A tale of 3 Lenses 70-200 F4 IS vs 70-200 F2.8 vs 70-300 F4.5 IS

[neuroanatomist]

.... If I understood neuro's tech posts correctly, the DOF will be more shallow on FF for the same subject distance and framing.
..

I thought for the same subject distance, the Crop has more OOF blur, but for the same framing the FF has more OOF blur...

Yes but what if you have both the same subject distance and the same framing, i.e. only a different focal length?

I will defer that one to Neuro ;D

If you have the same distance and same framing, but different focal length, the FF will have shallower DoF for the same aperture, because it will need a longer focal length. Example - 85mm f/2 on APS-C at the same distance will frame like 135mm f/2 on FF.

K-amps, you're correct that if you keep everything the same but the sensor - same aperture, same distance, same focal length, the crop sensor will actually have shallower DoF. But we don't usually care much about that because it's a different picture. So, if you're taking a head shot on FF, you could get more OOF blur (shallower DoF) by switching to a crop body and shooting with the same lens at the same distance - but then you'd have a shot of just the subject's eyes and nose (so, you'd move back to frame the head, and then your DoF would be deeper than with FF).

 

[Maui5150]

Just an update. Got the beast in yesterday.

Talk about solid construction... This is a lens you probably could soundly beat a mugger about in the head with, pound in some nails in a 2x4 and still take great pictures.

Weight: not really a factor to me. Does dwarf the 70-200 F/4L Non-IS girth wise, but have heard that can be a great thing... :

Speed... Seems fast, then again I am waiting for some of these to be sick hyper fast.

Sharp and IQ... I notice it in the view finder even. I was shooting fashion yesterday, and swapping between my 24-105 F/4L and the 70-200 F/2.8L IS II, and just "felt" the difference looking through... meaning I spent more and more time trying to work this lens in when I could, even though shooting in a tighter space. Lens is sharp. Annoyingly sharp. The model likes to wear color contacts and bugs me because the eyes are so clear, I can tell that their are color contacts because I can start making out the iris patterns

Something tells me my 5D MKII loves it too. When I put on another lens, I could swear I hear the body let out a little sigh or cry.