Thinking about selling my 17-40 F4L & 70-200 F4L.Please help!

[Kelv2888]

I read here and and other sites that I need 2.8 or faster lenses to take advantage of the advanced AF capabilities of the 20D. I wish I would have known this before I bought the lenses.Im sure these are still awesome lenses and a amatuer like me would probably not notice the difference but it still kinda irks me that Im not experiencing the full capibilities of my 20D. I'd rather have one 16-35 or 28-70 F2.8 L instead of two F4L s.
I feel like its putting regular gas in a premium sports car, know what I mean guys? Arrr....dont know what to do.
If I do decide to sell them where is the best place I can sell them for the best price?
My lenses are all brand spanking new.Bought it less than two months ago,under warrenty,have all boxes papers accesories ect.
KEH is knocking about $200 off even though I stated it was A+ mint.Didnt like there qoute much.
Any suggestions on my situation would be appreciated.

[garyhun]

Kelv

Can you or anyone else explain what this AF issue with the F4 is? I purchased a 20D with 17-40L today and nearly bought the 24-70 so am interested in what this AF thing means. I can return my lens within 30 days and exchange so if I need to I will!

[slin100]

I think you should first decide if the focus performance of your current lenses is not to your satisfaction. Frankly, I don't think you'll see much difference in focus accuracy, the claims notwithstanding. If I were you, I would only upgrade if I felt I needed the extra stop. Don't take a bath on selling the lenses just to eke out a neglible difference.

[tommykjensen]

Hmm I have yet to understand what the "advanced af capabilities" on the 20D actually means in real life.

I have a 24-70 mm f/2.8 and 50 mm f/1.4 and 85 mm f/1.8 but sofar I have not noticed any major difference in autofocus compared to my 70-200 f/4.

So if I were You I would not rush out and sell those lenses unless You need the 2.8 versions because of the extra light.

[Kelv2888]

http://www.photography-on-the.net/forum/showthread.php?t=75259

http://www.fredmiranda.com/forum/topic2/131641

Canon has equipped the 20D with a new 9-point AF module that is rated to work down to a light level of -0.5 EV, which is so low that a proper exposure requires 11 seconds of open shutter at f/2.8 and ISO 100. This is actually better than the 1-series AF, which is rated down to 0 EV.
It will take more shooting experience to draw a valid comparison between the 20D and the 1D Mk2, but using only the center AF point and fast lenses (f/2.8 or faster
http://www.robgalbraith.com/bins/multi_page.asp?cid=7-6458-7153-7161&print=true
With f/2.8 or faster lenses, the 20D's centre AF sensor still uses both sets of vertically-oriented pixel arrays, but switches from the inner horizontally-oriented pixel array pair to the more widely-spaced outer pair. This puts the centre AF sensor into high-precision mode, which Canon claims is 3x more precise than the 20D's normal precision mode. We're not sure what 3x more precise should feel like, but can attest to the fact that with both wide angle and telephoto lenses whose maximum aperture is f/2.8, the speed with which the 20D acquires focus using the centre AF sensor, even in dim light, is considerably quicker than the 10D (and gives the EOS-1D Mark II a run for its money also).

There seems to be a method to Canon's madness here, and we look forward to plumbing the depths of the new AF sensor further in the weeks ahead. Based on only two outings - night soccer games, one of which was on a poorly-lit field - and using the centre AF point only, we're already feeling confident that the 20D won't repeat the AI Servo sins of the 10D and EOS-1Ds. With the 20D, AI Servo feels responsive when acquiring the focus target, and smart about not shifting away to a passing foreground subject too quickly. In the end, we managed a healthy number of in-focus frames at both games, including the all-important first frame in a sequence, with the EF 300mm f/2.8L IS attached.

http://www.photographic.com/productreviews/digitalcameras/1204canon/
The cross-type sensor functions with lenses as slow as f/5.6; its dual-line component requires lenses of f/2.8 and faster. The eight surrounding AF points are single-axis sensors that function with lenses of f/5.6 and faster.

http://www.canon.com/camera-museum/tech/report/200409/report.html
The EOS 20D features a newly developed 9-point AF sensor (see Fig. 2). The center AF point is a high-precision cross-type sensor compatible with f/2.8 large aperture lenses (vertical line-sensitive at f/2.8, horizontal and vertical line-sensitive at f/5.6). The eight other AF points are sensitive to f/5.6(horizontal line-sensitive at top and bottom focusing points, vertical line-sensitive at the other six points), which is standard sensitivity for the EOS series.
The baselength of the center AF point sensor sensitive to f/2.8 is twice as long as f/5.6 compatible sensors
http://www.waltersphotovideo.co.uk/details.php?id=9442A017AA&productname1=Canon%20NEW%20EOS%2020D%20Body
Better Focusing
A new focus sensor and algorithm, and an increase from 7 to 9 point wideAF improves the auto focusing speed and accuracy, particularly evident with off-centre subjects. Auto focus points not only cover a broader area of the frame, they are distributed such that focusing is fast and sharp when the classic 'rule of thirds' or 'golden section' composition technique is employed. The centre focusing point functions as a cross type sensor when using lenses with an f/2.8 or faster aperture.

http://wetpixel.com/forums/lofiversion/index.php/t7873.html
The EOS 20D provides full cross-type performance with maximum apertures as small as f5.6, yet it achieves up to 3 times the standard focusing precision when used with EF lenses featuring maximum apertures larger than or equal to f/2.8.

http://www.digitalreview.ca/cams/CanonEOS20D.shtml
New 9-Point Autofocus System
The sophisticated 9-point autofocus system has a high-precision cross-type sensor in the center position. This new design seen for the first time in the 20D model provides full cross-type performance with maximum apertures as small as f/5.6, yet it achieves up to three times the standard focusing precision when used with EF lenses featuring maximum apertures larger than or equal to f/2.8. A new, convenient Multi-controller provides fast and easy AF point selection.

[tommykjensen]

Thanks for that but thats just a lot of theory.

I just did some quick tests of all my lenses and I really don't see a big difference in speed on the lenses with 2.8, 1.8 or 1.4 compated to my f4 lenses (see link in my signature to see which lenses I have).

But hey its You money, if You want to sell thoses lenses and buy the lenses that cost almost twice as much just because Canon claim this new AF is faster thats obviously You decision but I wouldn't do that.

[BlueTit]

I am hoping that someone will come along and explain this in simple English. I was not aware the 20d had a special centre sutofocus point. Does it only apply when using the centre point only? or All the time. So much to learn ... ...

[Kelv2888]

Isnt it a technical reality that something doesnt electronically "kick-in" until a 2.8 or faster lens is attached? The full time cross type sensor is only activated when a 2.8 is attached allowing all the horizontal and vertical sensors to funtion.

I mean thats only what they say I guess but not only from Canon but from other technical reviews.

[tommykjensen]

Isnt it a technical reality that something doesnt electronically "kick-in" until a 2.8 or faster lens is attached? The full time cross type sensor is only activated when a 2.8 is attached allowing all the horizontal and vertical sensors to funtion.

I mean thats only what they say I guess but not only from Canon but from other technical reviews.

I think the reviewers in most cases have just repeated what Canon have stated.

I suggest You keep the lenses and use them. By using them You will find out if the focusing speed is a real problem for You or if You need the extra light a 2.8 lens givbe You.

But as BlueTit also requests I would like to see a description of this in plain english that explains what this super af is and how it works and why it is faster.

[Andy_T]

Kelv,

I really doubt that you will realize much of this in everyday shooting.
More important is the speed and accuracy of the AF in the lens ... and here the 70-200/4.0 really rocks.

As far as the 17-40/4.0 is concerned, it has such a large DOF at f/4.0 that it really does not make any difference if you use a high precision or a normal precision AF.

However, if you want to spend more money, by all accounts go out and get those other lenses. But your argument that 1 f/2.8 lens is better than 2 f/4.0 lenses is utter bollocks (IMHO).

Best regards,
Andy

[Kelv2888]

Andythaler,
It isnt my argument,just some stuff I've found that bothers me a little.
In plain english, from what I understand,I think the AF funtions in all the pixels is not utilized fully horizontally and vertically until a lens with a wide enough aperature activates them.
Ah who knows? maybe I'll call canon tech and ask them to explain specifically HOW the AF is "better" with a 2.8

[KennyG]

This is one of those cases where you can get buried in opinions, most of which are as a result of unscientific testing. Even the post from FM vs the post from RG disagree, one stating the 20D is better than the 1 series and the other saying it is just giving it a run for its money.

I real life you won't notice the difference, unless, like me you shoot high speed objects, often in poor light. Can I ask you one simple question - does your current setup give you any problems? If not, then you are simply changing because of some technical minutiae that seems important to some people, and unless you earn your living from photography I can't think of a worse reason to throw away money.

[tommykjensen]

Can I ask you one simple question - does your current setup give you any problems? If not, then you are simply changing because of some technical minutiae that seems important to some people, and unless you earn your living from photography I can't think of a worse reason to throw away money.

My thought exactly, You just expressed it better than me. ;)

[mrclark321]

Thanks Kenny...I value your opinion, too easy to get caught up in all this!!

Dan

This is one of those cases where you can get buried in opinions, most of which are as a result of unscientific testing. Even the post from FM vs the post from RG disagree, one stating the 20D is better than the 1 series and the other saying it is just giving it a run for its money.

I real life you won't notice the difference, unless, like me you shoot high speed objects, often in poor light. Can I ask you one simple question - does your current setup give you any problems? If not, then you are simply changing because of some technical minutiae that seems important to some people, and unless you earn your living from photography I can't think of a worse reason to throw away money.

[Leorooster]

I tried my lenses and didn't feel any noticeable differences in speed between 4, 2.8 and 1.4. My take is don't sell your lenses unless you need the extra stops.

[gasrocks]

Kelv2888 - In what situaiton did you have problems SO FAR with the autofocus? Forget the theory. There are many things you can do to improve the results. A faster lens may not be the answer. You say you have not had all this for long - why worry until a problem arises? Technique matters. And, I can remember people taking pix before they invented autofocus. Don't read other people's reviews/opinions without actual experience to weigh against it. There are also times/situations were autofocus will not work - no matter which camera/lens you have.

[Kelv2888]

Well I did use my 70-200 once in a low light indoor situation in which the 20D was hunting alot as if it was confused.
I dont know if the F4 was the cause or not.
I think alot of my shots are not as sharp as I think they could be too,even with a tripod,do you guys think a 2.8 would help?
I do shoot more indoors than outdoors and find it hard to use a safe handholding shutter speed too.In combination with the 'faster AF with the 2.8 theory' is making me wonder whether I should upgrade.
Also,I know that the 20D is not weathered sealed but I also like the fact that the 16-35 2.8 and the 70-200 2.8 are weathered sealed.

[Mike2005]

If you got the money...then go for it. But, if you really don't have the money...then accept their limitations and work with it. Don't go nuts trying to sell them worrying whether you will recoup your investment if the financial issue is that much of a concern. The 17-40 and 70-200 are excellent lenses and a great value compared to the other two that you are thinking about upgrading to. Also, if it's the autofocus thing that is your main reason for upgrading, I would forget about it. There are so many other factors that can effect the sharpness of your image.

[Bob_A]

Isnt it a technical reality that something doesnt electronically "kick-in" until a 2.8 or faster lens is attached? The full time cross type sensor is only activated when a 2.8 is attached allowing all the horizontal and vertical sensors to funtion.

I mean thats only what they say I guess but not only from Canon but from other technical reviews.

The center focus point is always "cross type" for lenses that have a maximum aperature greater than f5.6 (i.e. your f4 lenses). The center focus point (and only the center focus point) becomes a "high precision cross type" for lenses that have a maximum aperature of f2.8 or larger. The high precision cross type sensor is three times more precise than the standard cross-type sensor.

However, I would think that at f4 the depth of field would be more than sufficient enough to make the decrease in precision totally unnoticeable. So, I can't see why anyone would be concerned at all about using one of these very fine f4 L-glass lenses on their 20D. Also, if you use any of the other AF points they work exactly the same for all lenses (no change in precision regardless of the maximum aperature of the lens on the camera).


Regards,

Bob

[Kelv2888]

Thank you all so much for the replys.

You guys have really made me feel better,more content about my equipment.
Im just kinda anal I guess and felt a little disadvantaged a little about the F_stop issue and the AF issue.
Besides pros and people with money comingout their ears, why DO people spend almost twice the amount for a smaller aperature?
Is the extra cost worth it for the UD elements,weather resistant capabilities,better bokeh,extra weight hehe,and most importantly,does it really increase your chances of getting better/more shots in the long run?
Two BMW 3 series or one M5?

[Kelv2888]

This is kinda off topic but can you guys help a newb here and share what else can I do to improve image sharpness besides a tripod,mirror lockup,aperature,ISO?
FYI I just enrolled in the New york institute of photography school!:lol: :lol: :lol:
Willlet you guys know how it is.

[BigRed450]

Kelv Be "VERY" content with what you have. There are many people out there drooling over those two lense. Since you are a newb it will be quite some time before you will realise the true need these 2.8 lenses and by then you will know yourself whether you need them or not. Skill should be #1 on your list. NYIP will teach you how and then you must practice, practice, practice.
Just remember it is the skill of the photographer that produces the image, the camera is only a tool as a paintbrush is to a painter.

[Kelv2888]

:lol: Great advice man! Thanks alot for all the advice you guys have given me!

[Kelv2888]

bigred450,
Did you take all those photos at your site?
AWESOME man!

[Marvinspu36]

I've found that most of my focus problems in low light are due to not placing the sensor over an area of the subject that has sufficient contrast. For instance, skin, clothing that is of one color, etc. This is just one of the many factors that can affect focus. Some things that might help improve focus:

Use a single focus point only (don't let the camera choose for you), and focus on an area that has good contrast. Try to find something with a distinct transition from light to dark. I typically will use the center focus point or the top one, depending on how the subject fills the frame. I try to put the transition from light to dark in the middle of the active sensor. If you find autofocus is hunting, try to find a different spot on the subject with more contrast.

Set the AF mode to AI Servo. In real low light, this may hunt too much, but in general, I've found I get more keepers using AI Servo.

Use a tripod (turn of image stabalization if using a tripod)

Use a remote shutter release

Use the highest shutter speed possible

Don't be afraid to use ISO's of 400, 800, or even 1600 to increase your shutter speed. It's better to have a slightly noisy image, which can be cleaned up with NeatImage, or someother noise removal program, than to have an out of focus image.

I don't remember the exact rule of thumb that some have mentioned here, but I try to keep my shutter speed at least twice the focal length of the lens. Three times if I can.

The best thing to do is take lots of pictures, varying your technique one thing at a time, and see how it affects the results. For example, try taking a picture of a person in low light, with the active sensor on their skin. Then try the same shot with the sensor on their eye. Try it on their hair, etc. Try increasing the shutter speed to see if that helps. The possiblities are nearly endless. Since it doesn't cost any more to take hundreds of pictures than one, shoot, shoot, shoot!

Have fun. Those are great lenses you have. I would love to have the 17-40 F4 L.

[Kelv2888]

Thanks for the great response.
Do you use TV mode more often and if so has that helped you get more sharp pictures?
I have found that even when I use AP mode and set a fairly small aperature like F8-F11,only the nose or one cheek of my kids are razor sharp.The rest is just ok.The pic doesnt really 'pop' IMO.
Why is that?
P.S
Ill sell you my 17-40 F4L for $1300 then ok?
:eek: :eek: :eek: JK!

[Bob_A]

Thank you all so much for the replys.

Besides pros and people with money comingout their ears, why DO people spend almost twice the amount for a smaller aperature?
Is the extra cost worth it for the UD elements,weather resistant capabilities,better bokeh,extra weight hehe,and most importantly,does it really increase your chances of getting better/more shots in the long run?
Two BMW 3 series or one M5?

For me, having a lens with a smaller aperature has the following advantages:

1. Less depth of field when I want one part of my photograph to really stand out
2. The ability to shoot in low light situations without having to use flash

Canon L-glass lenses are typically a higher quality build (if that matters to you) and have optics that are at or near the top of their class. Their are no doubt some less expensive lenses than "L's" that also have great optics, you just have to read the MTF charts, ask questions and look at the results some others are getting.

Bob

[Kelv2888]

So the quality of the glass in a F4L and a F2.8L is the same?

[DocFrankenstein]

So the quality of the glass in a F4L and a F2.8L is the same?
f/4 is slightly sharper

[Bob_A]

Thanks for the great response.
I have found that even when I use AP mode and set a fairly small aperature like F8-F11,only the nose or one cheek of my kids are razor sharp.The rest is just ok.The pic doesnt really 'pop' IMO.
Why is that!

If what you are focusing on is razor sharp and part is out of focus, it should be due to those parts of the image being outside of the depth of field. At f8 to f11 I would have expected a pretty large DOF for your 17-40 though. Anyway, you might want to try the following calculator (great to bookmark):

http://www.dofmaster.com/dofjs.html

DOF depends on the camera sensor size (format), focal length, f-stop and distance away from the subject.


Bob

[mvonditter]

Well I did use my 70-200 once in a low light indoor situation in which the 20D was hunting alot as if it was confused.
I dont know if the F4 was the cause or not.
I think alot of my shots are not as sharp as I think they could be too,even with a tripod,do you guys think a 2.8 would help?
I do shoot more indoors than outdoors and find it hard to use a safe handholding shutter speed too.In combination with the 'faster AF with the 2.8 theory' is making me wonder whether I should upgrade.
Also,I know that the 20D is not weathered sealed but I also like the fact that the 16-35 2.8 and the 70-200 2.8 are weathered sealed.

Sounds to me like you have no real problem, rather you are looking for us to justify you buying new glass. It's your money, have at. No one here is going to take the hit if you don't get what you want after spending the money.:D

[Marvinspu36]

Thanks for the great response.
Do you use TV mode more often and if so has that helped you get more sharp pictures?
I have found that even when I use AP mode and set a fairly small aperature like F8-F11,only the nose or one cheek of my kids are razor sharp.The rest is just ok.The pic doesnt really 'pop' IMO.
Why is that?
P.S
Ill sell you my 17-40 F4L for $1300 then ok?
:eek: :eek: :eek: JK!

$1300, such a deal! I'll take two at that price :)

It varies. If I'm shooting fast moving objects, then I might be more prone to using TV mode to guarantee that I don't get motion blur. If I'm more concerned with DOF then I will use AV mode and then verify that my shutter speed is appropriate for the shot. Picking the aperature lets me get the depth of field that I want. If I can't get the shutter speed I want with my selected aperature, I will either up the ISO, or if that won't work, I'll sacrifice some DOF and choose a larger aperature.

I'm rather new at this myself, so I'm still learning and experimenting. As time goes on, I'm getting more keepers.

As for only a portion of your image being in focus, I would recommend posting an image along with the EXIF data so that we can see what settings you used. Also knowing the distance to the subject will be very helpful. As you get closure to your subject, the DOF decreases. You might try either increasing your distance from the subject, or use a smaller f-stop and see if that helps.

[Kelv2888]

Little condenscending there huh mvonditter?
Just trying to gain some knowledge to aid in my decision to upgrade thats all.
Im just saying with what I've read after I bought the lens,in hindsight,maybe I shoulda started out with one 2.8L instead of 2 F4Ls for the same money. so I dont have to think about it in the future.Iwasnt really looking for a rally to support a upgrade.

[robertwgross]

Simple. Find your favorite Canon lens rental shop. Rent one for a day. See what you think.

---Bob Gross---

[Kelv2888]

robertwgross,
As always,simple,sweet and to the point.
Thank you.
Gotta look into a rental place in NYC I guess.

[BobbyC]

So the quality of the glass in a F4L and a F2.8L is the same?

I shot a race last month and used the 2.8 for about half the shots and the 4.0 for the other half and I guarantee, no one could tell which was which by looking at the pics. They are both very good lenses.

For me, having a lens with a smaller aperature has the following advantages:

1. Less depth of field when I want one part of my photograph to really stand out
2. The ability to shoot in low light situations without having to use flash


Can I assume that since you said smaller, you really meant a smaller number instead of smaller aperature?

A smaller aperature will give you just the opposite, more depth of field and require more flash power in low light.

[Bob_A]

Can I assume that since you said smaller, you really meant a smaller number instead of smaller aperature?


Yup, smaller f-stop value, larger aperature. Sorry for the confusion.:o

[BigRed450]

bigred450,
Did you take all those photos at your site?
AWESOME man!

Yes I did Kelv...

Thanks..

[mdude85]

In most situations, the photographer (you) is the regular gas, and the 20D is the premium sports car. Learn how to use the other features of your camera. You are worrying too much about 1/1000th of a second difference in autofocus speed (maybe less than that) but you've probably no idea of a lot of neat features from the 20D. Then again, there are very few photographers that know all the capabilities of a professional camera.

[Kelv2888]

You are right mdude,
Im still learning and I know I have plenty to learn.
Just wanna make sure I have the best equip I can afford to start with.