QHY5III462C Review

Posted August 8, 2020

The QHY5III462C uses Sony’s latest generation IMX462 back-illuminated sensor with extended red and near infrared response. It has nearly double the red and NIR sensitivity as previous generation BSI sensors and even greater sensitivity compared to front illuminated sensors. Because the RGB filters become transparent at NIR wavelengths, the camera captures RGB color images in visible light and monochrome images in NIR. (Source: QHYCCD)


General Features

This new camera features the same physical dimensions as the very popular IMX290 sensor (5.6 mm x 3.1 mm). It features a 1920×1080 pixel array with GBRG Bayer matrix for an effective 2 MP. However, the IMX462 improves upon the back-illuminated technology and is quite a bit more sensitive than the IMX290. It has a sHCG (Super High Conversion Gain) mode which drops the read noise to extremely low levels of 0.5e- at high gain. For more technical info, see the camera specifications on the QHY website.

Included Accessories

Aside from the camera, the box contains the following items:

  • 1.5m USB 3.0 cable
  • Guide cable for ST4
  • UV/IR Cut Filter
  • IR850 Pass Filter
  • C-Mount Adapter
  • Dust cover
  • Parfocal/limiting ring
  • Gasket (not sure what this is for honestly)

This is mostly standard equipment for all of QHY’s 5III planetary camera series, but the two included filters are real nice touch to be included with the standard package. It was recently announced that QHY will also be offering an expansion pack with a CH4 Methane filter, an All-sky lens, and CS Adapter for $50 more.

  • QHY5III462C with included UV/IR Cut
  • Included items
  • Cables, filters, and camera
  • UV/IR Cut and IR850 Filters

Putting It to the Test

The summer here in Florida is rather dreadful for anything to do with astronomy. Nevertheless, the planets are only out during this time (at least for a few years) so one must push on through the oppressive humid nights when there is a break in cloud cover.

On my first night out with the camera, the seeing was average. I rolled out my 18″ Starmaster f/4.5 Dobsonian and let the mirror warm up for a couple hours (yes, we warm our mirrors here). I set the QHY5III462C with UV/IR cut filter screwed on front into a ZWO ADC (atmospheric dispersion corrector) into a Celestron 3x X-Cel LX Barlow, then placed the assembly in my focuser with a 1.25″ adapter.

I had previously updated my camera drivers from the QHY website’s download page with the All-In-One System Pack (a very welcome and easy to use new addition). During installation, make sure you select the proper directories for which third-party software you are using, i.e. FireCapture, SharpCap, etc. I loaded up FireCapture and happily, it immediately detected the camera with no issues and began displaying preview frames. I also loaded SharpCap to make sure it worked fine in there too (again, make sure you select the right directory in the All-In-One driver installation if using).

After getting Jupiter centered in the FOV, I manually focused and began capturing a video after dialing in exposure settings. I was able to achieve high frame rate around 100fps (on subsequent nights I realized I could actually increase this to 150fps or so by setting the USB traffic to 0 in FireCapture). I have to keep my ROI slightly larger, because my Dobsonian tracking isn’t perfect and I have to manually guide it with a hand control to keep it centered. I was at around 800×800 for Jupiter.

The following image of Jupiter and Callisto was my best Jupiter video of the night, stacked in AutoStakkert 3, wavelet sharpened in Registax 6, and fine tuned a little more in PixInsight. I captured 150 seconds video at 300 gain, with a 4ms shutter time for a total of about 20K frames (with USB traffic at 0 on other nights I was able to get 25-30K in the same amount of time).

Jupiter and Callisto on 2020-07-09 – 07:01 UTC. More info here.

Naturally, I also had to try imaging Saturn. The seeing conditions got slightly better around the time I switched. For the following image I used a 300 second video capture at gain 360 with a 9.55ms shutter time, for a total of about 31K frames.

Saturn on 2020-07-09 – 06:06 UTC. More info here.

Next I exchanged the UV/IR Cut filter for the IR850 pass filter and tried it on Saturn and then the Moon, seen in the following two images. This camera is quite interesting with this filter because at this wavelength the Bayer matrix “becomes transparent” and it essentially makes it monochrome. Normally if you were to change to monochrome capture on a camera with a Bayer matrix you would see little squares over the image.

It requires quite a bit longer exposure time with the IR850 filter. For the Saturn image below, in 5 minutes, I captured 6K frames with a shutter time of 50ms with an average FPS of 20. I didn’t have a lot of time to experiment with the settings here but I probably could have increased the gain quite a bit to lower that shutter time more (it was set to gain 360 here).

Saturn in IR on 2020-07-09 – 06:21 UTC.
Aristarchus crater on the Moon in IR.

The following week seeing conditions were better than average and I was able to get some more attempts on Jupiter and this one came out much better. Io was near transit as well as the Great Red Spot. Once again I took a 150 second video and captured about 25K frames total.

Jupiter and Io on 2020-07-15 – 04:12 UTC. More info here.

QHY vs. ZWO Comparison

As is usual, both QHY and ZWO have a camera featuring the IMX462 sensor. Having not tested the ZWO ASI462MC personally, these are the most noticeable differences I found based off the specs from their website.

  1. The QHY has a 1.25″ eyepiece size with longer body, the ZWO has their standard short and wide body which then takes a 1.25″ nosepiece adapter. The ZWO also has 1/4″ tripod thread on the base and tripod mounting holes, presumably for all-sky camera use. QHY has a C-mount thread with included adapter and the ZWO has an M42x0.75 thread.
  2. The price (as of August 2020) for QHY is $299 including the UV/IR Cut and IR850 Pass filters. The base price for ZWO is also $299, but without filters. They offer an option for an IR850 filter at $319, a CH4 (methane) filter at $389, or the CH4 and IR850 filter at $399. From what I can tell, you must provide your own UV/IR Cut filter or order separately.

Conclusion

I would not hesitate to recommend this camera for anyone looking at buying a new color planetary camera. Even if you are currently an IMX290 user, you’ll still be getting an upgrade due to the added sensitivity, lower read noise, and added IR functionality. These improvements will allow you to crank the gain up high, lower the shutter speed, and ultimately capture more frames in the same amount of video capture time. The IR functionality makes it a more versatile camera since you can use the IR850 pass or Methane filter and achieve results essentially the same as a monochrome camera for lunar and planetary imaging.

Overall, I’m really impressed with this planetary camera and, while I haven’t tried all available planetary camera sensors, I feel comfortable saying this is easily the best color planetary camera available at the moment for most amateur planetary imaging setups.