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Canon L = Lousy?

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These are crops from the pics in the previous post. Center fokus, Single AF. You are looking at the Focus point. MFA pics are taken at 4,0 , I copy pasted text and forgot to change back from 5,6.

Changing light? Yes - but that shouldnt matter that much on FOCUS.

--
Mike the Viking
 
...take a look at the Post: Who can pic a L-lens.
The first is 24-105 (returned), the second my 17-85, the 3rd a another 24-105.

As you can see for yourself, and the post from Aperturewise; he thinks 1 and 2 are from the same lens. I thought the same and was perplexed.

Some of the other people are so ignorant, not discussing my simple question.

I think I have proved that there are unacceptable variations in the 24-105 L-lens.
--
Mike the Viking
 
Sonylover1 said:
...take a look at the Post: Who can pic a L-lens.
The first is 24-105 (returned), the second my 17-85, the 3rd a another 24-105.

As you can see for yourself, and the post from Aperturewise; he thinks 1 and 2 are from the same lens. I thought the same and was perplexed.

Some of the other people are so ignorant, not discussing my simple question.

I think I have proved that there are unacceptable variations in the 24-105 L-lens.
--
Mike the Viking
Click to expand...
Mike,

I've had the same experience with sample variation with a 24-105 and Photozone have repeatedly remarked about the variability in Canon lenses. I agree, it is unacceptable. However, I'm perplexed by your sample photos. Why did you choose such a subject? You are talking about differences in focus. It is impossible to know what you focussed on, but that doesn't matter for the moment as you used f/8 almost evrything is in focus, including the foreground. What I see are differences in contrast, colour and saturation. I can't see how you can test "focus" with such a subject. I'm not trying to be overcritical or ignore the real issue you raise, but you have to take a picture of something flat and at wide aperture. At the very least, you need to have an unambiguous target in the middle of the picture for your AF point to lock onto.
Neil
 
It is as whatever you show or write there is misinterpretation in this thread.

"Can you spot a L-lens" was not meant to prove anything about focus or whatever.

Just the appearance of a plain landscape with some features on to compare the pics. Of course I choose f8 to get the best out of the three lenses.

(If you want to comment on focus issues - look at other examples or in my gallery.

I know its hard to focus on green leaves. But why should I refrain from it when testing if people can see the difference from a chepo 17-85 and a expensive 24-105?

There are a lot of hurt feelings in the Canonzone...
But why defending variations on expensive lenses? I dont see the point.
--
Mike the Viking
 
Sonylover1 said:
I know its hard to focus on green leaves. But why should I refrain from it when testing if people can see the difference from a chepo 17-85 and a expensive 24-105?

There are a lot of hurt feelings in the Canonzone...
But why defending variations on expensive lenses? I dont see the point.
--
Click to expand...
Mike,

I'm not defending anything if you read my comment. But you are clearly talking about focus here:
http://forums.dpreview.com/forums/read.asp?forum=1029&message=35916710
And here:

"With MFA between +5 - +8 I got sharpness at the focus point. Using 24 and 105 was of course impossibly then.

First 3 is 4,0 - 8,0 with bad sample. Pic 4 and 5 with MFA. Pic 6 compared to 50 / 1,8 wide open. And finally sample 2 at 4,0 . "

You don't have to get all prickly about this! But you are talking about focus if you refer to MFA and something being "severely front-focussed" It is impossible to see any of that in your pics. What I can see in your composite crops are variations in contrast. My first 24-105 didn't have a focus issue or a contrast issue, it had a sharpness issue. The replacement doesn't.

The funny thing is now you're getting all hurt when people dispute some point you make; well just look at the title you gave this thread. You were obviously trying to provoke people, otherwise you'd have called it something a bit more neutral like "sample variation in Canon L lenses".
Don't shoot the messenger, ok?
Neil
 
Sonylover1 said:
These are crops from the pics in the previous post. Center fokus, Single AF. You are looking at the Focus point. MFA pics are taken at 4,0 , I copy pasted text and forgot to change back from 5,6.
Click to expand...
All of your samples are focussed on the trees in the foreground. Now you have to find the reason for that.
 
Well to be honest I don't think I can tell anything from your samples. When I test lenses I do not use AF. Otherwise too many factors come into play. I will instead tripod mount the camera and use manual focus with a certain point in the frame being the focal point each time. I will also use a focusing aid such as either 10x live view or at least my anglefinder set a 2X to set the critical focus accurately. Without taking such care in the test I don't see how you can make any judgement on the lens. If I had to rely on an AF system I'd have to do the proverbial brick wall test or something similiar with only one dominant single plane object to focus on.
--
Long live the HMS Beagle
Critiques always welcome!
 
Sonylover1 said:
but double checked with MF and Live View. Focused on the wood in the background one every pic.
Click to expand...
The actuall AF sensor is larger that what you see. If you used AF assist, it may get even worse in that particular case. There are foreground elements that are too close to the center.

You can blame the camera, if you wish, but I do not think that the problem are the lenses.
 
rwbaron said:
I've not seen the tests but you're paying for speed and the ability to be reasonably sharp at the fast apertures. This doesn't mean the lens will be any better (or even as good) stopped down than a slower, less expensive alternative. Grinding and polishing large elements is a lot more difficult to hold tolerance than for smaller elements.
Click to expand...
I'm wondering whether there is a "sweet spot" with current design/manufacturing technology for lens speed if all we want is the best possible stopped down performance across the frame, e.g. at f/5.6 or f/8 on full frame.

Let's say the target MSRP for a new 17-40 zoom is $1200. Can Canon make a zoom that performs significantly better at f/5.6 within this budget when it is a constant f/4 compared to f/2.8? One would think so, but there is really not much evidence that this is true. And if it indeed is true, it's a shame that those slower lenses are not made. A lot of landscape/architecture photographers would rather get a slower WA zoom with better stopped down corners than the faster lens for the same price.
 
you're doing, do you?

Give it a rest already and just sell your stuff and move to another brand so you can b!tch about the new stuff.

Gene
 
mattr said:
rwbaron said:
I've not seen the tests but you're paying for speed and the ability to be reasonably sharp at the fast apertures. This doesn't mean the lens will be any better (or even as good) stopped down than a slower, less expensive alternative. Grinding and polishing large elements is a lot more difficult to hold tolerance than for smaller elements.
Click to expand...
I'm wondering whether there is a "sweet spot" with current design/manufacturing technology for lens speed if all we want is the best possible stopped down performance across the frame, e.g. at f/5.6 or f/8 on full frame.

Let's say the target MSRP for a new 17-40 zoom is $1200. Can Canon make a zoom that performs significantly better at f/5.6 within this budget when it is a constant f/4 compared to f/2.8? One would think so, but there is really not much evidence that this is true. And if it indeed is true, it's a shame that those slower lenses are not made. A lot of landscape/architecture photographers would rather get a slower WA zoom with better stopped down corners than the faster lens for the same price.
Click to expand...
IMO it's the f4 L's. Many times they perform as well or even better than the closest f2.8 version at a much reduced price. For years the 17~40 was considered a better lens overall for FF at less than half the cost of the original 16~35f2.8. The 70~200f4LIS was considerably better than the f2.8 version again at about 2/3rd's of the price. The new f2.8II appears to be an excellent lens that is now on par with the f4LIS for IQ but at twice the price. Even the 24~105 with the exception of wide end distortion compares very well against the 24~70f2.8L but with a greater zoom range and IS.

Bob
--
http://www.pbase.com/rwbaron
 
Sonylover1 said:
...take a look at the Post: Who can pic a L-lens.
The first is 24-105 (returned), the second my 17-85, the 3rd a another 24-105.

As you can see for yourself, and the post from Aperturewise; he thinks 1 and 2 are from the same lens. I thought the same and was perplexed.

Some of the other people are so ignorant, not discussing my simple question.

I think I have proved that there are unacceptable variations in the 24-105 L-lens.
Click to expand...
of course , you are right here , there are many many lenses with QC issues.

and IMO, IQ difference among different lenses is less significant issue than IQ difference among copies or sample variation issue unless you go MF lens route.

this is one of many reasons why I dont buy lens on line any more and I tend to buy a MF prime now.
Sonylover1 said:
--
Mike the Viking
Click to expand...
 
double check the MF?

you cannot MF very well with 24-105 f4 kind of lenses because its MF ring really bad.

this is one of many reasons why you should buy a MF lens for MF work.
Peter 13 said:
Sonylover1 said:
but double checked with MF and Live View. Focused on the wood in the background one every pic.
Click to expand...
The actuall AF sensor is larger that what you see. If you used AF assist, it may get even worse in that particular case. There are foreground elements that are too close to the center.

You can blame the camera, if you wish, but I do not think that the problem are the lenses.
Click to expand...
 
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