Hi folks, a long overdue update here. The gap is good news in a way, as I’ve been rather busy in the old astrophotography hobby, so plenty to update you with.
Let’s get the big news outta the way first.
A camera revolution?
This month I fell across the above fantastic image, taken by Dr F Hemmerich. Click here to see the source. Amazing, no?
Yes, I know the lucky chap lives in Tenerife, at 1200 metres altitude (hehe, I know a buddy whos setting up his Obs at an even higher alt! Keep at it Chip!)
Yes, I know he’s using a very bright scope, a 14 inch Hyperstar f1.9! – though my scope ain’t a slacker at F3.3.
But more importantly, check out his camera settings. The LONGEST exposure is 200 shots of, wait for it…15 seconds. Yes folks, that’s FIFTEEN. SECONDS.
Taken at a ridiculously high ISO of 3200, yet the image is not grainy. A-ha, that’s the answer, he has taken this wonderful picture with a very new tech camera, the Sony A7s. The new King of the Low Light.
Here’s another picture of Fritz’s, but this time he only took shots of…4 seconds!
I have rapidly fallen in love with the potential for this new camera and its technology. The numbers don’t lie. A full-frame sensor with only 12.2mbs size means only one thing – pixels of a very large,light-sucking size. 8.4nm to be precise. Huge compared to the better Canon EOS’s, like the 5D mk III, with a sensor size of only 6.25nm. Plus with a class-leading Quantum Efficiency of 76%, it’s looking to be quite a few generations ahead of any other sensors available on the market today.
There are precious few ‘real world’ astrophotography example pictures available at this early stage. And very few, if any, above 30 seconds. Let’s face it, Fritz’s Tenerife location is hardly an average location. The best examples I’ve found are on Google Plus, by a Korean chappie, here. He’s taken a few classic shots at only 20 seconds, at huge ISOs of around 10-20,000. Incredible.
I’m aware of one other well known astrophotographer who has taken delivery of an A7s and am annoying him regularly to get him to take and post pics! I’ll keep you up to date as to progress.
This review over at Petapixel is quite thorough and has a great section on its ISO capabilities and its ridiculous ‘sweet spot’ of between ISO 3200-51200. Formidable.
So, the significance of all this excitement? Well, I’ve put my money where my mouth is and ordered a fully modded version from the innovative folk over at JTW Astronomy! The camera has cost me a relatively cheap $2,400 AUD (excluding GST, will cop that I’m sure..). Remember, that’s not just a brand new A7s, it’s lovingly modded per the link.
As you’ll see later in my imaging update, I feel I have made good progress since April this year when I first started using a telescope to take ‘star pictures’. I feel ready for a decent upgrade to my trusty modded EOS 40D, as I am already plateauing, limited by its abilities.
I have not taken this decision lightly – there are many great experts at the Astronomical Society of Victoria and other friends who have advised me, particularly in relation to the logical next step of getting a MONO CCD camera. I’m sure that will be my ultimate destination, where all the best imagers work within.
But this new course might be a ‘first’, a change in the standard approach, that many may follow. I have read comments from some owners of the A7s that say it is far better than ANY One Shot Colour CCD and comes VERY CLOSE to a mono setup. The only exception being that the Sony is far more sensitive and therefore QUICKER to image with than the mono. One chap has even stated that he can image more detail in Hydrogen Alpha in 20 seconds than his mono can image in 20 minutes! I find that hard to fathom, but look forward to testing myself.
So it is my hope that this little camera will be 80% as sensitive and ‘capable’ as a mono setup. It will enable me to capture great pictures in ONE NIGHT, avoiding the need to plate solve images over multiple nights. I can still do narrowband imaging, with a newly ordered 12nm Ha filter, giving my images a further level of detail and crispness.
In the end, if the camera gives me a leap in detail that is noticeably better than my 40D, I’ll be happy for a few years. It’ll save me having to buy a fragile mono camera, save taking more flats per filter and more interestingly, allow me to experience the early stages of what I suspect will be an astrophotography revolution. People like me, being able to take noticeably better photos, in very little time. Single night sessions rather than multiple.
But noise – aren’t DSLRs known for their long shot noise? Yes they are, in fact here is a comparison image of 30 second shot noise for the A7s and Canon 1Dx. No ultra dark background here, unlike the cooled CCD crowd. Won’t this limit me?
I doubt it. The 30 second images I’ve seen are pleasingly free of noise, giving the camera a fair bit of leeway before it becomes distracting. Heck, I’m quite happy with my 40D noise at 5 mins, especially after dithering, so this brand new sensor should be equally capable.
If the noise starts to become limiting, then the folk at JTW Astronomy tell me that they are planning to release an uber-cooled option, similar to their Canon 700D ULT model! Mark at JTW is literally salivating at the possibilities of such a large capable sensor being deep-cooled. So am I 🙂