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View Full Version : more useful low light lens?



Cozen
05-12-2010, 06:47 AM
I have a 135L that I've had for a few weeks and so far I'm happy with it. But I have an opportunity to trade it plus some cash for the 70-200 2.8 IS mkI. Obviously the 135 is faster, but the IS and versatility of the 70-200 is nice. If you aren't shooting action, which lens is actually faster after factoring in IS?





And for those of you using the big white lenses, how much harder is it to shoot events in a photo journalistic style?

Sheiky
05-12-2010, 07:54 AM
If you aren't shooting action, which lens is actually faster after factoring in IS?


If I understand your question correct this is an easy one. Since the 135L is at f2 it is 1 stop faster than the 70-200 2.8. This means that with the same ISO and aperture you can get twice the shutterspeed.


However the 70-200 2.8 IS mark 1 has a 3-stop image stabiliser. This means that you could make the same image 3 stops slower.


If you can do the math, the 135 is 1 stop faster than the 70-200 by aperture, but 3 stops slower by IS. Sum it up and the lens would be 2-stops faster after factoring IS. But of course at the expense of a different aperture and a slower shutterspeed.


Hope this answers your question


Jan

neuroanatomist
05-12-2010, 08:22 AM
Jan summed it up nicely - the 70-200mm f/2.8L IS will have a 2-stop advantage over the 135mm f/2L. But, keep in mind that IS only helps with camera shake - for subjects that aren't moving - and by 'moving' I don't just mean sports/action shots. The normal rule is you can handhold at 1/focal length (approximately) - meaning for your 1.6x crop body and a lens at 135mm, you should get a good keeper rate at shutter speeds of ~1/200 s. The 3-stop IS means with the zoom set to 135mm, you could shoot at 1/25 s. But, people move. Looking over a couple of shots in my trash can from yesterday evening, subject motion blur was pronounced in some shots at 1/80 - 1/100 s.


But, on the whole I suspect you'd find the 70-200mm f/2.8 IS to be a much more useful and versatile lens across the board.


One thing that may help your choice - look over shots you've taken with your 135mm f/2L, and check the EXIF data. How many shots required f/2 for speed (i.e. could not tolerate bumping the ISO up a stop, etc.)? How many required f/2 for the out of focus blur (you'll get a bit less OOF blur at 200mm f/2.8)?

Jon Ruyle
05-12-2010, 10:34 AM
If you can do the math, the 135 is 1 stop faster than the 70-200 by aperture, but 3 stops slower by IS. Sum it up and the lens would be 2-stops faster after factoring IS. But of course at the expense of a different aperture and a slower shutterspeed.


This is a good analysis, but it does not take into account the length of the lens. With shorter lenses, you can use lower shutter speeds (we're not talking about stopping action, right?) At the wide end, the 70-200 is about half the focal length of the 135, so used at the wide end you gain another stop that way. I would say the 70-200 f/2.8 IS is actually "3 stops more hand-holdable" than the 135 (which, despite its speed, isn't a particularly hand-holdable lens).


Looked at this way, the 70-200 f/2.8 IS is actually only one stop from being the most hand holdable lens canon currently makes (which happens to be the 70-200 f/2.8 IS mark II... one stop more hand-holdable than the mk 1 because of the additional stop of IS). Other very hand holdable lenses include the 35 f/1.4, the 24-105 f/4 IS, and the 200 f/2 IS.



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How many required f/2 for the out of focus blur (you'll get a bit less OOF blur at 200mm f/2.8)?


Only some of the time. In some cases, you actually get larger blur circles at 200 f/2.8. Furthermore, I think longer focal lengths give an impression of greater blur by magnifying background detail (larger blured stuff looks more blurry than small blurred stuff). For these reasons, I often prefer 200 f/2.8 because you get about as much blur as 135 f/2 but more DOF.



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neuroanatomist
05-12-2010, 12:35 PM
For these reasons, I often prefer 200 f/2.8 because you get about as much blur as 135 f/2 but more DOF.


That was one of the biggest reasons I sold my 200mm f/2.8L prime (which is even less hand-holdable than the 135mm f/2L) - unless I was shooting in bright daylight, there were a lot of misses due to camera shake. With the lens you call the "most hand holdable lens canon currently makes" (the 70-200 f/2.8L IS II), I've gotten handleld shots at 200mm after sunset, with shutter speeds around 1/13 s.



the 135 (which, despite its speed, isn't a particularly hand-holdable lens).


Yes, compression and angle of view do make a difference. One thing I'll say in favor of 200mm f/2.8 - I did get some wonderful outdoor candid portraits (with the prime lens, but the 70-200 2.8I or II would be similar for that) where reflections in the background are just big, smooth circles.

Cozen
05-13-2010, 01:06 AM
Thanks for all your responses. This is gonna be a tough decision. What would you do?





I shoot portraits as well as events. I think I'm leaning toward the 70-200. I just fear the weight and attention it will grab when trying to do candids.

neuroanatomist
05-13-2010, 08:24 AM
If it were me, I'd get the 70-200mm f/2.8. Oh wait, it was me and I did! I'd been wanting the 135mm f/2L as well, but now that I have the 70-200mm f/2.8L IS II, not so much. It's still on the list, but way lower down. I got used to the weight pretty quickly (and with the help of a BlackRapid strap). 200mm is long enough for candids without causing a stir...or you can flaunt that big white lens, and people will move out of your way.

Cozen
05-14-2010, 05:10 AM
Thanks guys, I think I'm going to do the swap. I guess if I need faster glass with similar focal length I can always pick up the 100mm 2.0

Dave Johnston
05-14-2010, 07:57 AM
I shoot portraits as well as events. I think I'm leaning toward the 70-200. I just fear the weight and attention it will grab when trying to do candids.


I think you will find the focal length versatility better with the 70-200 outweigh the size/weight. It should be understood that there will be a downgrade in image quality between the two, but hey, these are two freakin' L monsters. That is just splitting hairs.


As far as attention, you can get lens covers for them on the cheap tocamouflagethat baby. I've not met an event photographer that didn't have a 70-200 2.8. Take that how you will.


Good luck,


Dave.