So I got a 70-200 2.8L USM

[speedhop]

did anyone else think this this thread was going to be about a 2.8l engine going from 70-200 mph? im so disappointed...

No. If you're not a camera nerd, like me, than this thread means nothing.

I personally like the 4L IS because you get the added benefit of IS and the price difference is phenomenal. I just can't justify the 2.8 unless I shot in low light consistently, which I don't.

Great lens none-the-less!! Keep it!

[LovableSheep]

did anyone else think this this thread was going to be about a 2.8l engine going from 70-200 mph? im so disappointed...

The 70-200 is indeed an excellent lens. I've had the opportunity to use the IS version several times, and I found the IS to come in quite handy, but I guess it depends on the type of shooting you do. I tend to shoot low-light, non-moving subjects, so it works well for me.

Definitely on my to buy list when I have the money (first I have to stop spending so much on my E30 :)).

[CorvallisBMW]

200mm is 200mm whether you have a full frame or not, don't believe the 1.6x BS manufactures feed you with. I'll be more than happy to elaborate.

Not saying I don't love my IS but you can always bump the ISO up then a faster shutter.

I dont know, the 200 looks significantly different on my 1.6 crop XTi then it does on my old A1

[speedminded]

I dont know, the 200 looks significantly different on my 1.6 crop XTi then it does on my old A1

You said it right by calling it a 1.6 crop and not a 1.6x magnification that the camera and lens manufactures lead you to believe...

"There is no magnification; it's just a smaller portion of the same image."

http://photography-on-the.net/forum/showthread.php?t=45388

[CorvallisBMW]

You said it right by calling it a 1.6 crop and not a 1.6x magnification that the camera and lens manufactures lead you to believe...

"There is no magnification; it's just a smaller portion of the same image."

http://photography-on-the.net/forum/...ad.php?t=45388

Well, if you want to get technical :)

The FOV is equivalent to 320mm

[speedminded]

Well, if you want to get technical :)

The FOV is equivalent to 320mm

But the depth of field and perspective is exactly the same as 200mm ;)

[sumyungguy]

Actually its not... I have a FF and a 1.6 crop and the 1.6 has much more reach/narrow FOV, ie 320mm equiv. Yes, it isnt mechanically magnifying but in essence it is making a tighter FOV giving you more reach. The manufactures aren't BS'ing you, its simple math.

If what you are saying is true, than 16mm would be the same on FF and crop, which we know isnt. In order to achieve the same FOV as 16mm on FF you would have to use 10mm on a 1.6 crop body. There is a reason Canon makes its EF-S line of lenses for crop bodies only, made for the smaller sensor with less glass and wider focal lengths to simulate the zoom lenses that can be had for FF (ie 10-22 = 16-35, 17-55 = 28-88, ect.)

[LovableSheep]

I think speedminded has the right idea, just the use of the word "perspective" might be misleading, if it means what I think it does in this context.

200mm on a 1.6 crop has the field of view of 320mm. Which I think everyone understands now.

However, the lens itself is still a 200mm lens, so the depth of field is still that of a 200mm lens, just as a 10mm lens on a 1.6 crop will have a field of view of 16mm and the depth of field of a 10mm.

My interpretation of the use of the word "perspective" is that it does not mean field of view, but rather the "look" of the particular focal length. For example, the difference between the background and the subject. If we shoot the same subject with two different lenses, say a 20mm and a 200mm, keeping the subject size the same in each shot, the background will appear further away in the 20mm shot than the 200mm shot. The longer the focal length, the more "compressed" the image becomes. A lens of a particular focal length, regardless of what it is mounted on, retains it's "perspective" or "compression" or "look" or whatever you want to call it. On a cropped camera, you simply see less of the image circle, so while the field of view is equivalent to that of a longer lens, the characteristics of the particular actual focal length of the lens are retained.

[sumyungguy]

I understand, but in the same context... The FOV of 200mm on a FF is wider than the FOV of 200mm on a 1.6, so how is the "perspective" the same?

Think of it backwards, for the 1.6 to have the same FF 200mm FOV it would need to be at approx 125mm.

Yes 200mm is 200mm, but when using it on a crop its a 320 equivalent, which means if you put a 320mm lens on a FF the two images would look the same.

[LovableSheep]

Well I wouldn't personally use the word "perspective," I was just trying to interpret what speedminded might have been trying to mean with the word.

So if you asked me, I would agree that the perspective is not the same. I was just trying to explain the fact that a particular lens retains all it's specific characteristics such as "compression," distortion, etc. regardless of what it is mounted on. This I would not normally call "perspective," but I thought that might have been the intention when the word was used.