What focal length for high flying aircraft

gazza1137

gazza1137

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Gary
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Hello,

I often read the threads on here an use what I read to great effect, but now is the time to start one of my own. Here it goes.....

I am interested in photographing and identifying high flying aircraft which pass over where I live. (I live very close to a waypoint) The majority fly at a guess of 30,000+ feet and many are B747/A340's.

I have tried with my 70-300IS @ 300mm and despite heavy cropping struggle to get a shot which allows me to identify its registration.

If I attach a 2x teleconvertor, I oviously lose the AF, but the IQ suffers too, the end result being too soft to use.

The majority of the shots I take never come off my PC, the ones I print being no larger than 10inch x 8inch.

I am saving hard for a new lens but my pocket is not that deep - ultimately I expect to have saved £1000 later this year and have £600 available now.

My question is do I go for the Sigma 150-500mm OS ,Sigma 50-500mm, Canon 100-400L OS or the Canon 400mm L prime. I am unsure whether I am comfortable using a non stabalized lens, but acknowledge that as the only prime I have selected, the ultimate lens I choose will spend most of its time at the extreme of its focal length. Even with these option I know I will still need to heavily crop as a quick calculation suggests I need something like a lens with a 3000mm focal length to avoid any cropping:eek:

Sorry for the long post, but all comments are warmly welcome!

thank you,

Gary
 
If you give me a while..I'll find out a bit of info from my brother!

He uses a website which displays a live radar screen for the UK...(I think) it includes all aircraft, civil and military and their registrations, flight number, aircraft type etc....but don't hold me to that!

Should save you a few bob ;)

Edit - Just found one of them...sure there is more though Click me
 
What about an older manual prime lens? You may have to focus manually etc but you can get loads of mm for hardly any £££ compared to the newer stuff.
 
gman said:
What about an older manual prime lens? You may have to focus manually etc but you can get loads of mm for hardly any £££ compared to the newer stuff.
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I can't imagine focussing something at 30000ft will be difficult...whack it to infinity, job done :)
 
Should be fine to focus but not sure if these older lenses have any effect with the camera being able to expose?

Can't remember but there's a shop which has an online store which shows loads of old primes etc. Will try and dig it out.
 
Of the lenses you listed, if reach is everything, then the 400 f/5.6 prime for me. I have one and it is as sharp as my £4000 500 f/4. It's a great lens and would still offer good optical quality with a teleconverter (although it would be dark!)

Paul
 
Might be better buying a very long ladder instead? ;)
 
grumpybadger said:
Of the lenses you listed, if reach is everything, then the 400 f/5.6 prime for me. I have one and it is as sharp as my £4000 500 f/4. It's a great lens and would still offer good optical quality with a teleconverter (although it would be dark!)

Paul
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and will only manual focus using a canon 1.4 or 2x TC because he's using a 400D, unless if rumours are to be believed, use one of the 3rd party TC which are suppose to work or tape over some of the connections (contacts) on the TC, but this could damage you lens mechanism due to focus hunt, which would be more than likely if your trying to take shots of planes at 30,000 ft. As for a lens, buy a telescope, you won't beable to get that type of detail with a £1000 camera lens even with TC's attached

Peter
 
At 30000 feet you will struggle unless you have a really clear day with good light.
How big is the registration on the aircraft?
I'm sure if you know that, and the distance to subject, you could do a few sums and tests work out the focal length you would need for you camera to be able to resolve detail.
 
pete.rush said:
and will only manual focus using a canon 1.4 or 2x TC because he's using a 400D, unless if rumours are to be believed, use one of the 3rd party TC which are suppose to work or tape over some of the connections (contacts) on the TC, but this could damage you lens mechanism due to focus hunt, which would be more than likely if your trying to take shots of planes at 30,000 ft. As for a lens, buy a telescope, you won't beable to get that type of detail with a £1000 camera lens even with TC's attached

Peter
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You think manual focus to infinity is beyond the wit of man?
 
I think you may be on mission impossible with this one.

I cannot make out registrations at these heights with bincs.

Mostly these jets come out white in pics due to the light relected from them.
 
Ant said:
Get a 1200mm lens. SORTEED :D

Shame they're very hard to get hold of, and also very very expensive.
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If you want to go for something like this... and don't mind manual focus, then you can pick up a 600mm ED telescope for about £220, and something like an M42 adapter and M42 2xTC for not a lot from ebay. And a couple of T adapters. Of course with a scope, 30000 feet isn't infinity :D
 
OK, I done sums with the aid of a focal length calculator online and some rough estimates

First, I am assuming a distance from camera to plane as 10000 metres (That is approx 6 miles btw) IN reality it will be further becasue while altitude may be 10000 metres the polane may also be flying a track at least 4 miles from your position
I am also assuming the lettering on the aircraft is 1 metre high
I am using the 40D sensor size as the image size
and I am working with the output being cropped down to 75 pixels high (From the 2594 height the 40D starts with).
To do this you will need a focal length of 3500(ish)mm and you will get an image that is probably unusable for any sort of recognition at 75 pixels high.

I've put in bold the bit I feel is really really important to consider.
 
Surely it would be better to take the odd occasional trip to an airport at least that way you can actually get a shot where you can tell its a plane and not a spec of dust.
 
grumpybadger said:
You think manual focus to infinity is beyond the wit of man?
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No but try to get registration details on aircraft at 30,000 ft probably is.....sorry

Its difficult enough getting a low level jet / prop at Tebay with a 300mm lens with enough detail to read the pilot name, but at 30,000 ft, pushing beyond the boundaries
 
I think it will be possible, 2 x TC on a 400 mm lens, although the plane would have to be banking I guess, I have some somewhere that I can see the plane is Virgin, or American Airlines - Reg number will be tricky although I am sure not impossible !

img7182pg5.jpg
 
30D with 100-400 @ 400 + 1.4X teleconverter. I don't know the altitude of the aircraft, or which airport might be relevant, if any, but the nearest major airport (Stansted) is around 30 miles away as the crow flies. I don't know if that might give any clues as to the potential minimum altitude.

Full image :
20070623_155452_LR.jpg


100% crop :
20070623_155452_LR-2.jpg


The 100-400 has a reputation for being a little soft at 400mm and wide open, which this was, and the 400mm prime should be sharper than the zoom, but this doesn't look bad to me. I guess a 50D would have better resolving power for a plane that was further away.
 
I shouldnt think JA736J is more than 4 or 5 thousand feet up. Good luck with the high altitude ones.
Allan
 
Scotty B said:
Sounds like you need a telescope other than a lens. :thinking:
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not as silly as it sounds, can't you attach your camera to a telescope? don't astro photography guys do it, I vaguely remember hearing something on here but i can't remember much tbh

read about strobist doing it by just putting a 50mm prime to the eyepiece - LOL, not quite what you want
 
tdodd said:
30D with 100-400 @ 400 + 1.4X teleconverter. I don't know the altitude of the aircraft, or which airport might be relevant, if any, but the nearest major airport (Stansted) is around 30 miles away as the crow flies. I don't know if that might give any clues as to the potential minimum altitude.

Full image :
20070623_155452_LR.jpg


100% crop :
20070623_155452_LR-2.jpg


The 100-400 has a reputation for being a little soft at 400mm and wide open, which this was, and the 400mm prime should be sharper than the zoom, but this doesn't look bad to me. I guess a 50D would have better resolving power for a plane that was further away.
Click to expand...

There's no vapor trails, so I'd say it was less than 30,000 feet......

O/P, You could always get yourself an SBS-1 if it's that important to you.
 
david1701 said:
not as silly as it sounds, can't you attach your camera to a telescope? don't astro photography guys do it, I vaguely remember hearing something on here but i can't remember much tbh

read about strobist doing it by just putting a 50mm prime to the eyepiece - LOL, not quite what you want
Click to expand...

David, That's exactly what I suggested earlier. Prime focus astrophotography, basically turns your telescope into a potentially monstrous telephoto. If I remember correctly it's been done with a 1500mm scope, but I've used my 600mm scope with a 2xTC and a special t thread adapter so the 450d was at prime for some lovely moon shots (nearly fills the 450d frame top to bottom). I've even used some astro magnifiers to take it up to silly focal lengths (I think I worked it out at 24000mm, totally unfocusable and breathing within 10' of it made it bounce like mad...). If I get a chance with a day of clear skies I might see what I can get of a high altitude jet, be a lot easier to track and focus than a bird at 50'....
 
Andy Fozzy wrote:-
"There's no vapor trails, so I'd say it was less than 30,000 feet......"

Sometimes don't get contrails even at that height. Depends on conditions.

I think the aircraft was well below 30,000 (guess nearer 5 or 6 thousand).
Looking at the wings it appears that the leading edge slats are deployed which suggests the aircraft was on landing approach.
 
Wow!

Thanks everybody for your replies. I have thought of getting a SBS-1, linking into the Planeplotter program.

I live on the main approach to Leeds Bradford Airport which is only 15 miles away, but get a bit bored of getting the same aircraft.

I occasionally get aircraft on their descent into Manchester Airport (45 miles away) and some of the photographs I have taken are sharp enough to get the details I need, in essense what I get is a smaller version of tdodd's JA736J, though never as sharp, which requires heavy cropping. Also, as mentioned if the weather is anything but perfect, the chances of getting anything useable is low. I will try to post one of these once I have sussed how to post here and when I access the picture on my back-up drive.

I would love to get out and go to airports but due to health reasons this is not possible.

Thanks everybody,

Gary
 
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