Hey everyone, my name is Drew Evans here with OPT and today we're going to be talking
about the pros and cons of a monochrome camera. But first before we get started,
if you could take a second and smash that like button we would really appreciate it.
It really does help with the channel and gets the knowledge of space out to more people!
Here we have a QHY 168c color camera and the ZWO ASI1600 monochrome camera.
They are different cameras and shoot differently, but are also similar in many ways.
Let's start with the fact that both cameras actually use monochrome sensors.
Color cameras get their color by placing tiny filters on each of its pixels.
These filters allow you to get a full color image in a single exposure.
Now while that may be great, there are pros and cons to everything.
Even though you may have a super powerful sensor in your camera,
the full capabilities of that camera sensor will be divided up among the red, green and
blue filters. In other words, if you have four color filters - typically one red, one blue,
and two green - each color is only able to access one quarter of the sensor's capacity which means
the resolution and sensitivity is limited by not using the full power of your sensor.
When you image with a monochrome camera, you're using the full sensor capability to capture light
all at once. You are just capturing one color at a time using filters for each color,
this gives you a huge advantage in overall quality.
To elaborate here's how to get a color image from a monochrome sensor.
While the way we capture images is pretty much the same, the only difference is
we use color filters in front of the camera. In essence you are now using the entire sensor
to capture that color. The only catch about this is that you will now need to take at
least three images with three different color filters to get a full color image.
This is the first instance where the added investment of time comes into play. With a
one shot color or DSLR camera, you can get a full color image with just one exposure.
Now you might have seen this written as an LRGB.
The L, also known as the luminance channel is what we use to capture the brightness of the target.
Instead of a red, blue or green filter, we use a clear filter with some infrared protection.
So in order to get a nice complete full color image from a monochrome sensor,
you're going to have to shoot images with each red, blue,
green and preferably luminance as well, take calibration frames with each of them,
combine and align your images, and then you have a shot and data ready for processing.
Luckily enough there's a bunch of programs and
electronic filter wheels out there that can help automate your imaging sequence
so that you don't have to worry about changing filters - just set it and go.
Another advantage of a monochrome camera is narrowband imaging.
This technique involves capturing only very specific wavelengths of
light by using filters tuned to those wavelengths or bands.
Some of the most common wavelengths are hydrogen alpha (ha), hydrogen beta (hb), oxygen 3 (o3)
and sulfur 2 (s2). The advantage of this form of imaging allows you to capture specific details on
an object while excluding the data you don't want. And for all you urban city and suburban imagers,
this type of imaging is really effective under the most heavily light polluted skies.
Since these bands are very narrow this means that very little light will pass through the filters
and reach the sensor. This is where the increased sensitivity of the monochrome sensor really pays
off. Having added that sensitivity will allow you to capture these objects in narrowband wavelengths
at a level of detail and resolution that some would argue isn't possible with a color camera.
Once you've captured your data you can assign various color schemes to specific wavelengths
of light, giving you incredible artistic control of your results. Now just to be clear,
you can do narrowband imaging on a color camera and it is especially good
with filters like the Triad Ultra Filter which is very comparable.
Using a monochrome camera is a lot more time consuming, and it is a lot more involved,
but for those that have the time the payoff is well worth it. Most successful monochrome imagers
use filter wheels to hold their LRGB and or narrowband filters,
and they also control those filter wheels from a computer.
Alright, so we've seen a lot more can be done with a monochrome camera and filters that can be done
with a color camera alone. We've also realized that monochrome imaging is much more involved
than just imaging with a color camera and will require additional commitments of time and effort.
That leaves us with our final topic: the equipment we will need and what it will cost.
The monochrome cameras are a little more expensive than color cameras but not too much.
However, add-ons like the color filters, narrow bend filters and filter wheels are where costs
can start to add up very quickly. The good news is that these items are available in a broad range of
prices depending on quality, and you don't have to buy them all at once. For example you can purchase
an entry-level set of LRGB filters for under $200, and manual filter wheels for even less than that.
Most monochrome cameras will support the use of inch and a quarter filters
that are threaded onto the nose piece, and you can just change them out manually for each exposure.
We hope this video helped point out a few of the pros and cons of using a monochrome
camera and made your choice on what kind of camera is best for you a little easier.
Between a DSLR, one-shot color camera and monochrome camera they all have pros and cons
and it's important to know them before making a choice.
If you have any questions please feel free to reach out and contact us
and feel free to check out the links in the description to see our videos on one
shot color cameras versus DSLRs. As always, don't forget to click
the thumbs up and feel free to leave any questions you may have in the comments.
My name is Drew Evans with OPT. I'll see you next time!
Clear Skies!