Oh dear 24-70mmL!

[Georgey]

Hi all, I have been pondering over my purchase of this lens for ages and finally decided to go for it, now this lens costs 1,750Euro here in Dublin so when a friend of mine ( also a photographer ) asked me did I want anything in B&H while he was buying a 100-400L I of course said yes, now I had read all the threads regarding focus issues with this lens and this did concern me but as we all know the internet blows a lot of things out of proportions so I thought yes I will go for it. Now my friend was under orders to use this lens while he was there and to check the results and act accordingly i.e bring it straight back if there were any concerns. This is where the problem starts, he did try the lens, he used it for several days and rightly said no this is not the best, so off he goes back to B&H where he raised his concerns. He got no joy the member of staff that he spoke looked at the lens tried it and said NO PROBLEM AT ALL WITH THIS, THESE LENS NEVER COME BACK THEY ARE AS GOOD AS YOU CANT GET and looked at my friend as if he were mad.
I will post you some pics now, I'm not the best at postong pics so please understand, I only converted these from Raw default in CS2, I used a tripod MLU and a release cable so as to minimise any user error.
I'm really looking for you thoughts on this, also do any of you know a member of staff at B&H who I should speak to and will listen this time?
Thanks Philip
The first two shots are 1. Focus at 70mm shot at 70mm at f8
2. Focus at 24mm shot at 70mm at f8

[Ronald S. Jr.]

those links are e-mail links. Might wanna fix 'em.

[Skrim17]

your links make me send email...

[Georgey]

here are the shots

[Georgey]

Two more I hope the exif data is still there?
These two are 1. Focus at 70mm shot at 70mm@2.8
and 2. Focus at 24mm shot at 70mm@2.8

[Ronald S. Jr.]

1 is fine, 2 is your fault.

[Georgey]

Hope this is correct now?
Thanks for looking and all suggestions are welcome
Philip

[Skrim17]

These are both shot at f/8 according to the exif.

Honestly if he felt there was an issue he should have asked for a new lens, not discussed the problem. I bought a 17-55 IS from B&H and found it soft, I took it back and asked for another, they didn't even bat an eyelash. They have a whole separate entrance specifically for returns and exchanges.

[Georgey]

Ronald S.Jr. how do you come to that conclusion?

[Ronald S. Jr.]

because at the small size you posted, assuming these aren't crops, the first one looks just fine. In fact, very good for 2.8. (they look like they were stopped down, though)

The second, well, nothing is anywhere near in focus. Never seen something like that. Some people have had lenses that focus well at one end, and are soft at the other, but this is not the case.

Yours is as it should be at 70mm, and absolutely and completely blurred and out of focus at 24mm? I don't buy that.

[Georgey]

The focus is on the center post on the knot.
Philip

[Ronald S. Jr.]

I assume this isn't the case, but were you too close to focus at 24mm? That, or some other user error, is the only possible solution I can think of.

[Georgey]

The first two are at F8 so you are right they are stoped down, now the second shot is why I have posted, you think there is user error? well there is not any user error, center focus point, MLU, tripod, high shutter speed, cable release what else can I do???? Oh ye and its a 1D MKII, and my frind has tried as I have already said on his 30D
Philp

[Georgey]

No I was approx 1.5m from the post, when I focus at 70mm I get a good reading on the distance scale, when I focus at 24mm it shoots past infinity, this does improve at longer focus distances but its still dreadfull

[Ronald S. Jr.]

so you're saying it was in focus in the viewfinder when you took that second one, but there was absolutely nothing in any type of recognizeable focus when you reviewed the shot? Have you tried to manual focus just to see if it would work?

Never heard of such a thing. Gonna be hard to exchange it now that you're in Dublin, though, eh?

[Georgey]

it is as obvious in the view finder as the pics I just posted, of course when you focus at distance at 24mm you cant see it that well but pulling it in to 70mm and its mush!
I'm very disapointed with the service my friend got at B&H, the staff member took it from him and "tested" it and said no problems.

[Ronald S. Jr.]

Well your friend tried it too, so it's not the camera body, right?

Anyway, as to the manual focus?

[Georgey]

Manual focus is fine of course, so the lens can function well its not broken as such, it just has what can only be discribed as major back focusing issues.
Go Canon!!!!

[Tyreman]

plunk it on 'pod.
with shutter release cable.
see what it does.

[Kennymc]

here are the shots

Both these images look a little soft... The bottom one has focused on the wall for some reason, maybe too close to the knot to get a lock or it chose a different AF point...

[Kennymc]

Two more I hope the exif data is still there?
These two are 1. Focus at 70mm shot at 70mm@2.8
and 2. Focus at 24mm shot at 70mm@2.8

The focus is better on the top one, but it looks like the second one hasn't been able to achieve focus...

[Kennymc]

And here was I thinking of upgrading my 28-75 Tammy for one of those... LOL

[Georgey]

Tyreman, did you read through this thread???

[Ronald S. Jr.]

Manual focus is fine of course, so the lens can function well its not broken as such, it just has what can only be discribed as major back focusing issues.
Go Canon!!!!

I've said it before, and here I go again...14 copies of this lens I've used, and all were just peachy. Go figure.

[Georgey]

Kennymc, I didnt miss the focus point it was bang on with the confirm beep and all that the camera was on a tripod so if it focused correctly at 70mm it should focus right at 24mm. Thanks Philip

[Steve Parr]

I can only say that my 24-70mm f/2.8L is sharp as a straight razor.

I wouldn't hesitate to buy it again if I had to...

[Georgey]

Ronald 14 copies wow, I had a Sigma EX and just loved the focal range but hated the non HSM focus on it so I splashed out on the L for,, and this is funny "improved focus"
ye gotta laugh dont ye??

[Georgey]

Steve are you tryin to upset me??

[Ronald S. Jr.]

Maybe you could try just sending it to your "local" canon center for calibration. Chances are, it'd come back better than any copy would be new. It'll be free, too.

[Kennymc]

ye gotta laugh dont ye??

Nothings 1,750Euro funny... ;)

[Georgey]

Ronald I plan on tryin this tomorrow, I however dont think it will be free, I could be wrong but I think the warrenty is only a US one, the lens is a US one not a grey import.
Does anyone know any manager types in B&H I could email? maybe a name I could ask for?

[Georgey]

Your dead right there Kennymc!!!

[Ronald S. Jr.]

I can't imagine why on earth your friend wouldn't get you a grey copy. Why'd he buy you a US warrantied lens? :confused:

[Georgey]

I know, I should have said this to him but I did'nt think of it and did'nt to be honest realise that a grey would have international cover.

[ofdphoto]

Actually I think the US versions have international warranties. The grey versions need to go through B&H for warranty claims. At least that has been my understanding when buying from B&H as an Australian ...

[aIpha]

so off he goes back to B&H where he raised his concerns. He got no joy the member of staff that he spoke looked at the lens tried it and said NO PROBLEM AT ALL WITH THIS, THESE LENS NEVER COME BACK THEY ARE AS GOOD AS YOU CANT GET and looked at my friend as if he were mad.

So this is where I think the story is a bit fuzzy... you're telling me that whoever was assisting your friend with this issue in the B&H Returns and Exchanges department tested the lens themselves and said there were no issues? Did your friend come to the same conclusion at this point and was satisfied or he came out of the store still thinking it was a bad copy?

I think a lot of people are skeptical in this thread because two surprisingly unusual things happened in your story: 1) B&H refused(?) to exchange a lens after your friend went there to get it exchanged and 2) the 24-70mm f/2.8L lens is THAT soft.

If both of these things happened to me, I would be mad too but I would be setting up a tent inside the B&H store until I got to talk to a manager and showed them the issue.

Good luck.

[Georgey]

Thanks Iinarms maybe some light at the end of the tunel, I could swollow a centain price for calibration as I have saved sooooo much on the purchace price but why should I this is a top flight lens its too much lens for me really but having said that it should be perfect.
Thanks for all your help all, I wont be back to the computer for the rest of the day now.
Thanks Philip

[Georgey]

before I go, Alpha this is exactly what happened, the member of staff ( not sure in the exchange depot ) made him feel like an idiot, looked at him as if to say are you mad?
He got put off completley by this, I would'nt have I would have camped out side!
The lens is not soft as such it just wont focus correctly at 24mm, if I focus munually at a subject 2m from me the distance scale says 2m, if I auto Focus the same subject the distance scale says infinity or even past infinity (on the scale)
Philip

[Ronald S. Jr.]

Just one more idea...do you suppose there's any chance you may have focused on the light portion beneath the knot, and the lens couldn't find contrast?

I don't suppose that's it, as you said you tried other tests where it was slightly better but still bad.

[Tyreman]

Tyreman, did you read through this thread???
No not every bit.
I just thought(I shouldn't have) that trying the lens on a stable platform just to see(for interest sake) what it does thats all.
Sorry about that.:cry:

[malla1962]

What hapens when you focus at 24 and shoot at 24?:confused:

[rammy]

.. and 2. Focus at 24mm shot at 70mm@2.8

I take that as you had the lens ar 24mm, half pressed to focus, heard the beep, then zoomed into 70mm and then took the shot.

Is that right?

When I try that with my 24-105, focus at 24mm by half-press, zoom into 105mm, still half-pressing, then shoot at 105mm the images are out of focus as you are.

I don't think you can do this technique with zoom lenses.

[Steve Parr]

Steve are you tryin to upset me??

Huh??

[Ronald S. Jr.]

Oh boy...I didn't even make sense of that "focused at 24mm shot at 70 2.8" part. That could account for a whole lot of it.

[ofdphoto]

Focussing at 70mm and shooting at 24mm should work with most L zooms ... from memory they are parfocal. Focussing at 24mm and shooting at 70mm is asking for trouble though.

[Col_M]

I take that as you had the lens ar 24mm, half pressed to focus, heard the beep, then zoomed into 70mm and then took the shot.

Is that right?

When I try that with my 24-105, focus at 24mm by half-press, zoom into 105mm, still half-pressing, then shoot at 105mm the images are out of focus as you are.

I don't think you can do this technique with zoom lenses.
You're right, you can't focus at one focal length move to another focal length and expect anything to be in focus, you need to refocus every time you change focal length.
If that's what the OP is saying then that seems to be his problem and there's nothing wrong with the lens :)

[ed rader]

Focussing at 70mm and shooting at 24mm should work with most L zooms ... from memory they are parfocal. Focussing at 24mm and shooting at 70mm is asking for trouble though.


say that it will work.

what's the reason for focussing this way? i've heard people talking about this method before but i just can't see why you would do it.

what am i missing here?

ed rader

[Tom W]

say that it will work.

what's the reason for focussing this way? i've heard people talking about this method before but i just can't see why you would do it.

what am i missing here?

ed rader


I think that method might be useful with manual focusing, particularly if you have a rather poor viewfinder.

Also, it may be desireable to zoom in to focus and then zoom back out if the object you want in focus is so small in the scene (or of low contrast compared to its surroundings) that the AF sensor might be attracted to something else.

That said, not all lenses are parfocal. Not sure of all "L" zooms either - some are, I'm sure.

[ed rader]

I think that method might be useful with manual focusing, particularly if you have a rather poor viewfinder.

Also, it may be desireable to zoom in to focus and then zoom back out if the object you want in focus is so small in the scene (or of low contrast compared to its surroundings) that the AF sensor might be attracted to something else.

That said, not all lenses are parfocal. Not sure of all "L" zooms either - some are, I'm sure.


sounds likes something i would never want to do and that's probably why i've never done it. if something is so small in a scene exact focus just isn't that critical or focussing in this manner could cause more problems then it solves.

thank you for the explanation. i'm still confused by why the OP is focussing in this manner.

ed rader

[Tom W]

sounds likes something i would never want to do and that's probably why i've never done it. if something is so small in a scene exact focus just isn't that critical or focussing in this manner could cause more problems then it solves.

thank you for the explanation. i'm still confused by why the OP is focussing in this manner.

ed rader

I don't recall doing it either, though I may have a long time ago with the FT. At any rate, the method would be reserved for special situations in my opinion. I'm not sure why the OP chose this method.

[ofdphoto]

http://www.rogercavanagh.com/helpinfo/30_parfocal.stm

As Tom said, this can be useful for shallow DOF shots. Though I only very rarely rely on it ;-)

[TBAATAR]

just tried this focus at subject and zoom technique.

works on 70-200 F/4 L.

focused @ 200mm and shot
http://xs216.xs.to/xs216/07240/IMG_6218.jpg

focused @ 70mm, while holding the shutter button zoomed in and shot at 200mm
http://xs216.xs.to/xs216/07240/IMG_6219.jpg

The OP does have a point. But even if you can't return it, I don't think it will affect you 99% of the time.

ps: It took me 1 whole apple to understand what the OP was trying to tell us. LOL

[Tom W]

It took 1 apple to demonstrate a parfocal lens - not all lenses maintain equal focus across the zoom range. That is to say, there may need to be focus adjustment when the focal length is adjusted.

[ed rader]

It took 1 apple to demonstrate a parfocal lens - not all lenses maintain equal focus across the zoom range. That is to say, there may need to be focus adjustment when the focal length is adjusted.

i'd much rather trust the camera to focus properly than to use this method.

ed rader

[Tom W]

On page E-6 of the 24-70 manual -

"Be sure to finish zooming before focusing. Changing the zoom ring after focusing can affect the focus."

Does not sound like a parfocal lens to me.

[rammy]

Still need OP to confirm this is the technique they have been using, which isn't possible on some lenses.....

[Jon]

What hapens when you focus at 24 and shoot at 24?:confused:BINGO!!! I just came to this thread and that bit jumped out at me.

I take that as you had the lens ar 24mm, half pressed to focus, heard the beep, then zoomed into 70mm and then took the shot.

Is that right?

When I try that with my 24-105, focus at 24mm by half-press, zoom into 105mm, still half-pressing, then shoot at 105mm the images are out of focus as you are.

I don't think you can do this technique with zoom lenses.Certainly it's not a reliable method of focusing going from wide to tele. AF is accurate to within a percentage of the DoF; I forget exactly what Canon's spec is exactly; and as you zoom in from 24-70 your DoF decreases quite a bit.

[Georgey]

I'm back, reading your posts i'll will take it on board that this is not the best way to focus, I did this to try and show you clearly the problem i'm havin. I'll put it another way, if I focus on a subject 2m from the lens at a fl of 70mm the distance scale says the subject is 2m away, now when I focus on a subject 2m away with the lens at 24mm the distance scale says the subject is at infinity ( or beyond ) how can this be correct??
The subject has not moved nor have I, the lens is back focusing.
Philip
Jon when I focus at 24mm the shots are mush, I have posted pics and although I did zoom to 70mm surely the shots speak volumes, even moving to 70mm would never cause this amount of softness.

[AngryCorgi]

Two more I hope the exif data is still there?
These two are 1. Focus at 70mm shot at 70mm@2.8
and 2. Focus at 24mm shot at 70mm@2.8

The definition on this first one is showing very nicely in the spider's web. Very impressively sharp for f/2.8!!

Surely the second shot looked crappy in the viewfinder.

[Georgey]

AngryCorgi the shot looks just as bad in the viewfinder as here, as I have said the proof of the pudding is the distance scale readings, at 24mm it is wildley off, a 2m distance when focused at 24mm is consistently reading infinity. Now another odd thing is that when I focus at small distances, when the lens goes into the macro range of the distance scale, the photo's are nothing short of razor sharp.
Philip

[malla1962]

say that it will work.

what's the reason for focussing this way? i've heard people talking about this method before but i just can't see why you would do it.

what am i missing here?

ed raderI dont see the point of this focusing technique.:confused:When I use a zoom I just zoom then focus,maybe im doing it wrong:D

[goatee]

I can see that this technique is good if there is little contrast - zoom in (if there's more contrast zoomed in), focus, and then zoom back out to take the shot. To be honest, though, I'd try it on a couple of bodies, and if it aint working, call B&H, buy a Mack (international) warranty for it, and then get it repaired under warranty in your local Canon authorised service centre.

[Tom W]

AngryCorgi the shot looks just as bad in the viewfinder as here, as I have said the proof of the pudding is the distance scale readings, at 24mm it is wildley off, a 2m distance when focused at 24mm is consistently reading infinity. Now another odd thing is that when I focus at small distances, when the lens goes into the macro range of the distance scale, the photo's are nothing short of razor sharp.
Philip

Unfortunately, I've found that the distance scale on many of today's lenses isn't nearly as accurate as those of the past, manual-focus days. Especially when dealing with a zoom that goes from nearly ultra-wide to short telephoto. The scale is too short to be used as a true measure of distance, and serves more as an indicator than a true measure.

The only lenses I have that have very good focus distance scales are the 24 tilt/shift (manual focus lens) and the 85/1.2L which has a longer focus vernier than most AF lenses.

BTW, as I posted earlier, the owner's manual states that you should zoom first and then focus as zooming affects focus. That tells me that there is a difference in focus at a given focus-ring setting as you zoom through the range of the lens.

[Georgey]

Thanks all for your imput, I'll weigh up my options and use the lens for a week or so and look at the results from in the field shots, goatee I think i'll take your advise and get the mack warranty anyways.
Thanks Philip

[goatee]

just check with B&H how quickly you need to buy the warranty - I have a feeling it has to be within 30 days of buying the lens, but it's possible that it's sooner.

[Georgey]

Thanks goatee

[malla1962]

I can see that this technique is good if there is little contrast - zoom in (if there's more contrast zoomed in), focus, and then zoom back out to take the shot. To be honest, though, I'd try it on a couple of bodies, and if it aint working, call B&H, buy a Mack (international) warranty for it, and then get it repaired under warranty in your local Canon authorised service centre.Every usa lens I have had come with international warranty.

[Space]

Thanks all for your imput, I'll weigh up my options and use the lens for a week or so and look at the results from in the field shots, goatee I think i'll take your advise and get the mack warranty anyways.
Thanks Philip
I'd like to see you do that same test using a different subject.

[flipteg]

i can understand focusing while at 70mm, and then zooming out... i can see the usefullness in that... but i do not understand why you would ever want to focus at 24mm and then zoom in to 70mm... it's just seems counter productive...

[peanuthead]

Agree with you completely.

i can understand focusing while at 70mm, and then zooming out... i can see the usefullness in that... but i do not understand why you would ever want to focus at 24mm and then zoom in to 70mm... it's just seems counter productive...

[jra]

Very interesting post...I've never quite seen a problem like this. You're getting the focus confirmation beep while at 24mm but the lens is focused at infinity? Can you post a couple more examples using different subjects shot at 24mm, focusing on a point of rather high contrast?

[segasaturn]

I'd have to assume that it's user error. Post more pics with a more realistic subject, unless you always take pictures of fence posts.

[Georgey]

Here ye go jra, this is a shot of the distance scale with a tape showing the actual distance between lens and the subject, the tape reads 48" at the distance scale approx 45" at the lens and the distance scale as i'm sure you can see reads 3m +, also theres a pic of the sublect, focus was at 24mm and on the top of the candle I used a tripod and got focus confirmation bleep and light.
Segasaturn what would you have me take a shot of? Do you think a focus chart would really do a good job here, maybe a battery, maybe a brick wall some news paper perhaps? What difference does it make????? :evil

[JMHPhotography]

here's an idea... when you want to shoot something at 70mm, focus at 70mm, and when you want to shoot something at 24mm, focus at 24mm. It works for me every time. :P

[goatee]

Certainly looks to be a problem - I'd send the lens and body to Canon to be honest.

[Georgey]

Hey forkball you offer such an amazing insight into your technique its astonishing, congrats, did you figure it out all by yourself ??????????
Tks goatee I am gonna do that straight away and get it sorted.
Philip