Introduction
Narrowband and broadband are two ways you can take photographs of outer space. Both are used by astrographers around the world.
But in the debate of narrowband vs broadband astrophotography, where do you land?
The difference between narrowband and broadband is based on the spectrum of light they collect. Broadband astrography uses RGB filters that collect light from the whole visible spectrum. On the other hand, narrowband astrography only collects a specific spectrum of light.
Want to know more about the two fields of astrophotography? Read this article and hopefully we will be able to give you a better understanding.
General Comparison Between Narrowband And Broadband
Before we can get into understanding the two fields, we must know their general differences. The filters used, the light collected, the camera used all are different.
A summary of the differences maybe such:
| Differences | Broadband | Narrowband |
| Filters | RGB Filters | H-alpha, OIII, and SII |
| Light Spectrum | Entire visible spectrum (400 nm to 700 nm) | 656 nm, 672 nm, 496 nm |
| Camera | Mirrorless DSLR | Monochrome Camera |
| Degree of light pollution | Severe | Minimum |
So we can see that there are quite a few significant differences between the two.
In-depth Comparison
The chart above alone is not enough for a clear understanding of the differences. So let’s get into the details of narrowband and wideband astrography.
Filters
Filters control the collection of light. They dictate which spectrum of light may enter and which may not.
It goes without saying that photographs are completely dependent on light. So filters play a significant role in how the image will turn out to be. It is especially true in the case of astrophotography filters.
The differences between broadband and narrowband depend significantly on filters.
Broadband Astrography
The filters used in broadband photography are red, green, and blue also known as RGB filters. Each of these filters cover a part of the visual spectrum.
Broadband astrography is also called “true-color” imaging. The filters collect the natural colors of the night sky. The lights they collect also come from the complete visual spectrum
Narrowband Astrography
Narrowband filters, as the name suggests, are narrow. They let only restricted bands of wavelengths around specific emissions lines. The emission lines being of Ha, SII, OIII.
The filters used in narrowband are:
- Ha (Hα)
- S-II
- O-III
The filters for narrowband astrography isolate the light produced from specific types of gas. This inturn reveals a lot of information about the image. This helps scientists learn a lot about the composition of nebulas.
The colors of a nebula are because of the different gasses that emit or reflect light. Narrowband filters specifically isolate the colors of these gasses.
The narrowband filters help in restricting the light emitted from different sources of light pollution. This even helps in seeing the polaris in detail and color.
Winner: The winner for astrophotography is narrowband filters. The filters let in specific light that enables for better quality and more detailed images.
Light Spectrum
Light of different wavelengths enters the telescope. But not all light is good for the image. Lights of different wavelengths have different impacts on the image.
Filters and collection of light are closely interrelated. Filters are what control what light can enter.
So how do broadband and narrowband differentiate lights of the whole spectrum?
Broadband Astrography
Broadband collects light across the entire visual spectrum. This helps in creating the “true-color” imaging.
The broadband “true color” imaging has natural star colors.
Narrowband Astrography
Narrowband imaging isolates and captures specific wavelengths of light. This enables us to capture dynamic images of objects in distant space.
Narrowband astrography uses filters that pass a very restricted band of wavelengths. The wavelengths are:
- Ha (Hα) 656nm = Hydrogen-Alpha
- S-II 672 nm = Sulfur-II
- O-III 496nm = Oxygen III
Narrowband also implements the usage of Hubble Palette. A main feature of the hubble palette is that it reveals plenty of details. Even more details of the object than you could ever see with the naked eye.
Winner: This segment is also won by narrowband. Narrowband collects lights that are specifically good for astrophotography. On the other hand, broadband collects too much light. The image may have accurate color, but is not detailed.
Camera Used
The camera needed for narrowband or broadband might be a big factor. The cameras for the fields are not interchangeable. You will need specific gears.
So let’s see which field requires which camera.
Broadband Astrography
Broadband astrography can be done using regular DSLR or mirrorless cameras.
Narrowband Astrography
Narrowband astrography can be technically done with any camera you want. But using dedicated astrography cameras is highly recommended. Normal cameras cannot yield good or even satisfactory results.
Monochrome cameras are the best for narrowband astrophotography. This is due to the Red, Green, Blue filters on the surface of the sensor. When imaging through the filter all the pixels of the monochrome camera record the transmitted light.
We already discussed what kind of cameras you need for broadband and narrowband. If you already have a camera for your preferred field, you can skip this part.
Narrowband and broadband require different kinds of camera for the best performance. Let’s see where you can get them:
| Type | Camera | Where To Buy |
| Narrowband Astrophotography | ZWO ASI1600MM | Click Here |
| QHY 183M | Click Here | |
| Broadband Astrophotography | Canon 60D | Click Here |
| Nikon D7100 | Click Here |
All of the cameras are good overall. But there are some differences between the suggested astro cameras.
Winner: This section is also won by narrowband. The monochrome camera offers much more for astrophotography.
Final Verdict
If you are someone that is getting into astrophotography, then the choice for you is narrowband. Broadband cannot match the quality narrowband offers. Most of the images seen online are taken by narrowband.
Broadband does give you more natural colors, but it greatly lacks details and is heavily polluted. The difference between narrowband and broadband images are clear.
For very casual astrophotography you can use broadband. But for dedicated astrophotographers, we highly recommend narrowband.
FAQs
Does Narrowband Capture Accurate Colors?
No, narrowband does not capture accurate colors. The wavelengths narrowband captures cannot be seen by the naked eye. But the image captured is very accurate because it captures the specific wavelength nebulae emit. Broadband on the other hand captures less detailed but color-accurate images.
Do Broadband And Narrowband Have The Same Filter?
No. Broadband astrophotography uses RGB filters. They collect light across the complete visible spectrum. Narrowband astrophotography , on the other hand, uses filters that collect specific light spectrums. Narrowband generally uses Ha, SII, OIII filters
Does Light Pollution Affect Astrophotography?
Light pollution can impact astrophotography. But it is more prominent in broadband astrophotography. Broadband lets in light from a wide segment of the spectrum. This much light affects the image quality. Narrowband lets in specific light from the spectrum. This limits the pollution.
Conclusion
Now we have an answer for the debate of narrowband vs broadband astrophotography. Narrowband offers far superior performance in astrophotography.
For dedicated astrophotographers, narrowband is the recommended way to go. Less enthusiastic astrophotographers may be content with broadband though.
That’s it for today!
ZWO ASI1600MM Pro 16 MP CMOS Monochrome Astronomy Camera with USB 3.0 # ASI1600MM-P
Canon EOS 60D 18 MP CMOS Digital SLR Camera with EF-S 18-55mm f/3.5-5.6 IS Lens Kit - International Version
