Strange softness to images

Ok, my tea interval....
first image: 600d on a tripod, mirror lockup, self timer, IS OFF, 1/640s f5.6 ISO 400 300mm auto focus, centre spot
this is the full, image:
f5.6 tripod by Jonathan Allday, on Flickr

same image cropped:
f5.6 tripod b by Jonathan Allday, on Flickr

next image all as above, aside from live view manual focus
f5.6 live view by Jonathan Allday, on Flickr

taking more pictures of signs than cricketers....
 
Looks like the PDAF is back-focusing... the leaves behind are sharper and the sign blurrier in the first image. Unfortunately the 600d doesn't have AFMA capability.

You could send the lens/body in and have them calibrated to each other, but that could also potentially inhibit PDAF performance with other lenses/ at other distances... unless the camera's PDAF is just out of spec.
Some lenses just don't perform as well with some bodies... it's a mix/combination of "tolerances" and can't generally be isolated to any one thing in particular. It's a question of how long you are willing to be w/o the lens/body and how much it will cost. But I would be inclined to send them both in for testing/calibration. IMO, it is either that, or dump the lens and try your luck with another. You *could* just use it stopped down to f/11 all the time, but you shouldn't have to; and the results will still be worse than if you had started out better.
 
I think that the camera is still under warranty...I bought extended with the body.
 
I have the same combination and get similar results. The lens is definatly better when stopped down to f8 or more, which is probably not ideal for your needs. Backing off from 300mm a bit does also improve sharpness, not found the sweet spot yet, but seems to be around 250mm.
By way of comparison, have also tried on my EOS M mirrorless and it is much sharper lens at 300mm.

Had trouble finding examples at 300mm but here's a couple.

@ f11
Parallels by Steve Bennett, on Flickr

@ f16
Moonset June 4th 2015 by Steve Bennett, on Flickr

Not sure this helps any?
 
It's what happens when you shoot wide open on a cheaper long lens. I get it with my Nikkor 70-300 f4.5-5.6G when at 300mm/f5.6.

Stopped down it will be fine.

sk66 said:
Looks like the PDAF is back-focusing..
Click to expand...

I disagree. Those leaves look no more sharp than the sign.. the softness of the sign is just more noticeable due to it's colour.

Just stop down. Cheaper long zooms are crap wide open.
 
Well, I don't get results like that from any of my zoom lenses wide open...(i.e. 28-300, 70-300 1 series). And the OOF "flare" is more uniform in direction/character; this seems to be more unidirectional.
In the examples there is notably less of the flare, and the BG leaves are less sharp in the live-view focused image. I *would* expect better performance stopped down, but I would also expect better from the in focus portions wide open. Especially based on the review/test images I've seen of this lens at 300/5.6.
 
sk66 said:
Well, I don't get results like that from any of my zoom lenses wide open...(i.e. 28-300, 70-300 1 series). And the OOF "flare" is more uniform in direction/character; this seems to be more unidirectional.
In the examples there is notably less of the flare, and the BG leaves are less sharp in the live-view focused image. I *would* expect better performance stopped down, but I would also expect better from the in focus portions wide open. Especially based on the review/test images I've seen of this lens at 300/5.6.
Click to expand...


I'm sorry, but I'll put a large sum of money on it. I reckon if he goes back and shoots that sign again in exactly the same way, but at f11 it will be fine.
 
Pookeyhead said:
I'm sorry, but I'll put a large sum of money on it. I reckon if he goes back and shoots that sign again in exactly the same way, but at f11 it will be fine.
Click to expand...
Of course it would get better... but a lens that has to be stopped down to f/11 to get acceptable results??
 
sk66 said:
Of course it would get better... but a lens that has to be stopped down to f/11 to get acceptable results??
Click to expand...

No, I don't think it is acceptable either, especially when I know the Canon 70-300 IS peaks at f/8 in the centre at 300mm - and it looks better than that IMHO. I've MTF tested pretty much every 70-300 on the market (there aren't actually that many of them) and, David, if your Nikon 70-300 VC is no better that that either (it's the best consumer-grade 70-300) then maybe you should get yours looked at too.
 
sk66 said:
Of course it would get better... but a lens that has to be stopped down to f/11 to get acceptable results??
Click to expand...


It's the same with my Nikkor 70-300 wide open at the long end. It does exactly the same. Those are very magnified small section BTW. F11 sounds a lot, but that's only 2 stops down from wide open... it's not a fast lens.

HoppyUK said:
I've MTF tested pretty much every 70-300 on the market (there aren't actually that many of them) and, David, if your Nikon 70-300 VC is no better that that either (it's the best consumer-grade 70-300) then maybe you should get yours looked at too.
Click to expand...


Seems the same as the 6 others we have at work. They can't all be faulty. Cheap long lenses are just not great wide open at the extremities. Even 1 stop down it's massively improved actually, but still has a faint hint of that softness.

Here's 300mm one stop down at f8....

QRE2IqP.jpg


...perfectly acceptable for pretty much anything. Not quite in the same league as my 70-200 2.8, but perfectly fine, especially for ISO800 as well.

However, when at 300mm and f5.6.....

qsnbSBQ.jpg


...I get that exact same smeared look to contrast edges, and a general lowering of contrast. Every 70-300 AF-S VR 4.5-5.6G IF-ED I've used has done exactly the same thing (we've got a shelf full of them at work). You get what you pay for. I appreciate that it's not the same lens he has, but I wouldn't get too fixated on that lens being faulty.

Just knock it down a stop. If you need a fast lens, you've got the wrong lens any way, so just stop down.

It only seems to do this at the long end. anywhere else it's awesome.

170mm @ f8

MaRwy93.jpg
 
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Apologies for not being clear. I should have put `why 2?`.
I found the lens ok @ 5.6 (obviously not very long distance shots) but by 7.1 really pretty good.
(I was looking at the beach-shot & wouldn't expect F5.6 to be sharp at such a distance)

Also is it a case of what body the lens is used on?
Do the newer high Megapixel bodies `outperform` the older lenses? When I had mine it was used on the D700.
 
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David PH, I don't see the same issues with your lens at 300mm at all. It looks soft and low contrast because of the heavy atmosphere emphasised by distance. The OP's lens has a soft-focus look with those glowing highlights (spherical aberration?) characteristic of something out of whack.

That's only a guess of course, but it's a guess based on a fair bit of of experience with similar lenses. Heck, I've been getting much better results than that at 300mm with a Tamron 16-300 I've been using recently.

I'd be sending it in for a check. From the evidence, it's pretty much unusable IMHO at 300mm, so rather than the expense of a replacement, it could be a few quid well spent.
 
HoppyUK said:
David PH, I don't see the same issues with your lens at 300mm at all. It looks soft and low contrast because of the heavy atmosphere emphasised by distance. The OP's lens has a soft-focus look with those glowing highlights (spherical aberration?) characteristic of something out of whack.

That's only a guess of course, but it's a guess based on a fair bit of of experience with similar lenses. Heck, I've been getting much better results than that at 300mm with a Tamron 16-300 I've been using recently.

I'd be sending it in for a check. From the evidence, it's pretty much unusable IMHO at 300mm, so rather than the expense of a replacement, it could be a few quid well spent.
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Nah... can't be arsed. If quality is important, I use the 70-200 f2.8. I hardly ever shoot wide open with the 70-300. In fact, that is the only image I can find where I have, so hardly worth the effort. One stop down and it's fine.
 
Jonathan from that series of test frames the only sharpish ones are f9, which you have pointed out.
Now, to my mind that's an unacceptably hideous lens.
How about a repair/refurb/big clean?
Is it expensive?
Buy a new lens instead?
 
Pookeyhead said:
5.6 -> 8 -> 11
Yes.
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Mark had already replied when I posted ` 2?` (meaning why does it need 2 full stops) & I thought it was clear with my next post/reply, what I was getting at. :rolleyes:

The post I'm referring to is below, with what I thought was a reasonable question (highlighted in case you missed it, rather than just picking & choosing)


OldCarlos said:
Apologies for not being clear. I should have put `why 2?`.
I found the lens ok @ 5.6 (obviously not very long distance shots) but by 7.1 really pretty good.
(I was looking at the beach-shot & wouldn't expect F5.6 to be sharp at such a distance)

Also is it a case of what body the lens is used on?
Do the newer high Megapixel bodies `outperform` the older lenses? When I had mine it was used on the D700.
Click to expand...
 
OldCarlos said:
Mark had already replied when I posted ` 2?` (meaning why does it need 2 full stops) & I thought it was clear with my next post/reply, what I was getting at. :rolleyes:

The post I'm referring to is below, with what I thought was a reasonable question (highlighted in case you missed it, rather than just picking & choosing)
Click to expand...
In a very real sense the newer high MP sensors do outperform most lenses at most apertures. But that doesn't mean the results will generally be any worse... you just don't get all of the benefits/gains you might think you are.
 
UV filter? I thought we established that?
 
Thanks everyone for the debate on this. I did not think it would generate this much comment and interest!
I am not at all sure what I am going to do. The images above are as good as I have ever taken of a cricket game, and on the basis of these there does not seem to be much wrong with the lens!
However, the quality is nothing like as good at 300mm 5.6 and low contrast (those seem to be be the combined issues).
The UV filter is staying off.
Perhaps at the end of the season, I might get it checked out for peace of mind sake - there is a Canon service centre not too far away.
If that happens, I will resurrect this and comment.
Other than that, any last comments on these images?
Jonathan
 
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Those do look much better :thumbs:
 
Much better Jonathon, maybe not the reach you wanted but a sacrifice worth making I would say.
Reinforces my faith in the combo too ;)
 
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