New lens... err body?

[K-amps]

This might sound weird to some of you but I wanted to run this by you guys.

I want longer reach... but am thinking of buying a new body to do this.

I currently own a 70-300mm L lens on a 5d Classic body, I would like to take some bird shots, but upgrading to the 100-400mm wont give me much more reach. However if I get a 7D body for the same price of a 100-400mm, I get 480mm effective range due to crop on my current 70-300mm... and maybe more.

I can illuminate more pixels (photosites?) on the 7D's 18 mp sensor thereby giving me an additional increase in resolution of (18mp/12.7mp*100 =) 41.7%... thereby increasing this advantage to 480 * 41.7 = 680mm equivalent resolving power.

Is this making sense or am I way off?

 

[Fleetie]

Yep, makes complete sense.

The only correction is that your LINEAR resolution will not increase by quite as much as you said; it will increase by a factor of sqrt(18/12.7) ~= 1.191, i.e. about 19% better.

But that will be compensated for by the extra pleasure you'll derive from using the 7D itself!

[neuroanatomist]

Agreed, subject to Fleetie's mathematical correction.  If you're focal length limited, in practice an APS-C sensor is acting like a 'perfect' 1.6x teleconverter. The light loss with a TC translates to increased ISO noise, and there are no optical aberrations or loss of sharpness like you get with a TC.

[niccyboy]

Good plan although from a different direction - the 100-400 won't depreciate as much as the 7d financially.

[ianhar]

Wow you guys are really good with all this photography math.

[dr croubie]

and on the plus side, i'll buy your 5D classic off you...

(given that the 1D4 has been killed off for the 1DX, the 7D is now the king of currently-available birding cameras. 1D4 is probably better, if you can find any available and affordable)

I've got the 70-300L on 7D, and i've used the 100-400 borrowed from a relative. IQ isn't too much different, but i'd take the 70-300L any day.

[TexPhoto]

7D is  a great camera to get some extra length out of your longer lenses.  And yes it does appear to be a 640mm lens on your 7D vs a 400mm on a FF.  (or course it does this via a cropped sensor, and we can just crop in photoshop...)  But then of course the pixels are much more densly packed as has been pointed out.  So as long as the lens is sharp enough, and your shooting steady enough, you will get more detail.

7D is also a great sports/wildlife camera, it's focus system is awsome.

I bought a 7D as a companion for my 5D2 for the above reasons and am very happy with the combination.  The fact tehy use the same battery and CF cards has been a real bonus.

[Mt Spokane Photography]

I've done the same thing, I have a 5D MK II and a 7D.  My 100-400mm zoom becomes 1.6 longer, but the light loss can be a issue if not in bright light. 

I think a lot of people do this.  The 7D and 5D MK II use the same batteries, and both use CF cards, so I don't have to duplicate accessoroes.

[ianhar]

@mt spokane, yup i'm one of the people who do it.

[K-amps]

Good plan although from a different direction - the 100-400 won't depreciate as much as the 7d financially.

Yes and thats what is stopping me from placing the order already ... Got to think about this. Maybe if the 7D2 is not so awesome, I can pick up a 7d for a lower price?

[K-amps]

All:  Thanks for your input.

Neuro/others ... for a given light level, how would the 5d1 compare to the 7D? (if I were to get a 2x mk. III as well)

[neuroanatomist]

For birds, I'd definitely take the 7D over the 5Dc with the 70-300 L. 

What lens were you planning to get to use with the 2x TC?  Your 70-300 L cannot take a Canon TC.

[niccyboy]

Good plan although from a different direction - the 100-400 won't depreciate as much as the 7d financially.

Yes and thats what is stopping me from placing the order already ... Got to think about this. Maybe if the 7D2 is not so awesome, I can pick up a 7d for a lower price?

In Aus they are now selling on sale for around 1200!

Which sucks because I am wanting to sell my gripped one at the moment, and am reluctant to let it go that cheaply. Buttttt that's the problem with aps-c bodies and I guess bodies in general.

ANYWAY - I have heard very good things about the 100-400.... maybe get some new shoes so you can sneak closer and don't need the reach hahahaa.

[briansquibb]

I have a 400 f/2.8IS - fantastic on my 5DII. But I bought a 7D for birding - there is no equivalent ff to be had.

Just remember that the 400 on ff is the equivalent to the 250 of APS-C. I dont know how the 1DX people will manage their birding now - it was hard enough on a 1.3 crop.

Perhaps Canon will bring out an EOS 3D - 1.3, 12fps, 16mp, 63point AF - you get the drift. Canon have already said they are not dropping the 1.3 crop ........

[niccyboy]

I have a 400 f/2.8IS - fantastic on my 5DII. But I bought a 7D for birding - there is no equivalent ff to be had.

Just remember that the 400 on ff is the equivalent to the 250 of APS-C. I dont know how the 1DX people will manage their birding now - it was hard enough on a 1.3 crop.

Perhaps Canon will bring out an EOS 3D - 1.3, 12fps, 16mp, 63point AF - you get the drift. Canon have already said they are not dropping the 1.3 crop ........

Wouldn't it kill their 1dx sales... with a high frame rate, massive focus points and a comparable resolution... and a lower price?