Would the moon look like this if it was real?

General physics and astronomy discussions not directly related to Celestia
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FaLLeN_SOuL
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Would the moon look like this if it was real?

Post #1by FaLLeN_SOuL » 11.02.2009, 19:05

i shot this picture of a chemical plant this week:

Industrial_Revolution_-_I_HDR.jpg

since there was no moon shining in this night, i added one with the help of photoshop. now i wonder if it looks realistic, i mean...

- the dimension compared to the moons level over the horizon
- the color
- the brightness

thanks for suggestions!

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Re: Would the moon look like this if it was real?

Post #2by julesstoop » 11.02.2009, 22:52

The phase of the moon suggests that the sun is about to rise, so the sky seems too dark for the moment of the day.
The size of the moon also seems a bit unrealistic. I have a feeling you didn't take the picture with a (long) telephoto lens (a high magnification, so to say) so the moon should be smaller in my perception.
Thirdly, I suspect the moon should be a little brighter on an exposure like this.
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Re: Would the moon look like this if it was real?

Post #3by FaLLeN_SOuL » 12.02.2009, 10:05

ok, i understand.

- so, if i took this picture with a 55-250mm zoom lens set to 135mm (what is 216mm on a 35mm camera), the moon should be larger?
- the phase of the moon should be near to full moon?
- and brighter of course!

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Re: Would the moon look like this if it was real?

Post #4by julesstoop » 12.02.2009, 18:34

I underestimated the length of the lens obviously. With the focal lens you used the disk of the moon should fit about 13 times - side by side - horizontally. So the angular size of the moon seems about right.

On the other two accounts: yes :)
The moon should be fuller and brighter. Since it's so close to the horizon I would also suggest to give it a slight yellowish/orangy hue.
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Re: Would the moon look like this if it was real?

Post #5by FaLLeN_SOuL » 12.02.2009, 19:19

ok, here is the 2nd version of the picture.

Industrial_Revolution_-_I_HDR.jpg

- it now fits exactly 14 times horizontally
- brighter than first one
- has a yellowish/orangy hue

looks still too artificial to me. maybe the halo could be brighter/larger, and the color more desaturated?

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Re: Would the moon look like this if it was real?

Post #6by selden » 12.02.2009, 20:13

Another issue is the direction toward the Sun.

Since the city is dark, the sun is below the horizon.
Your moon is illuminated horizontally from the right: the center of the illuminated area points toward the Sun. I suggest rotating it at least 45 degrees clockwise, so it's illuminated from below the horizon.
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Re: Would the moon look like this if it was real?

Post #7by FaLLeN_SOuL » 12.02.2009, 20:29

v2.1:

Industrial_Revolution_-_I_HDR.jpg

- rotated moon 40° clockwise
- reduced yelowish/orangy hue from 20% to 15%
- larger halo

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Re: Would the moon look like this if it was real?

Post #8by LordFerret » 12.02.2009, 20:53

How about giving the location (lat/long) of this image, and then using Celestia to place the moon into position? You could then match the FOV to the lens used, and you'd have stars in the image as well.

:?:

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Re: Would the moon look like this if it was real?

Post #9by FaLLeN_SOuL » 12.02.2009, 21:03

LordFerret wrote:How about giving the location (lat/long) of this image, and then using Celestia to place the moon into position? You could then match the FOV to the lens used, and you'd have stars in the image as well.

:?:
when looking up the moons' position in celestia at the time and location the picture was taken, there is a full moon shining too high in the sky to be seen in the picture.

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Re: Would the moon look like this if it was real?

Post #10by julesstoop » 12.02.2009, 22:22

Talking from my own experience with photography:

When I take a picture of a skyline like this, I generally need an exposure of about 0,5 to 10 seconds depending on circumstances, aperture and ISO.
For taking a picture of the moon, while still being able to see any detail on the surface (using similar aperture and ISO-settings) my exposure needs to be shorter than about 1/30 (generally a lot shorter, depending on the atmosphere, but the moon hangs very low here). So the moon should have a halo of light and the surface should be overexposed. The halo might have a hint of yellow, but the overexposed surface should (obviously) be 100 white.
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Re: Would the moon look like this if it was real?

Post #11by LordFerret » 13.02.2009, 06:51

FaLLeN_SOuL wrote:
LordFerret wrote:How about giving the location (lat/long) of this image, and then using Celestia to place the moon into position? You could then match the FOV to the lens used, and you'd have stars in the image as well.

:?:
when looking up the moons' position in celestia at the time and location the picture was taken, there is a full moon shining too high in the sky to be seen in the picture.
Well that's the beauty of Celestia - using the location, you can change the time to a point where the moon would be lower in the sky and within the frame? Worth a try no?

*edit*
My Gimp skills are lacking, but the idea I had in mind is as follows -
Image


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Re: Would the moon look like this if it was real?

Post #13by FaLLeN_SOuL » 14.02.2009, 18:31

@LordFerret:
nice, but actually not what i am looking for.

@julesstoop:
based on the first picture, this is what i get:

Industrial_Revolution_-_I_HDR_mod.jpg

but comparing the whole picture to mine, i think mine is darker, so we can assume that the shutter speed is shorter, allowing a darker moon with some details mybe?:

Industrial_Revolution_-_I_HDR.jpg


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