Hi Bob,
Please keep in mind that the following comments are my own personal opinions based on my own experiences and observations. Other
people will have different opinions and I accept that.
Many people will have quite different needs, methods and aspirations to those I have and I am not saying I am the only one who is
right.
Major improvements in the 7D compared to the 40D (along with possibly some less
major improvements):
- brighter, larger optical viewfinder;
- greater battery capacity (part of that that may be a result of more efficient
electrics in the 7D system);
- greatly improved Auto-focus system; the 40D is pretty good in that department but the increased choices for focus-point selection
in the 7D are a big improvement;
- the addition of 'spot-focus' which allows the 7D to focus more precisely when the subject is partly obscured by vegetation, for
example;
- faster auto-focus lock;
- hugely improved LCD monitor (although, I find the LCD screen is a little too good - almost every shot looks sharp and focused when
reviewed on the camera monitor but they may not look quite so good on a computer monitor);
- improved Live View function; the improved LCD screen helps here but also the overall functionality is improved (I don't use the
video recording function so I can't comment on except to say it is good enough for the production of some TV soap-operas);
- higher frame rates;
- the higher pixel count on the 7D sensor gives much increased detail in the images (many photographers, a lot who do not actually
use the 7D, obsess over perceived 'noise' in the 7D images but my experience is that careful processing with the latest non-Canon
software deals with that to my satisfaction);
- hugely improved and flexible wireless control of external flash units (no
cables) by the built-in camera flash;
There are probably more improvements but that is all I can think of quickly.
A few downsides to upgrading from an earlier model Canon DSLR:
- new battery required - expensive, of course, and the available non-Canon batteries may not have the battery monitoring
compatibility of the Canon one;
- larger capacity and faster media cards (Compact Flash) are usually required;
- may have to update Photoshop if that is your software of choice;
- image files are very big so more hard disk storage space may be needed to
store images.
- there will be a learning period to get through before being able to get the
best out of the 7D.
Although I don't entirely agree with some of the things that Alistair said (or Chris Ross for that matter) but he has a good point
about thinking seriously about the lenses you should be using, assuming that your intention is biased towards bird-photography.
The Canon 100 - 400 mm L lens is definitely more than a 'consumer' lens. I won't go into the details but a direct comparison of any
of the Canon 'L' lenses and any of their 'consumer' lenses will quickly reveal why I say that. There have been questions about that
lens in the past but all the evidence I have seen (many, many images taken with several copies of that lens) indicates that any
problems with image quality have been solved in more recent production. It is an old design and the image stabilising system is a
bit dated and it is not weather sealed; the 'push-pull' zoom system seems to be guilty of sucking dust into the camera but the
latest cameras seem to cope well with that with their dust clearing systems. The 100 - 400 mm L lens is not as robust as either the
300 mm f/2.8 L or 500 mm f/4 lenses and it is not a good idea to use it at sea if the weather is not perfect. It is a very versatile
lens but, ultimately, it is just a bit short in focal length for the sort of bird-photography I prefer. The longer focal length of
the 500 mm f/4 lens (especially when fitted with a 1.4x Extender) enables shots to be taken from a distance that the subject is
more likely to tolerate.
On a 7D the 300 mm f/2.8 auto-focuses with the 2x Extender fitted. This gives the equivalent of 600 mm which is a good focal length
for most bird-photography. On a 'crop' camera (a camera with a sensor smaller in size to that of a 35 frame of film) the field of
view is reduced to the equivalent of that of a longer focal length lens. This lens combination on the 7D produces a reduced field of
view equivalent to that of a 960 mm lens. There is a great deal of 'discussion' surrounding this 'crop' factor subject and I don't
intend to go into it here. If anyone wants to argue with me about 'the facts' they will be disappointed - I will not argue about it
on line but feel free to discuss it amongst yourselves.
Upgrading from a 100 - 400 mm L lens to a 300 mm f/2.8 L or 500 mm f/4 L lens will, no doubt, be an improvement and is a worthwhile
thing to do if you can afford it or you can justify doing it even if you can't afford it.
There is no doubt that investment in a good lens is a good long term investment while investing in a good camera body is a good
short term investment.
One advantage in going for the 1 series Canon cameras in this respect is that the bodies are not replaced as often as the lesser
bodies are so there is less temptation or reason to upgrade.
Very good quality images can be recorded using a Canon EOS 450D (or 40D) fitted with a 300 mm f/2.8 L or 500 mm f/4 L lens but the
newer camera bodies will produce better quality images with those same lenses. Recording digital images involves sophisticated
mathematics which improve with each new central processor fitted to each new camera body; new sensor and processor design produces
better image detail/quality. But the latest digital SLRs are testing out even the best lenses so there will probably come a time
when the 100 - 400 mm L zoom lens is not good enough but it will have gone out of production by then.
Whether you go for a better camera body or a better lens you will not regret either choice. If you have a Canon DSLR and you don't
have a Canon L grade supertelephoto lens then a better lens would be the better choice. If you do have a Canon L grade
supertelephoto lens then an upgrade to your camera body would probably be the better choice.
Remember, those are simply the opinions of one person but someone who does have more than a bit of experience with the equipment
that Dick Jenkins asked about.
Cheers
Bob Inglis
Sandstone Point
Qld
Australia
http://users.tpg.com.au/inglisrc/
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