Getting high - F.P.S. - f-stop - shutter speed -ISO

[Tarnash]

Hi,  I've developed a passion (my wife calls it an obsession) for shooting birds in flight.  So, fast moving subjects in variable light at relatively long range.  I'm currently using a Canon 7D which works well some of the time, however my `keeper rate is...well...let's call it `modest'!  Much as I'd like a 1DX, 400mm f2.8 setup I can't afford both that and a divorce.  So, I'm wondering if something like the new Sony A7S II might work.  The larger photosites should mean less motion blur and the high ISO performance promises the ability to use high shutter speeds at smaller apertures  (the advantage being more DoF and therefore less requirement for absolutely precise AF).  I want to be able to print, perhaps up to 11X13 but no larger.  I'd welcome any discussion, suggestions, thoughts.         

[NancyP]

Are you shooting hand-held, or with a good gimbal mount, properly in balance, on a tripod? Practice, practice, practice! You need to develop very smooth panning to have a chance to get sharp BIF photos. And if you don't shoot for a while, you are going to be "off" - at least I am. What lens are you using with the 7D? I am shooting with the 60D (same vintage sensor, far more primitive focus system) and the EF 400mm f/5.6L NO image stabilization, using AI servo center point only focus. This is a pretty good lens with snappy autofocus, and it is light enough that you don't have to be Hercules to handhold and pan for any length of time (heck, I am not even Xena    ). If I am in practice and am panning across sky, my keeper rate is pretty high. Keeper rate tanks if panning across complex backgrounds. Other people have had excellent success with the old EF 100-400 f/4.0-5.6L IS and 7D. I have used half-press shutter-button-linked focus with OK results, and am trying to switch to back-button focus this fall and winter.

So my first suggestion would be to find some nearby seagulls or other "practice" birds, and practice. Consult with another 7D user to see if you have the optimal autofocus settings for BIF. See if your keeper rate goes up. Only then consider changing equipment - and you will know whether you need lens, camera, better tripod head, etc.

[Tony Jay]

My personal swing on this is that mirrorless cameras are not ready for the action/sports/wildlife/birds thing yet.
I am not knocking mirrorless by any means. I own two Sony bodies and they are great - just not for wildlife.

However, some of the best bird photographers I know of (Glenn Bartley, a frequent contributor to LuLa is one) use the Canon 7D and the mark II version.
The 7D has a good focusing mechanism.
You don't state what lenses you are using but there is no substitute for a fast super telephoto lens f.28 or f4.0 for 500mm or 600mm.
Technique and craft are key here - lots of practice is required.

Simply put if you are shooting in modest light then you will need to crank up the ISO to keep your shutter speeds high.
At the distances one is shooting the lens should be wide open - depth field is not an issue.
Obviously, setting up your camera for high speed shooting AI servo and high speed continuous drive mode goes without saying.

Almost all the bird photography that I do is with a 5D mark III (same focus mechanism as the 7D mark II and the 1DX) and a 500mm f4.0. I do also use a 1.4X teleconverter at times. Shooting birds in flight means doing it handheld most of the time. It is a tough gig with this rig given its weight and the exceptionally narrow field of view from an effective focal length of 700mm.
Strength, fitness, and stamina all play a role here.
Getting tack shape images is a challenge and I don't care who you are most images will be suboptimal.
Without continual regular practice one's skills atrophy a bit - this is an issue for me - I don't get to shoot nearly often enough to really keep my technique at optimum.

Tony Jay

[Tarnash]

To Nancy and Tony,  Thank you very much for your thoughtful replies and of course you are both absolutely on the money - I guess patience was never my strongest suit!  I'm currently using two zoom lenses for BIF an EF 70-200 f/2.8 mkII and a mk1 EF 100-400 f/4-5.6.  I guess my thinking was that bigger photosites might make for better edge sharpness/acutance on fast moving subjects and also higher ISO performance (I limit the 7D to ISO 400 and it's fairly noisy even there).  Those two things in combination might offer the potential to use higher shutter speeds and smaller apertures.  The higher shutter speeds obviously offer better `freeze frame' potential and the smaller apertures (and corresponding increased DoF) place less demands on AF accuracy.  My DoF calculations suggest that a 400mm lens at f/5.6 offers a DoF of about 3.34m at a distance of 50m.  A fast moving bird (say a tern) can cover that distance in about the time it takes the 7D shutter to cycle once during a high speed burst.  There is no doubt my technique could be better and I'll continue to work on that though I certainly take the point you both make that it requires continuous practice to stay `operationally fit'.  My other thought was that, I'm about to `retire' the 7D and, although it's no substitute for technique, if there is `an edge' to be gained from technological advances - well - I want to consider all the options.  Thanks again though for your helpful answers.       

[Tony Jay]

The mark I 100-400mm does not have very good autofocus ability.
Very slow and hesitant.
The mark II is a much better lens in this regard and by all accounts is also much sharper.

Tony Jay

[BJL]

What lenses (focal lengths and minimum f-stops) would you plan to use with that larger sensor camera? Because roughly speaking, the "low light, high shutter speed" performance advantage of using a larger sensor relies on also using it sith a bigger lens, in the sense of one with a larger effective aperture diameter and thus larger front elements. And even then, the speed advantage comes with reduced DOF, maybe not good for your BIF scenario.

If you goal is to fill the same fraction of the frame with the bird, the focal length needs to be 1.6 times longer. To keep the same DOF, you then need to use an f-stop about 1.6 times higher — a bit over one stop. So to get the same shutter speed, you need to increase the ISO speed by the square of the f-stop increase, or 2.56 — a bit over two stops.  How is the IQ ccomparison with that ISO speed difference?

If instead you plan to use the same ISO speed, the longer lens must offer same minimum f-stop at the longer focal length (like replacing the 70-200/2.8 by a 300/2. and the ability to use the same ISO speed comes with DOF reduced by a factor of 1.6.

My gut feeling is that for wlildlife photography within the constraints on weight and cost (and DOF needs) that most of us are under, the smaller ILC formats serve better.


P.S. Given the far lower resolution of the Sony 7SII (12MP vs 20MP, and about half the "line per mm" on the sensor) getting equally detailed images ("equal pixel count on the bird") requires more than that 1.6x shift. Instead, if 12MP is enough, compare to the 12MP crops you could get with the 7D, with the crop allowing a shorter focal length than needed to fill the frame and so a lower f-stop for a given needed DOF. In that comparison, the 7SII would need twice the focal length (400/2.8 here we come!) and either four times the ISO speed for equal DOF, or half the DOF at equal ISO speed, or some balance like one stop higher ISO speed with "one stop less" DOF.

P. P. S. How do I disable smileys after the upgrade?  I typed "parenthesis followed by comma" and it became an emoticon!

[Hans Kruse]

To Nancy and Tony,  Thank you very much for your thoughtful replies and of course you are both absolutely on the money - I guess patience was never my strongest suit!  I'm currently using two zoom lenses for BIF an EF 70-200 f/2.8 mkII and a mk1 EF 100-400 f/4-5.6.  I guess my thinking was that bigger photosites might make for better edge sharpness/acutance on fast moving subjects and also higher ISO performance (I limit the 7D to ISO 400 and it's fairly noisy even there).  Those two things in combination might offer the potential to use higher shutter speeds and smaller apertures.  The higher shutter speeds obviously offer better `freeze frame' potential and the smaller apertures (and corresponding increased DoF) place less demands on AF accuracy.  My DoF calculations suggest that a 400mm lens at f/5.6 offers a DoF of about 3.34m at a distance of 50m.  A fast moving bird (say a tern) can cover that distance in about the time it takes the 7D shutter to cycle once during a high speed burst.  There is no doubt my technique could be better and I'll continue to work on that though I certainly take the point you both make that it requires continuous practice to stay `operationally fit'.  My other thought was that, I'm about to `retire' the 7D and, although it's no substitute for technique, if there is `an edge' to be gained from technological advances - well - I want to consider all the options.  Thanks again though for your helpful answers.       

I'm no longer shooting BIF, but when I did a Canon 500 + 1.4x TC with a full frame camera like the 1Ds III or even 5D was the usual combination. I had the 7D for a while but sold it again as I did not like the IQ. With the 7D I could often avoid the 1.4x TC. To shoot with a 500 you need to practice a shooting technique where you can see a bird and lift the camera and lens and frame it immediately. Back button focus with continous focus for tracking the bird and small bursts where the bird position and background is good is my advice for keepers. But a lot comes from studying the birds and how they behave to get interesting shots. With the 100-400 mk2 and the 7D mkII you would have a great combo although a second hand 500 f/4 mkI would be better in many cases.