7 Tips to Understand and Improve Your 50mm Astrophotography
Using a 50mm lens in astrophotography may not be the right choice for some photographers but as long as you live to love 50mm photography in general, indeed, you can obtain astonishing results even in astrophotography or photographing the night sky with a 50mm lens in special if you follow our tips to improve your 50mm astrophotography.
Therefore, what are the main tips to improve your 50mm astrophotography? Capturing night sky with a 50mm lens attached on a full-frame camera your shutter speed needs to be faster than 10 seconds, on an APS-C Nikon, under 6.6 seconds, wherewith APSC-C Canon faster than 6 seconds. Always keep your ISO under 6400 and capture multiple exposures for further stacking in Photoshop.
Although there is a quick answer given above on what are the main tips to improve your 50mm astrophotography, there is a way lot more to expand and further discuss in this post, therefore, I recommend you to keep reading in order to gain the best information about photographing the night sky with a 50mm lens.
Can you capture the night sky with a 50mm lens?
In my professional opinion, yes, you are able to capture the night sky and get started in astrophotography even with a 50mm prime lens. It is well known that a 50mm prime lens is relatively cheap on the market for most of the major camera manufacturers, therefore, sometimes this may be the quickest way to get into photographing the night sky.
Astrophotography is not easy. You will need to have besides good gear and lenses, some skills in post-processing as for the best results, you will need to capture multiple exposures of the same frame of the night sky.
Remember, you won’t be able to get started with the stock lens (e.g. 18-55mm f/4.5 – f/5.6) due to the very narrow aperture. You NEED a prime lens in order to capture the night sky (disclaimer: some zoom lenses would work if it has a relatively wide aperture). But now let’s get into using a 50mm prime lens, shall we? (as I do).
Disclaimer 2: This guide will not cover everything is to know about astrophotography or photographing the night sky but to share with you some extra tips in order to improve it using a 50mm prime lens. Furthermore, I wanna share with you another related post I wrote: “is a 50mm lens good for astrophotography?“
Tips to improve your 50mm astrophotography: #1 The real shutter speed.
One of the most important factors when capturing the night sky is to know the duration of the shutter speed you are going to use. Depending on your real focal length, you may have to limit it in order to avoid star trails.
Therefore, to capture the night sky with a 50mm lens, you will have to use the following shutter speeds:
- On a full-frame (FX) camera with a crop ratio of 1.0x, the maximum shutter speed you can use with a 50mm lens is 10 seconds. I strongly recommend dropping the shutter speed to 8 seconds for the stars to be as sharp as possible when magnifying beyond 1:1 ratio (good for printing).
- A DX (crop sensor) Nikon camera has a crop ratio of 1.5x, therefore, the shutter speed needs to be faster than 6.6 seconds in this case. A good area of practice would be to use 5-second shutter speed for the same reasons as above.
- Some of the Canon crop-sensor cameras has instead a crop ratio of 1.6x, where, the maximum shutter speed to use without to get star trails would be 6 seconds. Same as above, I recommend you to use a 5-second shutter speed or faster with your 50mm canon lens.
To explain the above settings a bit, I will have to share with you how I know these exact settings. There in astrophotography, when we are not using an equatorial mount, we have to apply the rule of 500.
The rule of 500 is as follows: SS = 500 / (CF x FL). SS is the shutter speed, CF is the crop factor and FL is the focal length, which in our case is 50mm. This is a simple mathematical formula which can calculate the maximum shutter speed to use with any focal lengths and any camera if we know the basic values of the camera’s crop factor and the lens focal length.
As an instance, we calculate the shutter speed we need for a Nikon DX camera and a 50mm lens. Nikon DX as mentioned above has a crop ratio of 1.5x therefore, the formula would look as following: SS = 500 / (1.5 x 50mm); SS = 500 / 75; SS = 6.6666… sec, which to round up is 6.6 sec
Tips to improve your 50mm astrophotography: #2 Balance your ISO accordingly.
The ISO can be our friend or our enemy. In most of the cases, it is our enemy as we have to increase the ISO accordingly, in order for our cameras to perceive as much light as possible. Many times, due to light pollution, “as much” can become “too much”, and mainly, to balance it with our aperture.
We have to know in concordance with the area we are photographing the night sky what ISO to have. Therefore, generally, it is good to have a few tests before we start to capture multiple exposures.
As an instance, I use Nikon D750 full-frame camera with my 50mm f/1.2 lens. For the Orion constellation, I used ISO 2000 with an aperture of f/2.0, 8 seconds exposure, where for the observatory silhouette photo, same settings but ISO 3200.
Because I had a full-frame and my camera could manage well an ISO 3200, I found useful to step down the aperture (more info will follow).
But not many cameras could do well on high-iso, where, for a DX camera and 50mm lens, you can have only a couple seconds exposure, where, the ISO has to be increased a lot more. Here we may have a battle of settings in order to obtain the right one for the night sky not to look underexposed.
Anyway, I found useful with my full-frame camera and my 50mm lens to use ISO settings between ISO1600 and ISO 3200, wherewith my DX Nikon D500, between ISO3200 and ISO6400.
Once you start increasing more and more the ISO to be able to properly expose the images, you will definitely need to have more exposures, to stack them for the noise reduction. And because you will be able to reduce the noise, you can further play with settings for an extra boost of the final image.
Know your camera and ISO capabilities before everything. Find a compromise between the right ISO settings, the shutter speed and the aperture of your lens.
Tips to improve your 50mm astrophotography: #3 Step down your aperture
Many photographers know that the great advantages of prime lenses in special of a 50mm lens are the very wide apertures they benefit. Most of the non-expensive 50mm prime lenses have an aperture fo f/1.8 where some other of f/1.4 and even f/1.2 such as the Nikkor 50mm f/1.2 manual focus lens I own.
As well, many photographers are always using the maximum aperture when capturing the night sky but this is relatively wrong for a couple of reasons, to say:
- With a full-frame camera with good ISO capabilities and a very wide aperture, due to most of the light pollution present, you can easily over-expose your night sky photographs
- Stepping down the aperture increases the sharpness overall, and when you shoot with a full-frame camera, you may not even need very wide apertures.
- If you would have to choose from sacrificing between sharpness and image noise, what you would do? Increase sharpness by stepping down the aperture although you use a higher ISO – do not forget, you can drastically decrease the image noise when you stack multiple exposures in photoshop but you can never obtain perfect sharp images on the widest aperture settings but lower ISO
All the lenses, in special prime lenses, when you shoot on the widest aperture (e.g. f/1.2, f/1.4 etc), the images will look a bit softer than stepping down the aperture to an f/2.0 as an example.
It is much better not to use the widest aperture of your prime lens and increase the ISO a bit more to obtain the same results, but remember, your images will look sharper than before.
Tips to improve your 50mm astrophotography: #4 Know what you can capture with a 50mm lens
Because of a 50mm lens (50mm – 75mm+ focal length, depending on your camera), there are only a number of elements you can frame into your scene.
Shortly to say, with a 50mm lens you will NOT be able to capture the night sky as a whole, the milky way across the mountains etc.
It is important to know what you can capture with a 50mm lens. As an instance, these lenses are great for capturing constellations as the Orion constellation in the first image I shared with you, or only parts of the milky way.
Find a foreground to photograph with a starry and beautiful background, to increase the pleasantness of an image. Even in the case of a foreground, you may be able to capture only part of it and not as a whole (again, another example would be the image with the silhouette of the observatory from above)
Tips to improve your 50mm astrophotography: #5 Limit your exposure stacks
As I did mention above, you are going to benefit a lot from capturing multiple exposures of a night sky, in order to drastically reduce the noise from higher ISO images and to further take the post-processing to a whole another level.
Here I want to share with you a video from YouTube as a reference to the method I am using to manually stack the exposures in photoshop. (the video is not mine though)
But now moving forward, why would I say that you should limit the number of exposures you should take with a 50mm lens?
Because of the medium focal length and earth’s rotation, the stars would appear to be moving at a fast rate on each exposure, therefore, after per every exposure, the frame of the scene becomes narrower.
In order to benefit from all the exposures you have, every each exposure you are going to add, will reduce from the frame size due to the earth movement. As an instance, if you are going to take 20 exposures you may be using only 50% of the scene in order to stack them all.
I always find very useful to take a specific number of 8 exposures per scene.
Tips to improve your 50mm astrophotography: #6 Why you should use a shutter remote control
A shutter remote control should be mandatory to use in order to minimise the shake induced when you are pressing the shutter button on your camera.
With very wide lenses such as 14mm, this would be barely noticeable, but jumping to a 50mm lens and further, even the slightest vibration could blurry the photos.
A shutter remote control, either wired or wireless (I always prefer wireless) is not expensive at all and it can bring great value in special in astrophotography.
Tips to improve your 50mm astrophotography: #7 The tripod and weather conditions
For the same reasons as above, because of the medium focal length of a 50mm lens, even the slightest vibration could be noticeable on your final image. And this would be reflected a lot on the weather condition, such as windy.
In general, we need to find an open field for taking astrophotographs, therefore, open fields are more predisposed to winds, which can be a nightmare after all. I cannot say how many photos I had ruined just by the wind gusts.
Having a good and solid tripod with a weight attached to it may drastically reduce the vibrations caused by wind gusts.
Wherever you tried or not astrophotography with a 50mm lens, you gotta love it. Not everyone has my taste in picking the oddest lenses for astrophotography but I could say that I am positively pleased by the final results of doing this.
You could try wider lenses for better milky way results, but if you are just starting in astrophotography and you have a limited budget where you can buy an additional lens, some of the 50mm prime lenses come cheaper than anything else and still, the sharpness excels.
But if you read this post, you may already have it. Why don’t give it a try and tell us how it was?
With this, I have to say thank you for remaining until the end of this post and I hope to see you around. Take care and good luck!
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