Autofocus comparisons: Canon 1V vs 50D

I wanted to see if the 50D (which I borrowed from Canon) could autofocus and
track as fast as my 1V. They both have a maxumum frame rate of about 6 fps
(with a power pack with 8 AA batteries on the 1V), so they are fast enough
to catch the peak of wildlife action. (Because of the 1.6 crop factor, the
50D would be for wildlife, not scenics.) It has the new Digic 4 processor
and a 15 MP CMOS. Canon could not tell me any objective way to assess
autofocus. (It seems there should be some standard.) Anyway, I tried a
couple of subjective tests.

1. Point at a far subject and set lens to focus at minimum. Engage
autofocus and time how long it takes to focus. On "One shot" it beeps when
focus is achieved. Repeat for close subject, starting focused far.

Both cameras did about the same, about 1 sec or less.

2. Track birds in flight. There's a place near me (Arcata Marsh, northern
California) where hundreds of Marbled Godwits, Avocets, Willets, etc., hang
out on some small islands and start to fly out to feed in the mudflats in
Humboldt Bay as the tide goes out. I could position myself with the sun
behind me late afternoon, and the birds would fly out singly or in groups of
about 20. They came straight toward me or at various distances off to the
side, as the flats were behind me. They generally stayed close to the water
until they got close to the land spit I was on (between the islands and the
flats), then went up and over. So initially the background was water, then
trees, then sky. It took about 90 minutes for them all to leave, so I had
lots of opportunity to get a feel for how well each camera did. I used a
600 f/4 L IS with a Wimberly head, switching bodies every few minutes. I
tried them both with just the center focus point active, or with about 12
active. I took plenty of pictures, but was mainly concerned with how well
I could track.

The 1V was the clear winner in the tracking test. It was always easiest to
stay with a bird if the initial acquisition was while they were just coming
off the islands, about 100 yards away. Sometimes I would lose focus (as
when I could not keep them in the viewfinder), then re-acquire. It was
easier to re-acquire when sky was the background vs trees (about 100 yards
away). But the 50D had a very hard time when trees were the background. It
would not focus on anything. Often I would follow an out-of-focus bird the
whole way and the 50D never got it.

This suggests I might not be buying a 50D, as it does not do wide angle for
scenics, and cannot keep up with fast wildlife. There are, of course lots
of advantages to the 50D, and I still have not compared the digital images
to film.

So next I'll try the 1D Mark 3. It has 2 Digic 3 processors and a 10 MP
CMOS. Canon tells me that it is their fastest autofocus (but, again, no
objective measure).

--
Alan Justice

Alan Justice wrote:
I wanted to see if the 50D (which I borrowed from Canon) could autofocus and
track as fast as my 1V. They both have a maxumum frame rate of about 6 fps
(with a power pack with 8 AA batteries on the 1V), so they are fast enough
to catch the peak of wildlife action. (Because of the 1.6 crop factor, the
50D would be for wildlife, not scenics.) It has the new Digic 4 processor
and a 15 MP CMOS. Canon could not tell me any objective way to assess
autofocus. (It seems there should be some standard.) Anyway, I tried a
couple of subjective tests.

1. Point at a far subject and set lens to focus at minimum. Engage
autofocus and time how long it takes to focus. On "One shot" it beeps when
focus is achieved. Repeat for close subject, starting focused far.

Both cameras did about the same, about 1 sec or less.

2. Track birds in flight. There's a place near me (Arcata Marsh, northern
California) where hundreds of Marbled Godwits, Avocets, Willets, etc., hang
out on some small islands and start to fly out to feed in the mudflats in
Humboldt Bay as the tide goes out. I could position myself with the sun
behind me late afternoon, and the birds would fly out singly or in groups of
about 20. They came straight toward me or at various distances off to the
side, as the flats were behind me. They generally stayed close to the water
until they got close to the land spit I was on (between the islands and the
flats), then went up and over. So initially the background was water, then
trees, then sky. It took about 90 minutes for them all to leave, so I had
lots of opportunity to get a feel for how well each camera did. I used a
600 f/4 L IS with a Wimberly head, switching bodies every few minutes. I
tried them both with just the center focus point active, or with about 12
active. I took plenty of pictures, but was mainly concerned with how well
I could track.

The 1V was the clear winner in the tracking test. It was always easiest to
stay with a bird if the initial acquisition was while they were just coming
off the islands, about 100 yards away. Sometimes I would lose focus (as
when I could not keep them in the viewfinder), then re-acquire. It was
easier to re-acquire when sky was the background vs trees (about 100 yards
away). But the 50D had a very hard time when trees were the background. It
would not focus on anything. Often I would follow an out-of-focus bird the
whole way and the 50D never got it.

This suggests I might not be buying a 50D, as it does not do wide angle for
scenics, and cannot keep up with fast wildlife. There are, of course lots
of advantages to the 50D, and I still have not compared the digital images
to film.

So next I'll try the 1D Mark 3. It has 2 Digic 3 processors and a 10 MP
CMOS. Canon tells me that it is their fastest autofocus (but, again, no
objective measure).


Good luck with the tracking focus Alan. I've never found Canon's DSLRs
to be as good as their film SLR cameras at this. Nikon works good but
only with their ultra expensive lenses.

I believe Minolta (now Sony) had and still have the market cornered when
focus tracking a moving object coming towards you. At some point, they
all fall down.

It sounds to me like you already know it's easier 50% of the time to
manually track for focus with birds. After using a 50D for about 10
minutes at a Canon demonstration, I certainly wouldn't be lining up for
one if wild life was the prime criteria for a purchase - regardless of
any investment I might have in lenses.

"Jurgen" wrote in message
...
Alan Justice wrote:
I wanted to see if the 50D (which I borrowed from Canon) could autofocus
and
track as fast as my 1V. They both have a maxumum frame rate of about 6
fps
(with a power pack with 8 AA batteries on the 1V), so they are fast
enough
to catch the peak of wildlife action. (Because of the 1.6 crop factor,
the
50D would be for wildlife, not scenics.) It has the new Digic 4
processor
and a 15 MP CMOS. Canon could not tell me any objective way to assess
autofocus. (It seems there should be some standard.) Anyway, I tried a
couple of subjective tests.

1. Point at a far subject and set lens to focus at minimum. Engage
autofocus and time how long it takes to focus. On "One shot" it beeps
when
focus is achieved. Repeat for close subject, starting focused far.

Both cameras did about the same, about 1 sec or less.

2. Track birds in flight. There's a place near me (Arcata Marsh,
northern
California) where hundreds of Marbled Godwits, Avocets, Willets, etc.,
hang
out on some small islands and start to fly out to feed in the mudflats
in
Humboldt Bay as the tide goes out. I could position myself with the sun
behind me late afternoon, and the birds would fly out singly or in
groups of
about 20. They came straight toward me or at various distances off to
the
side, as the flats were behind me. They generally stayed close to the
water
until they got close to the land spit I was on (between the islands and
the
flats), then went up and over. So initially the background was water,
then
trees, then sky. It took about 90 minutes for them all to leave, so I
had
lots of opportunity to get a feel for how well each camera did. I used
a
600 f/4 L IS with a Wimberly head, switching bodies every few minutes.
I
tried them both with just the center focus point active, or with about
12
active. I took plenty of pictures, but was mainly concerned with how
well
I could track.

The 1V was the clear winner in the tracking test. It was always easiest
to
stay with a bird if the initial acquisition was while they were just
coming
off the islands, about 100 yards away. Sometimes I would lose focus (as
when I could not keep them in the viewfinder), then re-acquire. It was
easier to re-acquire when sky was the background vs trees (about 100
yards
away). But the 50D had a very hard time when trees were the background.
It
would not focus on anything. Often I would follow an out-of-focus bird
the
whole way and the 50D never got it.

This suggests I might not be buying a 50D, as it does not do wide angle
for
scenics, and cannot keep up with fast wildlife. There are, of course
lots
of advantages to the 50D, and I still have not compared the digital
images
to film.

So next I'll try the 1D Mark 3. It has 2 Digic 3 processors and a 10 MP
CMOS. Canon tells me that it is their fastest autofocus (but, again, no
objective measure).


Good luck with the tracking focus Alan. I've never found Canon's DSLRs
to be as good as their film SLR cameras at this. Nikon works good but
only with their ultra expensive lenses.

I believe Minolta (now Sony) had and still have the market cornered when
focus tracking a moving object coming towards you. At some point, they
all fall down.

It sounds to me like you already know it's easier 50% of the time to
manually track for focus with birds. After using a 50D for about 10
minutes at a Canon demonstration, I certainly wouldn't be lining up for
one if wild life was the prime criteria for a purchase - regardless of
any investment I might have in lenses.

I've got too much invested in Canon lenses to consider switching, but it's
good to know about alternatives (Sony). I had never considered a non-Canon
non-Nikon before.


--
Alan Justice

Alan Justice wrote:

So next I'll try the 1D Mark 3. It has 2 Digic 3 processors and a 10 MP
CMOS. Canon tells me that it is their fastest autofocus (but, again, no
objective measure).

Good luck with the tracking focus Alan. I've never found Canon's DSLRs
to be as good as their film SLR cameras at this. Nikon works good but
only with their ultra expensive lenses.

I believe Minolta (now Sony) had and still have the market cornered when
focus tracking a moving object coming towards you. At some point, they
all fall down.

It sounds to me like you already know it's easier 50% of the time to
manually track for focus with birds. After using a 50D for about 10
minutes at a Canon demonstration, I certainly wouldn't be lining up for
one if wild life was the prime criteria for a purchase - regardless of
any investment I might have in lenses.

I've got too much invested in Canon lenses to consider switching, but it's
good to know about alternatives (Sony). I had never considered a non-Canon
non-Nikon before.

Sony have introduced some exciting lenses while retaining many of the
best Minolta designs, but they do not have the breadth and depth of
Canon or Nikon.

If one is very choosy and willing to part with the bucks, one can build
a very good Sony/Minolta lens set, but there are some gaps v. Canon and
Nikon.

Having bought the Carl Zeiss designed 135 f/1.8 (a stellar lens), I'm
looking forward to the 85 f/1.4 and the soon to be released 16-35 f/2.8.

I have Minolta era lenses that are also up to 24 Mpix sensors such as
the 100 f/2.8 macro, 80-200 f/2.8G, 300 f/2.8 and 28-70 f/2.8.

It remains to be seen if the 50 f/1.7 and 20 f/2.8 are up to it (and the
28-70 might not be very great at 24 Mpix).

Despite the CZ 135 I still have a hankering for the Minolta 135 f/2.8
[T4.5] STF - a lens in its own class (and also made with a "Sony" badge)
that is very sharp, yet provides for exceptionally smooth OOF renderings.

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