon alternatives.
 
Gary Coyle said:
Genuinly dont know how you expect anyone to comment regarding sharpness, with images this size its impossible, even clicking through to flickr isnt any use
Click to expand...

Ah I hadnt realised the pics were just small res ones i uploaded them from my phone. I'll have to put some full res ones up tonight.

I took some of the photos in this thread with my mates sigma which is the exact same lens and its perfect.

I hope that parcelforce dont make it a nightmare to make a claim for it as the photo he sent me taken a day before he sent it was fine.

simonbarker said:
Have you tried a focus test to make sure the focus point is where you expect it? Use a ruler if nothing else is at hand.

If you really need best in class wide open then you can pay double and get the Canon/Nikon alternatives.
Click to expand...

I wasnt expecting it to be sharper than the canon version, obviously this is quite a bit cheaper but you'd expect them to be useable, I'm going to try the focus test and micro adjustments tonight but its the same manual and autofocus. The problem looks like the middle photo in this link .........

Hope its a simple fix otherwise looks like lots pf phone calls to parcelforce!
 
The bottom edge of that `dog` ornament possibly looks a little sharper slightly in front? but as said, uploads are too small to tell.

Presume you were using single/centre point?
 
Mine is a bit soft at f/2.8, but is very sharp at f/5.6. I dropped it on some cobbles in Leubeck and had to send it to Sigma for repairs. Still a good lens. Definitely worth doing a focus check using a chart.
 
OldCarlos said:
The bottom edge of that `dog` ornament possibly looks a little sharper slightly in front? but as said, uploads are too small to tell.

Presume you were using single/centre point?
Click to expand...
Yeah single point focus on the text on the bottle, and the one of the sign was manual focus with the sensor parallel to the sign
 
Brazo said:
Have you tried it with Manual focus?
Click to expand...
Yeah I've tried it manual focus, autofocus, live view and viewfinder, tripod and handheld at all focal lengths and all apertures and it seems the same all over.

Here's hoping the micro adjustment sorts it but i think it may be more serious. I've spoken to the seller and he's emailing me the receipt with all the details on, it was insured with Parcelforce so if its knackered i'm hoping I'll be able to make a claim for it. I have a shot taken the day before he sent it and a one the day after i recieved it, I may get it tested somewhere to check it with a report if they need it. pretty annoying having to run around to get it sorted!
 
nickjohnwatson said:
Yeah I've tried it manual focus, autofocus, live view and viewfinder, tripod and handheld at all focal lengths and all apertures and it seems the same all over.

Here's hoping the micro adjustment sorts it but i think it may be more serious. I've spoken to the seller and he's emailing me the receipt with all the details on, it was insured with Parcelforce so if its knackered i'm hoping I'll be able to make a claim for it. I have a shot taken the day before he sent it and a one the day after i recieved it, I may get it tested somewhere to check it with a report if they need it. pretty annoying having to run around to get it sorted!
Click to expand...
Only the sender can make a claim Nick, he paid for the service so they will ony deal with him.
 
Micro adjustment is purel to adjust the autofocus so if it's not sharp using manual focus then it never will get sharp.

That said the results look ok and not unusual at wide open for a sigma lens, some veiling haze perhaps? I would reshoot outside in better light and manually focus before coming to any conclusions.
 
Have you got any shots from your trip out with the lens to share? The examples you've posted don't look valid as a test to me as I'm not sure if you were square to the subject. If you're testing for sharpness you need to be really careful with your test shots, as anything close will have minimal depth of field, particularly at f/2.8, and shooting at an angle will have results like the first image.
 
Furthermore this is not a macro lens, and as such will perform at its worst with small, close subjects. Point it to something at least 2-3 meters away, ideally further and then shoot. From experience the lens isn't fantastic at the long end (copy variation?) however if you can't get pin sharp shot at 70-135mm range in the distance, things are really bad.
 
I'm beginning to think i'm going mad.
Last night I looked at a load of shots that I took with it on tuesday and the results were different to what i saw in the house.
The shot i posted above (yellow sign) was taken from about 4 ft away (outside of min focusing distance) at f2.8 in manual focus and its not sharp, however the photo of the lobster pot and the castle were shot at f2.8 and that one's fine, a bit of sharpening in LR and its perfectly useable. Am i just expecting too much at the extremes? zoomed right in at f2.8 its bad but wound back a little its not too bad. I know 2 other people who use this lens and i've used both of them and they are both sharper wide open at the long end. I'm used to using the canon 50mm which is very sharp and the 17-40L which again is really sharp so i don't know whether i'm just being over expectant?

here's the shots from tuesday and to be honest they're all fine.

please tell me im not going mad and you'd be happy with these?
click the photos for full res files on flickr.

f2.8 - manually focused on the front edge of the lobster pot


f4 - auto focused on the rope


f5.6 - manual focused on the face of the 5th rock up in the stack


f8 - auto focused on the flat face of the wall thats in the sunlight


f11 - manual focused on the front face of the nearest hut


f16 - manual focused on the face of the 5th rock up in the stack
 
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I went out on my lunch and gave the micro adjustment another try, in more real world conditions as recommended.
I shot a car numberplate from about 10 metres away and with no adjustments it was front focusing quite a bit. I've had to tell it to back focus as far as it will go (+20) at both the telephoto and the wide end but it seems a lot better in AF now. I'll stick a photo of the difference up later on. Hopefully it'll be ok and thanks for putting my mind at ease folks :-)
 
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