I have been to RIAT again last weekend and once the show got going, it was pretty good and the main thing was lots of opportunity for plane photography.

I kitted my EOS40D with my (new to airshow) 100-400mm L series lens and expected at least a few brilliant results. However, at first glance at least, it looks as though I have the same sort of blury/shakey/grainy photos as I used to get with my EOS300D and inexpensive 70-300mm lens.

I know the camera is more than capable of taking excellent photos- just look at The Fly on my Flickr if you don't believe me (and that's not a shameless plug)- and I know that the lens takes decent photos because I've used it at football matches and got some excellent shots. So what is going on?

Well, I am wondering about Image Stabilisation. Should I have turned it off at high shutter speeds- during the afternoon, I was reaching shutter speeds of 1/3000th at ISO 200, or is it that I was using Mode 1 (general stabilisation) when I should have switched to Mode 2 for panning shots.

Barring that, I was wondering whether I should have used AI Focus, rather than AI Servo mode for autofocus. I am not sure that I fully understand the difference, but I do think that some shots are definitely not in sharp focus, rather than shakey.

Any thoughts would be welcome, but I will be following this up myself. Thanks.

AI servo is basically tracking autofocus. I have it on my compact G12 camera. Supposed to track the item and keep it in focus. Doesn't work so well in the compact if you move camera too much (though I was just messing about). Autofocus focusses on the object and then keeps that focus so if the object moves, it'll be blurry.

Any examples? Also what aperture were you using?

Loads of examples. Much like the lot I showed last time this happened. (No I don't expect you to remember all that.) but there are over a thousand to sort. First impressions are not good, however

Aperture was wide open the whole day (f5.6 at 400mm). I tried playing around with things, but one photo would be at 1/3000th and the next at 1/750th or even slower, so didn't see that I could close it down too much.

This is something I've never quite understood- the sweet spot. If a lens has an aperture range where the pictures are at their best, then what's the point of really fast and really expensive lenses, just to get better shots at f4.5, for example. Maybe that's just another thing I've got wrong.

Will try to get some pics up, but just was interested in what other people have found on the issues raised.

I have just found one picture of the Vulcan where I can just about read the name (The Spirit of Great Britain) on the nose and the shutter speed was only 1/750, so something has affected the others.

I will try to find some consistency between pics of a certain speed or other issues- panning, moving toward or away, etc.

If you were shooting with the aperture wide open, you've given yourself a really tight depth of field. I'd have thought you'd want to get it up to at least f8, to allow for any movement of the plane.

Shooting at up to 1/1000th should be ok for your purposes, and will enable you to narrow the aperture and increase DOF as Alex mentioned. You could probably use a higher iso as well.

I appreciate the depth of field issue, but although the depth of field might be relatively shallow, I wouldn't have thought that it would have been a massive problem- even at 400mm/f5.6 given that the aircraft are at least 500m away.

This is one of things that perhaps I need to revisit in a "back to basics" session. but given the size of some of these planes (Hawk being the smallest) I would have thought that the depth of field would have been adequate to take in the whole aircraft.

As the Vulcan was the largest aircraft flying this year, and I've found one picture of it that is near-perfect, I am not sure that this is the issue. I will certainly bear it in mind, though.

We have a local airshow next month, so I am going to have to try and get to grips with this so that I can practice again.

Thanks all for your time.

Well 'every little helps' and if you can eliminate or reduce some possible causes it may help to find the main culprit.

Just had a play with an online DOF calculator and at 300mm on a 5.6, with your 40D, pointed at a plane 500m away, your DOF is about 930m.
So yeah, should be plenty of space to get a plane into.

From what I'm reading, your choice of AI Servo was correct as well.

Thanks, Matt, and Prof. I didn't go so far as to work DoF out, but I didn't think I had too much to worry about.

Have had a very busy day and only just got onto PC.

I will try setting Tv rather than Av and set the shutter speed to 1/1000th or higher at the local show and see how I get on (weather permitting). I'll have to try IS on and off and see what happens.

The Brightling wing walkers will be there and they bore the [LIFTED] out of me, so I'll use their part of the display to play around.

I will try and get a few examples uploaded early next week, but I'm having a busy old time now that school summer hols have started.

there was an airshow crash in england somewhere not long ago, WW2 p38 I think got hit by another one and he bailed out, would of made great shots

I've started sorting the pictures out- initially just getting rid of the obvious errors and I may not have done quite as bad as I first thought. There are one or two corking pictures and that's before any extra work on enhancement.

Nonetheless, those that are run of the mill for quality look just like the previous years' and not only that, but my son was using my 300D and old telezoom and his shots look as good as many of mine.

Some are clearly out of focus, but the ones that look just not quite right or grainy- I'll put a couple up as soon as, plus at least one good one to compare.

Apologies Mr K - have just stumbled upon this thread.

I have the same kit as you - 40D + 100-400. For aviation I use Tv and at least 1/650th sec mimimum for fast jets. The 100-400 is a stonker of a lens but you need to know its little foibles (as well as the sweet spot) so the first thing I should mention is the lock ring. The lock ring sits next to the focus ring and being that the lens is of the trombone type and not twist zoom this is where a lot of your pics may become soft. Just tweaking the zoom sometimes results pressure being applied to the focus ring just as the camera has implemented the shot which results in the focus hunting. Because the camera has started taking the shot it continues and if autofocus has not sorted the problem out.......

Image Stabilisation (IS) on or off? Well I usually have it on unless I'm at a shutter speed of 1/1,000th sec or less but it has to be off when on a tripod. All switching it off will do at these shutter speeds is give the camera less to do when initiating the shot - could be an advantage or not... I have the lens set from 6.5m to infinity to save battery power and on stabiliser mode 2 - this ensures both vertical and horizontal stabilisation. I always pull back from the stops at both ends as this is where the lens is softest - at 400mm especially.. You will need superb light and slow aircraft to be able to use the lens at 400mm and get away with it.

And so to the sweet spot. It is generally accepted that the sweet spot on a lens is +2 stops so for the 100-400 at F/4 it's going to be F/8. I could go on about the sweet spot but advise a quick search and many hours reading - that should put you right.

Back to the camera. So you've got it set to Tv, the speed selected at 1/650th sec and you want F/8. The only way you can get that is to change the ISO. I shoot ISO200 all the time and up it as far as 800 for those darker moments. I believe RIAT this year was overcast when not torrential and looking through your pics I can see where the issues arose. The idea of getting prop blur is balanced by the practicality of everything working in unison to get a clean image - very difficult at under 1/250th sec shutter speed. I can't see the exif info but notice the trend of nose being soft and the rest of the aircraft being more sharp. This is down to panning and I know because most of my shots are similar Increasing the shutter speed should fix this.

AI Focus or AI Servo? AI Focus lets the camera choose between single shot and AI Servo. AI Servo all the way for moving objects unless you're pre-focussing.

I also use an add-on noise removal filter in Photoshop. It's the dogz really and has improved the end product no end. It's called Topaz DeNoise5.

Finally (yup), I shoot RAW and whilst I try and get the exposure correct as I press the shutter release it provides a great way of rescuing naff pics. Also opening up the shutter by at least +1 of a stop helps in the miserable weather.

Apologies if I've come across like teaching Gran to suck eggs but if you need to discuss anything just give me a shout.

Here's one I took at Leuchars a few weeks back - miserable weather but old aircraft look better in black and white anyway...



Al