The Snake Tips

Thinking Critically about Photographs

Critique 50


This is LONG overdue. I apologize to the person who sent this to me that I haven't gotten it up sooner. Part of what I do in workshops is teach night time photography. I hope that on most of our trips we are lucky enough to get a clear night with interesting skies.  It's getting to be winter, so it's not the perfect time for photographing the stars. The main reason is the dry cold air. This causes less humidity in the atmosphere. Humidity is what causes stars to seem like they are "twinkling". You can see of this image, that is what is going on. Right above the horizon line you see small green haze. It's humidity (and maybe some light pollution from a nearby town).

Here's the questions this photographer asked me to address. I LOVE that they asked, because it means they are actively thinking about what is going on. Night time photography is very challenging. Before I start, I think that this is well done. Overall I would be happy with it and use it as a "I can do this" photo.

  1. funny green cast above the horizon - That's humidity and light pollution. Not a lot you can do about it and I don't think it detracts that much from the image.
  2. I get a black halo if I increase exposure - You can try and turn it into a black and white image and paint back in with layers and a lower opacity.
  3. way more stars than what I saw naked eye - Yep, your camera will tend to expose for more stars than your eye can see.
  4. definite problem with distortion correction - To photograph big star fields you need a very wide lens, this is going to cause some distortion. You can use a lens profile from Adobe to correct for it (or DXO labs) or use Photoshop to manually correct for distortion. I don't overly correct for it, because it's somewhat expected.
  5. star trails or vibration (should have used mirror up) - The dreaded star trails. These are cause by having an exposure to long. Unless you want star trails always try to keep your exposure to under 30 seconds. The shorter the better. But they are star trails and not vibration.  I blew it up and you can see the all tends to go up and down, you don't get that kind of movement from vibration. Vibration will make it look blurry. Starmove
  6. cabin too bright? - I think the bright parts of the cabin are just right. If anything I would have liked to see a little more of the outside of the cabin. A little light painting.
  7. stars and sky too blue - They look a little blue, but not overly so. The mind thinks cold and blue is usually associated with that. If they were red or orange, I'd worry. Blue keeps the sense of night time and coolness.