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I am trying to shoot a building (the space needle) during night time With a shutter speed of 30s.

The red light emitted by surrounding buildings has high luminance.

How do I decrease the luminance without compromising my focus.

Can I use some kind of filter?

Maybe I can use some settings in Lightroom?

Alaska Man
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user5731434
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  • Hello and welcome. please can you attach an image. – Abdul N Quraishi Jun 14 '20 at 09:50
  • @AbdulQuraishi thanks a lot. Heres the image url: https://ibb.co/Z17HWwk Basically, I want to make it clear that building on the left side of Space needle reads "Key Arena", right now it looks a bit blurry because too much luminance from red light. – user5731434 Jun 14 '20 at 11:44
  • Related: The subject is completely different, but the answer is similar. You can shoot it when the sky is brighter and reduce the overall exposure to make the sky look darker. That also prevents blowing out the bright light sources, as the relative difference between the brightest and darkest parts of the scene are much less. This answer to How do I capture the moon and its surrounding context? – Michael C Jun 16 '20 at 15:00

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Luminance is simply brightness. To decrease it, you must allow less light in or reduce sensitivity. Using a shorter shutter-speed would automatically achieve this but since you are set on 30s, then you other options are:

  • Lower ISO sensitivity, unless you are already at the lowest. This has the advantage of giving you higher image-quality until the native ISO of the sensor, which is often between 100 and 200.

  • Close down aperture: This will increase the depth of field, so you will have more in focus. Be careful to avoid passing the diffraction limit which will cause the image to be softer, so it might look like it missed focus.

  • Use an ND filter. These filters reduce the brightness of the image by diminishing incoming light. They come in different strengths and even graduated versions that lower brightness more on one side. Even a polarizer dimninishes light somewhat, some by over a stop, although it will have other effects, particularly if there are any reflections.

Itai
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  • If you don"t reduce the relative luminosity of the parasite light you aren't going to improve the result? – xenoid Jun 14 '20 at 22:15
  • @Itai I gave it one more try after ur recommendation, the text “key Arena” looks sharper but still the extra red light from “long exposure” on its sides is far from perfect. Any more tips specific to this condition/image. Shot with kit lens Nikon D3500 f/8, 15 seconds, 55mm, iso 100, single point light meter off of red light sign on key Arena. https://ibb.co/c2T39k2 – user5731434 Jun 15 '20 at 23:09
  • @user5731434 Much better! Seeing the example is great. What you have is a scene of high contrast and essentially you cannot do much more in-camera because lowering the exposure were turn the rest of the photo mostly black when the sign becomes completely readable. The only way to reduce contrast is to come back to the see earlier, even just minutes makes a difference for night photography. The only to get out of this situation is to capture a much darker picture and a bright one and then use software to blend them together. Lookup Exposure Fusion, there is a Lightroom plugin for that. – Itai Jun 16 '20 at 00:28
  • @Itai thanks very much for the tip! This is exactly what I needed because I was having a hard time to search “what I was looking for”. I will look into exposure fusion and get an earlier picture. I will post a pic here once I’m done. – user5731434 Jun 16 '20 at 00:45