A 5D question....

^^Gord^^

^^Gord^^

^^Gord^^

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I was mulling over the differences between the 30D and the 5D whilst shooting in poor light on Monday / Tuesday. They are basicly the same camera but with the obvious difference of the 5D being full frame and having a higher megapixel count.

I mainly shoot mil aviation at the moment and a lot of it is tricky light but I need to maintain a high shutter speed due to the speed of the aircraft so having a full frame sensor would really help. I can deal with the "loss" of the crop factor by manually cropping into the image and still have a resolution high enough for my needs.

But, my question is about the auto-focus. With the 30D and 5D having the same diamond nine AF system I would expect it to perform better on the 30D as the crop factor of the 30D would mean the plane would fill more of the frame and therefor the AF would be more likely to hit more points of the plane and less likely to miss-focus of something else in the shot.

Would you agree?

Please don't suggest a longer focal length lens to compensate for the crop factor, using the centre point AF or using a 1-series as they are all non-starters.
 
The 5D has an extra 6 invisible focus points round the centre point which are only used for AIServo predictive tracking. I would assume that these would give you better performance than the 30D although how much better is debatable.
 
dpreview will tell you whether the diamond focussing pattern covers the same part of the image on the 30D as the 5D. I suspect the 'size' of the pattern will be larger on the 5D so to cover the same portion of the image. *** 5D does have extra focus points though. The performance of the autofocus will therefore be the similar on both cameras.

The increased resolution on the 5D won't make much difference as the sensor is larger. The pixel density is therefore similar.
 
also remember that you will loose legs on focal length when using the 5d.

One factor I would think is a clear advantage on the 5d is the viewfinder. Much bigger and far nicer to use than the 30d.

Hold both cameras...I think you will want the 5d.

AF...not as quick as a 1 series but its good. I would never think the 5d is an aviation camera really but it will also do other stuff far better than the 30d - its more of a good allrounder.

dont get me wrong they are all great cameras...there isnt a bad one about but if you can afford it, go FF.
 
The 5D is regarded to have a very much improved AF system over the 30D and again the 6 invisable AF points located central will really help track a moving object central of your frame.. The technological difference will help and your personal skills will be helped with the huge big bright viewfinder to make viewing a more comfortable experience.
 
Psilonaught said:
you say the 30D and 5D are virtually identical, I thought the 5D had a bigger body??
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Marginally yes it is but I was referring to it's spec rather than physical size.
 
^^Gord^^ said:
...I need to maintain a high shutter speed due to the speed of the aircraft so having a full frame sensor would really help.
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How does having a full frame sensor help with shutter speed?
 
It doesn't per se but it would allow me to use a lower / usable ISO setting than the 30D in tricky light whilst still getting a high enough shutter speed.
 
Shimmyhill said:
How would it ?
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From what I understand, if the 5D gives you 1-2 stops better noise performance at any given ISO, then you can set the ISO at 1 or 2 stops higher and get the same quality of picture, but at the same time keep the apiture constant, and increase the shutter speed by one stop.

But on the other hand, since there is inherently less DOF, then you actually need to increase the apiture to get the same DOF had you used a 30D, and so to get a silimar picture you migh actually end up with a slower shutter speed, compared to if you had used a 30D.
 
Shimmyhill said:
How would it ?
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The full frame sized sensor wouldn't need as much time to correctly expose an image compared to the APC (physically smaller) sensor in the 30D. The 5D also has a much better noise control than a 30D so even if you did even us at something like ISO 1000 the amount of noise in the image would be like using a 30D at about ISO 400.

From my experience shooting aircraft you really don't want to go any higher than ISO 800 (ISO 1000 at a push) for a 30D even with noise reduction programs. Aircraft provide a fairly unique shooting situatution as usually need to crop the image, you have a grey jet against a bright sky and you usually have a very limit choice of places to shoot them from. All of these factors mean you can struggle to control noise under certain (i.e. non Summer) lighting conditions.
 
FranchiseJuan said:
But on the other hand, since there is inherently less DOF, then you actually need to increase the apiture to get the same DOF had you used a 30D, and so to get a silimar picture you migh actually end up with a slower shutter speed, compared to if you had used a 30D.
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Remember, you are using telephoto lenses when shooting jets so DOF really isn't an issue. You will find lots of serious aviation photographers will be using f/2.8 lenses on cropped bodies.
 
^^Gord^^ said:
The full frame sized sensor wouldn't need as much time to correctly expose an image compared to the APC (physically smaller) sensor in the 30D.
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:confused: :confused: For a given aperture it will need exactly the same time. The advantage, as you've already said, is going to be in better noise handling.
 
I really can't see any difference??? And the noise of the 5D sensor is pretty much the same as the 30D anyway. The 5D will need exactly the same amount of time to exposure the shot at say ISO400 as the 30D would at ISO400. Plus you have the advantage with the 30D of effectivly having a longer lens, which i presume is good for aircraft photography.
 
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^^Gord^^ said:
The full frame sized sensor wouldn't need as much time to correctly expose an image compared to the APC (physically smaller) sensor in the 30D.
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Ive never heard that before! Could you back that up please, as it doesnt make any sense to me.

Thanks
 
I have a 5D and after one year of ownership looking through the EXIF data have come to the conclusion i may have been better off buying a 30D.

Almost all my photographs are in the 50mm range and longer. I have 2 long lenses that I use frequently 100-300 Sigma and EF 100-400 IS L .

I also use a 70-200 f4 L lens but mostly use an EF 28-70/2.8 L

I also still own a 10D which is confined to a side pocket of my camera bag. It awful and having borrowed out of curiosity a 350D can honestly say my copy must be ******. I wish I had sent it in for a service before the warranty ran out. It doesn’t focus reliably at all.

My mate down the pub... no really! has a 400D and produces awesome wildlife photographs. maybe I might buy one and if it suits sell the 5D while it commands a reasonable second hand price.

Check your work flow before deciding. The 5 D is awesome make no mistake. Its super high ISO is amazing. Its one reason I don’t own super fast tele’s.

Just my thoughts.
 
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