The Triad Quadband Ultra Filter from OPT is both amazing and fun to use.
For those astrophotographers using a one-shot-colour (OSC) DSLR or cooled cmos camera to image with, the new Triad Quadband Ultra Filter from OPTcorp.com is a must have.
This extraordinary filter not only cuts through light pollution but it also tunes in four specific wavelengths of light allowing you to capture H-beta, H-alpha, Oxygen III and Sulphur II all at the same time. If you’ve used monochrome cmos or CCD cameras with a filter wheel, you’ll know you have to have a separate filter to capture each light channel. So the Triad Quadband Ultra Filter is quite revolutionary and opens up a new world of astrophotography for those using OSC cameras.
I had the opportunity to test this filter and found it to be amazingly effective and a lot of fun!
Due to weather conditions I haven’t had many opportunities to image with the Triad Quadband Ultra Filter, but the few times I did, I was focused on the Elephant Trunk nebula (IC 1396). This is a good test target for the filter, given it’s low in Bortle 8 light pollution from my location starting just after dark and slowly rises over the coarse of the night.
Since this filter blocks out a lot of light pollution, it easily captured some great details with even a small amount of data acquisition such as just 50min.
I am using a QHY 168C cooled cmos camera (16mp, APS-C sensor) and a William Optics Zenithstar 71mm APO refractor operating at F4.7. The Triad Quadband Ultra Filter is a 2″ mounted design that threads on in front of the camera, in my case onto the field flattener/reducer.
As you can see in this graphic the Triad Quadband Ultra Filter acts like an FM radio, tuning in specific channels. In this case wavelengths of light! Due to this, the filter is very capable of blocking out light pollution that can interfere and ruin your images when doing astrophotography from the city.
While the weather hasn’t been very cooperative I did manage to get more data on IC 1396 and collected 4.5 hours in total so far. I did the calibration and alignment of these light frames in Pixinsight. I then did some quick processing of the unstretched stacked image using Pixinsight again. The result of this 4.5 hours of data taken with the Triad Quadband Ultra Filter was jaw dropping! Considering the level of light pollution I contend with from the city and using a OSC camera for this test (the bayer matrix divides the colour channels making it not as sensitive as a monochrome camera would be) I was completely blown away by the image. I’ve had to image much longer than this using other equipment to obtain this level of detail and faint nebulosity.
I must also say I’ve been really impressed with the QHY 168C cooled cmos camera. It’s been nothing but a joy to work with and seems to be very sensitive for capturing faint detail while providing low read noise. The 16 megapixel design with 4.8 micron pixels is a perfect match for a wide variety of telescopes and lenses. Making for a very versatile and affordable astro imaging camera. You can learn more about the QHY168C here at the OPT website.
Watch my Youtube video below to see my update as to what I’ve been doing and talk about my imaging tests with this filter. If you’re doing city astrophotography, imaging from your backyard, and have a one shot colour like a DSLR camera or cooled cmos camera, then this filter is for you. So far I’m super impressed and I think you will be too!