Upgrade questions with AF speed the clincher

pooley

pooley

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Name
Mike
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Hi all,

I'm considering selling my motorbike and spending the funds on upgrading camera gear. My main subjects are wildlife.

My current gear is as follows -

Canon eos 20d - Great camera for low iso and minor crops but the AF struggles with subjects moving towards the camera (i.e. birds in flight) and comparitively poor iso at 800 and above when a crop is applied.

Canon 400mm f5.6L - cracking lens but a bit slow aperture wise and only focuses to 3.5m

Canon 70-200mm f4L - brilliant lens which I dont get to use enough

Has anybody had any first hand experience with the new sigma 120-300mm f2.8 OS and can offer an opinion on AF speed, sharpness and its quality with converters.

Also, with regards to a new body, is there much AF speed difference in the 7D against the 50D, i.e. enough to notice in real world situations?

Any other suggestions also welcome. I have no brand loyalty, and am happy to use any system, I firmly believe that you can get used to any camera after a few shoots, and don't mind buying second hand. As a rough guide, if I sold all my current gear and my motorbike, I'd be looking at a budget of around £3-3.5K

thanks

Mike
 
I was wondering when you'd get round to changing the 20D:)
As far as the 7D goes, I'm not that happy with the images at 800 ISO when taken in low light and cropped. In fact I'm going to put my 300 F4 on a 5D2 next week and make some comparisons.

AF and tracking are very good but as I've never used a 50D I can't help you there.
Now comes the 400 F5.6. You turn out brilliant images with that lens and it's unrivalled for sharpness at that price point.
I can't imagine any zoom outclassing it.

You could always try the Canon 300 F4L IS, either by itself or with a 1.4x TC to gain the extra reach, they're on a par pricewise with your 400.
 
I've found that the benefits of the 7D AF are more related to the control of the AF rather than outright speed. I don't know that it is much quicker than my old 40D (I hink the 50D is broadly similar) but the ability to control the twitchy-ness and to select various focus points makes it much more flexible. The tracking in AF servo is much better with the 19 AF points providing you use them in the right way.
 
Cheers gents. I've got so many possible variations going around my head at the moment its frightnening! There's a nikon 300mm f2.8 in the classifieds at the moment which I've considered sticking on a D300 (or do I get a D7000?!) with a converter? Do I stick with canon? Do I just get a 50D and keep my motorbike? AAAAAAAAAAAAAAAAARGHHHHHHH!!
 
pooley said:
Cheers gents. I've got so many possible variations going around my head at the moment its frightnening! There's a nikon 300mm f2.8 in the classifieds at the moment which I've considered sticking on a D300 (or do I get a D7000?!) with a converter? Do I stick with canon? Do I just get a 50D and keep my motorbike? AAAAAAAAAAAAAAAAARGHHHHHHH!!
Click to expand...

You are looking to upgrade your body and do you think you'd be happy with a 50D over a 7D, bearing in mind the summers coming (if we get anymore sun, thats another question) and it's great motorbike riding time...

I have been told the 7D is a better AF system than the 40/50D and yes I would notice a difference, but I don't have many issues with my 40D AF and couldn't really justify the extra expense to upgrade at this moment - I've been umming over upgrading for a good many months now. Now the 5D mk III looks very interesting, but thats a long while off for me...

Don't forget Canon do F2.8 300mm and they do appear in the classifieds, as do the Sigma equivalent.

Hope this is of some help, but I doubt it :lol:
 
Tricky question, and one that I'm wrestling with at the moment. AF performance is something that rarely gets properly reviewed and compared side by side so you're left with trawling what information you can glean and making a best guess.

Comments I would make are: 7D is best of the Canon croppers by far, but at your budget the 1D4 also comes into the equation. Bear in mind that AF performance also depends on the lens and for Canon users that basically means L grade. Only other lens I would seriously consider is Sigma 120-300 OS you mention. Gets some very good reviews - search micloi on here.

Personally, I think I've decided to get a 5D3 when the price settles. AF is top drawer, from the 1DX, if you can manage with 6fps and don't need massive reach. BTW, the 5D3's 22mp crops down to 8.7mp equiv on 1.6x format.
 
I know Artyman (Ken) has got the sigma 120-300 OS and rates it very highly. Have a look about the forum as he's a regular on here. He'll be able to tell you all about it, I've seen some of his photos with it and they are excellent.
 
I have the 120-300 OS and use it with a x2 on my 7d. Without the converter the af is very quick and the images sharp from f2.8 and up. With the x2 its slower but not as slow as my old 150-500 was an the images are good at f5.6 and get better as you stop down. It makes a great combo with the 7d. Have a look in my Flickr for a few examples.
 
I moved from the 50D to the 7D purely for the autofocus.

Outright speed... well that is near impossible to measure as they both lock on very quickly. AF tracking... well that was easier to measure.

The 7D is miles ahead of the 50D. But not the outright speed, the capability. If you set both cameras to use centre AF point only on default settings there is very little difference - the 7D maybe looses lock less often that I did with the 50D.

However if you spend the time learning how to use the autofocus system on the 7D properly, and tune it to how you shoot, you notice a huge difference. But you need to understand the focus modes and when to use them. My initial 7D experience was almost a step back from the 50D until I had spent time learning how to shoot with it.
 
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