f4 for zooms plus a few primes vs f2.8

[Superman]

I currently have a Rebel T1i and already have the 17-40mm f4, 50mm 1.8 and the 70-200 f4. Thinking of buying the 24-105mm f4 plus a couple of primes (85mm and 135mm maybe). I mostly shoot outdoors which is why I started with the f4's. When I am indoors I find I can move around and use the 50mm. I am starting to rethink this now that my subject (daughter) is doing a lot of indoor stuff like sports and theater. I am starting to think if I should sell the f4's and buy the 3 f2.8 zooms covering 16-200mm and not bother with the primes (budget reasons). Is 2.8 going to be fast enough for that kind of indoor shooting?


Clark

[Daniel Browning]

Thinking of buying the 24-105mm f4 plus a couple of primes (85mm and 135mm maybe).

Great idea! []

Is 2.8 going to be fast enough for that kind of indoor shooting?

Probably not. It depends on the venue lighting and shutter speed needed to stop action. The venues that I frequent are quite dim, and they require ISO 12,800 for f/4 @ 1/500. An f/1.8 lens brings me down to a much nicer ISO 2500 for 1/500.


I suggest going for the primes.

[Colin500]

Probably not. It depends on the venue lighting and shutter speed needed to stop action. The venues that I frequent are quite dim, and they require ISO 12,800 for f/4 @ 1/500. An f/1.8 lens brings me down to a much nicer ISO 2500 for 1/500.

Do you (or does anybody else) manage to successfully use the f/1.8 primes wide-open for non-staged shots of relatively fast-moving subjects like small children? I'm having great difficulty handling the thin DoF, heck, even for static subjects I still need to practice some...


Ciao, Colin

[SupraSonic]

EF300mm F4 L IS[:P]

[Daniel Browning]

Do you (or does anybody else) manage to successfully use the f/1.8 primes wide-open for non-staged shots of relatively fast-moving subjects like small children?

Yes, but it's very difficult. There are several things you can do to make it easier. Try to tune autofocus into the best performance. Get a different viewfinder screen (they show thinner DOF). Try live view. Prefocus on a certain spot and snap it as the subject moves into it. Only attempt wider compositions such as environmental portraits instead of closeups. Arrange yourself so the DOF is parallel to the movement of the subject. Focus bracketing: rapid fire a lot of shots at slightly different focus or subject position. I'm sure there's more tips and tricks.

[lcnewkirk]

Do you (or does anybody else) manage to successfully use the f/1.8 primes wide-open for non-staged shots of relatively fast-moving subjects like small children? I'm having great difficulty handling the thin DoF, heck, even for static subjects I still need to practice some...

Almost all of the photos I take are with my 50/1.8II, indoors,of my 1 year old son. I typically use f2 to f2.8, and I handle the thin DoF by not looking at 100% crops. If it looks good on my screen, it looks good as an 8x10 print. A few days ago I shot a still with my camera on a stack of books (wanted the camera close to the ground) and stopped down to f5. The 100% crop of that shot was amazing, and the print is also, but it doesn't look enough better for me to start to worry about what the 100% crops on my handheld action shots look like.


Lewis

[neuroanatomist]

Do you (or does anybody else) manage to successfully use the f/1.8 primes wide-open for non-staged shots of relatively fast-moving subjects like small children? I'm having great difficulty handling the thin DoF, heck, even for static subjects I still need to practice some...

Sure, but yes, practice helps, and not every shot will be a keeper. Focus on the nearer eye, and shoot in continuous mode. Here's an example, with a 100% crop shown (it looked better prior to uploading - eyelashes could be counted). Of course, this is outdoors so the shutter is fast enough to stop motion. Indoors with ambient light, I can still get reasonably fast shutter speeds with f/1.8, but motion blur becomes more of an issue and keeper rate goes down correspondingly.


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Rebel T1i,EF 85mm f/1.8USM, f/1.8, 1/500, ISO100

[Kamelot]

If you are taking a photo indoors, try take it with flash. Did you ever tryed it?


What amazing photo you can do with flash pointed to white <span class="HW"]ceiling. And you will never have to <span class="HW"]bother your head about is it enough DoF, light to stop movement or spend money for expensive fast lenses

[Colin500]

Thanks to everybody for all the ideas and hints; the first thing I tried is switching into servo af and/or shooting several pictures in rapid succession, and that already helps a lot.


Regarding the "DoF parrallel to the movement", is the focal plane typically a really flat plane? (I suppose it can't be spherical, at least not with the camera (sensor) as center point, because otherwise focus-and-recompose would work better&hellip


Regards, Colin

[Daniel Browning]

is the focal plane typically a really flat plane?

Typically it's pretty close. When it's not (like in my Tamron 17-50 f/2.8), it's called "curvature of field".