f/2.8 with IS --- vs --- f/4 with IS

[coachboz68]

I'm going to ask an imperfect question, so bear with me, but I think it will lead to the answers I am looking for.  Iv'e started a new thread but this topic arises in many other threads in different bits and pieces. 

Let's take a lense like the EF 16-35 where we have the choice of f/4 with IS that (I believe) is rated at something like 4 Stops, and the f/2.8 with no IS. 

Let's further assume that I'm going to do walk-around city/street shooting where I will most frequently shooting WITHOUT a tripod. 

While the 2.8 affords me faster shutter speeds, I am afraid that the shallow DOF will be undesirable in many shots.  Therefore, for mostly handheld shooting where shallow DOF is not desireable, would one be better off with the IS with a min of f/4 given shutter speed (for these kinds of pics) is not the major concern?  

I know there are a lot of variables still left unexplored, so the answer will likely still be "it depends" but hopefully this the above scenario is enough to help me start understanding the real-life tradeoffs between a smaller aperture with IS vs a larger aperture without.  

Thanks

[Waddizzle]

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@coachboz68 wrote:

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@ebiggs1 wrote:

You do need to learn more about DOF as it is not that shallow at 16mm on a 1DX.  Think of this, my friend, if you don't need f2.8 and you own the f2.8 version, you don't need to use it.  It has f4 just like the other one but if you need f2.8 and don't have it available, you are screwed. Do you want to give that fact up for IS that may be of little value anyway on a WA zoom?

No, no way, not never!

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This thread is giving me the exact info for which I hoped.  I think my attraction to the IS was coming from a scenario that seems very unlikely, which would be needing a narrower aperture for DOF and not having enough light for a faster shutter speed, hence wanting the IS to help me with the clear image.  But after realzing that especialy with a wide angle lense, DOF is going to be way less of an issue, then (assuming one can afford the extra cost) the 2.8 is the better approach, all things considered.  

Also, regarding hyperfocal length, from sports shooting I have learned to intuit the general scenarios where my DOF is going to be shallow or deep, (but honestly that matters so much less than getting the great action shot).  I will start learning more about the mathematical calculations to determine it vs just gut as that will help me with the types of shooting I am starting to explore.  Thanks everyone! 

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DOF?  Take a look at the tool at the link that I posted.

[coachboz68]

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@Waddizzle

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DOF?  Take a look at the tool at the link that I posted.

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Waddizzle... already printed out a few pages for my lenses and common zooms.  Thanks! 

[coachboz68]

Just downloaded an app for my Android phone called HyperFocal Pro.  Simple, straightforward, exactly what I need.  

As an aside, back to my original hypothetical with the 16-35... for my IDX II, when I play with some inputs, I see that 16mm @ f/2.8 has a hyperfocal distance of only 10.3 ft.  Looking at other numbers, the DOF is much larger than I suspected at that lens length. 

Fantastic info in this thread.  Thanks again to all.  This has been hugely helpful.  

[ebiggs1]

"Waddizzle... already printed out a few pages for my lenses and common zooms."

I have no idea what this suggestion was but experience is way better that picking up a chart evey time you want to know something.  Especially as DOF.  Its OK to check one out to get the general idea I suppose but as you get more experience you won't need it.  Go out and shoot some stuff.  Just anything and edit it.  Study what you did.  Like I say way better than a chart.

BTW, are you going to carry a ruler or tape measure along, too?

[coachboz68]

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@ebiggs1 wrote:

"Waddizzle... already printed out a few pages for my lenses and common zooms."

I have no idea what this suggestion was but experience is way better that picking up a chart evey time you want to know something.  Especially as DOF.  Its OK to check one out to get the general idea I suppose but as you get more experience you won't need it.  Go out and shoot some stuff.  Just anything and edit it.  Study what you did.  Like I say way better than a chart.

BTW, are you going to carry a ruler or tape measure along, too?

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I switched to an app, so I don't have to print the paper. 🙂   For my learning style, it will augment my field experience.  I remember things better when I know the "why" behind the "what" and this helps me do that.  And I find the math interesting.  Just the way I'm wired.  

No tape measure, but from a life spent in football, I can call out distances in yards more accurate than the average bear, at least within 100yards. 🙂 

[ebiggs1]

"I can call out distances in yards feet more accurate than the average bear ..."

I knew you could and it is the best way to go.  Let the chart readers read their charts while you make photographs!

[Waddizzle]

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@ebiggs1 wrote:

"I can call out distances in yards feet more accurate than the average bear ..."

I knew you could and it is the best way to go.  Let the chart readers read their charts while you make photographs!

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“It is human nature to reject that which one does not understand.”

BTW, the link contained a layman’s explanation of hyperfocal distance.

[RobertTheFat]

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@ebiggs1 wrote:

"Waddizzle... already printed out a few pages for my lenses and common zooms."

I have no idea what this suggestion was but experience is way better that picking up a chart evey time you want to know something.  Especially as DOF.  Its OK to check one out to get the general idea I suppose but as you get more experience you won't need it.  Go out and shoot some stuff.  Just anything and edit it.  Study what you did.  Like I say way better than a chart.

BTW, are you going to carry a ruler or tape measure along, too?

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Do you not have a tape measure in your bag, Ernie? I thought everybody did.

[ebiggs1]

"Do you not have a tape measure in your bag, Ernie?"

Dang it Bob, I know I had one somewhere if I could only remember where I left it.  Ya know I can even judge a scenes exposure pretty accurately just ny looking.  Amazing I know and if it were easy everybody would be doing it.

Chimpers unite!  

[coachboz68]

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@Waddizzle wrote:

It is a wide angle lens.  With a fast shutter, the lack of IS won’t matter.  Besides, the only times I use f/2.8 with my 16-35 is in close quarters when I am indoors.  Otherwise, I am shooting at f/5.6 to f/8 outdoors on bright sunny days.

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Thanks.  Only part of my question is practical; the bigger reason is trying to learn about the tradeoffs.  Toward that end... in poor light scenarios, the only way to get the faster shutter speed is with f/2.8, which concerns me as too shallow DOF for a lot of shots.  More specifically, I was shooting a prom event using my 70-200 at f/2.8 and had several shots where the DOF was so shallow that in a side-by-side shot, with one person slightly back, the back person was out of focus while the front person's face was tack sharp.  I also know this is my fault for not understanding (quickly and in the moment) how DOF is affected by zoom and distance to target.  As I said, just trying to learn.