Astrophotography: is faster better?
In astrophotography it is usually better to go for the mid-range settings for the best results.
Over the last few years, I've been impressed by how fast developments have taken place in the field of digital imaging, and indeed by their effect on astrophotography.
It's not just features such as integrated intervalometeres (that's built-in programmable timers to you and me) or rear tilt-able LCD screens that are useful to night sky photography: the ever-increasing sensitivity or ISO setting is often a talking point on astro forums
Yet although recent years have seen an amazing boost to the highest ISO speeds found on DSLRs, it is interesting to note that high ISOs are not always that useful for astrophotography.
Indeed, our resident astrophotographer Pete Lawrence has often pointed out, when reviewing such high ISO cameras, that the very highest values often lack the dynamic range and colour saturation to really be that useful.
So although it seems like a great selling point, in astrophotography it is usually better to go for the mid-range settings for the best results.
In this month's issue, Pete takes a look at the latest Sony a7S, which is a Mirrorless Interchangeable Lens Camera or MILC, making it more compact and boasting a whopping ISO 50-409,600 range! So what did he make of this full-frame camera and high ISO?
Check out his review in the April issue to find out if it really is worth drooling over.
In the same issue, Pete also enjoyed testing the Celestron Rowe-Ackermann Schmidt Astrograph which is a fast f/2.2 system designed solely for astrophotography, while I enjoyed putting the Vixen ED81SII Apo refractor through its paces, in-between the inevitable cloudy nights.
So make sure you get the April issue without delay!
Paul Money is an experienced astronomer, BBC Sky at Night Magazine's Reviews Editor and author of the annual stargazing guide Nightscenes.