QHY5-V: First impressions and comparison
On September 30, while Zerjillo was attending to the U2 concert in Seville, Antonio decided to try to get some videos of Jupiter from Churriana. In fact that was a special ocassion because he was trying the new QHY5-V camera that the people from Lunático has lent us to evaluate it (by the way, thanks Jaime and Débora). This camera is similar to the QHY-5 but it is a color camera with a smaller sensor.
Some of our first impressions about the camera are quite possitive. Some others not so possitive.
The first possitive aspect if the high frame rate that the QHY5-V is able to acquire: we've got more than 60 frames per second and we think that it could be possible to get more if the USB bandwidth was not limiting the take. Very short exposures allowed us to get between 3000 and 4000 frames y a minute and a few seconds. Having lots of frames is very important to get a final shot without too much noise. Moreover, the camera uses the True Snap (Global Shutter) technology which allows to freeze the seeing in a more effective way (and from our experiments it does really works, specially in not very good nights).
As the pixel size are different in the sensors of the different QHY5 models (QHY5 - 5.2 μm, QHY5-V - 6 μm) the images in the V camera are a little bit smaller than the ones in the QHY5 at the same focal lenght. In our case we were shooting at 6 meters, f30.
Something that we have not liked very much about the camera is that it uses a Bayer array to get the color images (as almost every camera in the market) and this reduces the final resolution of the image (not in the number of pixels but in the details of it). This kind of technology is quite useful to take color images without trouble but, if you want to get really professional looking images it seems that you have to use RGB filters and a monochrome camera. However, it is important to note that this cheap camera it is quite good to have nice results whilst using filters is much more expensive (camera + filters + filter wheel), much more difficult as you have to take some videos in a very short timespan refocusing for every different filter and the processing is also more complicated.
In any case we do still have to run some additional tests with this camera. We have planned to do some experiments using a binocular viewer and thus compare the images of the two cameras with exactly the same seeing conditions.
Finally, we think that the QHY5-V is a good option to begin with color planetary imaging without many complications and with a low budget.