f2.8 vs. f4

whilst a 1 stop difference,seemingly a corresponding large difference in size/weight/cost in most lens.
question is,how big a difference btw these 2 in terms of photographic benefits are there of the f2.8 over the f4?

for indoor/lowlight situations,won't flash cover the 1stop difference(with exception of situations where flash would ruin the feel of the picture/or flash photography not allowed..eg. certain sports events)?

i know it's highly subjective to quantify 'how big a difference' but do give your personal thoughts anyways

Yes, flash would cover the difference, technically.

But.

2.8 will give you a bit more DoF control, and it will give you faster shutter speeds.

I'm tired, so I'll let someone else tell you more.

1 stop faster is a big difference if your in low light, it could be the breaking point of "getting the shot" or having a blurred picture. Personally I dont want anything slower than 2.8, with the exception of the 17-40. If you are always outside, in bright light, there really isn't much need for 2.8 if you dont need it. I hate using flash, so I always get fast lenses to try and use the ambient light available.

What lens were you looking at?

I'd be willing to wager it's one of those ever present 70-200 struggles.

well 2 comparisons actually Michael,Ronald

the 17-40 f4L vs. 16-35 f2.8L and
the 24-105 f4L vs 24-70 f2.8L

for the 70-200 i got the f4L already to cover the long end

well, for the 24 pair, the 24-70L is a no brainer for me. I'd rather be able to stop action in not so good light than take slower speeds without blurring. I want things to happen quicker, not slower.

As for the other...the 16-35L is just....mmmm. One fine piece of yum yum. That having been said, it's what...twice as much as the 17-40L? Do the opposite of what your budget tells you.

The 24-70 is an awesome lens so is the 16-35, but if you dont need to get fast shots. I'd say go with the 17-40. What kind of pictures do you take?

The difference between F4 and F2.8 is one stop, so you can use one notch down on ISO (eg 400 instead of 800) or get half the shutter speed (eg 1/100th instead of 1/50th). This can be very helpful in places you can't use a flash, if you can use a flash or don't mind high ISO the F4 will be ok. I don't buy lenses slower than F2.8 unless I have a very good reason.

the 24 pair,was my consideration of a walkaround/travel lens,as such most shots would probably be outdoors rather than indoors.also weight would be an issue,lugging it around the whole day.ability to not switch lens/not bring extra lens too would be nicer,and longer reach would be nicer.
thus i am leaning towards the 24-105 for all my reasons above.but i am wondering how big a difference this 1 stop would make.when it is mentioned stop action,how fast action are we talking about here?would a crowd of people walking by be considered a tough scene to capture on a f4?

plus it doesn't help that in the 17vs16 pair,the 2.8 cost about double that the 4 where i am at.

sorry if these seem like very basic questions but are things that have been pretty much nagging at me for some time now

I'd go for the 24-105 then, cheaper, longer focal length and a pretty good lens from what i hear. People walking in a crowd would depend on the lighting, if its really sunny out, then no it wont be a problem. You could easily stop it, but if its getting dark, then it might be a bit blurry.

i like taking landscape and architectural shots,hence my 12-24(for taking it all in) and 70-200(when i need architectural details) investments,and 'general day to day scenes' shots(my current 24-85 as walkaround).i seldom take portraits/macro.

Based on your stated useage, it sounds like the 24-105 is the best lens for you. After much going back & forth I chose it over the 24-70, and so far am very pleased. The significant difference between the two lenses concerns DOF, and for that you can get a 50/1.8 lens that will do the trick at a very reasonable cost. Either lens is excellent and you dont hear many complaints from users of either lens.

Here are some good reviews if you haven't already seen them;

http://www.the-digital-picture.com …L-IS-USM-Lens-Review.aspx

http://luminous-landscape.com/reviews/​lenses/28-105.shtml

already have the 50mm f/1.8 Scott

I tried indoor highschool basketball (not as fast as university teams) with my 70-200 with f4 @ iso1600 without flash and was able to freeze most actions maybe... 75% of the time. Touched up after noise ninja left me with some very clean impressive action shots.
I also tried dim lighting indoor party pictures with f4 and 580ex flash and have no issues of subject blur.

my opinion is thus, the gain in f stop really helps more in the department of background blur... say you're shooting an unsuspecting person on the street from a distance and you'd like a creamy blurred background... then f2.8 can surely get you a better photo than f4 ... on the other hand, if i was shooting mostly landscapes, i'd very likely be using f8 and beyond so the gain wont matter that much... all in all... it depends on what you like to shoot more often...

just out of curiousity... how do you find your tokina 12-24? does it produce good colour and sharp landscapes? do you have a few samples to post? I dont have it... just wondering if it's a good lens to have in the pocket when i travel...

Incredirebelz wrote:
I tried indoor highschool basketball (not as fast as university teams) with my 70-200 with f4 @ iso1600 without flash and was able to freeze most actions maybe... 75% of the time. Touched up after noise ninja left me with some very clean impressive action shots.
I also tried dim lighting indoor party pictures with f4 and 580ex flash and have no issues of subject blur.

my opinion is thus, the gain in f stop really helps more in the department of background blur... say you're shooting an unsuspecting person on the street from a distance and you'd like a creamy blurred background... then f2.8 can surely get you a better photo than f4 ... on the other hand, if i was shooting mostly landscapes, i'd very likely be using f8 and beyond so the gain wont matter that much... all in all... it depends on what you like to shoot more often...

just out of curiousity... how do you find your tokina 12-24? does it produce good colour and sharp landscapes? do you have a few samples to post? I dont have it... just wondering if it's a good lens to have in the pocket when i travel...

When you're shooting with your flash in E-TTL, the extra stop can also help improve your recycle rates since your flash isn't being taxed as heavily for each shot.