Why don't crop sensor cameras have crop weight bodies?

The Canon 7D with its 1.6-factor sensor weighs 900 g with battery --
the Full Frame Canon 5D2 weighs 907 g.

What the hell?

Why aren't the smaller-frame bodies significantly smaller than the
bigger frame models, as used to be the case between 35mm film cameras
and the medium format models like the RZ and the Hasselblad?

The small frame normal zoom for the 7D is the 17-55mm lens, and it
weighs 645 g. The corresponding model for the 5D2 is the 24-105mm, at
670 g -- only 25g heavier.

Put body and lens together and the bigger format weighs only 2% more.
The difference in price is around $1000. But for that extra cash, I'm
getting so much more camera.

The 24-105 lens has a smaller aperture, but considering the size of
the sensor, gives about the same DOF as the 17-55mm lens for the same
composition with both lenses wide open. I can compensate for the
slower speed of the 24-105 lens by dialling in one stop more ISO. I
won't get more noise because the pixels are larger. So DOF and noise
are roughly equal, after making these adjustments.

But the bigger format gives me better resolution. The lens has a 4.4x
zoom, instead of only 3.2x for the smaller camera. The 5D2 is less
limited by diffraction. And all reports suggest the 5D2 produces much
better IQ than small frame models.

All this for a diff of a thousand bucks.

What am I missing here?

Wally

 

They have the same size lens mount is the most obvious answer and the
sensor it a tiny fraction of the overall weight and size. I dare say it
has many similar components as well.

If the weight is so important attach a couple of 100g weights via the
tripod socket.

Mike

 

You're comparing about the lowest spec 35mm format dslr camera on the
market with one of the highest spec crop sensor dslrs.

 

As far as I am concerned if I were to change from my 7D to 5D2 I would lose
140mm of zoom. That is, my 100-400mm zoom lens would show the same field of
view as it would on a 35mm camera. With the 1.6 crop factor on the 7D my
field of view is the same as a 160-640mm on a full frame sensor camera and I
can hand hold the 7D and lens when I shoot. Try hand holding the 5D2 with a
160-640mm zoom lens! I don't really care what the "normal" lens is or what
a wide angle lens is on the 7D as my 100-400mm lens is the only lens that I
have had on my 7D.

Ron

 

now compare it with the canon 550d, which weighs 530g, just over half
the weight.

they *are* smaller & lighter, depending on which model.

now compare a 18-200mm crop lens versus canon's 28-300 full frame
version. one is a *lot* bigger, heavier and more expensive.

 

Since the D3/D700/D3s/D3x, 1dsIII, - perhaps also the A900.
It has a slow frame rates (and faster frame rates with short blackout
time need a faster / stronger mirror assembly), and an old and fairly
limited AF system, it also doesn't have a popup flash with wireless, nor
a fully weatherproofed body design. The D700 weighs about 200g more
than the 5dII.

 

Stop being glued to Nikon and Canon and you might FIND some.

 

Not much difference in the actual size and weight of the silicon sensors.
Not a good idea to try to remap old film facts, in this case. Analogies
tend to fail miserably in high-tech replacements.

Those little Si sensors are a marvel of modern technology and tend to be
near the cutting edge (when first released). With the rapid change we now
enjoy(?), they tend to be boring after just a few years.

 

Right -- for long lenses, the 7D would be much better, because the 7D
has much higher pixel density.

Wally

 

Not really, it might even be worse. You need a lens that can actually
make full use of the sensor. The tighter the pixel density, the
better the lens has to be. In other words, ask yourself why Olympus
measures its Top Pro lenses at 60lpmm where other companies only use
30 or 40. When you stuff 12 megapixels into a 4/3rds sensor, you need
superb lenses to deal with that pixel density, which is higher than
any other camera's, except Panasonic's 16 megapixel sensors.

 

Yes, but the extra pixels don't weigh much.

 

That's sloppy wording even for you, Rich. Much higher pixel densities
exist in 14 MP and 16 MP point and shoot digicams whose sensors are a
tiny fraction of the size of (Micro) Four Thirds sensors.

Just a word on the Panasonic GH2 with the 16 MP sensor; it is a
noisebox, with luminance noise clearly visible at anything over ISO
160 and severe from ISO 640 upwards. I have just finished testing one
for a magazine review and it was quite a disappointment.

Given the sheer excellence of the Sony 16 MP APS-C sensors that are
available in Sony NEX and Alpha, Nikon and Pentax bodies, it would
appear that (Micro) Four Thirds has hit a very solid wall beyond which
any progression would appear unlikely.

 

So is my toothpaste tube.
I wonder if the OP uses toothpaste.
Or, perhaps he rubs it in his eyes before he posts articles. Hmnn

 

I hope you mean 1600 and 6400, and that you have a good editor.

 

I doubt if you will ever see the review, or learn the name of the magazine.

 

"If a sensor weighs just three grams then why does the
camera weigh 900 grams?"

A sensor is not a camera.
A camera is not a sensor.

Get a clue.

 

Yup. Might as well ask why a film camera doesn't weigh much less when
you load 12-exposure film instead of 24.

 

An interesting thought. Or perhaps not. ;-)

 

Interesting theory. We have lossless compression. Do we now have
weightless film?

 

Maybe the manufacturers pour cement into them to give them extra heft.
Makes them feel more expensive and justifies the high price.

Wally