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Why Aperture priority? (1 Viewer)


I used to try Digiscoping many years ago (found it very difficult to say the least)! And everybody suggested using aperture priority mode.

Personally, I can't see why shutter priority mode can't be used? They both give the same outcome;)

If you set the widest aperture you get the correct shutter speed (fastest)
If you set the fastest shutter speed you get the correct aperture (widest).

IMHO, Just the same:t:

Any comments?


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If there is too little light for the shutter speed set even with maximum aperture, the picture darkens, whereas the speed can be reduced till enough light is gathered.
\Of course that may then allow motion blur, but that is to encourage people to buy better cameras and faster lenses. ;)
Depth of field will come into the equation. So your answer/question is partly right - but how much depth of field do you require?
Depth of field will come into the equation. So your answer/question is partly right - but how much depth of field do you require?

But, my understanding is depth of field is negligible especially photographing through a scope, because of the focal length involved! Also changing ISO settings changes the other parameters on your camera if set on auto!

Nowadays using a modern SLR gets better photographs than in my era:-O


The correct answer depends on the camera and lens, if any, that is used in combo with the scope.

The Aperture Priority mode is the preferred mode for getting correct exposures for prime and fixed aperture zoom lenses since there are only a limited number of aperture settings but a sometimes infinite number of shutter speeds (depends on the camera software). With variable aperture zoom lenses the aperture will always change with the zoom focal length.

When digiscoping the system aperture is determined by the eyepiece or camera adapter exit pupil. In this case, best to maintain at least a 1/125sec shutter speed to minimize image blur if shooting in less than ideal conditions, e.g. moving target, wind, long distances/high magnification. This min speed can be difficult to maintain with larger sensors, but larger sensors give better high ISO noise performance. It's a balancing act against the final output IQ. If you are making large prints, then your options are limited. If you don't print and don't crop more than say 25%, you can get away with using pretty high ISO's to maintain shutter speeds.
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I use shutter speed priority when using camera and lens taking bird images. I use manual when digiscoping, and set aperture and shutter to get a good exposure.
Not being the most expert photographer, I went with Aperture Priority because...those far more skilled than I am said so and had the exact same camera. :t:

I will say I accidentally had my camera in Shutter Priority once and it was making my photos super-dark and fuzzy. I do tend to be shooting in the first 2 hours after sunrise, if that makes a difference.

I have since started playing with contrast settings, focus priority, and other things (mostly to improve dynamic range and to play nice with my scope) so I'm not using these exact settings, but they were a great jumping-off spot for a novice.

Shutter priority for video with Sony RX100 compact camera.

Hi Chris,

Let me give you a perspective of Shutter priority from a video view point.

I use a Sony RX100 for digiscoping and normally take video footage from which I can grab selected jpeg images (not to be compared with DSLR quality stills but horses for courses).

Technology has advanced greatly and the RX100 allows you to set shutter speed real time while taking a video. The beauty with using shutter priority with video is that you can set the highest shutter speed for any given light condition. For example, in good light you can set a shutter speed of 1/2000th. This effectively gives 50 frames/second (normal UK video frame rate) with limited blurring of individual frames but choppy video. I'm more interested in "freezing" the image so choppy video isn't a problem. Anyway video editing software can sort out choppy video.

In lower light conditions with the RX100 you simply decrease the shutter speed (frame rate still 50/second) until the LCD shows an appropriate brightness. In video mode with the RX100 what you see on the LCD is what you get on the video footage (WYSIWYG). Obviously with the slower shutter speed you get less sharp images but smoother video. You simply optimise the setting for the lighting conditions.

The RX100 also allows you to adjust exposure compensation, REAL TIME, thus allowing you to fine tune the light level on the LCD and thus the light level on the video footage.

Hope this gives you some insight into using Shutter priority in video mode.

I should imagine that as technology advances and higher definition video become available it will be astonishing the quality of images that can be grabbed from video, thus the best of both worlds !

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