DoF differences at f2.8 and f4

futureal33

futureal33

Messages
2,390
Name
Nick
Edit My Images
Yes
I know this is something I have spent many hours searching for - while I know about DofMaster - which gives you the numerical difference, I wanted to see a real world example of how much more background blur you get at f2.8 than at f4

So i decided to do the test myself!

Photo 1 is at f2.8
Photo 2 is at f4

I cant really see much (if any) difference to be honest. Both look equal in terms of background blur, and softness of the bokeh

2.8

IMG_6743 by futureal33, on Flickr

4.0

IMG_6742 by futureal33, on Flickr

With this is mind, I might reconsider my choice on getting a 70-200 f2.8 lens and just go for the cheaper Canon 70-200 F4L.

What are other people's thoughts/comments on the difference between f2.8 and f4 when light is not an issue at all, ie purely for DoF reasons

Thanks, I hope this helps anyone in my similar situation
 
the f4 version of the 70-200 is reportedly sharper then the 2.8 version. the softness of the bokeh also depends greatly on the focal length you use, try doing your test at a shorter focal length.

M.
 
futureal33 said:
What are other people's thoughts/comments on the difference between f2.8 and f4 when light is not an issue at all, ie purely for DoF reasons
Click to expand...

If light isn't an issue, I'd imagine most 2.8 users will have stopped the lens down slightly anyway for better optical performance :)

In terms of the background, my untrained eye can't notice any difference, but I'd say the bird looks better at f/4 as more of it is in focus.

I think the decision is pretty simple, if you need to use f/2.8, then you don't have a choice. If you don't, the f/4 version is just as good (apparently sharper in fact), lighter, and a whole lot cheaper :)
 
For me the decision would be made on light conditions I planned to shoot in more than getting background out of focus, if you need low light high shutter speed get the f2.8, if you need low light but not so important to have the higher shutter speed then get the f4 IS (that is quite a lot sharper than the non IS f4 lens).
 
Those comparisons look fine DoF wise, no reason to choose f2.8 over f4, but what about when shooting larger subjects like real people?
 
Another quick two

F2.8

IMG_6864 by futureal33, on Flickr

F4

IMG_6865 by futureal33, on Flickr

I prefer f2.8 on every picture so far. Ok the difference isnt massive...but its there. Now is that difference worth the price tag difference between a Canon 70-200 F4L IS and Canon 70-200 F2.8L IS Mk2 ?? Thats the question.
 
You must log in or register to reply here.
Back
Top