Damn it, soft sigma 120-300 f/2.8

lensview wrote in post #2009886

That's a dark side of photo gear forums....the peer pressure, the advice which usually propels credit cards into k-dollars balances in an absolute nonchalant manner as if there is no tomorrow.

What I do with the 20D servo AF.......I look for steady focus maintenance first (by eyeballing the target and verifying it is locked on), then I start firing. The key is to have that center AF sensor on the contrasty/desired part of the target as steady as possible...again, STEADY is the word ! Before I came up with that little startegy I was concentrating too much on capture and firing first at the expense of attaining/maintaining/​verifying the focus....all too often the focus was either not attained or it fell out in the process.
I like to describe the 20D servo AF as "wobbly"....relatively slow to attain and then one loses it easily.

Let me try to illustrate the above with a mistake I have made today (again).....came accross a resting hawker, so I stated firing hastily before even checking if I could get more DoF or verifying focus ....just driven by fear that I might lose the bug any moment (one shot AF on 20D, 70-200 f/4)...as a result, I got six OoF shots as opposed to geting one or two which would be properly focused, with sufficient DoF.

i've been in involved in a lot of hobbies and they are all the same. you can really see the process with some guys and then disillusionment afterwards.

and then they disappear or moderate and stick around .

that's a nice picture of a dragonfly. very nice.

the targets i have the hardest time with are moving so fast that you lock onto anything you can...if you can .

ed rader

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ed rader wrote in post #2010861
i've been in involved in a lot of hobbies and they are all the same. you can really see the process with some guys and then disillusionment afterwards.

and then they disappear or moderate and stick around .

that's a nice picture of a dragonfly. very nice.

the targets i have the hardest time with are moving so fast that you lock onto anything you can...if you can .

ed rader

Ed, that dog seems in focus (see it on the tag) and the capture is good. From the standpoint of Servo AF lock and maintenance, I'd say black n' white target colouring like that on your photo is probably as good as it gets. However, in this particular case your challenge might have been in the exposure, particularly so given the very light background.

windoze wrote in post #2008274
... so in real terms, im tracking the player(s) while my thumb is continually pressed against that * button and then at the time i want to shoot, i assume i still have to half way press the shutter - wait and fully press??

No half-pressing required. Just fire away when you see what you want to shoot. Another nice about the back button which hasn't been brought up is that if another player or referee starts to run in front, you just let off your thumb so to avoid the focus jumping onto the wrong person.

lensview wrote in post #2009267
Edward, the only way to shoot RBR properly is to have the 1D/1DMkII/1DMkIIN in Servo AF mode.
The 20/30D Servo AF can not handle RBR.
I do not know for sure, but I doubt it the 5D could either.

This statement is just not true.

lensview wrote in post #2009267
Edward, the only way to shoot RBR properly is to have the 1D/1DMkII/1DMkIIN in Servo AF mode.
The 20/30D Servo AF can not handle RBR.
I do not know for sure, but I doubt it the 5D could either.

Where can we read a comparison of both systems performance. Canon does not divulgate such specification. I have problems to shoot soccer player in AI-Servo mode, I always end up with back focusing with almost no keepers.

JTL

My Sigma 120-300 has been on my camera about 90% of the time this year.. The reasons for this, is because I just can't get enough of it. I just think it's so good, and don't see anything wrong with the shots shown.

http://wazza.nfscity.c​om/temp/07.jpg - a full res shot

And with AI servo, posted some shots recently :
http://wazza.nfscity.c​om/gannets/
http://wazza.nfscity.c​om/sports.htm - most the recent motorsport is taken with AI Servo also, and focus rarely misses, and the lens is always sharp.

JohnTheLuck wrote in post #2011442
I have problems to shoot soccer player in AI-Servo mode, I always end up with back focusing with almost no keepers.

Sounds like you are not holding your camera on your subject properly. Soccer is a fairly easy sport to shoot to get a high percentage of keepers.

For a real challenge, try volleyball.

JohnTheLuck wrote in post #2011442
Where can we read a comparison of both systems performance. Canon does not divulgate such specification. I have problems to shoot soccer player in AI-Servo mode, I always end up with back focusing with almost no keepers.

JTL

I do not know of one. The closest thing I am aware of is Canon's "white paper" on getting most out of 1 Series cameras. There has also been some sort of a compilation of Canon SLR AF function kicking around the net...I do not have the links handy, if you Google a bit you might find them.

There are also testimonies of a large body of professional and hobby photographers who shoot fast action...be that sports or birds in flight and similar...they shoot with MkII(N)'s not only for high FPS but Servo AF competence as well. Because......having 8.0 FPS much of which is OoF tends to be income/satisfaction limiting.

Naturally, there are people who make do with the 300D ( ), 350XT or 20/30D Servo AF performance.....that's not illegal yet, is it ?

Knowing your camera's limitations and working within them is part of photography. My chosen subject moves quicker than a sportsman/woman and is smaller. Yet I still get keepers with my 20D and 120-300mm. I feel no need for a 1 series to improve my shots as used correctly the 20D AF is more than capable (THat's not to say I wouldnt like one... ).
However the 20D AF is much less forgiving of errors - as has been said previously keeping the AF point in the right place is of paramount importance. The 1 series have more high accuracy AF points and more points as such that will make the system mor reliable.

THe two images below were with the 20D - 120-300mm combo in AI servo. The importance of giving the combo a little time to track is very high, and it is hard to do when using centre point only - it took me a few weeks of practise to get up to a level with the lens I am happy with

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lensview wrote in post #2011305
Ed, that dog seems in focus (see it on the tag) and the capture is good. From the standpoint of Servo AF lock and maintenance, I'd say black n' white target colouring like that on your photo is probably as good as it gets. However, in this particular case your challenge might have been in the exposure, particularly so given the very light background.

that was a keeper. the other 10 weren't. it wasn't till the dog was passing me that i could hold a bead on him.

the white sand and overcast makes it very difficult especially with black dogs but i take so many pictures that i always get keepers.

getting back to my original point....AI servo hasn't drastically improved my keeper ratio but i'll keep trying!

ed rader

Gatorboy wrote in post #2011426
This statement is just not true.

i think he was kidding ... my clue was he called me edward .

ed rader

I thought he just forgot the smiley face at the end myself

Wazza wrote in post #2011447
My Sigma 120-300 has been on my camera about 90% of the time this year.. The reasons for this, is because I just can't get enough of it.

Likewise.

I've used mine enough to know that any poor results are down to the dodgy bloke holding the camera...me

I have the EX HSM 100-300mm f4 model.
At first I had problems focusing which really pissed me off however after some practice, I cured the problem by improving my skills

I used it for a 24hr race event and now I just can't wait for the next motorsport day.

RichardtheSane wrote in post #2011685
Knowing your camera's limitations and working within them is part of photography. My chosen subject moves quicker than a sportsman/woman and is smaller. Yet I still get keepers with my 20D and 120-300mm. I feel no need for a 1 series to improve my shots as used correctly the 20D AF is more than capable (THat's not to say I wouldnt like one... ).
However the 20D AF is much less forgiving of errors - as has been said previously keeping the AF point in the right place is of paramount importance. The 1 series have more high accuracy AF points and more points as such that will make the system mor reliable.

THe two images below were with the 20D - 120-300mm combo in AI servo. The importance of giving the combo a little time to track is very high, and it is hard to do when using centre point only - it took me a few weeks of practise to get up to a level with the lens I am happy with

What are the settings on these shots? The Dof seems to be large, so I guess f/8 or f/10.

I practiced a lot with soccer shots, and I pretty sure my technique is not that bad (I shoot all 15 games this summer, with 100 shots average each game!). Most of my shots present back focusing problems, looking at the grass beneath the player. It could be Ai-servo speed limitation of the 20D (which I doubt by looking at your dog shots) or a problem with the AF system on my 20D or my Sigmas (one 120-300 EX and the other 120-300 EX DG).

I tried both of them with a 300D and I got more in-focus shots, but I confirm the AI-Servo speed is a lot slower than on the 20D. Both lens showed correct focus.

When shooting at f/8 or f/10, since the Dof if larger, the back focusing problem have a lot less significance.

JTL