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Category: Exposure Settings

Photography Question 

Pamela K. Barrett
 

Shutter Vs. Aperture Priority


Seems like some photographers prefer aperture priority, and others prefer shutter priority. What are some of the pros and cons of each of these? Personally, I shy away from aperture priority because I think it would automatically compensate with a slow shutter speed resulting in blurry images because of camera shake. Is that a wrong assessment?


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July 21, 2008

 

David Van Camp
  It all depends on the shot you are trying to take.
- A mode is used when controlling Depth of Field is the top priority. (examples: macro and landscape).
- S mode is used when freezing or blurring motion is top priority. (examples: sports and blurred waterfall).
- P mode is used when you're willing to let the camera make a reasonable trade-off for you (sort of like auto but with a bit more control (example: unpredictable events with little time to capture scene).
- M mode is used when you want absolute control (examples: studio still life, fireworks, etc.).
Good photogs don't blindly prefer any one of these modes ... they use whichever mode best fits the occasion.
dvc


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July 21, 2008

 
- Gregory LaGrange

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  These aren't that drastically different, because you can use them for the same purpose. You pick one and the camera picks the matching other.
You can easily use av mode for sports by simply choosing wider apertures that give you faster shutter speeds. It doesn't require anything more than looking at the display in the viewfinder.
Some people who use auto modes for action prefer av mode so that they don't keep shooting pictures that should've been with an aperture that their lens doesn't have.


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July 21, 2008

 
- Gregory LaGrange

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  That sounds like a sports mode if you have a camera that will change iso automatically. But maybe with newer cameras, shutter priority will do that when a max aperture is needed if the lens doesn't have it.
If you want to stop action, I think in terms of a range of shutter speed. Not a particular one. And for some, they prefer to not shoot in a shaded area and have a set shutter speed and be under exposed.


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July 21, 2008

 

Pamela K. Barrett
  Thank you David, Greg, & W. Smith: You've been very helpful. I didn't know that about the ISO adjusting with shutter speed. I'm also going to try to start adjusting according to the situation.


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July 22, 2008

 

Bruce A. Dart
  Hi Pam,
David is right on with this. It all depends on what you are trying to do. You can, in theory, get the same shutter and aperture combinations no matter which mode you select, including manual. Setting in an automatic mode doesn't solve ALL problems, you still have to pay attention to what the settings are. In aperture priority you can set a smaller aperture and get a slower shutter or vice versa. Setting an aperture of say F/16 in low light with give you very long exposures that will need a tripod. I use aperture priority and manual exclusively, not of necessity, but more out of habit. Each time I still check the settings and adjust. Don't try to outguess the camera but you need to know if the settings aren't going to give you the optimum effect you are looking for. Once in a great while the wrong camera settings give you a wonderful surprise and a very nice image. Most times, it results in a bad image and a reminder that you need to pay more attention. We've all been there. Ansel Adams in his wonderful book "The Making of 40 Photographs" tells great anecdotes about each image, including "I forgot to stop down the lens." With a view camera, you adjust and make another exposure. With every other, most times you can do the same but once in awhile that means you've lost an opportunity and are reminded of why you need to check the settings. Keep shooting and enjoy!!
Bruce


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July 22, 2008

 
- Gregory LaGrange

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  In practice, not just theory.


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July 22, 2008

 

David Van Camp
  Greg, yes, you're right.

However, the point is that, in Tv (shutter priority) the user sets a shutter speed... let's say 1/1000s... and then the camera will

1) open the aperture to get the right exposure, then, if that's not enough,
2) increase the ISO to get the right exposure

But the camera will not change the shutter speed.

No other mode will do this (excepting, possibly, a special "sports" mode or similar, if the camera has one.)

dvc


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July 22, 2008

 
- Gregory LaGrange

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  I know that.
But which cameras do you know of that will change the iso on their own?


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July 22, 2008

 

David Van Camp
  I have a Nikon D80 which does this. Also a Cannon A570IS, which I think also does, but haven't really tested it.

dvc


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July 22, 2008

 

David Van Camp
  Oh, I should say, the A570 I think does this in Tv mode, but that camera I tend to shoot in scene modes mostly, where I KNOW it changes ISO automagically. I'm just not sure about Tv, since I don't use that mode much on that camera ('cause I get lazy with it :D )

dvc


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July 22, 2008

 
- Gregory LaGrange

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  In a powershot camera, but that is something I've never heard of being in any of Canon's slr's, nor would I expect it to be part of Tv mode for their slr's.
At least anything above a rebel.


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July 23, 2008

 

Pamela K. Barrett
  How do you determine that your camera changed your ISO setting? What about a Canon 30D? That's what I use.


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July 23, 2008

 

Bruce A. Dart
  Hi Pam,
I had never heard of a camera changing the ISO to compensate for exposures; most times they (used to anyway) just not work at those settings. So I called my local camera dealer and "Oh Yeah! several cameras will do that!!" I guess you just have to test it and see. Testing your equipment in the extremes of the kinds of images you will do, NOT a trial by fire when you really need it, but a TEST, is always a good idea. Once you do it, you will know and can watch for it in those situations. When I got a new flash to use for weddings that was supposed to be "automatic" from 2-22 feet, I tried it at 2 feet and at 22 feet and found that it was overexposed at the 2 feet and underexposed at 22. So I stopped down a stop on the lens when I moved in close and opened up when at far distances. (This is before TTL obviously, but the point is the same.) Now cameras tend to compensate for all sorts of things and the photographer has to watch the settings for find out why.
Bruce


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July 23, 2008

 
- Ken Smith

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  Pam, I have the 30D and use the P, shutter, aperture, and manual modes. And the ISO does not change, unless I manually change it.


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July 23, 2008

 

Pete H
  Some of the higher level Nikon DSLR's have a "Auto ISO" function.

It is NOT used to compensate for exposure problems. It IS used to automatically (UP) the ISO when shutter speed falls to a "user defined" point.

EX: The ISO will automatically increase (IF) shutter speed falls below 1/30th; or ANY shutter spped the user dictates.

I'm not sure about the D-80 etc; but this feature is highly customizable with the Nikon D-3 and D-300; probably the D-700 too.

This is one feature many reviewers agree on; in that Canon has fallen short leaving this out in their fine line of DSLR's.

Pete


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July 24, 2008

 
- Gregory LaGrange

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  Fluff feature.


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July 24, 2008

 

W.
 
Some camera models use ISO adjusting and call it 'vibration reduction' or something similar. But that's a plain lie: it doesn't reduce vibrations but it ups the shutter speed by setting a higher ISO.
Of course that also increases noise.


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July 24, 2008

 

David A. Bliss
  The 40D has an auto ISO setting. I've never tried it. I don't want my ISO being changed without my knowledge.

I used shutter priority when I was shooting the dragsters at the Mile High Nationals. I wanted a specific shutter speed for a certain amount of panning blur, but yet fast enough to keep the car sharp.

Most of the time I use aperture priority, and manual when needed.


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July 24, 2008

 

Pete H
  "Fluff" Greg?

Do I detect a Canon user in the house? ;)..or ya just stirring the pot again?

David is quite correct in that choosing the ISO gives us greater control; especially when we have time to set up the shot.

The Nikon Auto ISo feature is quite useful in some instances.

EX: A photo journalist is walking around, shooting candids, street life etc....all of a sudden he/she sees a great capture in a dimly lit alley and zooms in.

"Nuts!..ISO 100 forced me to shoot at 1/10th sec and I missed the fleeting moment." "Hold it!; lemme' adjust my aperture..Rats!..Too late!"

Not sure about other systems, but in the D-3 and D-300, the user can select at what shutter speed auto ISO kicks up and then limit the ISO to any value..say; don't go above ISO 1600 or 3200 or whatever.

Hardly "fluff" to some styles of shooting.


Pete


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July 24, 2008

 
- Gregory LaGrange

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  Fluff, as in not needed, regardless of brand. Like sports mode, landscape mode, cruise control.
You can use them all, some people feel they have to have it. What's it take to do without out? Nothing.


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July 25, 2008

 
- Gregory LaGrange

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  Besides, if got away from f/11 at 30ft, you'd probably wouldn't need it either.


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July 25, 2008

 

David A. Bliss
  A friend of mine thinks that anything beyond a wooden box and a shutter that opens with a timer is fluff, so it is all relative. The correct tool for the job makes any job easier.


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July 25, 2008

 

David Van Camp
  No, David B, your friend is absolutely right... all this camera/digital/exposure compensating/auto what not is totally a waste :D :D NOT!!!!!! (JK!)

Seriously, (all), the tools either let you get the pic you want or not. If you're spending your time diddling with ISO or other params, while missing the shot, it does you no good.

Yes, the Nikon D-80 WILL adjust ISO for you automagically in A (Av) or S (Tv) modes... I know, because it's done it to me.

Also, the Cannon A570IS WILL do this too, at least in certain scene modes... I know, beause it's done it to me.

All you need to know is in the EXIF data and whatever software you have that will show it to you.

EXIF data is gold! Study it. Understand what it tells you about how your camera reacted / compensated for a particular scene. Learn from it to understand how to control your camera when control is needed or let your camera make choices when it is good at doing so.

dvc


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July 25, 2008

 

David Van Camp
  Oh, and just to note: in the Nikon D80, auto ISO is NOT used a "vibration redution" approach, just exposure comp, nothing else. Same for the Cannon A570IS, from what I've experienced.
dvc


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July 25, 2008

 

David A. Bliss
  Pam, I reread your original post, and I would like to answer your question. Yes, using aperture priority could result in a slow shutter speed. I tend to shoot lansdcapes with foreground elements that are feet or inches away from the front of the lens, so I need a lot of depth of field. I set the apeture to what I need, and the shutter speed falls where it may. I almost always shoot on a tripod. For me, a slow shutter speed is expected.

If you are in a situation where you need a fast or specific shutter speed, then shutter priority is absolutely a valid tool.


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July 26, 2008

 
- Gregory LaGrange

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  Her original assessment of av mode was wrong, though.


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July 26, 2008

 

Pete H
  Pam,

DOF is important in a variety of situations. Av is the preferred way to accomplish this.
Often the shutter speed will be too slow to hand hold with a certain combination of ISO & aperture..This is why we have tripods.

I guess it depends on who yuo ask this question to. Personally, I rarely use shutter priority since controlling the DOF is important in what I shoot.

I suppose I COULD shoot shutter priority and keep dialing until I reach the DOF (f/stop) I desire.

It's a simple matter of convention....I'm more comfortable setting my f/stops.

all the best,

Pete

all the best,

Pete


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July 26, 2008

 

Pamela K. Barrett
  Thank you everyone for such helpful comments. I will definitely start being more flexible with the AV, TV, M, & P Modes. I wished I would have done this on my Caribbean vacation. I would have gotten much better landscape shots if I would have used AV instead of TV. Also, I need to utilize my tripod more. But the thing is, it's a bit of a hassle to carry around on vacation. Any tips on how to carry all the gear easily?


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July 28, 2008

 
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