Monochrome vs Color: Which One is for You?

Monochrome vs Color: Which One is for You?

For newbies in astronomy, the realization that cameras come in both monochrome & color can lead to a lot of confusion. Why spend thousands of dollars, just to shoot in black and white?

To answer this question, we need to first examine the sensor in your everyday DSLR. Sensors are made up millions of pixels, and each pixel is responsible for recording a single value. If light hits the pixel, the sensor records a 1. If light does not reach the pixel, it records a 0. Easy right? Not so fast…

In order to make a color image, DSLR sensors have a series of Red, Green and Blue filters to help differentiate photons. If you look at the diagrams below, you should notice two things: that the filters only allow one color to trigger the pixel, and more importantly, there are twice as many green pixels than red or blue. This is called a Bayer filter, or color filter array (CFA).

To correct for the green-bias, most cameras go through a ‘demosaic’ process, which effectively downsamples your images by eliminating pixels and creating artifacts such as false colors and more. For some, these problems are unrecognizable, while for others, this is a deal breaker. Shooting with a monochrome camera lets you utilize all of your sensor, giving you approximately 4 pixels to every 1 pixel used by a one shot color camera. This will give you greater detail.

Making the Case for Monochrome

Shooting in Monochrome doesn’t mean you’re restricted to producing black and white photography, but it takes much, much longer to produce a color image. If you’re used to shooting 30-40 sub-frames with a one-shot color camera or DSLR, then be prepared to shoot 90-120 sub-frames.

This also means that in addition to the monochrome camera, you’ll need a filter wheel. By shooting the same target with individual red, green and blue filters mounted in front of the camera, the channels can be aligned during post-production to create a natural color image. This makes your editing more time consuming but allows you to capture more detail in the red and blue channels.

Despite the time commitment, shooting in monochrome also has some advantages as well.

Making the Case For One Shot Color:

One Shot Color (OSC) cameras benefit from having a simple imaging process; Every frame you shoot can be used to stack with other OSC images, however, you’re limited to full-spectrum images. Although filters are not required with a OSC camera, H-alpha and narrowband imaging will not yield the same detail as they will with a monochrome camera.

But the biggest consideration for anyone making this decision is the time it takes to capture and process images from a monochrome camera. OSC cameras require less images, and only a fraction of the time required for post-processing, but although it will help you reach the finish line faster, you may find it will hold your images back to a certain point.

If you’re considering

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