Archive 2005 · F2.8 vs. F4? Is it really THAT signifigant?
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
p.5 #1 · F2.8 vs. F4? Is it really THAT signifigant?
I haven't been reading the whole thread abut the AF speed of different Canon lenses.
This is Canon's fastest lenses for the AF speed. And also the fastest in the world (when used on a 1:series body)according to Canon and their EF lens work III book. These lenses has faster AF speed than the zoom both with and without extender.
300/2,8 IS
400/2,8 IS
500/4 IS
600/4 IS
Jul 27, 2005 at 01:51 PM
The Big Bad Offline • • • • [X]
p.5 #2 · F2.8 vs. F4? Is it really THAT signifigant?
But Phil, half this thread has been you, me and that other guy going back and forth with us giving you documented information and your saying that we are not creditible and why should you take chucks word over your own eyes etc
Its not a theoretical figure though, its a specifically programmed feature that is built into the lens/tc/body combo
You kept saying it was 35% remember ?
I simply dont understand how you can think your test is an accurate means to overturn stated documentation. Just think of how many variables there are
subject to camera closing distance
subject contrast
if the lens is near prefocused or if it has to fully travel the focal distance
if you have the focal limiter switch on
which AF point your using
availible light and countless others
No one has ever said the 70-200 isnt a very quick lens. Shooting superbikes I needed to resort to the 70-200 over my 120-300 because it couldnt track the bikes coming at me fast enough. Additionally with the 1.4x TC the 70-200 couldnt either. Under the most demanding situations the TC slows focus to where I couldnt get the shots I needed. The sigma HSM just isnt quite as snappy and probably is also a bit slower due ot all the elements it has to move.
Im not even going to venture to guess by what percentage because I dont have the means to test such a thing. I leave that up to Canon and take their word for the figures.
Alot of times I do however use the 70-200 IS with a 1.4x TC and it works very well. Images are still very sharp, good contrast, and its still a very fast AF. Its one of Canons best lens out there for the money
Id like to hope we can put this matter behind us or at least we'll have to agree to disagree. Maybe you have a TC thats broken and it doesnt slow the AF as much. Im personally going with all the documented sources Ive read over your test.
p.5 #3 · F2.8 vs. F4? Is it really THAT signifigant?
It would be great to have a listing of all Canon lenses ranked by AF performance. I am sure the 70-200IS would be ranked near the top of the zooms and most of the primes.
Insofar as is relevant to this thread, comparing the F/4 to the F/2.8, the IS model is the only one of the three 70-200's with optimized AF.
Jul 27, 2005 at 01:58 PM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
p.5 #4 · F2.8 vs. F4? Is it really THAT signifigant?
Yes I'm sure that zoom is one of the fastest zoom lenses.
p.5 #5 · F2.8 vs. F4? Is it really THAT signifigant?
Lars Johnsson wrote:
I haven't been reading the whole thread abut the AF speed of different Canon lenses.
This is Canon's fastest lenses for the AF speed. And also the fastest in the world (when used on a 1:series body)according to Canon and their EF lens work III book. These lenses has faster AF speed than the zoom both with and without extender.
300/2,8 IS
400/2,8 IS
500/4 IS
600/4 IS
Is there a ranking list of lenses by AF-speed?
Jul 27, 2005 at 02:07 PM
The Big Bad Offline • • • • [X]
p.5 #6 · F2.8 vs. F4? Is it really THAT signifigant?
Its a rather hard thing to list Phil because the different apetures obviously can have a large difference in the overall performance.
My 70-200 2.8 IS seems faster than my 135 f2 for example, but depending on the amount of light, the 135 will lock faster overall
The 70-200 f4 seems a little faster than the 2.8 IS, most likely due to the smaller/lighter elements it needs to move around but then again, depending on the light, it may end up hunting.
Then on top of that, theres the whole issue of if were talking servo tracking speed, time it takes to cover the whole focal distance etc
The 400 5.6 prime I used to own for example had a pretty long minimum focal distance and even if it had to hunt, it would hunt less because it had less range to cover than a lens like the 300 f4 which had a very short minimum focal distance
Additionally, I personally dont find the lens with the new AF drives to be any faster. I think its a measurement on paper but in real world use Ive found it to be too small to notice. Im not saying they arent faster but having owned the 300 2.8 and the new 300 2.8 IS which has the new algorythm, I couldnt tell a bit of difference. Having the additional IS elements in the optical path could negate the advantage right there
but of course thats my opinion and we know how little credibility I have with some members of this forum.....
p.5 #9 · F2.8 vs. F4? Is it really THAT signifigant?
Big Bad said:
Chuck Westfall and now also Lenswork III are both not good enough for you ? How many sources does it take ?
At least I provide direct quotes and links to the quotes when I invoke other people's names and quotes from them. Likewise, others here have provided the actual source documents of their information
How are we to ascertain the context in which Chuck made the remarks that you are attributing to him? There is a reason that hearsay is not admissible as evidence in criminal court.
Big Bad said:
but of course thats my opinion and we know how little credibility I have with some members of this forum.....
You have demonstrated the ulterior motive in this thread to personally attack me. This was made obvious by your infantile name calling and statements of blatant untruths, i.e: That I insinuated that I knew more than Chuck, that I said you did not know anything about AF, and so forth...
So unless I see hard sources, I hope you can understand why I am now inclined to regard everything you say as either an outright untruth or possibly misconstrued, twisted, distorted or otherwise tainted by your obvious personal animus and demonstrated tendency to personally attack me.
I mean what the HELL do you expect?
Jul 27, 2005 at 02:38 PM
The Big Bad Offline • • • • [X]
p.5 #10 · F2.8 vs. F4? Is it really THAT signifigant?
Phil, I started off the whole thread by simply trying to inform you of something that we now both know is documented as fact. Why I you couldnt take my word in the first place was beyond me ?
I say that Chuck Westfall has specifically commented on this matter and you said I was simply throwing out names and titles
Lars Johnson says that Lenswork III has the same information and its accepted by you no problem.
Why would I possibily make up information in this thread ? Am I just going to say its 50% because I made that number up ?
Ive been a working photographer for years, I am the chief photographer and photo editor for a large publication. I do freelance and wire work for countless other sources. I conduct photo classes. I own or have owned basically every EF mount lens thats Canon has produced. I have an upcoming photo exhibit in one of the most respected muesums of american art in the country, and Ive been a contributing member of this forum for many years. I recieve countless emails and messages each and every day seeking my advice and opinions. I have conducted probably 30 business transactions with forum members all of which have resulted in nothing but positive feedback.
Im not saying any of this to brag, but to show that I am in fact a knowledgeable photographer and members can rely on what I say as correct and accurate.
p.5 #11 · F2.8 vs. F4? Is it really THAT signifigant?
This is getting like, as the Thais say, "paddling a boat around in circles in a water tub," (Phai rua nai ang). Going no where fast.
The documents say one thing, and my 70-200 IS apparently outperforms the numbers in the docs.
What do you want me to do, untruthfully state my 70-200IS performs according to the numbers in the docs?
Guess what, with the 1.4TC the 70-200IS AF even out-performs the 135L with the 1.4 TC attached, which w/1.4xTC, tends to hunt more than the 70-2000IS with the TC!
Now what does old Chuck baby have to say about that?!!!
p.5 #13 · F2.8 vs. F4? Is it really THAT signifigant?
And don't forget the 1.4xTC! Despite what the expert naysayers here say (who haven't even tested it), it works just fine with the 70-200 f/2.8 IS - some decline in AF performance but still very usable, as my handheld photos, above, show. With a 1.6x crop it feels about like shooting a 400mm.
In fact, my tests show that the image quality using the 1.4xTC is better than the resulting image quality of shooting a subject w/o the 1.4xTC, then resampling/resizing up to get the same size image as with the 1.4xTC.
Jul 27, 2005 at 08:07 PM
The Big Bad Offline • • • • [X]
p.5 #14 · F2.8 vs. F4? Is it really THAT signifigant?
Who says I havent tested it ? Ive used the 70-200 2.8 IS since it was introduced. Who says its not useable ?
Only thing Ive ever said all along was the exact information I firsthand read Chuck Westfall comment on, and which was thusly backed up by the Lenswork III book.
How many times over did you repeat your test ? If I have a child run towards me I can be assured to get the same results ?
Simply explain how you have the super human ability to measure something that takes place in hundredths of a second with no timing devices.
The difference between 1/3rd as you say, the1/2 which all other sources indicate is probably the difference of several miliseconds you do realize ?
Are you really able to tell the difference at that level ? I dont know of any humans who can.
