# Im confused between IS and fstop advantages



## CJRodgers (May 29, 2012)

Hi all, 

Im wanting to get either a 100mm f2.8 L IS or a 135L f2. Im getting into gig photography and ive noticed that even f1.8 can struggle so im assuming the faster the glass the better!? But would the IS actually help me achieve the same results by allowing me to use a slower shutter speed due to the IS, or would this just incur motion blur from people moving on stage?


My problem is that i want the 100mm IS because i also have an interest in video, and i like the ability to do macro. Its not my thing right now, but the ability to do it in the future would be good. However i feel like i should go for the 135L becasue its faster and the brokeh is awesome. Theyre both sharp so thats good. The 135L seems like a very good price used on ebay. There isnt too much price difference between the two lenses.

What would you do? Also its worth mentioning, I might get a 85mm 1.8 or sigma 85 1.4 at some point too. (I only have a 50mm 1.8 atm and a 5dmkii - just bought this weekend)

Thanks for your help


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## neuroanatomist (May 29, 2012)

With shorter telephoto lenses (100mm and 135mm on FF are in that category), IS helps primarily with static subjects. Sure, I can handhold my 70-200mm f/2.8L IS II at 1/6 s - but usually at least 1/60 s is needed to stop random, involuntary subject motion, and faster to stop active motion. I'd get the 135/2.


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## preppyak (May 29, 2012)

neuroanatomist said:


> I'd get the 135/2.


Agreed, and mostly because you won't be hand-holding the 135mm lens for video anyway...or if you do, even IS won't keep it from being shaky. You're just past the focal length where hand-held video works well.


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## CJRodgers (May 29, 2012)

Thanks guys. I think if i get the 85mm too id be happier with a 135, so that its not too close. Plus a 1.4x extender would make it 189mm f2.8?

Now i just need to choose between 24mm and 35mm for my wide angle. I think ill have to rent them both though.


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## neuroanatomist (May 29, 2012)

CJRodgers said:


> Now i just need to choose between 24mm and 35mm for my wide angle. I think ill have to rent them both though.



Perhaps...unless you have a 24-xx zoom. When I wanted to make that decision, I set my 24-105mm to 24mm for a while, then to 35mm for a while. I found myself cropping most of the 24mm shots, was happy with the 35mm AoV, got the 35L and I love it.


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## awinphoto (May 29, 2012)

i'm a little late to the party, but general rule of thumb, IS is good for camera shake and operator involuntary movement such as wind/hand/breathing, etc... As neuro said, it's great for static images. I will not however do any better job stopping motion blur or subject movement. So if you're doing more low light night scapes and product or macro, IS comes in smelling like a rose, but if your subject is people or whatever and you need to freeze action, the 135 buys you 1 extra stop of shutter, which may or may not stop the action depending on the subject and situation. Hope that helps.


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## woollybear (May 29, 2012)

> Perhaps...unless you have a 24-xx zoom. When I wanted to make that decision, I set my 24-105mm to 24mm for a while, then to 35mm for a while. I found myself cropping most of the 24mm shots, was happy with the 35mm AoV, got the 35L and I love it.



On the 5D or 7D?


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## neuroanatomist (May 29, 2012)

woollybear said:


> > got the 35L and I love it.
> 
> 
> 
> On the 5D or 7D?



On the 5DII. Haven't really used it much on the 7D (which is mainly used for birds/wildlife).


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## Act444 (May 29, 2012)

The 35L offers a very natural FOV on my 60D. I suppose it approximates the revered 50mm that FF shooters seem to love so much.

I don't do video but if I did, that lens would be my choice.


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## briansquibb (May 29, 2012)

Act444 said:


> The 35L offers a very natural FOV on my 60D. I suppose it approximates the revered 50mm that FF shooters seem to love so much.
> 
> I don't do video but if I did, that lens would be my choice.



135 is the length we used for film - there was only really a choice of 35, 50, 135 and 200 when on a reasonable budget although I did get a 500 f/5.6


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## Tammy (May 31, 2012)

i have and love both lenses.. while you gain an extra stop of shutter speed and some truly AMAZINGGG bokeh with the 135L it needs to be noted that it actually gets negated because if/when you're hand holding it then you need to be at or above 1/135s, regardless of whether the subject is static or not.. whereas with the 100L, the 4 stops IS helps shoot at lower shutter speeds and more importantly lower ISOs for higher image quality when able to..

honestly you can't go wrong with either.. both have great image quality and are great bang for their buck.. I prefer the 135L for its outstanding bokeh, sharpness, color and contrast but i do leave it and take the 100L when i'm going to be shooting low light portraits etc without much motion..

the 100L is also awesome for macro.. you mentioned you would like that capability and that is specifically what I keep mine for, other than the flexibility for low light and portraits with MFD issues.. if you're only going to get one, the 100L might be a better choice.. ?


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