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I just took two moon photos: one at shutter speed= 1/400 and the other at 1/200. Both @200mm, f/8, 100 ISO

moon

I can understand with a higher shutter speed less light will enter into camera sensor, hence the photo should be darker.

But why does the moon appear a little orange with the higher shutter speed?

MikeW
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gaganyaan
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3 Answers3

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but why i can see little bit of orange color with shutter speed 1/400 ?

My best guess is that you had the camera set to automatic white balance (AWB). In the 1/200s shot, the moon was bright enough to easily be the brightest thing in the frame, and the white balance algorithm decided that that object was most likely to be white. In the 1/400s shot the algorithm chose differently. Maybe because the moon was only half as bright, it took a more evaluative approach and factored in all the blue light coming from the rest of the sky, setting the white balance more toward blue and turning the moon orange as a result.

Although the sky looks black in the photo, I bet it appeared more like a deep blue when you took these shots, right?

Caleb
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    yes, camera set to AWB. Sky was almost dark and there wasn't any starts near to moon. I just full zoomed image in photoshop very hard to find blue color but i tried with color picker tool on some pixels i was getting around R=5,G=3,B=6 more pixel were in violet color range but dark side. – gaganyaan Mar 23 '16 at 19:54
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    Many cameras have a separate white balance sensor that reads the light coming through the wide open lens. When you stop down to f/8 and use a shutter speed like 1/400s, the image sensor isn't going to record much of the blue light coming from the sky, but the white balance sensor might. – Caleb Mar 23 '16 at 20:05
  • @Caleb I don't think the D3300 is one such camera. – Michael C Mar 24 '16 at 00:43
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    Shoot raw files. You can make sure they are set the same in the raw processor, and use tge eyedropper tool to check the pixel value. If you llok at that in hsb or lab space, it's easy to see if the color is the same. I beleive if the developed white balance is "right" they will differ in brightness only. – JDługosz Mar 24 '16 at 01:04
  • @Caleb why would the aperture affect the blue light more than other wavelengths? – Chris H Mar 24 '16 at 10:33
  • @ChrisH It doesn't, but the sky is blue, and very deep blue after the sun sets. I was guessing that the white balance was probably thrown off by the blue sky even though it looks black in the photo because it's underexposed. – Caleb Mar 24 '16 at 12:29
  • That makes sense, but doesn't need a separate white-balance sensor. Also it appears to rely on whatever sensor (or AWB algorithm) being close enough to reading zero that the response is nonlinear on that one channel. – Chris H Mar 24 '16 at 13:05
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    @ChrisH There's definitely some speculation here on my part about exactly why the camera shifted the white balance in one shot and not the other, which is why I used the word maybe. Even knowing what camera model is involved (we didn't at the time I wrote this) it's hard to know exactly how white balance is determined at different exposure levels. But the gist of it is this: the camera was set to AWB, and it obviously shifted the white balance between the two photos, and one possible reason for that is the blue sky and the difference in moon brightness between the two. – Caleb Mar 24 '16 at 13:17
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There are a number of reasons for this.

  1. AWB, as mentioned already.
  2. Different saturation due to tonal curves. Lighter object may get lower saturation depending on tonal curves.
  3. Different chromaticity due to bad tonal curves. This is a neutral output from quite pricey RAW image editing program - Adobe Camera RAW. Problem is that with these curves same object may get different chromaticity depending on it's EV.
Euri Pinhollow
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If you set a shorter shutter speed, less light enters so things will look darker. Adequate light enters when you have a longer shutter speed; things will be brighter and I have experienced that pictures tend to be more white in the latter case. That is what has happened with your pictures. This is generally why we take longer shutter speeds when shooting in a dark environment.

user
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anurag
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