The histogram is your best friend.
I will explain in the most simple way I can to help you understand how easy it is to use, and you will love using it because it will help you keep inside the boundaries of exposure.
For example, looking at the histogram image above shows these boundaries. Too much to the left is too underexposed. too far to the right is overexposed. try to stay off the left wall and the right wall.
Try to keep the histogram in the happy middle area of the diagram shown above.
However, you can break the rules a little sometimes, Like if you’re taking sky photos at night and your image shows it’s too underexposed.
just remember you will probably be taking a time shot, this means your slowing down the shutter speed to let more light in over a longer time period like maybe 26 seconds or more, and the histogram will not help you in real time in this situation, because it thinks your taking an underexposed shot. the histogram doesn’t know you’re taking a time shot. now you’re in the experiment mode, you have to take multiple shots to get it right, this is common for all photographers.
No one can say what are the right settings on your camera to take night sky photos. there are base starter settings, for example, you will want to let more light in by turning the aperture F/Stop to the widest setting F/1.4 or F/1.8 or maybe yours is F/2.0 F/2.8 some kit lenses are a little higher F/3.5 and you can still take great night sky photos with that too. after you set the aperture, now go to the ISO to increase the overall light, the ISO measures the sensitivity of the image sensor, for night time photos I would start with an ISO 800 to 6400 then take some test shots to see where your best ISO setting work for you. after taking the shot look at the histogram of the shot taken to see if it is in the safe range so you can edit it later, your camera has a setting in the review mode to show what the histogram says about the exposed image. as long as it is anywhere between the two walls left and right in the histogram, you are safe to edit the data in the photo to bring it to proper exposure in post editing software.
I use Adobe Lightroom for editing, It’s only $10.59 a month to use, I think that’s well worth it.
You will learn these types of photos over time by taking them over and over, we all do!
I won’t take a photo without seeing my histogram on the camera viewer. before and after I take the photo, always check it after you take it too.
I always use the live view feature so I know what I’m getting in real time, this way I’m not always looking down and hitting the preview button to see if the test shot is good, that takes extra time, and if you’re trying to make money taking photos, your wasting precious time.
Most cameras have the live view feature, so look for it in your menus on your camera. and if you can’t find it, try downloading the PDF file, I’m sure you can google it for download for most cameras, Make sure you type the camera name and the model number for the correct PDF. it will help you find all your settings. or watch youtube videos. about your camera’s settings. here is a very good explanation of the histogram and how it will help you in this video below.