• Log in with Facebook Log in with Twitter
Photo

selecting a camera with Autofocus priority


  • Please log in to reply
45 replies to this topic

#1 toni-a

toni-a

    Advanced Member

  • Members
  • PipPipPip
  • 905 posts
  • LocationLebanon

Posted 04 June 2010 - 04:37 PM

I am considering upgrading my gear in a few months, I am not a student anymore so money is not a problem :)

Don't care about brand, full frame or crop, pixel count etc...
I need a camera with a high performance autofocus, I need the autofocus points to cover all the frame and be very acurate, since I will be using fast glass.
what annoys me most on my 30D, is that autofocus points are all close to the center, I often have to recompose after focusing.
What's the point of having more than 50 AF points if they are all close to the center ??
Basically I shoot everything, ok I am mainly a portraits shooter, but I often do nature photography, I also shoot sometimes sports and weddings, that's why I am demanding.
Which camera body would you recommend ?

#2 janez

janez

    Member

  • Members
  • PipPip
  • 22 posts

Posted 04 June 2010 - 06:31 PM

d300s
nice day janez

#3 toni-a

toni-a

    Advanced Member

  • Members
  • PipPipPip
  • 905 posts
  • LocationLebanon

Posted 04 June 2010 - 07:21 PM

just looked at the specifications, nothing impressive, no AF in the upper and lower third of the frame,all AF points close to the center

#4 mst

mst

    Advanced Member

  • Moderators
  • 1,904 posts
  • LocationWesterwald, Germany

Posted 04 June 2010 - 09:07 PM

If you want really wide frame coverage of the AF system, then you need to look at crop cameras, not full frame.

And of all the crop cameras I've tried myself, the D300 AF covers the largest part of the image frame. There currently is no wider AF coverage, at least not for DSLRs.

It's possible of course to allow complete frame coverage with contrast based AF, like in the mirrorless systems. But with those you lack speed and precision (in servo mode).

-- Markus
Editor (Nikon, Leica, Samsung reviews)
photozone.de

#5 toni-a

toni-a

    Advanced Member

  • Members
  • PipPipPip
  • 905 posts
  • LocationLebanon

Posted 04 June 2010 - 09:20 PM

you mean that a camera like 7D could be ideal for this job ??
I am used to Canon system so if 7D and D300 are the same in this aspect, i would go for 7D

#6 larsrc

larsrc

    Advanced Member

  • Members
  • PipPipPip
  • 86 posts

Posted 04 June 2010 - 10:28 PM

just looked at the specifications, nothing impressive, no AF in the upper and lower third of the frame,all AF points close to the center


I don't see anything better than the D300 among any of the major brands. There's no AF points in the upper and lower *quarter* of the frame, and sideways they leave only 1/8 of the frame empty in each side. That's a lot of AF points to scroll through, though.

-Lars

#7 toni-a

toni-a

    Advanced Member

  • Members
  • PipPipPip
  • 905 posts
  • LocationLebanon

Posted 04 June 2010 - 10:52 PM

compared to 7D is the difference big enough to justify a swith from canon ?

#8 Brightcolours

Brightcolours

    Advanced Member

  • Members
  • PipPipPip
  • 4,368 posts
  • LocationThe Netherlands

Posted 04 June 2010 - 11:05 PM

No, the difference between the D300(s) and all other APS-C cameras is marginal.
D300:
http://gallery.techa...-Viewfinder.jpg

7D:
http://gallery.photo...10107279-lg.jpg

As you can see, a little bit wider for the D300, and vertically the 7D has the advantage.

It has to do with the optics needed for the phase detect AF module, that AF point distribution is the way it is.

#9 Nick

Nick

    Newbie

  • Members
  • Pip
  • 3 posts

Posted 04 June 2010 - 11:23 PM

The 7D has the advantage that all its focus points are cross type, too. In truth I don't think there's much practical difference between the 7D and D300s in use. I bought one a few weeks ago for sports and wildlife photography, and have been mightily impressed with its overall performance. One thing you do have to do with it, though, is spend some time learning how the AF works and how to set it up to best cope with your shooting style and lenses - manually selecting focus points in high-speed use isn't recommended! It's time well spent. It also produces great all-round results for general photography, although it's a bit of a shock to have to go back to sharpening everything after using a 5D II for a year, but that's another story.

#10 thw

thw

    Advanced Member

  • Members
  • PipPipPip
  • 131 posts

Posted 05 June 2010 - 01:48 AM

Standard answer to folks looking for advice on camera choice:

" 1. Do your level best to get something you really, really like.

2. Make a promise to yourself—set a time goal in order to limit the time you might waste shopping and the money you might waste buying successive iterations of the same item. The best experiences I've had with new cameras were when I invested in exactly what I wanted and promised myself in advance that I'm going to commit to it for a certain period of time. I committed to the M6 for one year, and used it for nearly three; the OM-4T for three years, and used it for nearly five. Both experiences were great—very focused on pictures as opposed to gear. It's fun to shop, but it's crucial to stop.

3. While you own something, no matter what it is, use it as hard as you can and enjoy it."



#11 larsrc

larsrc

    Advanced Member

  • Members
  • PipPipPip
  • 86 posts

Posted 05 June 2010 - 07:06 AM

No, the difference between the D300(s) and all other APS-C cameras is marginal.
D300:
http://gallery.techa...-Viewfinder.jpg

7D:
http://gallery.photo...10107279-lg.jpg

As you can see, a little bit wider for the D300, and vertically the 7D has the advantage.

It has to do with the optics needed for the phase detect AF module, that AF point distribution is the way it is.


There's no way you can get all your wishes, then, it's like wanting a 200 f/1.2 that doesn't weight a lot. Had it been just the placement, live view and electronic viewfinders could have worked, but you also want it to be very fast, which they aren't. Tough.

-Lars

#12 mst

mst

    Advanced Member

  • Moderators
  • 1,904 posts
  • LocationWesterwald, Germany

Posted 05 June 2010 - 08:40 AM

compared to 7D is the difference big enough to justify a swith from canon ?



No, certainly not. There'd have to be lots of reasons before you should even start to consider switching. I guess I'm not the only one who had to learn the lesson that switching systems costs a lot of time, money and nerves.

From my limited personal experience with the 7D and things I have heard from others using the camera it seems to me the 7D is easily the best and most professional APS-C EOS to date. It's close to what I had always hoped and waited for when I was shooting with Canon myself, a digital EOS 3 (just lacks in sensor size).

-- Markus
Editor (Nikon, Leica, Samsung reviews)
photozone.de

#13 PuxaVida

PuxaVida

    Advanced Member

  • Members
  • PipPipPip
  • 757 posts
  • LocationIstanbul

Posted 05 June 2010 - 09:51 AM

Regardless of it's AF performance, any comments on the rumours that the 7D requires high quality lenses because of it's high pixel density?... When it comes to %100 views I suppose...

Serkan

#14 wim

wim

    Advanced Member

  • Members
  • PipPipPip
  • 1,039 posts
  • LocationMaastricht, Netherlands

Posted 05 June 2010 - 06:01 PM

Regardless of it's AF performance, any comments on the rumours that the 7D requires high quality lenses because of it's high pixel density?... When it comes to %100 views I suppose...

Serkan

Hi Serkan,

I think you have to look at it in another way: 100 % view is a view you can use to spot the smallest defects in a lens. That is useful in order to know what you can and can't do with your equipment, but serves no other purpose than that.

Essentially, in my view, digital shooters need to get over two trends which are common, namely the one where you always have to look at 100 % from a close distance to apparently view a photograph at its best, and the other where we apparently have to expect nothing but perfection from lens and camera manufacturers, at any price point.

When it comes to the first point: 100 % was ok up to about 12, maybe 17 MP in FF (60 - 70 lp / mm), and about 6 MP to 10 MP in APS-C (translated to FF that is 40 - 55 lp / mm, at 1.6X enlargement of course). Why is this you may ask? Simply because as very good amateurs using colour negative film we would get 20 - 40 lp / mm from our colour negative films in print. Professionals would get 60 lp / mm, maybe a little more. We had film like sharpness then, so it didn't matter all that much. There was a nice transition from sharp to unsharp when going out of DoF, and there was quite a bit of fall-off from centre to extreme border too. And we were all quite happy with that.

This changed with digital when the first newness wore off. MTFs looked flat, from centre to extreme corner, unlike with most pictures taken on film. This was due IMO because of the different characteristics of the sensor vs film, for one caused by the difference in thickness of the medium (0 of the sensor vs 0.2 mm of the film), the even distribution of "particles" on a sensor, the direct integration of sensor with camera and enlarging equipment (computer and printer), and the sensor assembly, which cut off high frequency resolution drastically. We also saw sharpness come in very rapidly close to the DoF zone, stya more or less th esame, and then disappear quite fast again.

It is much easier to see any defects now then we ever could see with film as a result, although I can assure you that with film it also has been visible all the time, if you cared enough to look. This also gets me to the second point, namely that in t e past we would do occasional 20 x 30's, sometimes a 40 x 50, and often that was it. Most stuff, even today, was printed and viewed on 10 X 15 or 13 X 18 (all cm of course). With 100 % viewing, at 72 dpi, or even at 90 dpi if that is the definition of ones display, you are looking at an image of more than 1 by 1.5 m with most modern cameras, including a 7D, and preferably from 30 or 40 cm away.

The latter is not proper viewing distance. The diagonal X 2 is. If you look from that distance, a proper viewing distance, I can assure you that many of the defects become totally irrelevant.

Coming back to high pixel density: because the combination of high pixel density and AA-filters which cut off only frequencies that are much higher than before, we start seeing the response with sensors we used to see with film, namely a clear or clearer transition from centre to extreme corner, even with the best of lenses, and especially the wider the AoV of a lens is. This is optical laws at play here, we are back again at the normal interaction of optics and medium, no longer screened off as it were from an artifical cut off, which made us believe things looked better than they actually were.

However, things are actually becoming much better than they were, basically because optics still get better, be it at a price. Modern optics from a specific class are better than most stuff produced in the past, and that is not only true for professional lenses, but also for consumer or advanced consumer lenses. Examples are the new 15-85 IS vs the 17-85 IS, the range of 20-35 -> 17-35 -> 16-35 -> 16-35 II, etc , and a bunch of others too, inclusing lenses of other brands.

The things we used to do in the past, and that is IMO where we are right back now with 15 MP+ APS-C cameras and 20 MP+ FF cameras, is to learn to use the camera-lens combinations we own to their best advantage, and/or make use of their weak points to our advantage. Do note that although some lenses may get to "only" 1200 or 1400 lines per image height in their extreme corners when used wide open, this is stil a lot more than we ever got out of film.

And a camera like the 7D is one that ups the level quite significantly again in APS-C land, especially considering all its other characteristics (with the exception of my own pet hate, caused by my eye problems, the frame in the VF which I can't see in one go :)).

Finally, although the 7D has upped the ante with regard to resolution another step, as it has the staggering resolution of ~120 lp/mm in APS-C format, it still doesn't come close to what the best lenses are capable of, yet. 400-450 lp/mm is what a really good lens can do at F/4 (and theoreticall better at larger openings, although only specialist lenses, designed for monochromatic light, manage that , generally speaking). And according to the lens formula that means that combined resolution is about 90 - 100 lp / mm. And this is what we seem to be achieving.

I do expect, however, that by the time we get to similar resolutions as we get from the lenses by themselves, we will have sensor sites that are photon counters, however, no longer traditional well sites. When you get to sites that are the same as or relatively close to the dimensions of the wavelenght of light, it is likely we need to have a different type of sensor to capture anything at all without capturing just noise from the electronics.

Kind regards, Wim
  • mst, Sylvain, Symple and 1 other like this

#15 eltoucan

eltoucan

    Member

  • Members
  • PipPip
  • 24 posts

Posted 05 June 2010 - 06:40 PM

Hi Toni

Since you own the superbe 17-55 IS I would suggest you the 7D.
It has the best AF point coverage in Canon land.

But the best coverage from all DSLR to date is the D300s.
I my opinion it is not worth switching from Canon to Nikon just for that.

I was considering swithing to Nikon until the 7D arrived.

I would say that it is not worth switching from Nikon to Canon for the 7D and
it is not worth switching from Canon to Nikon for the D300s.
Both are equal.

Regards
Emmanuel

#16 Sylvain

Sylvain

    Advanced Member

  • Members
  • PipPipPip
  • 562 posts
  • LocationBrussels, Belgium

Posted 05 June 2010 - 11:02 PM

Wim, now that we have a new forum, there is hope to make a "sticky" post with all your elaborate posts :)

sorry for interrupting,
  • Project2501 likes this

#17 wim

wim

    Advanced Member

  • Members
  • PipPipPip
  • 1,039 posts
  • LocationMaastricht, Netherlands

Posted 05 June 2010 - 11:34 PM

Hi Sylvain,

Wim, now that we have a new forum, there is hope to make a "sticky" post with all your elaborate posts :)

sorry for interrupting,

:). I wouldn't consider yo r post interrupting. I must say however, that I just looked back, and got a little shock. I hadn't realized how long that post had become :D.

I guess I take to the new forum better than to the old one :D.

Kindest regards, Wim :)

#18 Project2501

Project2501

    Member

  • Members
  • PipPip
  • 11 posts
  • LocationWales, United Kingdom

Posted 06 June 2010 - 01:13 AM

If money really is not an issue here, have you considered the full frame speed horses of both Canon and Nikon?

Nikon D3s ($5200)
>> Review 01: dpreview.com
>> Review 02: letsgodigital.org

Canon EOS 1D Mark IV ($4900)
>> Review 01: dpreview.com
>> Review 02: the-digital-picture.com
>> Review 03: whatdigitalcamera.com

Nikon D3 ($4100)
>> Review 01: dpreview.com
Preview 01: letsgodigital.org

Nikon D700 ($2400)
>> Review 01: dpreview.com
>> Review 02: letsgodigital.org

Canon EOS 1D Mark III ($2000) <- Is this a bargain?
>> Review 01: the-digital-picture.com
Preview 01: letsgodigital.org



Canon EOS 7D ($1500)
>> Review 01: dpreview.com
>> Review 02: the-digital-picture.com

Nikon D300s ($1500)
>> Review 01: dpreview.com
>> Review 02: letsgodigital.org

I do not own any of the cameras above, but I can tell you that in terms of ergonomics the EOS 7D and D300s are both very comfortable to hold even with longer lenses such as the 70-200mm f2.8 variants. I would say that the Nikon MD-10 battery grip is in a league of its own compared to my Canon BG-E2N ergonomics :)

All prices from www.amazon.com (www.idealo.com is not working yet in the US)

Edited by Project2501, 06 June 2010 - 12:31 PM.

  • Project2501 likes this
:: 4creation.net :: Digital Photography by Harald Brauer
Canon EOS 40D / 17-40mm f4 L / Speedlite 580EX II / Manfrotto 055XPro / Datacolor Spyder3 Elite

#19 eltoucan

eltoucan

    Member

  • Members
  • PipPip
  • 24 posts

Posted 06 June 2010 - 09:30 AM

If money really is not an issue here, have you considered the full frame speed horses of both Canon and Nikon?

Canon EOS 1D Mark IV ($4900)
>> Review 01: dpreview.com
>> Review 02: the-digital-picture.com
>> Review 03: whatdigitalcamera.com

Nikon D3s ($5200)
>> Review 01: dpreview.com
>> Review 02: letsgodigital.org

Nikon D3 ($4100)
>> Review 01: dpreview.com
Preview 01: letsgodigital.org

Canon EOS 1D Mark III ($2000)
>> Review 01: the-digital-picture.com
Preview 01: letsgodigital.org



All prices from www.amazon.com (www.idealo.com is not working yet in the US)



Even if money is not an issue, the weight can become one.
That is the reason why I took the 7D over the 5D.
And I still find my system too heavy.
Weight is actually stopping me each time I consider the 17-55IS.

#20 PuxaVida

PuxaVida

    Advanced Member

  • Members
  • PipPipPip
  • 757 posts
  • LocationIstanbul

Posted 06 June 2010 - 12:41 PM

Wim, thanks for the very "brief" info Posted Image... I understand that the high quality lenses produce way better resolutions than the sensor can.

But when it comes to the IQ produced, do you think the 120 lp/mm resolution of the sensor is prone to diffraction (even with high quality APO lenses), or do we still have a room for it in there? This question is asked ignoring the fact that 7D is not the best body for wide angle &amp; closed aperture shots, but better for tele&amp; bird shots. I'm playing my "theoretical discussion" card and try to get from you what I can Posted Image...

Regards,

PS: I'm not sure how I could manage not to post this message as a reply to Wim... but it was... anyway, long live the new edit mode !...

Serkan




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users



© by photozone.de