24-70mm 2.8 not sharp

<p>I own the 24-105mm f 4 lens and use it primarily on the 5D. On two occassions recently, I rented (from Calumet Photographic) the 24-70 2.8 lens to compare it to the 24-105. To say bthe least I was extremely disappointed. Unless they are renting me a bad copy, the 24-105 is much sharper, has IS, and I feel is a much better lens. Has anyone had the same experience as this? Also, I find that the lens being so heavy, and without IS, unless you are really steady (handheld) at slow shutter speeds, a 30th - 50th of a second, the images are just not sharp. Am I nuts, or has anyone else experienced this?</p>

<p>The 24-70 should be marginally sharper than the 24-105 but at the shutter speeds you mentioned, the IS of the latter lens should make the images appear clearer.</p>

<p>You could have a bad lens. Rental lenses are usually abused pretty badly so I always recommend mounting the camera on a tripod and doing a quick test as soon as you get the lens (and definately before you use it on a job). While the 24-70 is heavy, that should actually help keep the lens steady (inertia is on your side here)</p>

<p>You are spoiled with the IS. A heavy lens like the 24-70L requires higher speeds to achieve sharp focus. Having daid that, I own the 24-105! Like you, I would not want to miss the IS.</p>

<p>I suspect that you are getting a bad lens. I used to have the 24-105 F4 but sold it and bought the 24-70 F2.8. I do not regret this as the F2.8 lens is sharper - especially at the edges of a full frame shot. In addition I rarely found that I needed IS (especially now I have the 5DII where high ISO is very good quality) but for DOF and film bodies F2.8 was important. Don't get me wrong, both are very good lenses but the 24-70 is the sharper of the two but as you observe quite a bit more substantial. I find I can hand hold without issues at 1/30 to 1/60 depending on the focal length used but I generally try for slightly faster shutter speeds.</p>

<p>No, the 24-70 should not be sharper than the 24-105. They have different characteristics - different points of strength and weakness, but both are very sharp lenses.</p>

<p>Dan</p>

<p>-- "unless you are really steady (handheld) at slow shutter speeds, a 30th - 50th of a second, the images are just not sharp"</p>

<p>At that speed, one would expect quite a few blurry images due to camera shake.<br>

If you want to compare the two lenses, use a faster speed (and/or put the camera on a tripod).<br>

If your test did compare the two lenses under "real life conditions", you have chosen a too low iso setting, or you should have opened the aperture by one to two stops. (If changing iso or aperture isn't possible, your test simply showed, that the 24-105 4L serves you better in your real life needs).</p>

<p>I have both and find my 24-70 sharper than my 24-105. Off-center textures and fine detail get vague and indistinct with the '105, comparing to the '70. It's not a vast difference though, and unless you're viewing at 100% it's not discernable.<br>

You migh have got a bad/abused copy of the 24-70, or are not holding steady enough. The latter is very likely (at the shutter speeds you mention) since the 24-70 unfortunately does not have IS. It might also have a front/back focus issue. Try shooting a test chart made for this, there's one available at the top of this page:</p>

<p><a href="http://focustestchart.com/chart.html">http://focustestchart.com/chart.html</a></p>

<p>Mike,<br>

Opinions vary about this particular lens, I for one tried it several times and performance was rather poor on 5DMKII, nonetheless some people claim it is sharp so at best there is a lot of sample variation and I recommend you try a 2nd copy and decide for yourself. Sharpness is very subjective, what is razor sharp to some people maybe super soft to some other...Keep in mind that 1/30-1/50 is not fast enough for handholding a rather heavy combo you need to be above 1/100 sec to be safe.</p>

 

<p><em>"...unless you are really steady (handheld) at slow shutter speeds, a 30th - 50th of a second, the images are just not sharp. Am I nuts, or has anyone else experienced this?"</em></p>

<p>Basic newbie user error -- don't blame the lens for lack of technique.</p>

<p>The 24-70 2.8L lens is a top performer. It's "sharper" than the all-in-one 24-105 4L I.S.</p>

<p>Mike... As you probably know:<br>

It takes a lot of practice to shoot a 1/30 of a second at 50mm without IS, but with ASA 400 film we learned to shoot available light at 1/30 at F1.7. With digital it is just too easy to bump the ISO to 800.<br>

The technique that I use is to let out my breath with pursed lips slowly as I slowly press the trigger. I am not aware of when the camera will fire so I do not "jerk" the shutter. I brace my left elbow into my rib cage. Even then results are going to be variable at 1/30. The overall rule of thumb is that most of us cannot hold the camera steady at less than 1/focal length. My best is at 1/30 at 50 mm on an SLR and 1/15 at 50 mm on a Leica rangefinder camera without IS. I have both the 24-70L and 24-105L lenses. I prefer the 24-70 results and the weight and "reach" of the 24-105. I agree that the only way to fairly compare the _optics_ on these two lenses is to shoot on a tripod at identical f stops since one has IS and one does not. The fact that you are getting better results with IS suggest to me that the IS lens is better for your shooting style and may be the better lens for the way you shoot and thus may be the better lens for you.<br>

Jeff</p>

<p>Not sure how long you rented the lens for, but renting for a couple of days would have cost roughly 20% of the cost of a brand new Tamron 28-75 F2.8 lens! This is a fantastic lens at a fraction of the cost of the Canon version, and don't let anyone tell you it is a fraction as good. It is really excellent and very nicely compliments my 24-105 F5 IS. To me they serve entirely different purposes, hence owning both.</p>

<p>G Dan Mitchell - interesting that you found the 24-105 and 24-70 similarly sharp. I am not doubting you for a moment but it is making me wonder if I (and by the sound of it some others) have got a poor example of the 24-105. I found mine fine in the center but ratehr soft at the edges (full frame) especially at F4 to F8. Did you test several examples - I bought mine by mail from Adorama. While I only owned both lenses for a short period the results were fairly compelling.</p>

<p>Thanks to all for the responses. I am convinced that the problem is definitely the use of slow shutter speeds, hand held, with this lens. I have never had this problem with the 24-105mm, probably because it has IS. I'm sure the weight of this lens is the problem. Through the years I have always been able to hand hold medium format cameras at slow shutter speeds ( back in the film days) that were much heavier than the digital SLR'S of today. Perhaps it's the weight of the lens (and my age) that causes this. And as a footnote to Ken, who was kind enough to offer an answer which was... <em><strong>"Basic newbie user error... don't blame the lens for lack of technique"</strong> </em> . I have been in the photography business for 40 years.</p>

<p>I have the 5dII along with the 24-105 among other fast primes. The 24-105 has been a great all-around lens but I find myself reaching for the primes when I can. However, now that I am getting into more of the video part of the 5dII I am finding the IS on the 24-105 very valuable. I wouldn't trade it for a second for the big 24-70 without IS for video. I'm guessing from your post you have the original 5d so this may not apply to you. The 24-105 is a match made in heaven for the 5dII for all around photo/video use.</p>

<p>Jonny, truer words have not been said. Excellent insight and response.</p>

<p>choice of aperture makes a big difference; I avoid shooting the 24-70 at 2.8 or even 3.2 whenever possible. I find the 24-105 sharpest at f8-11, the 24-70 softest at 2.8, and they overlap and are more similar at everything in between.</p>

<p>I've just wasted 5 minutes of my life removing a bunch of childish comments from several poster. They know who they are. If they engage in such public exhibitions of impropriety again in this forum, they will find themselves banned.</p>

<p>Those who find themselves unable to restrain themselves from personal atacks and insults are not welcome here.</p>