Low light, Night, Moon photography etc.

[oldgreygary]

Here's a shot of the moon I took about a year ago.

That's a terrific shot of the moon with some really nice detail!

Cheers for now

Gary

[rtbaum]

This is my first attempt at a dedicated moonshot, unfortunately my last for a while as well, as I dropped camera a couple days later

[oldgreygary]

Randy, sorry to hear about the accident with the camera. It seems as though you have similar issues as I had when photographing the moon. In some of the earlier posts there are some suggestions to get round this. Faster shutter speed and merging two images together. By exposing for the moon, then the landscape/seascape and merge in PP. The faster shutter definitely works as I have tried it! But, not yet tried the 2 exposure merge.



I tried some further experiments with exposure. Over a two hour period from 5:20am to 7:20am I took an image every 10 minutes of the same scene. The sunrise time was 6:26am. I left my camera (Canon G2) in aperture priority mode. The fstop was f/5.6, ISO 50. The scene was looking across from a shady area to a road and some office buildings with some street lights. A small part of the sky was also in the scene. It wasn't until about 20 minutes after sunrise (6:40am) that the camera changed the shutter speed. Up until that point it stayed at 1 sec. The initial images were all underexposed with no detail. It wasn't until about 40mins after starting (6.00am) that some detail began to show in the images.

That sort of leads me to the conclusion that pre-sunrise and I guess post sunset using manual exposure would be the best way to operate. As it seems like the 'in camera' meter will not be effective in those conditions? It would also be useful to be able to have an 'auto-tmer' to do this sort of experiment as every 10 minutes I had to manually press the shutter button! It's quite an interesting experiment as although it seems to me anyway to be light outside the camera has a different view and requires a lot more exposure time than my brain and eyes are telling me that is required?!

Cheers for now

Gary

[Dave Humphries]

Here's another attempt at the scene in the first post only this is at the beginning of the day pre-dawn. There was a low lying fog in patches and in the far distance are the airport lights which are being muted by this. Any thoughts or comments? I think it was f/2.5, 1 sec, ISO 50, resting the camera on a bench!

Hi Gary,

I like this one, with the added interest of the distant fog patches over the first in the thread.

My only thought would be to query the blue-ness of the mid-tones, but I say that because I'm not sure it is a simple white balance issue, as I have little experience of PP on this type of shot.

Cheers,

[drjuice]

rtbaum -

Your picture upload didn't work. Thought you'd want to know. Sorry to hear about the camera. v

[Dave Humphries]

rtbaum -

Your picture upload didn't work. Thought you'd want to know. Sorry to hear about the camera. v

I do see the picture, it is hosted at TinyPic.

I hesitate to ask, since I doubt I can do anything positive to help; but which browser are you using?

[rtbaum]

Other lessons learned (Other than hold onto friggin' camera when changing lenses)

#1 Moon moves in 30 sec
#2 turn off VC, lost some gorgeous shots the next night of orange moon

[oldgreygary]

Hi Gary,

My only thought would be to query the blue-ness of the mid-tones, but I say that because I'm not sure it is a simple white balance issue, as I have little experience of PP on this type of shot.

Cheers,

Dave, thats an interesting point you raise. The white balance as shot was 6300k(cloudy setting). I tweaked it back to about 5500k (in Lightroom). As I understand it the lower the kelvin number the warmer the light is and the higher the cooler the light is.

Thats what confusing me in Lightroom. The Temp slider if moved to the left shows bluer while moving to the right shows yellow. Moving to the left decreases the number while to the right increases the number. So, that seems to me anyway to be counter intuitive. As lower kelvin equals warmer, higher cooler. So, why does the Temp slider show blue which I associate with cooler but is lowering the kelvin number which is warmer??

I guess that this is an area that I don't fully understand and appreciate. What is early morning light? The ambient temperature can be quite cool so it makes you feel that you should make the image that way. But, the sun is rising so it actually starts to have a warm feel to it. If any of that makes sense then perhaps someone can comment?

Cheers for now

Gary

[escoville]

Gary, I know your viewpoint very well, and have taken many pics there myself (but not at night). Your first pic (the one that opened this thread) can be processed quite easily on PhotoFiltre with 3 clicks of the Gamma Minus button. The second, pre-dawn, one: the sodium glare (from the town lampposts, not the airport) is a bit disturbing, but it's part of the scene. You could probably deal with each of the very glaring lamps individually using the anti-red-eye feature of most processing programs.

[John Morton]

Dave, thats an interesting point you raise. The white balance as shot was 6300k(cloudy setting). I tweaked it back to about 5500k (in Lightroom). As I understand it the lower the kelvin number the warmer the light is and the higher the cooler the light is.

Thats what confusing me in Lightroom. The Temp slider if moved to the left shows bluer while moving to the right shows yellow. Moving to the left decreases the number while to the right increases the number. So, that seems to me anyway to be counter intuitive. As lower kelvin equals warmer, higher cooler. So, why does the Temp slider show blue which I associate with cooler but is lowering the kelvin number which is warmer??

I guess that this is an area that I don't fully understand and appreciate. What is early morning light? The ambient temperature can be quite cool so it makes you feel that you should make the image that way. But, the sun is rising so it actually starts to have a warm feel to it. If any of that makes sense then perhaps someone can comment?

Cheers for now

Gary

Hi, Gary;

The disconnect you describe between 'warmer' and 'cooler', and color temperature, comes from two very different sources of expression being mixed in together.

In fashion and color theory and anything to do with graphic design, reds are considered 'warm' (like fore) and blues are considered 'cold' (like ice).

In physics, the Kelvin scale of temperature starts at Absolute Zero (no movement at all) and climbs up to the point where there is so much movement (heat) that atoms start to emit photons from their electron shells. These emission spectra are very, very specific and show up in spectrographs as very narrow vertical lines that correspond to specific electron shells of specific atoms at specific temperatures. These emission spectra also have specific wavelengths that correspond to the energy level differentials (between excited state and base stat after a photo has been emitted) of each electron shell for each atom - that's where the colors of the photos that make up light come from.

So, in astronomy, red stars for instance are considered "cool" because they are usually large, massive objects that have a lot of volume so their heat is more spread out; and they emit light in the red part of the spectrum because that's where the energy levels that they sustain tend to excite electron shells in the atoms that compose those stars.

These stars are often older, and have burned up a lot of their fuel so their gravity is less and as a result they are less compact than at the start of their life.

Very dense and compact blue stars in contrast are very "hot" because they are (generally) young and have a lot of fuel so they have a deeper gravity well that holds everything together in closer proximity.

You can see how this works by having a look at a Hertzsprung Russell Diagram, which plots energy output of stars against their color:

http://www.atlasoftheuniverse.com/hr.html

As you can see, red is indeed cold and blue is in fact hot (except for fashion designers).

Since blue light has more energy than red light (it is of a shorter wavelength, so there is more energy in a smaller volume), it tends to be less affected by whatever it passes through than red light; so it is the colder, longer wavelengths of light that scatter and bend the most at sunrise and sunset (bending through the earth's atmosphere over the horizon when the sun is not in our direct line of sight). Really high energy wavelengths, from ultraviolet into x-rays and gamma radiation, not only tend not to bend but can actually destroy things that they pass through (such as the chromosomes of cells; which is why high energy wavelengths can cause cancer).