Hello,
I have a couple of suggestions you might like to consider. I've been using Sky Safari 5 Pro for some time. It is very good, but I have some difficulties with it. I've also been an amateur astronomer for more than 35 years, with my niche in astro being sketching at the eyepiece, http://alexanderastrosketching.blogspot.com.au/ .
I have also built most of the telescopes I use, and also sell a few too that I make through my small business Gondwana Telescopes. I've also been working closely with Sergei Antonov from Astro Devices, installing his fabulous Nexus systems onto the scopes I use and sell. So my perspective on astronomy is a unique and very considered one. The suggestions I make below come from my many years experience and my changing thinking on what has been considered "a given" in astro, namely the use of red lights.
* Night Mode - horrible. The use of red light is a throw back to the days of black and white photography when red light were used when processing B&W prints. But the use of red light does not take into consideration the human eye. The human eye cannot make out contrast very well at all under red light. So in order to read anything with red illumination, the brilliance needs to be increased and increased to the point when dark adaptation is actually compromised. And this only gets worse with age. I actually prefer to use the full colour display than the night mode feature on Sky Safari, as I can control the brilliance of the full colour display to a lower brilliance and still read the display compared to the night mode which I find next to impossible to use. My suggestion is to allow for some hue manipulation so hue selection can be made between a full red display and a more amber one. If the wavelength of the illumination can be shortened just a little, say to amber, our eyes can better make out contrast AND the brilliance of the display can be much lower than what a red display will be, and dark adaptation won't be compromised. I've been experimenting with amber lights with my own astronomy niche - sketching at the eyepiece. A dim amber light is much easier to work with than a brilliant red light! On Apple devices, this amber hue can be selected through the devices settings. But on Android devices, this feature is not available. It would be fantastic if the Sky Safari app allowed for more hue variation in the Night Mode! :)
* Relative magnitude difference between stars. In many instances, there are objects one wants to find that are not only dim, but also lie within a field of dim stars. What currently happens with Sky Safari is once the limiting magnitude of the field of stars is reached, it does not matter if the stars are Mag 12 and Mag 14 (as an example), they are all the same single pixel size on the display. But our eyes can make out significant brilliance differences between Mag 12 and Mag 14. The trouble then comes to distinguishing which stars are which on the display because they are all the same size! My suggestion here is to allow the programming of the app increase the size of the stars on the display once a certain zoom range is reached. This way, Mag 12 stars will be a little larger on the display, making distinguishing between Mag 12 and Mag 14 stars much easier, and allow for much easier star hopping. Combine this issue with a horrible red colour display, and we humans have a terrible time using your app in the dark. It would not take much to produce the necessary algorithm that will allow for the pixel size of stars to become larger once a certain zoom range is reached.
I hope that my suggestions make sense to you. I think Sky Safari is a fabulous product. My suggestions are made in good faith in order to further improve the quality of your product.
Kind regards,
Alexander Massey.