Setting manual focus

[Jochen]

I've started to use manual focus more and more on my A2.
But it takes me quite some time before I get it right and then when I do only at home do I discover it wasnt actually.

Apart from shooting and trying are there any rules of thumb to set it up check it and see if its too close too far?
Do you start close and go further or vice versa and what parts of the practice shots are best to zoom in on and judge on small lcd?

Im hunting to have the nose in focus and the rear not so sharp.
http://jvc.pingus.be/fotos/TF_2004_0...CT2199_PSs.jpg
http://jvc.pingus.be/fotos/TF_2004_0...CT2118_PSs.jpg

Thanks,

Jochen

*fixed url

[IFRYCE]

mate, i do believe it has nothing to do with focus..

getting a "sharp" front end and a "blurred" rear end has to do with the apature.. having a "large" apature (small number on the lense/camera) means the apature hole is big. What this means is there is a lot more light flooding through the lens and not all the light goes to the focus, as there is a lot of it

basically what i'm saying is, when you have a large apature, the forground object will be crisp clear and the background will be blurred

basically, to get this "blurred" effect at the rear of the car, chuck the apature as large as possible (small number) with appropriate shutter speed, will be fairly quick as there's a lot of light going through the lense, you might have problems with it looking too "frozen" and not much motion throughout the picture.. so my suggestion is to try a range of shutter speeds and apature settings

focus don't really have anything to do with it

i just hope i didn't confused the shizer out of you

btw - hi guys - i'm new to the boards


Cheers
Ben

[Jochen]

Thanks for the usefull info Ben.
I am aware with DOF and such so not too confused.

What I do with my camera is set the shutter time and it sets the corresponding aperture (matching environment light I believe), resulting in relatively small DOF, which is fine by me, as said.

I would like to know some tricks to know how I can make the part of the picture that is sharp as sharp as possible, regardless DOF.
I manipulate this sharpness with the focus ring on my camera but am seemingly pretty clumsy at that so hence my question.

Cheers,

Jochen

[IFRYCE]

i don't think you can use focus for what you want.. it's either in or out of focus

i think you just try and have to get the lowest possible apature... aside from this, sorry, i can't help you out any further

although - there seems to be a fair few pro's on here, so i'll just shut up and move to the back of the room, now

happy snapping


Cheers
Ben

[Peter Mallett]

If you are talking motorsport, pick a spot on the track surface where the cars will pss. Focus on that and as each car passes through that spot you'll get your picture. Also use the smallest apperture you can to increase the depth of field. (As you have already alluded to that process).

[KennyG]

You can increase the ISO which will mean that the aperture will close down to compensate. Try ISO400 and see if you can live with the extra noise.

With my 1D or 1 1D MK-II I tend to shoot at ISO400 to get the extra DOF for head-on or three-quarter shots. For pans where the vehicle is directly opposite when you take the shots, you don't need a large DOF and can get away with ISO200 or even 100.

Experiment, as each camera is different and the noise levels with some of them at high ISO's is so bad you can't use the technique. ISO with digital cameras should be thought of as just another adjustable setting to control shutter speed or aperture, depending on which mode you are in.

[KennyG]

As a follow-up to my post, I have been looking at the Exif details of your shots.

1/100 is too slow for this angle. Fine for a pan shot, taking it when it is side-on opposite you, but you should be at something like 1/320 or 1/400 for a three-quarter shot. It will still keep enough wheel blur.

There is a degree of camera shake due to the slow shutter speed. I don't know the A2's AF system well enough to know how it copes with fast moving objects, especially at that angle where the distance is different from the camera sensor to the front and rear of the car, and therefore the approach speeds will appear different. Just to confuse matters further, sensor size has an effect on the outcome, especially the DOF and the AF system may be similarly effected.

Next time, for that type of shot, try 1/320 ISO400 and let the aperture take care of itself.

[pao]

I've had good luck prefocusing my A2 using the AF at the correct spot on the track then locking it back to manual focus. The key is to leave the zoom ring alone after doing this, or you will change the focus point. (EDIT: Also make sure you're keeping your fingers away from the focus ring, which has screwed me up before!) I typically keep the aperture set around f/5.6, influenced (for racing at least) primarily by weather.

[Jochen]

Kenny,

Thank you very much for the advice, especially using the ISO like that.
I will try it out next weekend.

Because of a coincidence I forced ISO400 yesterday and the resulting noise seems to be nothing Neatimage cant handle so ...

Regards,

Jochen

[Jochen]

Originally posted by pao
I've had good luck prefocusing my A2 using the AF at the correct spot on the track then locking it back to manual focus. The key is to leave the zoom ring alone after doing this, or you will change the focus point. (EDIT: Also make sure you're keeping your fingers away from the focus ring, which has screwed me up before!) I typically keep the aperture set around f/5.6, influenced (for racing at least) primarily by weather.

Thanks for that,

Can you explain me how to lock using AF and then switch to MF, this does not seem to work for me. :K

I choose Shutter speed priority only, aperture is set automatically.
I understand you use the full manual mode then?

Jochen

[pao]

Yeah, I stick to full manual to keep the camera from having to think when I hit the shutter. If it knocks off a few milliseconds of shutter lag, I'll take it. With the live histogram, it's not too hard to set correct exposure. Alternatively, you can point the camera at the track or a car, half-press the shutter in whichever priority mode you like, and just note the other setting and then switch to manual and set that.

To lock using AF, just half-press the shutter when in AF mode and slide the focus switch back to MF. Note that this will work easier if you have Full-Time AF set to "Off", since you don't have to hold the button down or worry about accidentally moving the camera after you get focused.

[Jochen]

Originally posted by pao
Yeah, I stick to full manual to keep the camera from having to think when I hit the shutter. If it knocks off a few milliseconds of shutter lag, I'll take it.

Right, didnt realize that extra timeloss.

Originally posted by pao
With the live histogram, it's not too hard to set correct exposure. Alternatively, you can point the camera at the track or a car, half-press the shutter in whichever priority mode you like, and just note the other setting and then switch to manual and set that.

Equally simple as effective

Originally posted by pao
To lock using AF, just half-press the shutter when in AF mode and slide the focus switch back to MF. Note that this will work easier if you have Full-Time AF set to "Off", since you don't have to hold the button down or worry about accidentally moving the camera after you get focused.

Ok will try.

Thanks!

Jochen

[zonda]

Just a quick question relating to this. I know about the AF and then locking to MF but is it that the EVF is just not giving a clear enough image of the focused area ? I know it zooms in for you on the EVF but i always wondered how accurate it is.

Cheers,

Dave

[vwpilot]

I'm going to chime in here and say that I dont think it has anything to do with focus, dof, iso or anything such as that.

In the photos I viewed, you are doing a 3/4 pan. When doing this kind of shot you have to remember that not all of the car is moving consistently in the same plane as you are panning your camera.

The front, the middle and the rear of the car are all moving toward, away, and sideways at different speeds in relation to the camera. The car is essentially rotating around a point that is staying consistent with your pan, but the other parts are moving at different speeds. Its virutally impossible to get a pan like this with the entire car sharp unless you use a fast enough shutter that will freeze the entire thing.

What you are trying to do is make sure that the nose of the car is the part that is moving in the same plane as your camera so that its sharp. You can either manual or auto focus, whichever is easier and depending on whether your camera can keep up focus or not. But you want to make sure when you are panning that you are keeping the front of the car in perfect position in the viewfinder. If you focus on the door, that is what will be sharp. That nose has to make sure its not moving forward, backward or up or down in the frame as you are shooting.

Focus on the nose and concentrate on keeping that still in the frame and it should come out sharp, the rest of the car will then blur as it moves differently around the frame. The slower the shutter the more the rest of the car will be out of focus and the harder it will be to keep the one part you want sharp.

Generally shooting slower shutters like this you will have plenty of DOF to have the object sharp as long as your pan is on. So that should not be an issue, what will be the issue is the quality of your pan.

Practice practice practice, thats whats going to do it for you. Your settings are fine and its only going to be how well you learn the technique that will do it for you. This is one of the absolute hardest shots in motorsports photography. Even experience shooters have pretty low keeper ratios for such a shot, especially at shutter speeds of 1/125 or lower. I generally shoot my 3/4 pans at about 1/200 or so, still enought to get plenty of wheel and background blur while upping the keeper ratio slightly.

Here are a couple of extreme examples with wide lenses and slow shutters. The effect is magnified greatly with shorter focal lengths and slower shutters.

This one the point of rotation is the nose of the viper and is sharp while the rest is blurred.
http://www.motorsportsimaging.com/SC...VIR04_0265.htm

This one the point of focus is more centrally located and so the nose and tail are blurred.
http://www.speedarena.com/gallery/al...aceday/001.jpg

Both of these were also taken standing very close to the track (if I bent over the guard rail too much you could actually get hit) and with the wide angle, so the panning motion was very fast and therefore also exxaggerated the effect greatly.

Here is a more standard 3/4 pan shot with a 70-200 and shutter speeds in the 1/160-1/200 range. Again though, focus point more centrally located, its hard to get the nose sharp on these shots.

http://www.speedarena.com/gallery/al...actice/077.jpg

But just keep practicing, you'll get what you are looking for, but I would stop trying to kill yourself over correct focusing modes or settings. In this case its all about the slower shutter and the technique. Good luck.

[kdr]

i think one other thing is try to find a place on the track where the cars are moving at a nice speed to photograph. sometimes they can be too fast...and even more annoying is where they're moving too damn slow!

[JamesC]

vwpilot... how did you read my mind! - I wrote a post on what you just wrote this morning and then my browser crashed before I pressed the submit button!

I've experienced this loads this year - especially when shooting hairpins.

I agree!

[Jochen]

VWPilot, thanks for taking so much time to help me in such a clear way. Very much appreciated.

Now after reading this I am wondering ...
As it is the spot where the examples are taken has a dip.
This upsets the suspension of the car, proof.
http://jvc.pingus.be/fotos/TF_2004_0.../photo_40.html

Is it possible that this difference of vertical motion between front and rear cause this kind of effect?
Or is it that travel too small and is it all down to different approach speed?
http://jvc.pingus.be/fotos/TF_2004_0...s/photo_3.html
http://jvc.pingus.be/fotos/TF_2004_0.../photo_62.html

If this would be the case its probably impossible to get the motion right?

Cheers,

Jochen

PS The pointers I got here definitely helped me last weekend (still processing) thanks for that!

[vwpilot]

From those shots it looks like your pan just was not on, as there is no real sharp part of the car in the whole image. The dip could be causing the problem because as you are panning left to right, the car then moves up and down as well. It doesnt take a lot of movement to blur the image.

What you might want to do there is to start with a higher shutter speed and slowly move down, finding out where the limit is that you can get a sharp portion of the car. Start in the area of 1/400 or so and take a bunch of shots, then move it down a step and take some more, etc. till you find the limit of where you can get sharp images.

[JamesC]

Don't be afraid of using high shutter speed - especially when the suspension is working hard. It can give that frozen look - which works equally well as the blurred background if the car has the "action" going on internally.

I've learnt this lesson - if you need to get *that* shot then shoot it fast and take no chances.

This may sound controversial - but you can always fake it in Photoshop! But you can't go back to that "moment"...

Other than that its just practice...

[Jochen]

Got a bit more practice in using your tips previous weekend.
I felt like I improved, not least in getting more consistent and faster in getting my settings right.
Thanks guys!

http://jvc.pingus.be/fotos/VLN_2004_.../photo_30.html
http://jvc.pingus.be/fotos/VLN_2004_.../photo_32.html

Jochen
www.nurburgring.be

[pao]

Pretty good, but they do look a bit overexposed. You may want to dial in some compensation if you're autometering. If that's making your shutter speed too short, get a polarizer or an ND filter to cut the light down.