Canon 24-70mm 2.8 L soft/sharp question

[rcdc]

Hello all, new here. Kind of a newbie, been shooting for a couple years. Recently purchased a 24-70L lens, and I kind of feel like it's a little soft. I took a batch of pictures today in AV mode, mostly @ f4, and my shutter speeds vary roughly between 1/125 and 1/160........it's my understanding that this lens should be razor sharp under these settings.....I'm finding them to be a little soft.

other aspects I'm finding ok or acceptable; exposure, color, saturation, etc.

Now I am shooting with a Rebel XSI (450D) and my ISO was high (800) I'm wondering if the high noise level is perhaps what I'm perceiving as softness?? I feel like I can differentiate between a noisy photo and a soft photo.

I am attaching one of the photos with two 100% crops from the center (the necklace), and the bottom of the frame (hands and sleeves, where it appears to get slightly less soft) here are the settings for this photo:

f4
1/160
ISO 800
34mm Focal length

(and no exposure compensation)

is it me or does this seem soft? and should this lens be performing better given these settings? like wise can you see something I am doing to create these results? any advice is greatly appreciated! thank you.

PS: i just inspected the attached images for this thread and the crops are accurate, and do not appear to have been compressed.

[carregwen]

Hi rcdc (it helps to put your first name in your profile as it comes out on posts) and welcome to the forum.

How did you shoot these images in the camera - RAW, or JPEG?

Nearly all images need post-processing sharpening, especially RAW files, as no in-camera sharpening is applied. It might be useful if you could take another RAW shot (unless this one was RAW) and upload it here so we can take a closer look at it. If you shoot in JPEG then upload a JPEG that has come straight out of the camera (no post-processing)

It's hard to answer this just by looking at the supplied images. You can load it to here http://uploading.com/signup/

[rcdc]

Hi Rob, Thank you for getting back to me.

I shot that photo in RAW. there is only minimal post, in fact all that was done was hitting the 'auto' button in adobe Camera RAW. (which only very slightly 'brightened' the image from its original state)

While I can appreciate what your saying about all photos needing post processing, I'm not sure I subscribe to that in terms of sharpness. I also own the nifty fifty, $99 plastic 50mm lens, and I have gotten phenominal sharpness with no post. Surely the "sharpest zoom lens" on the market should be able to perform at comparable levels to the cheapest prime lens, no?

My over all goal here is to figure out if I have a bad copy of the lens. It stands to reason that part of why you get L glass is to get better optical performance, This entire shoot was consistantly soft, and the settings barely changed from shot to shot. At f4 this should have been tack sharp, My shutter speed was fast enough for the focal legnth (even considering crop factor) so hand shake isn't the issue, I'm baffled at the softness.

I agree, lots of variables can be and often need-to-be changed in post, but in obtaining pro level gear, is it foolish of me to have the basic expectation that the sharpness of the photo be there?? if my settings are correct my lens should be able produce sharp images, I've seen f2.8 images from this lens that are crazy sharp, stopped down to f4 should only be an improvement.

Here is the link to the raw file: http://uploading.com/files/cec9mc58/...63%2Bcopy.CR2/

Thank you so much for your efforts, I know there are lots of other things you could be doing, and I appreciate your time.

[Donald]

Robb

Here it is with only sharpening and LCE added in. I use The GIMP so the figures don't equate with Adobe numbers.

I gave it a capture sharpen, put in a bit of Local Contrast Enhancment across-the-board, reduced the size and then put in a final bit of output sharpening.

I can't agree with your assertion that sharpening is not a necessity. I would argue it's an absolute must. I have never processed a RAW file without sharpening being involved. I think most others on here would be the same.

I'm also wondering why you went with an ISO of 800 at 1/160th at f4.

Nothing wrong with the lens so far as I can see.

[rcdc]

Robb

Here it is with only sharpening and LCE added in. I use The GIMP so the figures don't equate with Adobe numbers.

I gave it a capture sharpen, put in a bit of Local Contrast Enhancment across-the-board, reduced the size and then put in a final bit of output sharpening.

I can't agree with your assertion that sharpening is not a necessity. I would argue it's an absolute must. I have never processed a RAW file without sharpening being involved. I think most others on here would be the same.

I'm also wondering why you went with an ISO of 800 at 1/160th at f4.

Nothing wrong with the lens so far as I can see.

Donald, thank you for investigating, Your suggestions are great and produced a very nice result, I will definitely give all that a whirl! To answer your question about the ISO, I normally try to stay at ISO 100 and 200, but I'm a newbie that works full time and has a family, so I'm learning as I go. I choose ISO 800 because while staying in AP mode other ISO's were not producing desired results. Also I didn't want to lose any moments as babies turn on you very quickly. I didn't have a lot of experiment time. I used f4 because ,looking at the LCD screen, results were good, I wanted to blur the background, and was aiming to stay below f8. 1/160th was selected by the camera as I was in AP mode.

Thank you so much for your assistance on this.

[Colin Southern]

Hi Robb,

1. ALL RAW captures require capture sharpening, regardless of lens used, for three reasons ...

(a) Most cameras (inc all Canon cameras) have an anti-aliasing filter over the sensor which is - in essence - a "blur filter". Sounds crazy I know, but without it, one runs the risk of banding when the frequency of some element in the shot approaches the sampling frequency of the sensor.

(b) The demosaicing process introduces a degree of unshaprness when it samples adjacent pixels to determine the correct colour (the point where "X" number of monocromatic samples (red, green, or blue) are turned in to full colour pixels, and

(c) The digitisation process itself introduces a small degree of unsharpness.

For most cameras you'll need an unsharp mask of 0.3 pixels @ 300% and threshold 0 (Canon say threshold 1 for base ISO, but I prefer 0). At higher ISO's you MAY need to increase the threshold to avoid emphasising noise.

2. Be aware of DoF issues. @ 34mm I'm guessing you're probably a couple of meters away from your subjects which at F4 gives you a DoF of around 50cm, which MAY be enough, but depending on where you're focusing, you may be pushing it. Personally, on a crop-factor camera I'd have taken this shot at at least F5.6 if not F8.

3. The reciprocal rule for "avoiding" camera shake is really a rule for minimising camera shake. Although on the face of it 1/160th may seem to give you a good margin, it's still possible to contribute a wee bit of blur at this speed if your hands aren't steady.

4. Keep in mind that the sweet spot for this lens is at least a couple of stops down (I've had one for over 5 years).

So - having said all that (and looked at your RAW file), what do I think is the problem? Short answer is "I'm not sure" - there really is quite a lot of noise for evaluation at that level.

So "jury still out" in my opinion ... but what I'd suggest is setting the camera on a tripod - using a remote release (or the self-timer) - Mirror Lockup if you have it - focus on something specific (at a range of F-Stops) - at ISO 100 - and lets see what you get.

With regards to the 24-70 being Canon's sharpest zoom - perhaps at one time, but it's a pretty old design now (but still a great lens - still one of my favourites) (used it today in fact).



Just to rub it in, this is what the EF85mm F/1.2L USM II can do for a 100% crop

[rcdc]

Hey guys thanks again for your insight into this. First, Donald I tried your suggestions and got similar results, thank you!

Colin, thats a lot to absorb and consider moving forward, and I certainly will. Thank you.

I think after pondering your posts, and going over the shoot several times, I feel my problem is a combination DoF and High noise, certainly user error, and certainly correctable. I feel better knowing that the lens is doing it's job. I think Colin is right about being on the edge of acceptable DoF at those settings. throw in a ton of noise and it's soft photo central.

Thank you all for your insight and expertise. I really appreciate it.

[LeoLeo]

Hi Robb,

I feel I'm in the same situation like you. "Why most of my pictures are not sharp?" I've blamed the camera and objective for this ... for almost 3 months. In fact .. pictures have quite much noise, and because of this, looks unsharp. For me "expose to the right technique" works (as much as I'm able to pu**** to the right without clipping) with very clear pictures, and, as result, very sharp after post procesing.
Take a look here:
https://www.cambridgeincolour.com/tu...techniques.htm

On the other hand, my Canon 40D seems to add bit much noise @ ISO 800. Below 400 it's ok, and quite ok (fair) @ 400.
My son is 9 month old, and I deeply understand your problem . I need an average of 200 pictures for one with a smile. Shooting in middle of the day ("because is warm ...let's take the kid outside"), in parks, forests and so one... you don't have the best light.

Regards,
Leo

[Glenn NK]

Hi Robb,

With regards to the 24-70 being Canon's sharpest zoom - perhaps at one time, but it's a pretty old design now (but still a great lens - still one of my favourites) (used it today in fact).

The Photozone review suggests in their Verdict on this lens that "Canon should think about an update" to this lens. It also points out that one striking weakness is that it exhibits "pronounced field curvature at the wide end".

http://www.photozone.de/canon_eos_ff/528-canon2470f28ff

Glenn

[Donald]

The Photozone review suggests in their Verdict on this lens that "Canon should think about an update" to this lens. It also points out that one striking weakness is that it exhibits "pronounced field curvature at the wide end".

Glenn

But you're being very selective in the text you're choosing to quote. The overall tone of the review, plus those on, e.g. Fred Miranda, The Digital Picture, advise that this lens is still one of the best that's out there.

[Colin Southern]

The Photozone review suggests in their Verdict on this lens that "Canon should think about an update" to this lens.

There are rumours of an IS version ... only problem is they rumours have been floating around for around 3 or more years now

[Hansm]

I have this lens also and can say it's razor sharp.
Lot of issues are going around on the net about softness Back or front focussing etc.
Most things have been mentioned already in this tread and what I want to mention is that the latest bodies have micro adjustment for focussing.
This can "fix" not correct focussing . I did it whit this lens on the 5D MKII and fine-tuning it gave me very good results.
And yes, sharpening in PP, definitely when shooting RAW, is necessary.

[rpcrowe]

Something that I have noticed lately is that my images out of the camera look a tad sharper when I shoot with my 24-70mm f/2.8L than when I shoot with my 17-55mm f/2.8 IS lens.

I have not made a head to head comparison because I use the lenses for different purposes, usually the 24-70L for my studio use and the 17-55mm for walk-around and travel shooting. I have my reasons for liking each of these lenses for their specific purposes but, image quality is not one of the criteria.

I have been doing a lot of shooting of the numerous rescue dogs that I am fostering. I tend to use whichever lens happens to be on the camera that is handy at the moment. The images I shoot using the 17-55mm seem to require a tiny bit more sharpening than those I shoot with my 24-70L. In the long run, it really doesn't make any difference because the final product is identical.

BTW: My 24-70L is an older one that I bought from a professional photographer who was converting to the 24-105mm f/4L IS lens soon after that lens was introduced. I don't seem to remember any derogatory posts or comments about the 24-70L during the period prior to my purchasing that lens and I certainly have absolutely no problems with this great lens except that it is pretty darned heavy. I wonder if there have been some manufacturing glitches at the 24-70L assembly line to cause concerns amongst recent buyers of that lens?

[carregwen]

There is not much in it (Wirefox would have a good Northern term for that) but I think the baby is slightly sharper than the ladies face. Especially the front of the baby jacket, sleeves and his hands. Where was the focus sensor picked up on the shot? Wherever it was, Colin was correct in saying you need to apply normal sharpening to this, and most other shots.

Both of these were taken from the native RAW file without any changes applied. They are 100% views. I tried to edit it but I couldn't do any better than Donald, which is making me rather cross!