Canon EF 24-105mm f/4 L IS USM

On closer look, the thumbnail looks like there might be some areas of better focus. Are there?

nekrosoft13 wrote in post #10372823
here is 100% raw image with AF points visible.
i'm new to SLR, maybe i'm doing something wrong

Which body are you using? When I had the 24-105 on my 50D I had to make C.Fn Micro adjustments. The 24-105 lens was front focusing and I adjusted about 3 clicks to compensate and then it performed much better. Not my screen shot.

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i will post full image later, its about 10mb jpg/30mb cr2

here is the full size image

http://img229.imagesha​ck.us …themortonarbore​tum001.jpg

nekrosoft13 wrote in post #10374516
here is the full size image

http://img229.imagesha​ck.us …themortonarbore​tum001.jpg

Looking at the full size image, I think it is safe to say that there are 2 possibilities:

1. The lens is not focusing properly at all - front or back focusing problems would still reveal wide focus bands in front or back of the target points, and should be very visible at f/4.5.

2. This photo is a victim of camera shake, especially since it is at 1/40 sec.

If you still get this result from a Tripod with timer, or with a shutter speed 1/125 or higher, then option 1 is likely.

Any more examples, with higher shutter speeds?

JH

here is another example, full size again.
shutter 1/197
http://img718.imagesha​ck.us …icagobotanicgar​den116.jpg

Just shot a wedding shooting with the 24-105 as well as a 70-200 but this was one of the best of the day and sure enough it was with the 24-105, I LOVE THIS LENS!!!

nekrosoft13 wrote in post #10375186
here is another example, full size again.
shutter 1/197
http://img718.imagesha​ck.us …icagobotanicgar​den116.jpg

nekrosoft13,

This is better, and I think it does help illustrate that there may have been camera shake on the first shot. Curiously, I used Metadata search in Lightroom to pull up everything I have ever shot with the 24-105L at 105mm and f/4.5. I was searching for an example of a really razor sharp image with similar parameters as yours. Much to my surprise, I found that on closer examination, all of these were softer than I expected as well. Of course I never deleted them, because they still look great at normal viewing sizes, and printed. But I was not satisfied because this lens has always been razor sharp. After further investigation, I have clearly determined that it is soft at wider apertures at full FL. Backing down the focal length, I started seeing the sharpness come back at f/4 - f/5. And when stopped down to f/5.6 it is super sharp across the board.

JH

jhoag, thanks! I will try at smaller apertures

I recently purchased this lens as well as a Canon 5D MK II but have some questions I hope someone here can enlighten me on.
I searched the forum for len's "sweet spot" and most concured that the sweet spot for most len's is around 2 stops down from wide open. Ok..that is easy enough to understand EXCEPT at what TV setting?
I went out on my deck and did some comparison shots using the 2 step down method shooting in AV mode, TV and M. I found that each shot depended on BOTH f stop and shutter speed as well as ISO setting so I set the ISO to AUTO and with that of course you will get more NOISE the higher your ISO.
This has now REALLY got confusing.
I just can't make the mental calculations to figure out on any given light reading and distance to subject how to figure out how to obtain the best image quality for any given lens.
While shooting in Monument Valley Utah in December I was shooting with both my 70-200 and new Canon 85mm f/1.2. I was so disappointed in the clearity of the 85mm compared to the 70-200 I returned it as soon as I returned home. Now I wish that I would have had a understanding of calculating this equation. I look at some of the photos you folks take with the same camera and lens and wonder why mine are not near as clear as you guys.
I think I understand DOF pretty well ie: wider opening more bokeh. But am I missing something here?
I have invested pretty heavily in my equipment to get the best shots possible but will not get the full benefit of my equipment until I can learn the formula for this problem.
I own:
Canon 5D MK II
Canon EF 400mm L f/5.6 USM
Canon EF 70-200 L f/2.8 IS USM
Canon EF 17-40 L f/4.0 USM
Canon EF 24-105 L f/4.0 IS USM

thanx
Donny
PS. Since posting this a couple hours ago I went back out and in AV mode took two photos: 1st with aperture of f/4.0 and the other a f/8.0. Using the 2 step down rule didn't work in this situation. The f/4 was more detailed then the f/8. At f/4 the shutter speed was 1/4 and at f8.0 was 1.0. So it would seem that the shower the shutter speed the less detail and the f stop had little to do with it.

Did you use a good tripod/ballhead for these two shots? If not, your f/8 shot will be likely to show some shake, even from the shutter being pressed and the mirror slapping.

This lens is not bad wide open, although for optimum sharpness, sure, f/5.6 - f/16 is a good range to pretty freely shoot in as long as you use the right techniques for the variety of shutter speeds.

Here are a couple links to peruse:

Here's a sticky that covers some testing to evaluate your camera/lens combo for sharpness:

https://photography-on-the.net/forum/showthre​ad.php?t=857871

Here's one that gives some fundamentals about exposure parameters:

https://photography-on-the.net/forum/showthre​ad.php?t=414088

General tips and tutorials:

https://photography-on-the.net/forum/showthre​ad.php?t=52418

Bear in mind that each setting will have an effect and a potential drawback, so think before you shoot! You mentioned Auto ISO leading to more noise, well, a high ISO is used if you don't have enough light coming in to get a good exposure at a lower ISO. The underexposure (less light through the aperture and shutter) leads to more visible noise, especially in shadows but also in smooth areas like the sky. So the more light you let in the cleaner your image, but when you reach the limits of your shutter and aperture settings that you need for a scene, you raise the ISO to get the proper brightness. I never use Auto ISO because I want to have more control of when and how I use it, but I do use high ISOs plenty because I often shoot in lighting conditions that are not optimal and I'm frequently shooting in conditions where a tripod is not preferred.

You may have heard of the book Understanding Exposure by Bryan Peterson -- it is a pretty quick read that helps you to get a grasp of some of the basics. It was first written for film and so shows some differences from the digital realm, but it's still very good for explaining how the aperture, shutter speed and ISO work together to collect and process light.

You mentioned comparing the 85L to your 70-200 -- not sure how to respond to that without seeing the shots and knowing more detail. The 85 is considered one of the very best primes and the 70-200 is considered one of the very best zooms. The 85L should show some advantage in sharness and overall IQ (and of course a wider aperture which has its own advantages) but the 70-200 in my opinion holds its own quite well and performs better in some ways. I have them both and enjoy them both.

Posted these in Urban Travel section but...

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is that 100% crop or downsized?

Shedd Aquarium in Chicago IL.
Lizard taken through the glass from like 8ft.
24-105L, Servo mode, F4.0 ,105mm

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If these shots were hand held then you will most likely than not there was camera shake. Test in better light where shutter speed is at least 1/100. At f4 and 1/4 and f8 at 1.0 you were shooting in the dark or almost anyway. These are tripod and shutter release territories or at least the timer. Have any photos?

Dlarsen wrote in post #10381642
... At f/4 the shutter speed was 1/4 and at f8.0 was 1.0. So it would seem that the shower the shutter speed the less detail and the f stop had little to do with it.