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mini696
22-01-2012, 10:36pm
I am trying to test my lens (18-250 Sigma) out using continuous focussing. But it just doesn't seem to have the speed I need to track the subject (RC cars and skateboarders/scooters).

Please could you recommend what I need to be looking for in a lens that could track these kinds of fast moving objects.

Old Skool
23-01-2012, 7:52am
You need a lens with ring USM (Canon case) or in Sigma case I think HSM focusing. Normal Micro motors that drive the focus are too slow to keep up with fast action. A faster lens, ie F 1.8 to F2.8 will also help so you can get the shutter speed up. Also some camera bodies are faster than others at locking and tracking focus.
Do you have your camera focus settings set to single centre point and AI Servo so it can track the action? That will help for a start.

ricktas
23-01-2012, 8:04am
Agree with Russell. You are now seeing the limitations of a 'kit' lens, and the reason why professional sport photographers use 'faster' lenses like the 70-200 f2.8 or bigger. Expect to pay around $1000 minimum for a high quality lens for sport

mini696
23-01-2012, 8:55am
Thanks guys. Part of my problem is the RC's are so small I am having to zoom in (to have the car fill the frame) thus reducing the depth of field and making focus so much more critical. I dont want to have to crop too much if I can avoid it.

The lens I was using is a Sigma 18-250mm f/3.5-6.3 DC OS HSM Lens for Canon. I had it on center focus, but am unsure wether I had it set to AI Servo or not. It is on a 60D body.

Would turning the image stabilisation on or off make a difference?

Getting the shutter speed up isn't really an issue, its mainly focus that I am having trouble with.

LJG
23-01-2012, 9:05am
What camera body you have can also play a part in this as well.

falke
23-01-2012, 9:11am
Maybe "catch in focus" is an option - if your camera has it. Here the camera's focus is set to a certain distance and when the car gets to that point where it is in focus, the shutter releases automatically.

mini696
23-01-2012, 9:40am
I have a Canon 60D.

mini696
23-01-2012, 9:43am
I have a Canon 60D.

I have never heard of "catch in focus" so I will do some research on that.

Old Skool
23-01-2012, 1:00pm
You should be aiming for a shutter speed of at least 1/800, prefer a lot more - up to 1/2000 to catch the action, so at that speed image stabilization is not required. Depending on how the IS works, that could maybe slow the lens down as well.

mini696
23-01-2012, 1:22pm
Thanks Old Skool. I don't look for the IS to do any work during these shoots. I was (as you suggested) wondering if having it turned on would slow the focus down.

Bennymiata
23-01-2012, 2:18pm
A superzoom like your Sigma is not really designed for fast focussing, and you'll need to look at an L lens to do what you want.
The faster the lens, generally means the faster the focussing too as the image is so much brighter for the focussing sensors to work with.
You'll need to set your focussing to AI mode and not the One Shot mode to get follow focussing, but what you can do is to manually pre-focus on a spot, then wait for the car to hit that spot and then click the shutter.

As Ricktas said, you'll need to spend at least $1,000 and more like $2,000 and up, to get a really good, fast focussing lens.

I've also got a 60D, and it's a great camera, but it won't focus as fast as 7D will, as the 7D has a superior focussing system and dual processors so it is the pick of the Canon smaller sensor SLR's for fast focussing without spending lots more for a 1DsMkIII.

Try and put a good, fast L lens on your camera, and you'll be amazed at how quickly they get focus in reasonable light. almost instantly.
Good glass is never wasted, and as you get better and better cameras, the glass will always be good and will work even better with a better camera.
If you get sick of photography, a good lens will hold its re-sale value too, whereas cheaper glass does not hold its value anywhere near as well.

There is a reason why serious sport photographers buy expensive cameras and expensive glass, becaue nothing else will REALLY do the job as well.

Wayne
23-01-2012, 2:21pm
I'll disagree and say IS is essential despite the shutter speed. When shooting such small, fast moving things while zoomed to the max, the field of view is quite small and thus IS or VR will be a big help in stabilising the view through the viewfinder, especially if the camera/lens combo has any weight. The more zoom you use the more IS will help.

I would suggest a 70-200/2.8 IS USM +1.4TC which would still give 280/4 at worst, which should be fast enough for focusing on these things with a good camera technique.

J.davis
24-01-2012, 12:36am
I shoot model aircraft at distance and use a Sigma 70-200 HSM F2.8 and crop to suit - works well and I am shooting at futher distances than RC Cars.
S/H Sigmas go relitivly cheap.

Speedway
24-01-2012, 1:17am
I have the sigma 18-250 on my 7D and find it keeps the focus very well shooting in AI Servo, High & Low speed continuous mode and have sequences up to 16 shots fired in 2 seconds of cars going over jumps coming toward me, I always shoot with OS on, I also do a lot of go kart racing using this lens for slow shutter speed 80-90sec panning and have a good keeper rate, you can check out some of my shots here (http://www.keithgossphotography.com/Gallery%20Motor%20Sport.htm). Fast action motor sports takes a lot of practice so keep at it. Either the 70-200 F2.8 OS Sigma (cheaper) or the 70-200 F2.8L is Canon (the ultimate) would be a step up.
Keith.

mini696
24-01-2012, 9:00am
Thanks guys, I was playing around with the AI Servo mode last night and the focus was keeping up reasonably fast (faster that I can refocus using my finger). So I will try that next race meeting. I was using AI Focus, because thats what I was told (after a google search) to use.


Keith, what it "High and Low speed continuous mode"?

LJG
24-01-2012, 9:14am
mini, if you can get a chance try the Canon 70-200. It has lightning fast AF that'll just about tear your socks off!

mini696
24-01-2012, 9:20am
I will give one a try in-store soon, even rent one for a day.

Then again I could just sell some of my RC's to fund a new lens.

N*A*M
24-01-2012, 9:47am
is it just me or have people have gotten lazy these days. why is the answer is always better and more expensive gear? photographers have been shooting action with gear that is nowhere near as good as the stuff we have today. they had good technique, not gadgets or bigger wallets.

my advice is to work with what you have. firstly, learn everything you can about your camera's AF system. learn it's limitations, and all the configuration (what it does and when to use which).

get closer so you don't have to zoom so much. as you zoom, your maximum apperture gets smaller and the focusing system has less light to work with.

learn your subject and it's motion. predict where it will go and pre-focus in that area. rather than aiming for the RC car, put your AF point down low and find a high contrast surface that the car will pass over. focus on that, and work on timing your shutter release so that the car passes over your pre-focused zone at the right time.

as you get better, learn to work with slower shutter speeds and work in panning technique. you are shooting high speed motion so the images should convey that. super high shutter speed will freeze action, and that creates one look that is easy to achieve in good light. but nothing impresses more than a well panned shot, with a sharp car, and blurry background. good panning technique will separate you from the rest, when the light starts to fade. here i would suggest IS is helpful.

lastly, practice makes perfect.

mini696
24-01-2012, 9:53am
I agree NAM, If I can practice and train myself to get great shots with "lesser" gear, imagine what I will be able to do in a few years when I can afford the good stuff.

Speedway
24-01-2012, 10:09am
Mini the 7D has 2 continuous modes. High 8fps and Low 3 fps. The 60Donly has 1 @ 5.3 fps.
Keith.
Ps I also agree with the comments by Nam.

mini696
24-01-2012, 10:13am
Thanks Keith. I am guessing the difference is slightly more accuracy using the low speed, yet fewer frames compared to the high speed mode.

Speedway
24-01-2012, 10:32am
Mini I don't find much difference in accuracy between the High and Low modes using this lens, the only difference is the number of shots to go through at the end of the day, which at a go kart title meeting can be well over 2000 per day at a 2 day meeting and that is shooting in low speed. Although I have never shot RC cars I have shot helicopters see here. these (http://www.keithgossphotography.com/RC%20Model%20Gallery%2024-12-10%2001.htm) were shot using my 150-500 Sigma which handles AI servo about the same as my 18-250.

Bennymiata
24-01-2012, 4:16pm
Actualy, the 60D does have 2 continous speeds of shutter.
Just in front of the top LCD readout, there is a button (the second one from the left) which controls your delay and continous shooting speeds.
Hit the button, and then use the wheel just behind the shutter button to cycle through the different options.
First option is one shot, then depending on which way to you turn the wheel, either the 10second delay, then 2 second delay and and the slow and fast continous modes.
The fastest setting is the 5.3FPS, the slower one is around 2-3FPS.

Learning to pan with the cars will give you the best shots, as they will convey motion by keeping the car sharp, and give the background some blur.
The correct shutter speed you use will depend on which type of R/C cars you're taking, and the speed they are going.
If you're taking shots of 1/8th scale gas models, going at around 100km/h, 1/60th second is a good speed to start, and if you are doing off-road 1/10th scale, then around 1/25th or so would be the speed to start with.
The longer the shutter speed, the more background blur you'll get, but it is also harder to keep the car perfectly in frame, but sometimes, getting some motion blur on the car can be a good thing too.
Also, try and keep the camera as low to the ground as you can as overhead shots are quite boring.
You'll need to practise, practise, practise to get it right, but you should start to get the hang of it after 10 or so shots, then you will start to learn what shutter speed you'll need for what type of shot you're trying to get.

As was said before, if you take the cars at a high shutter speed with no panning, you might as wll just place the car on the track and take a static shot.
The whole idea to is to convey the speed of the car.

In good, bright light, you'll need to use a small aperture (big number) to use such slow shutter speeds, but put your camera on Tv (shutter speed priority and dial in the speed you want, and let the camera take care of the rest.
Set your ISO as low as you can to keep the most detail, but the ISO will also depend on the available light.

Hope this helps you a little.

photomike666
24-01-2012, 6:59pm
Agreed pre focus and panning is the way. With the motorbikes I watch them past a few laps to see what line they take and pick a point on the track. I then pre focus on that point and follow the action come past. A few attempts to get the framing right, then a few more on timing. Seeing the focus sharpen lets you know when to fire the shutter

mini696
24-01-2012, 8:18pm
Unfortunately prefocusing is not easy to do with the RC's. The drivers aren't as consistant as full sized bikes or cars and trying to focus on a 30cm wide object which could be anywhere on a 4m wide track with a DOF of 40cm is really hard. Getting closer is usually not an option as there are only so many spots to sit.

I think my biggest issue last time was using such a large aperture. I cant wait to fix that next time I go out.

So far the best shots have come from the slow corners as they accelerate out.

pascal110
25-01-2012, 3:44pm
Hello Mini

Your best bet at a reasonable price would be a Canon 70/200, if this kind of shooting is you main usage you will not need IS as it will counteract panning .
If the light is good you maybe happy with a 70/200 f4 Canon which is very sharp too, if your budget is more consistent a 70/200 f2.8 is the way to go.
Tamron does offer a similar lens but the a/f is slow on it, not sure about the Sigma on that matter but the price is very similar to Canon with some kind of out of focus issues, so stick to the brand you will not regret on the long run and you won't have to stop down to enhance the sharpness :)

Speedway
25-01-2012, 4:17pm
Your best bet at a reasonable price would be a Canon 70/200, if this kind of shooting is you main usage you will not need IS as it will counteract panning .

I disagree re is/os not needed, it does help especially when shooting at slow shutter speeds as in paning. I have looked at photos taken at the Go Karts taken with the 70-200 F4 as I was looking to upgrade to this and could not pick the difference between them and mine shot with the 18-250 Sigma

pascal110
25-01-2012, 7:01pm
I was looking to upgrade to this and could not pick the difference between them and mine shot with the 18-250 Sigma Used at the right aperture you won't pick any difference between two lenses especially at web low resolution you correct, hit rate will be different that's all, I guess the pictures you saw were the good ones.
Simply an a/f module is a lot more happy at f4 or more than f5.6. Don't really see how you use IS with panning unless it's the new system with dual mode. Pricewise non is/os 70/200 are 1/2 price than their IS counterpart.

Speedway
25-01-2012, 7:42pm
I was looking at and comparing 8x12 prints and talking to the person with the 70-200 our keeper rate is similar, My keeper rate went up slightly with OS on. 90% of my motor sports shooting is done in TV mode with shutter speed set to 1/80th the aperture can vary widely, the slow shutter speed gives the blurred BG. As for is/OS the 18-250 has only 1 setting, the 150-500 has 2 and I never turn it off. as far as the non is/os 70-200's they are not even on my wish list now.
Keith.

pascal110
25-01-2012, 10:29pm
Hello Speedway, fair enough 8x12 is decent size print, I'm very surprised that your a/f keeps up with these lenses but that's good sign.
1/80 is a fairly slow speed good job :th3:.

Cheers