# Am I missing something in the math/conversion here?



## crasher8 (Aug 5, 2013)

I'm getting an M. Mostly this will be my Parks (WDW) travel setup where the 5D3 is too bulky/heavy. 

I'm thinking for Animal Kingdom in bringing the M with the Tamron 70-200 + 1.4 TC. I get 448mm @ f/4. Is that right?


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## neuroanatomist (Aug 5, 2013)

The FF equivalent of the long end would be 448mm, and f/6.3 in terms of DoF for equivalent framing.


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## Mt Spokane Photography (Aug 5, 2013)

crasher8 said:


> I'm getting an M. Mostly this will be my Parks (WDW) travel setup where the 5D3 is too bulky/heavy.
> 
> I'm thinking for Animal Kingdom in bringing the M with the Tamron 70-200 + 1.4 TC. I get 448mm @ f/4. Is that right?


The "M" is APS C, so you will see a angle of view 1.6 X that of a 200mm lens, or 320mm. 
Have you tried one with the Tamron? I would not expect it to work well with a Tamron lens, it may be extremely slow to focus. Most third party lenses do not play well with Canon's live view. There is no phase detect with a EOS M, so try first or make sure you can return it.
With a huge lens, the body size makes only a slight difference, and balance may be poor. You might be far better off with a SL1 and the ability to use phase detect AF if you want a small body. Tamron Af will work reasonably well with phase detect.

Good Luck.


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## ecka (Aug 5, 2013)

Mt Spokane Photography said:


> crasher8 said:
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> > I'm getting an M. Mostly this will be my Parks (WDW) travel setup where the 5D3 is too bulky/heavy.
> ...



+1
SX50'HS is a nice, small, almost pocketable, cheap super telephoto, but if you want better IQ, then you should avoid TC's on zoom lenses as well. Otherwise, you won't get a much better result than a super-zoom P&S camera.


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## neuroanatomist (Aug 5, 2013)

Mt Spokane Photography said:


> There is no phase detect with a EOS M



Actually, the EOS M has Hybrid CMOS AF, meaning it uses pixels on the image sensor for phase detect AF. Not as many as the 70D, of course...


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## Sella174 (Aug 5, 2013)

Yes, you are missing something in the maths ... the 70-200mm lens will remain a 70-200mm lens without and be a 98-280mm equivalent lens with the converter. Sensor size does not change focal length and thus the magnification factor of the lens. Pixel density of the sensor does, however, create the illusion of more magnification, provided the lens is up to the task.


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## neuroanatomist (Aug 5, 2013)

Sella174 said:


> Yes, you are missing something in the maths ... the 70-200mm lens will remain a 70-200mm lens without and be a 98-280mm equivalent lens with the converter. Sensor size does not change focal length and thus the magnification factor of the lens. Pixel density of the sensor does, however, create the illusion of more magnification, provided the lens is up to the task.



No, it does not change the focal length, that is an intrinsic property of the lens. However, the smaller sensor does mean a narrower angle of view. I suspect we all know that that is what the OP was talking about…


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## Drizzt321 (Aug 5, 2013)

Sella174 said:


> Yes, you are missing something in the maths ... the 70-200mm lens will remain a 70-200mm lens without and be a 98-280mm equivalent lens with the converter. Sensor size does not change focal length and thus the magnification factor of the lens. Pixel density of the sensor does, however, create the illusion of more magnification, provided the lens is up to the task.



While mostly correct, focal length doesn't _actually_ change, the Field of View is what changes since you are really taking a smaller part of the image circle. With a smaller sensor that has a higher pixel density than a larger sensor, this gives an _appearance_ of a longer focal length lens, and is a handy shorthand way to describe the effect a smaller sensor will have on the output. What also doesn't change is the lens' maximum magnification value. However, due to the previously mentioned Field of View difference, it may appear to have a higher maximum magnification.


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## Mt Spokane Photography (Aug 5, 2013)

neuroanatomist said:


> Mt Spokane Photography said:
> 
> 
> > There is no phase detect with a EOS M
> ...


 
I guess I thought it used phase detect to get a partial AF and contrast detect to fine tune the AF. You have one, does it work well with third party lenses? Many third party lenses do not work well with Canon's contrast Detect AF, and the 70D reportedly does not work well on all Canon lenses using the dual pixel setup. I was merely recommending caution on his part, it would be a shame to end up with a lens that struggled to AF with the camera.


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## neuroanatomist (Aug 5, 2013)

Mt Spokane Photography said:


> neuroanatomist said:
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> > Mt Spokane Photography said:
> ...



I have the M but no 3rd party lenses. But it's a sensible caution...


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## sdsr (Aug 5, 2013)

I don't want to rain on your parade, but I would worry less about your math than the practicality of this sort of lens/body combination (assuming the lens otherwise works on the M). Having a tiny camera body which you have to hold away from your face is awkward, to say the least, when the lenses you attach aren't also tiny (since you're concerned about weight, presumably you won't be lugging a tripod around with you). Much of the time, it's lenses, not the body, that's the weight problem, and here you're saving little overall weight at the considerable expense of a high degree of physical inconvenience. I infer from your post that your M hasn't arrived yet. If that's so, try it before you leave and see what you think.

For these reasons I don't plan to use on my M (assuming I keep it) anything other than lenses made for it and perhaps the 40mm pancake and one or two of the other smaller primes. To me it makes much more sense, if size and weight matter, to buy into a _system_ designed to be small and light. That means small and light lenses, not just small and light bodies; and of course the M is far from competitive in that area, with just two lenses to date in the US. If I were in your position I would either take my 5DIII + Tamron or rent/buy an Olympus OM-D and the Panasonic equivalent of your Tamron 70-200 2.8 (35-100mm) and a few more m43 lenses as well (including the surprisingly good Panasonic 100-300).


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## Mt Spokane Photography (Aug 5, 2013)

neuroanatomist said:


> Mt Spokane Photography said:
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> > neuroanatomist said:
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Another thought is that AF speed of the "M" is not blindingly fast in any event, so fast AF speed with a 3rd party lens may not be a issue as long as it does not hunt to find focus.


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## bholliman (Aug 5, 2013)

sdsr said:


> I would worry less about your math than the practicality of this sort of lens/body combination (assuming the lens otherwise works on the M). Having a tiny camera body which you have to hold away from your face is awkward, to say the least, when the lenses you attach aren't also tiny ...



+1 I purchased an M last month and find it to be a great portable camera for when I don't want to lug a DSLR around. But...after lots of experimentation with my EF lenses, I have found that most of them are too heavy and unwieldy for practical, carry-around use. 

On Saturday I carried the M with 24-70 2.8 II attached to a festival. I came back with some great pictures, but found the combination to be somewhat awkward. After carrying this combo half the day, I switched to my EF-M 22/2 lens in a Dashport 20 case. It was MUCH lighter to carry around and easier to handle. I've taken a few shots with my 70-200 2.8 II on the M, but would not take this combo out of the house! :-[

When I purchased the M, I intended to use my EF lenses for focal lengths above 22mm, but now I'm leaning toward purchasing a EF-M 18-55 and 11-22 at some point. The reason I purchased the M was size and portability. Using it with a large, heavy lens defeats that purpose. Going forward, I'll take a DSLR along if I want to use on of my larger EF zoom lenses.


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## bholliman (Aug 5, 2013)

I do like to use my 50 1.4 on the M with Canon adapter. It makes 80/2.2 FF equivalent combo that is great for portraits and its not too heavy or bulky. The 40mm pancake would be even better size-wise, but you would lose most of the shallow DOF capability.


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## neuroanatomist (Aug 6, 2013)

bholliman said:


> sdsr said:
> 
> 
> > I would worry less about your math than the practicality of this sort of lens/body combination (assuming the lens otherwise works on the M). Having a tiny camera body which you have to hold away from your face is awkward, to say the least, when the lenses you attach aren't also tiny ...
> ...



I haven't done the experimentation, but my plan was to use the M with EF-M lenses or the adapted 40mm pancake (which works great!). The only time I'd use it with other EF lenses would be if the 1D X died during a trip (or down the line on a tripod if I get it IR converted, which I'll likely do once an M with dual-pixel CMOS AF comes along).


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