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-   -   Using Aperture priority (

Imacer Apr 28, 2007 12:42 PM

By using this mode will it be good or not for sports and moving objects?

eric s Apr 28, 2007 1:58 PM

I use Av all the time for moving subjects. Specifically wlidlife.

Unlike with Tv, you can't pick setting that is impossible to expose correctly.

So you can tell yourself "I Want the highest shutter speed possible so you pick the largest aperture your lens supports. Then you'll get the fastest shutter speed that the metering mode you choose will give you.

I find it works well.


Imacer Apr 28, 2007 2:35 PM

Thanks Eric, I wasn't sure if it was a good idea or not. Hey can you post a pic using Aperture mode, fast moving object.

eric s Apr 29, 2007 1:04 PM

What do you define as fast? I'm not really shooting racing cars, but birds can move fast.How about these:

This isn't exactly "Fast" moving, but it isn't stationary. These are a bit faster:

Now, this these two was fast:


Imacer Apr 29, 2007 2:52 PM

WOW, Eric nice photos. What lens are you using and ISO.

JohnG Apr 29, 2007 5:02 PM

I will second Eric's notion to NOT use Tv mode. The question then becomes - AV or manual mode. I can understand why Eric uses AV so much - with wildlife you can't count on a continuous light source.

But with sports, I try to shoot manual exposure as much as possible. I only use AV mode when the lighting is very inconsistant (lots of shadow areas or sun moving in and out of clouds). The biggest problem you'll encounter with shooting sports (indoors or out) with AV mode is white jerseys. If you're outdoors and it's bright sunlight the white jerseys can cause you to underexpose by 2-3 stops which means faces will be in complete shadow.. You can encounter the same problem indoors where a white jersey mat give you a misread by as much as a stop of exposure. So, if you're going to use AV in sports you have to be aware of this - your goal is to expose for faces - if uniform highlights get blown, it's no big deal. Heck, even if it's just a sport with hats / helmets - you might need +2/3 EC to get the faces exposed properly in AV mode. It all depends on the lighting. It takes experience to recognize when you'll need to override the camera's metering and by how much.

But I do agree with Eric - TV is the worst mode to use for sports or wildlife.

NHL Apr 29, 2007 10:40 PM

Actually I'm the odd man out again... ;)

I tend to shoot wildlife exclusively in Tv - It depends on the effect you want, but for most of my flight shots I strive to keep the wing tips just blurry enough to convey motion by picking a slower shutter speed, a higher shutter speed would freeze the birds in space otherwise which might look unatural

1/640s, f/13 @ 600mm:

and even @ 1/500s @ 700mm:

-> Also for panning action shot you might want to keep the shutter slow in Tv (or manual) to streak the background which you would lose control otherwise if Av is used... (A car/motorcycle racing @ high-speed will look like as if it's parking in a lot otherwise if you let the camera pick the shutter)

eric s Apr 30, 2007 9:28 AM

To answer you question about gear... well, you're not going to want to hear this.
Nearly all of those were taken with the Canon 600mm f4. I take photography very seriously. I hang out here mostly because I teach wildlife photograph and the type of questions I get here help me practice for what I get from students.

I believe the short eared owl picture (second shot) was taken with the Canon 100-400. The rest were taken with the big lens. All were taken from a tripod.

I prefer to shoot at 200ISO on the Canon cameras. I find that is the best tradeoff for shutter speed vs. noise. Some times, very rarely, you'll find me shooting at 250 or 320. Maybe even 400. But never over that. But that is about standards... mine are high. Other people are very happy with the results at 400ISO. You have to pick what meets *your* standards.

Images 1, 2 & 4 were taken with the 20D, the others were taken with the 1D MkII N.

On to shooting modes.....

My problem with Tv is that I can try to take a picture that will absolutely be the wrong exposure. Because I can say "shoot at 1/500 so I get proper blur" (which makes perfect sense to me, some times you want some motion blur, I completely agree!) But what happens if that won't work? What if to get the correct exposure I need to be at f/4, but I'm shooting with an f/5.6 lens? If you don't spot it, you've blown it.

In Av, the problem is different (but there is still a problem.) In Av, you run the risk of having the shutter speed so low that the shot doesn't come out (all blury.)

I guess I'd rather have the lower shutter speed than an incorrect exposure.
Because Av, when I'm on a stationary subject, will just be a low shutter speed (but since I'm always on a tripod I can probably get the shot) but with Tv it will be incorrectly exposed even if the subject is stationary.

Now, you talked about using Tv only with flight shots. And I buy that. I guess I just don't want to have to think about switching modes.

I do agree, though, that when the light is consistent (like when I'm shooting eagles and its a nice clear blue sky - like the included eagle shot) I take a few test shots and then shoot in manual the entire day. The bird will never be in shadow and I can pick an aperture/DOF and shutter speed (motion blur or not) that I want and go with it. The camera will never be fooled if the bird is in front of the sky or in front of trees.

But when I'm shooting smaller, moving things. Warblers and such, I'm in Av because the bird are going between being lit by the sun and being in shade.... but the bird is rarely fully backlit (when the exposure will be wrong in all but spot-metering & manual modes.) So I've found I get better results in Av in mixed environment that are rarely backlit.

Manual definitely has its place, though. I don't use it often, but I do use it (and I'm using it more and more. It's a good way to force you to learn about exposure. I'd just rather pay more attention to the bird than have to adjust exposure if it flew into the shade.)


Mark1616 Apr 30, 2007 6:38 PM

I'm going to add another option and say that all 3 have their place. Like John I shoot almost exclusively sports and being in the UK where the light is constantly changing due to cloud etc I shoot a lot in Av (Aperture Value/Aperture Priority for the casual observer reading this) but if possible will go to manual as the exposure is not messed around by light or dark kits that players are wearing. However I do use Tv (Timed Value/Shutter Priority) for subjects where I want some motion blur such as motorsports. I do however keep an eye on the aperture being selected by the camera to ensure that I'm not going to get an under exposed result, if this looks likely I will then up the ISO setting. I would love there to be a mode where I can set the shutter speed, aperture and then then camera will change ISO to give the exposure but hey that's just being greedy and if light is consistent manual will sort this.

NHL Apr 30, 2007 9:55 PM

Mark1616 wrote:

I do however keep an eye on the aperture being selected by the camera to ensure that I'm not going to get an under exposed result, if this looks likely I will then up the ISO setting...
Why are you worrying about underexposure? ;)

In Tv one really picks the lowest shutter speed for the desired effect (i.e. motion blur of the subject) in the worst case (i.e. lowest light level @ a certain ISO) - If the light/background changes to anything of higher EV then you already have all the f-stops from the wide open lens to maximum stop down... at least a mimimum 6-stops to cover for over exposure in most lenses!

-> The nice thing about Tv is if you're walking about and happen to go under the shade of trees or shooting up against the foliage of the rainforest (i.e. strong backlit) then turning on the flash will immediately put you in the right shutter speed (1/250s) whereas in Av one is forced to change mode (i.e. manual) regardless because Av wouldn't cut it as a result of its poor selection of shutter speed (too slow in most case for fill only).
With Tv the toggling of the ON or OFF flash switch is the only thing required - Yes I do put on the external flash when I wandered in the woods... IMO this is much faster to switch mode than in Av especially on a 1D MrkII where multiples buttons/dial are required to change between normal daylight and flash photography and missed out on the subject

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