Buying my first L lens- Not an easy choice

[Kenny]

[8-)]The more I learn the more I realize how little I know about all of this.


Of course the good news is all of your recomendations are saving me some money so thats not a bad thing, thanks again

[calmars]

bburns, the f/2.8 doesn't turn into a f/4.5 just because it's mounted on a 7D. Only with extenders. However I agree with everything else you and everyone have said. The 70-200 is definitely the way to go.

[Brendan7]

bburns, the f/2.8 doesn't turn into a f/4.5 just because it's mounted on a 7D. Only with extenders. However I agree with everything else you and everyone have said. The 70-200 is definitely the way to go.

yes, it does. Not only does a crop body multiply focal length by 1.6x, it does the same to effective aperture. I learned that in this thread:


http://community.the-digital-picture.com/forums/p/2861/22988.aspx#22988


About halfway into it it's explained.


brendan

[neuroanatomist]

bburns, the f/2.8 doesn't turn into a f/4.5 just because it's mounted on a 7D. Only with extenders. However I agree with everything else you and everyone have said. The 70-200 is definitely the way to go.

yes, it does. Not only does a crop body multiply focal length by 1.6x, it does the same to effective aperture. I learned that in this thread:


http://community.the-digital-picture.com/forums/p/2861/22988.aspx#22988


About halfway into it it's explained.


brendan

In terms of depth of field, yes - for an identically-framed subject, because to get that framing, you must be further away. Not in terms of light-gathering ability - the sensor does not physically affect the lens, obviously, although a crop sensor only 'sees' a portion of the image circle projected by an EF lens.

[Brendan7]

According to Daniel the Great (Daniel Browning, duh!) f/4 on FF is brighter than f/4 on 1.6. You need a slower shutter speed on a 1.6 to get the same brightness. Daniel, correct me if I'm wrong [:P]


woops...I just hijacked another thread.

[Atomhot]

neuroanatomist is correct – the incident light per square centimeter @ the image plane is identical regardless of sensor type used.


Collar mount a 70-200 ƒ2.8 IS on a sturdy tripod ~ 25 feet from a quantitative test subject ( i.e. ruler @ 60° ). Now take following three test shots using the same shutter speed, aperture, and iso…


1. ~200mm on a 5D ( should have a ~0.8 ft * 2 range on your ruler)


2. ~153mm ( 200 / 1.3 ) on a 1D ( ~1.0 * 2 )


3. ~125mm ( 200 / 1.6 ) on a 7D ( ~1.3 ft * 2 )


human and camera induced variability aside, the result should be nearly identical framing and exposure across all three shots with significant differences in subject DOF, Bokeh.

[elmo_2006]

A couple of months ago, I was at an indoor hockey game watching and taking photos of my bosses kids playing. Along came a gentleman with the 300/2.8 mounted on a 1D Mark xx (can't recall) which in turn mounted to monopod and the conversation started:


me: Wow, great rig, love the lens


him: Thanks, she sure is.


me: You know, that's one of my dream lenses.


him: An awesome lens and great for those tight shots


me: Not sure if it deserves to be on my little Xsi


him: Why not, but you will be snapping up photos of this game from the parking lot


me: LOL


him: Besides, unless you plan on making money (as he is an actual photographer), this lens deserves to be utilized on a FF or an APS-H camera, your choice of the 70-200 2.8 is a good choice.........


Suffice to say, these guys in these forums are correct and do know what they are saying, stick with the mentioned lenses and you won't be disappointed. But hey, if you've got the dough, the sky's the limit!

[RonG]

If you are going to stay with a 1.6 crop factor then buy a Canon 17-55mm f2.8 IS USM lens and a canon 70-200mm f2.8 L IS USM lens. this combo will bring you close to or a little over 3 grand. If you plan on upgrading to APS-H or FF then get the canon 24-70 f2.8 L USM lens instead of the 17-55mm. This Two lens combo will cover everything you will need even for football and soccer. Use the remaining 1300 dollars from the price of the 300 f2.8 to buy a good image software like lightroom or aperture, Noise Ninja for noise reduction and genuine fractals to create any size enlargement you want. You might even have enough left over to get a nice 50mm f1.4 lens to boot. And IMHO you will never regret spending more money on canon lenses vs. less expensive 3rd party (caveat, I love my sigma 50mm f1.4). Good Luck