Understanding Aperture priority


buzzmario

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Mar 12, 2011
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Hi, Went to HK last week. Brought an Nikkor 70-300mm f/4.5-5.6G IF-ED AF-S VR Zoom in HK for my D7000 and went shooting in ocean park. However I face some problems on the shooting. Hope advise from you as I am still newbies here.

You see, when i use aperture priority outdoor, the shutter speed will auto set to a higher such as 1/250 to 1/800 as photos on the link below.

Dophine1- Aperture priority 1-800s f4.5 70mm ISO200 | Flickr - Photo Sharing!

Dophine2- Aperture priority 1-800s f4.8 116mm ISO200 | Flickr - Photo Sharing!

Sea Lion- Aperture priority 1-250s f5.6 270mm ISO200 | Flickr - Photo Sharing!

Tiger- Aperture priority 1-500s f4.5 70mm ISO100 | Flickr - Photo Sharing!

The photos look ok and it is not blur.

However when i shoot indoor with AP, the shutter speed is auto set toward a low side and resulting blur image. below is link to photos taken indoor with AP.

Sea Lion Indoor Aperture priority 1-25s f4.8 140mm ISO640 | Flickr - Photo Sharing!

Stage Indoor -Aperture priority 1-20s f5 180mm ISO320 | Flickr - Photo Sharing!

Hope experts here and advise me on understanding AP mode on indoor and outdoor shooting.

Thanks
 

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You're forgetting the 3rd element: ISO. Indoors, there is MUCH less light, you need to increase ISO to get a faster shutter speed.

Please read the stickies on the Newbies guide to Photography.
 

when set to AP mode, your decide the aperture value and the camera will calculate the shutter speed to give you the "perfect exposure"

when outdoor (where there's bright light), you get a fast shutter speed when you open the aperture wide, this is so that you dont get over exposure

when indor (low light), the camera will need to open the shutter longer so as to allow more light in, hence slow shutter speed


to counter motion shake due to low speed, set your ISO higher
 

thanks both bros here.

i did set my iso to a higher of 320 and 640. however the Shutter speed still auto to lower in AP mode resulting blur pix, is it that AP mode is not recommended in indoor mode , a SS mode or manuel is prefer? thanks
 

thanks both bros here.

i did set my iso to a higher of 320 and 640. however the Shutter speed still auto to lower in AP mode resulting blur pix, is it that AP mode is not recommended in indoor mode , a SS mode or manuel is prefer? thanks

No. You're not getting it. 320 and 640 is NOT "high". Try 3200 or 6400.

Your camera metered correctly for the scene. However, you are trying to freeze motion, So you need an even higher shutter speed.

There is no "recommended indoor mode". It all depends on how much (or little) you understand. You set the mode for the NEED. If you NEED to have a faster shutter speed, you can use shutter priority mode. That's what it's there for.

The low shutter speed is NOT the fault of Aperture priority mode, but rather your fault for not "telling" the camera what you need.
 

Your indoor shots are blur because based on the aperture you selected and the ISO used (way too low), the camera is forced to choose a very low shutter speed to achieve a proper exposure. For outdoor shots, because there is usually lots of light, the shutter speed set by the camera to get a proper exposure is usually high enough to avoid motion/handshake blur. To get sharp(er) shots indoors, you could pump up your ISO and shutter speed (e.g. use TV or M mode). Some cameras allow you to set minimum shutter speed while using AV mode, no idea whether the D7000 has this feature. Last but not the least, usually for low light/indoor photography (without flash), you need minimum F2.8 to get enough light so your zoom lens might not be fast enough for indoor/low light situations for a proper exposure even if you did pump up the ISO (to a limit 'acceptable' to you).

I'm not an expert, just sharing my two cents.
 

Hi, Went to HK last week. Brought an Nikkor 70-300mm f/4.5-5.6G IF-ED AF-S VR Zoom in HK for my D7000 and went shooting in ocean park. However I face some problems on the shooting. Hope advise from you as I am still newbies here.

You see, when i use aperture priority outdoor, the shutter speed will auto set to a higher such as 1/250 to 1/800 as photos on the link below.

Dophine1- Aperture priority 1-800s f4.5 70mm ISO200 | Flickr - Photo Sharing!

Dophine2- Aperture priority 1-800s f4.8 116mm ISO200 | Flickr - Photo Sharing!

Sea Lion- Aperture priority 1-250s f5.6 270mm ISO200 | Flickr - Photo Sharing!

Tiger- Aperture priority 1-500s f4.5 70mm ISO100 | Flickr - Photo Sharing!

The photos look ok and it is not blur.

However when i shoot indoor with AP, the shutter speed is auto set toward a low side and resulting blur image. below is link to photos taken indoor with AP.

Sea Lion Indoor Aperture priority 1-25s f4.8 140mm ISO640 | Flickr - Photo Sharing!

Stage Indoor -Aperture priority 1-20s f5 180mm ISO320 | Flickr - Photo Sharing!

Hope experts here and advise me on understanding AP mode on indoor and outdoor shooting.

Thanks
the lighting between outdoor and indoor is so much different, you can tell by the range of shutter speed, human eyes are able to adjust accordingly very fast and of course you will not take notice of the different of the brightness.

so at indoor, you need to compensate with higher ISO, wider aperture and lower shutter speed. or simply use a flash.
 

aperture, ISO and shutter speed, these 3 make up the exposure triangle.

if any of the 3 changes, you gotta adjust the other 1 and or 2 to compensate, in order to obtain the same exposure again.

basically in Av, for the same scene(ie outdoor setting):

ISO 200, f2.8, 1/100s = ISO 400, f2.8, 1/200s


but let's say you go from outdoor(ISO 200, f2.8, 1/100s) to indoor, suddenly your indoor setting drops to ISO 200, f2.8, 1/25s. notice the differences between the shutter speeds, due to the lack of light in indoor setting.

to keep the shutter speed at 1/100s, you have to set to:

ISO 800, f2.8, 1/100s

why? 1/25s to 1/100s is 2 stops of differences. so to maintain the 2 stops differences in exposure, you have to bump the ISO up by 2 stops(while keeping the aperture constant), from ISO 200 to ISO 800(ISO200 x 2 x 2).

get the idea now?
 

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Hi, Went to HK last week. Brought an Nikkor 70-300mm f/4.5-5.6G IF-ED AF-S VR Zoom in HK for my D7000 and went shooting in ocean park. However I face some problems on the shooting. Hope advise from you as I am still newbies here.

You see, when i use aperture priority outdoor, the shutter speed will auto set to a higher such as 1/250 to 1/800 as photos on the link below.

Dophine1- Aperture priority 1-800s f4.5 70mm ISO200 | Flickr - Photo Sharing!

Dophine2- Aperture priority 1-800s f4.8 116mm ISO200 | Flickr - Photo Sharing!

Sea Lion- Aperture priority 1-250s f5.6 270mm ISO200 | Flickr - Photo Sharing!

Tiger- Aperture priority 1-500s f4.5 70mm ISO100 | Flickr - Photo Sharing!

The photos look ok and it is not blur.

However when i shoot indoor with AP, the shutter speed is auto set toward a low side and resulting blur image. below is link to photos taken indoor with AP.

Sea Lion Indoor Aperture priority 1-25s f4.8 140mm ISO640 | Flickr - Photo Sharing!

Stage Indoor -Aperture priority 1-20s f5 180mm ISO320 | Flickr - Photo Sharing!

Hope experts here and advise me on understanding AP mode on indoor and outdoor shooting.

Thanks
the lighting between outdoor and indoor is so much different, you can tell by the range of shutter speed, human eyes are able to adjust accordingly very fast and of course you will not take notice of the different of the brightness.

so at indoor, you need to compensate with higher ISO, wider aperture and lower shutter speed. or simply use a flash.
 

just rem this triangle.

ISO - Aperture - Shutter Speed

they are interlinked.

ISO high = grainy photos
ISO low = less grainy photos

Big aperture (f1.4) = more background blur
Small aperture (f22) = everything in focus, sharp

Fast Shutter speed = frozen action (eg running athletic frozen in his running spot)
Slow Shutter speed = blurred action (eg light trails)

Here's a diagram:
aperture_shutter_speed_overall_exp.gif
 

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under low light condition. open up your aperture. up your ISO till your shutter is equal or faster than (1/focal length) sec..

e.g. focal length 200mm, shutter speed = 1/(200*1.5) for DX camera to reduce camera motion shake.

Hope it helps
 

under low light condition. open up your aperture. up your ISO till your shutter is equal or faster than (1/focal length) sec..

e.g. focal length 200mm, shutter speed = 1/(200*1.5) for DX camera to reduce camera motion shake.

Hope it helps


thanks all,

happyranchu, as you highlight, say, my focus length is 200mm , my shutter speed should be (for d7000) at least 1/300?

btw, i just wondering, in AP mode, i cant set my shutter speed, hence for low light, i still need to take pix in SS mode of manuel mode? thanks again.
 

thanks all,

happyranchu, as you highlight, say, my focus length is 200mm , my shutter speed should be (for d7000) at least 1/300?

btw, i just wondering, in AP mode, i cant set my shutter speed, hence for low light, i still need to take pix in SS mode of manuel mode? thanks again.
you still don't get it,

Aperture priority, means you gave priority to Aperture, YOU let camera decide the shutter speed for you.

what is SS mode in manual mode? Super Star mode in manual mode?


anyway, when in low light, that is not enough light for making decent exposure. if you want to have faster shutter speed, you need to compensate with using bigger aperture or higher ISO.

for the example you shots in indoor. the shutter speed is 1/25s, to increase your shutter speed to 1/400s, you need to increase your ISO from ISO 640 to around ISO 5600
 

Try to google Sunny 16 rule. You have to learn how to play around with the numbers, be it sunny or not sunny.
 

And hopefully you understand why people are paying so much for a f2.8 lens :bsmilie:
 

thanks all,

happyranchu, as you highlight, say, my focus length is 200mm , my shutter speed should be (for d7000) at least 1/300?

btw, i just wondering, in AP mode, i cant set my shutter speed, hence for low light, i still need to take pix in SS mode of manuel mode? thanks again.

for how fast is ur shutter speed on certain focal length, is just a guide.. good to follow if you dont have steady hands.

for your exposure problem.. an easy way out is to set your ISO as Auto.. so you can concentrate on aperture and shutter speed..
dont worry, D7000 is one of the DSLR that has great high ISO performance..
 

philosophically speaking, exposure is like a bucket which needs to be filled with water.

the size of the bucket is the iso setting. higher r iso, less water needed.
the water being poured in is controlled by aperture. aperture is like a tap size. big tap ( wide aperture aka small f eg f1.8 ), don't have to keep the tap on so long ( fast shutter speed ). small tap (smaller aperture ) means must keep the tap open longer (slow shutter speed )

aperture priority lets the camera calculate the time for correct exposure, for the aperture setting which user has determined.

hope this helps. do correct me if I'm erroneous
 

Last edited:
thanks all,

happyranchu, as you highlight, say, my focus length is 200mm , my shutter speed should be (for d7000) at least 1/300?

btw, i just wondering, in AP mode, i cant set my shutter speed, hence for low light, i still need to take pix in SS mode of manuel mode? thanks again.

That guide is for handshake compensation. In your case, you are trying to counter motion blur from the moving animals. You may need to go even hiher than 1/300s, regardless of the focal length.
 

Shizuma said:
philosophically speaking, exposure is like a bucket which needs to be filled with water.

the size of the bucket is the iso setting. higher r iso, less water needed.
the water being poured in is controlled by aperture. aperture is like a tap size. big tap ( wide aperture aka small f eg f1.8 ), don't have to keep the tap on so long ( fast shutter speed ). small tap (smaller aperture ) means must keep the tap open longer (slow shutter speed )

aperture priority lets the camera calculate the time for correct exposure, for the aperture setting which user has determined.

hope this helps. do correct me if I'm erroneous

Good analogy. Unfortunately on mobile so will have to 'like' this post later. Btw mods could we have likes in the mobile app. I know your plates are full just a request if possibility arises.
 

philosophically speaking, exposure is like a bucket which needs to be filled with water.

the size of the bucket is the iso setting. higher r iso, less water needed.
the water being poured in is controlled by aperture. aperture is like a tap size. big tap ( wide aperture aka small f eg f1.8 ), don't have to keep the tap on so long ( fast shutter speed ). small tap (smaller aperture ) means must keep the tap open longer (slow shutter speed )

aperture priority lets the camera calculate the time for correct exposure, for the aperture setting which user has determined.

hope this helps. do correct me if I'm erroneous

haha i like this analogy too... first read it in 'Enjoy! Digital SLR Cameras' guide ;)
(can see picture here: Enjoy! Digital SLR camera)

And remember your eyes are much more powerful than camera sensors! I never appreciated how much brighter the sunlight is compared to indoor lighting until I learnt about exposure :)