Lately, I’ve been thinking more about whether it might make sense to capture RGB data with a one-shot color (OSC) camera instead of continuing to shoot RGB with a mono camera and separate filters.
At the moment, I mostly work with a mono camera. The benefits are obvious: maximum control, high efficiency for narrowband, and the ability to capture luminance separately. But the RGB workflow in mono feels increasingly cumbersome to me. The more mono I shoot, the more I notice how much time, effort, and handling goes into the RGB part of the process.
At the same time, I’ve already been considering buying an OSC anyway. That opens up an appealing option: simply let the OSC handle the RGB data, while keeping the mono camera for luminance or narrowband. Depending on the target, I could either shoot just one to two hours for star color, or spend an entire night capturing RGB as a base and then refine the result with mono data afterward.
One thing motivating this thinking is the reduction of routine complexity. Even something as mundane as taking flats – three sets for R, G, and B-adds up. Combined with filter swapping, alignment, and general handling, the idea of simplifying that part of the workflow is attractive.
First Experiments with Two Cameras
I’ve already experimented with the concept, though not yet with an OSC. For M45 and M31, I collected RGB data using my EOS R and then added luminance with my Touptek mono camera. That worked surprisingly well. I also invested in Baader filter drawers for each camera, which turned out to be a very practical setup.
Rotation between sessions is, of course, a known issue. In my case, I found a workable solution: I shoot with Ekos, and there I can use an earlier image as a target during plate solving. After slewing and plate solving, the software tells me exactly how many degrees off my rotation is. Combined with my Baader M68 quick changer, I can loosen, rotate, and re-tighten the camera with minimal tilt risk.
Why I Use Drawers Instead of a Filter Wheel
More than once, people have suggested a filter wheel. I consciously went the other direction and chose Baader UFC drawers, and so far I’m very happy with that decision. The reason is simple: for my full-frame camera I use 50.4 mm filters. A wheel for filters that large becomes quite heavy and bulky, and with my small APO I wanted to keep the setup as mobile and compact as possible.
Whenever I drive to darker sites like the Eifel, I pretty much only shoot luminance anyway. In that scenario, a drawer saves weight and mechanical complexity. Also, outside of RGB I rarely change filters mid-session. I choose the filter before the night starts, and then it stays in. That convenience is also part of what makes the OSC idea appealing: it fits the way I already work.
And since I already plan to buy an OSC for galaxy and star cluster imaging on my Cassegrain, it could double as my RGB source as well.
Quality vs. Convenience
What I find interesting is that this decision doesn’t seem to hinge primarily on image quality. I don’t get the impression that shooting RGB with mono filters is inherently superior in all cases. The choice seems to be more about handling, workflow, and equipment. In my case, it’s the convenience factor driving the thought process: fewer filter swaps, fewer flats, fewer opportunities to introduce mistakes.
Where I Stand Now
So at the moment I’m leaning toward a hybrid approach:
• Mono for luminance and narrowband
• OSC for RGB
• Simpler workflow overall
• No obvious quality penalty for OSC RGB
• More mobility and less gear overhead
The open question for me is: am I overlooking a compelling reason to stick with full mono RGB? Or is the combination of both systems exactly the flexible setup I’ve been looking for?