F4 > F2.8 question

Paul11

Paul11

Paul11

Soldato
Joined
28 Sep 2003
Posts
10,413
Location
London
theres a huge price difference for lenes that offer F2.8 over their F4 brothers.

my question is, is using F2.8 not too wide for most things as the DOF will become too great (ie indoor shots) to make 2.8 useful

am i missing something ?
 
it wasnt so much asking why there more expensive.

the question was more if it was worth paying the extra for what seems like a small gain as it would be un-useable in most situations to use 2.8
 
Last edited:
It's all about getting more light into the lens and hence being able to use a faster shutter speed to either stop the action or reduce the effect of camera shake. The DoF issue only really comes up a short subject distances, for indoor sports there's plenty of DoF at 200mm/f2.8.
 
Problem is probably the wrong word. If you keep the focal length and aperture constant the DoF will increase as the subject distance increases.

There's a useful DoF calculator here
 
rpstewart said:
It's all about getting more light into the lens and hence being able to use a faster shutter speed to either stop the action or reduce the effect of camera shake. The DoF issue only really comes up a short subject distances, for indoor sports there's plenty of DoF at 200mm/f2.8.
Click to expand...

Exactly. Even when using a f/1.4 lens the dof is plenty if the distance is great enough. It's only when your taking pictures very close to the subject that the limited dof becomes a problem.
 
For portraiture F/2.8 (and lower!) is very useful for isolating the subject from a distracting background.
Also it's a godsend when the light gets lower.

Night time indoor shots at ISO1600 JUST work without flash at 60 or 50 shutter speed I find!
 
Not adding anything here. But I wondered something along the same lines as the OP. Just goes to show if you hang around long enough, somebody will ask that question that you always wanted to know but were too shy to ask for you.

mmm wonder if that works with regards to asking the other half for unusual sexual favours lol
 
Another advantage, many lenses are a softer wide open so you need to close them down a little to sharpen things up. If your starting at f2.8 you have more ability to stop the apperture down to get things sharper and still let in more light.
 
If you are worried about DoF, there are loads of DoF calculators on the web...

are 2.8 lenses worth it? i would say yes, not only just for that extra maximum aperture, but also for the fact that these lenses are usually much better quality for a given aperture.

Having said that, i don't have the cash to pay for one....
 
You must log in or register to reply here.
Back
Top Bottom