# What is wrong with the focus in this image



## parish (Jun 29, 2006)

OK, so it's a [email protected] pic, but I heard the thing fire up and had to run to the trackside and was stood on uneven ground trying to keep my balance. That aside, the focus varies quite considerably along the length of the car. Not just this photo but quite a lot of action shots I took suffer from this. I don't think it's DoF as static shots taken with similar settings are fine.

I'm not bothered about the rear wing as that was probably shaking about a fair bit due to engine vibration since it's mounted on the gearbox

The car is Ayrton Senna's Lotus-Renault Turbo 98T

Canon EOS 400D, 17-55 kit lens, 1/60 @ f/10, 42mm FL, ISO 100









Here's 3 100% crops showing the variation in focus


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## chargedvr6 (Apr 7, 2007)

up the iso a touch that will allow faster shutter speeds or allow you to raise the aperture to increase depth of field 
having said that the settings look ok and dof shouldnt apply in the photo shown above much have you checked another lense?


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## Adam Moran (Mar 8, 2009)

I would say shutter speed is too slow. You want enough movement to get speed in the wheels but freeze the car.

ISO 200 up to ISO 400 but no more than that.

Also what metering setting was used? I susspect you had it on spot metering hence the focusing.


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## spitfire (Feb 10, 2007)

At f10 there should be plenty depth of field but at 60th of a second there's not enough shutter speed to freeze the car motion sufficieciently when panning. Remember also when panning to follow through when you press the shutter. Try 250th or even 500th sec at a minimum of f8.:thumb:


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## VIPER (May 30, 2007)

Nothing to add other than what's already been said about the photo, but I just wanted to say what a car!! Probably my all time favourite F1 car, for both the machine itself, but also just because it was Ayrton's.

Anyway, as you were.....


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## parish (Jun 29, 2006)

Thanks for the input guys.

@Adam, not sure what the metering mode has to do with the focus - except indirectly due to the aperture used 

The settings were Evaluative Metering, Av mode (yes, it should have been Tv for action shots but, as I said, it was rushed so more a point-and-shoot situation) and the AF was in AI Servo mode.

Also, I was using only the centre AF point which lies on the rear wing end fence, just below the 'i' in 'elf'

Re the shutter speed. Advice on TalkPhotography was to use between 1/60 - 1/125 for motorsport shots so the wheels are blurred and there is motion blur in the background. In my first attempt at motorsport - Eurofest last year - the results were poor as I kept the shutter speed at 1/250 or faster and it froze the motion giving the impression that the cars were going really slowly. This weekend I took that on board and kept the speeds down to 1/60 - 1/125.

However, none of this explains why there is such a variation in focus in that pic - especially as the in-focus (or least OOF) point is the 'Ayrton Senna' on the air intake despite the AF point being on the rear wing.


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## chargedvr6 (Apr 7, 2007)

it might well be you not tracking the cars properly then mate. 1st time i ever used an slr (nikon d70s with 70-300 lense) was at cosford airshow just left it on auto as id no idea what to do and practised tracking the planes got a few really good shots and it was a very good baptism of fire tryin to folow a typhoon pulling god knows what gs at 400 knots+ lol


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## IGADIZ (May 21, 2006)

Parish .. 
The focusing issues you see in that image are nothing more than car vibrations. 
The shutter speed is not fast enough to remove them, try increasing the ISO.
Is nothing to worry about, this is quite normal when photographing racing cars.


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## parish (Jun 29, 2006)

chargedvr6 said:


> it might well be you not tracking the cars properly then mate.


But in that case the whole pic would be blurred - motion blur like the background?

That's a cracking photo there :thumb:


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## parish (Jun 29, 2006)

IGADIZ said:


> Parish ..
> The focusing issues you see in that image are nothing more than car vibrations.
> The shutter speed is not fast enough to remove them, try increasing the ISO.
> Is nothing to worry about, this is quite normal when photographing racing cars.


Thanks - I did wonder about that (already had that as the cause of the rar wing being badly blurred) but didn't think it would be that noticeable.

Thinking about it, the area where the focus is OK would be close to the CofG of the car so I guess that would be the point/plane that moves the least?
Prescott were OK - certainly didn't see this problem - but I was using much higher shutter speeds but, as I mentioned above, I reduced the SS this time to capture the effect of speed.

Guess I need to be up closer to 1/125th?


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## CK888 (Apr 23, 2006)

Nothing wrong with it, I thinks it's a good capture panning at 1/60:thumb:


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## chargedvr6 (Apr 7, 2007)

parish said:


> But in that case the whole pic would be blurred - motion blur like the background?
> 
> That's a cracking photo there :thumb:


his or mine?


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## parish (Jun 29, 2006)

chargedvr6 said:


> his or mine?


I meant yours of the plane is a cracking pic - caught the vapour over the wing :thumb:


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## bretti_kivi (Apr 22, 2008)

IGADIZ hit the nail on the head, I've see exactly the same thing. You'll freeze parts of the body but others are blurred. Normal. Maybe 1/90 or 1/125 will give slightly better results, but it depends massively on the speed of the car at that point. 

Bretb


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## Dahl (Mar 8, 2009)

This can be many factors but the most likely will be it was either down to vibration with the camera as this increases the more you zoom in on something or a slow shutter speed. Also, did you use manual focus or auto focus??


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## bretti_kivi (Apr 22, 2008)

couple of examples where I've had the same thing happen...









and









on both, you'll see that there's at least one part of the bodywork in perfect focus, but the rest is vibrating. Where they're going slower, like this:









the effect isn't so pronounced.

Bret


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## parish (Jun 29, 2006)

Thanks Brett :thumb:

That ice racing looks fun :driver:


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## bretti_kivi (Apr 22, 2008)

i got really jealous


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## chargedvr6 (Apr 7, 2007)

parish said:


> Thanks Brett :thumb:
> 
> That ice racing looks fun :driver:


i so want a go of that :driver:


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## Dahl (Mar 8, 2009)

i think you guys have your focus set to 'spot'. This means you can alter which part of the photo you focus into. The selected part of the photo will become in focus where the rest will be out of focus.


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## snoop69 (Jun 16, 2007)

Ive gone from one extreme to the other :lol:

First i was getting shots which were reasonably clear.

Then i made the mistake that you have made - shutter to slow.

I have been advised that 200-320 should give me what im looking for so
will try again.


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## parish (Jun 29, 2006)

snoop69 said:


> Ive gone from one extreme to the other :lol:
> 
> First i was getting shots which were reasonably clear.
> 
> ...


That pic looks spot-on - 1/60 @ f/9 - sharp car, blurred wheels, motion-blur of the background :thumb:


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## parish (Jun 29, 2006)

Dahl said:


> i think you guys have your focus set to 'spot'. This means you can alter which part of the photo you focus into. The selected part of the photo will become in focus where the rest will be out of focus.


Yes, I did. As I said above, I had only the centre AF point set, but in the photo I posted that point is on the rear wing end fence. I think IGADIZ and brett have identified the cause.


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## Mike V (Apr 7, 2007)

Parish, here is an example to help explain what others have been saying.









this BMW is drifting and I am following the front. Now the back it out of focus for two reasons. 1. I am using a shallow depth of field. 2. The back end is moving more than the front.:thumb:


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## Mike V (Apr 7, 2007)

Another example.:thumb:
Might have to enter them into the comp!


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## parish (Jun 29, 2006)

Mike V said:


> Parish, here is an example to help explain what others have been saying.
> 
> this BMW is drifting and I am following the front. Now the back it out of focus for two reasons. 1. I am using a shallow depth of field. 2. The back end is moving more than the front.:thumb:


In that shot - great shot BTW - it makes sense as the front of the car is coming towards you whereas the rear is moving across the frame. The difference is that in mine I was panning with the car and the point that is in focus is not the point where the AF was focussing on. Even though the shot is at angle to the car so the from is further away than the rear, the difference in distance is not enough to be explained by DoF

*Edit* While i was typing this you posted your second shot which is much more the same thing I got :thumb:


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## Pauly_G (Jul 8, 2006)

The difference you're seeing across the photo is due to the fact that as you pan the car is not staying the same distance from you. In fact if you split the photo into thirds, the car is in the last third of the photo meaning the car is moving away from you, thereby increasing the distance between car and camera. This movement is happening whilst the shutter is open and obviously something the lens cannot and camera cannot accommodate.


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