# New lens... err body?



## K-amps (Oct 24, 2011)

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?


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## Fleetie (Oct 24, 2011)

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!


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## neuroanatomist (Oct 24, 2011)

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.


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## niccyboy (Oct 24, 2011)

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


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## ianhar (Oct 24, 2011)

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


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## dr croubie (Oct 24, 2011)

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.


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## TexPhoto (Oct 25, 2011)

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.


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## Mt Spokane Photography (Oct 25, 2011)

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.


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## ianhar (Oct 25, 2011)

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


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## K-amps (Oct 25, 2011)

niccyboy said:


> 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?


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## K-amps (Oct 25, 2011)

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)


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## neuroanatomist (Oct 26, 2011)

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.


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## niccyboy (Oct 26, 2011)

K-amps said:


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



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.


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## briansquibb (Oct 26, 2011)

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 ........


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## niccyboy (Oct 26, 2011)

briansquibb said:


> 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?


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## briansquibb (Oct 26, 2011)

Wouldn't have the high iso capability - essentially a tweaked 7D with the 1D4 sensor


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## ianhar (Oct 26, 2011)

niccyboy said:


> K-amps said:
> 
> 
> > niccyboy said:
> ...



Damn which store is this niccyboy?


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## K-amps (Oct 26, 2011)

neuroanatomist said:


> 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.



I read a review that it takes the Mk. III converters. The guy shot some pics with the 2x Mk. III


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## dr croubie (Oct 26, 2011)

K-amps said:


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


The 70-300L can definitely *not* take canon extenders. Check out the shots below. See how the glass in the extender extends 'beyond' the flange (thanks to TDP for the pic).
And I couldn't find a pic of the 70-300L so i took a quick one myself, sorry about the quality. That's at 300mm, minimum focus distance. The glass extends back from the flange the other way. Put those 2 together = crunch.

Apparently there are Kenko extenders that fit the 70-300L. Some translate the aperture, and some dont. (ie, at 300mm f/5.6, a 1.4x converter gives 400mm f/8. Some (i think the cheaper ones) still tell the camera 300/5.6 and AF works, some tell the camera 420mm/8 and AF doesn't work. I wish I knew which ones did what, then I'd buy one)


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## neuroanatomist (Oct 27, 2011)

K-amps said:


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



Ahhh the Internet, fountain of Truth. :


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## wickidwombat (Oct 27, 2011)

Howdy I have the kenko C-AF 1.4X teleplus pro 300DGX it works with all lenses fully translates the aperture I used it for ages on a 28-300 L and it is awesome (I since sold that lens and got a 300f4L IS instead, some softening of the image wide open but drop it 1 stop in good light and iq is still awesome. I've tested it on all my lenses even works on the 16-35 not that i actually use that combo but it does work really nicely with the 50mm f1.4 and gives very sharp f2 images


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## K-amps (Oct 27, 2011)

neuroanatomist said:


> K-amps said:
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> > neuroanatomist said:
> ...



The source was: Shutterbug Magazine.

Aug 2011 issue

The reviewer was Farace or something IIRC.

Edit: found it on the "internet" too. Here's the URL for it:http://www.shutterbug.com/content/canon-ef-70-300mm-f4-56l-usm-long-short-it


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## neuroanatomist (Oct 27, 2011)

Thanks for the link. I agree with the one comment posted to the review - that was a pretty bad misrepresentation. As Dr. Croubie points out, the rear element of the lens is right at the back. I think he mis-typed when stating it's at 300mm - I think it's at 70mm and the rear element moves further 'in' (away from the lens mount) as you zoom to 300mm - at least, that's how most extending zooms behave (except the 24-70mm which uses a reversed design). So, it's 'compatible' at longer focal lengths, but not 'compatible' (= lens damage) at shorter focal lengths.


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## dr croubie (Oct 28, 2011)

neuroanatomist said:


> ...I think he mis-typed when stating it's at 300mm - I think it's at 70mm and the rear element moves further 'in' (away from the lens mount) as you zoom to 300mm - at least, that's how most extending zooms behave...


Well, yes and no.
a) I'm bored.
b) It just started raining so i've got nothing better to do than take photos inside.
c) I just got my first-ever speedlite in the post from ebay (a 430EXmk1) that I wanted to try out, i put it on the floor pointing at the rear element to reflect to make it easier to see.
d) The 70-300L is not a "normal" design, it's got 'floating elements' all over the place. At 70mm, the difference between macro and infinity is not much. Leave the focus at macro and zoom to 300mm, the rear element will come out a bit (200mm or so) then go back in by 300mm. At 200 - 300mm, the difference between macro and infinity is more than a few cm travel into the body.
e) In a way, that article is right. you *can* physically mount the 2x TC onto the lens, there's nothing stopping you. **BUT** you can only focus at infinity, and above 200mm or so. Focussing any closer than 5m @ 300mm, or infinity @ <200mm (a guess because I don't have one in from of me) will be crunching stuff. He may have meant "it was obvious I would have to shoot using manual focus" because of the aperture, but also because if AF hunts it's going to break something.
f) It's probably ok to use a t/c if you put an extension tube in between the t/c and lens. But then you're at macro only.


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## dr croubie (Oct 28, 2011)

(and the two others at 210mm or so, when the element is closest to the sensor at macro-focus)


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## neuroanatomist (Oct 28, 2011)

Thanks! 

I think the take-home is that it's *not* compatible. I mean, you _can_ mount an EF-S 10-22mm on a 1D III, if you remove some plastic and don't use 10mm...but I wouldn't call that compatible, either...


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## K-amps (Oct 29, 2011)

neuroanatomist said:


> Thanks for the link. I agree with the one comment posted to the review - that was a pretty bad misrepresentation. As Dr. Croubie points out, the rear element of the lens is right at the back. I think he mis-typed when stating it's at 300mm - I think it's at 70mm and the rear element moves further 'in' (away from the lens mount) as you zoom to 300mm - at least, that's how most extending zooms behave (except the 24-70mm which uses a reversed design). So, it's 'compatible' at longer focal lengths, but not 'compatible' (= lens damage) at shorter focal lengths.



An apt theory.. since it will be used for longer lengths anyway, it could work. 

Dr. Croubie: Thanks for the extra pics, I would not have understood it well without them.

Is lens damage really a concern? I mean there's plastic hitting glass, so unless someone is careless, I would think the risk is limited if used with the knowledge that the floating lens hunts, No AF to be used and should keep the zoom at 300mm?... I guess not worth buying a brand new 2x over the 70-300mm unless one had one lying around....


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