I was floored the other night, when on Facebook I saw this stunning image of Orion.
It supposedly comprises, I quote, "65 x 1/3 sec (for the center) and 200 x 15 sec (!!)"
I'm sorry, but that's absolutely ridiculous, gob-smacking. Yes it's using a 14 inch scope, but wow, that's such a sensitive, superb sensor!
What cam?
A $3,000 modded Sony A7s. Full format to boot.
I'm googling every day for further examples of astro images with this thing, there are virtually no astro images other than another small test shot from the lucky chap on FB and dozens of run of the mill milky way shots. One other well known Astro photographer has just taken delivery, can't wait to see his first light and impressions.
I've been planning on just acquiring a Ha filter for my EOS 40D (ordered), but this single image looks like a game-changer to me. A new era of pretty cheap, full format and noise free sensors, no need for mono filters, ultra efficient acquisition of images. Frankly if I could achieve such a single image only once in my lifetime, I would be ecstatic. My god, what would an astro-specific, cooled version do??!!
I hope I'm not the only dude excited by the possibilities!
I'll post any further images I see. If I see ONE more pic that is as impressive, I'm pressing the big red button pronto...
Hi simon
Any details of the mods? Ir and cooling?
I've been waiting for some shots from it. That is better than I expected it up be still the core is blown even with shorter subs!
So it looks like this is a JTW modded camera and they are looking to also maybe offer a cooled version. About time OSC chips evolved to allow us city slickers without an observatory to capture faint objects in a single night. Although this camera is only 12 megapixels it sure looks like it is mega sensitive!
That's insane... but why the need for 200 subs? The only reason I can think you would need to do that would be to reduce noise. Unless of course it was totally unnecessary and the photographer just got sub happy 'cause why not, they're only 15s each.
I was about to say, for a field like that captured using 15 sec subs the ISO would have to be cranked, the back ground is a little bit grainy. A 14 inch scope, at the focal length presented, this would have to be a Hyperstar image taken @ F2. Shot at a very dark site too.
Not sure about the "no flats". If it was shot using the hyperstar lens, flats would be absolutely necessary to correct massive vignetting the hyperstar would cause on the full frame sensor.
Pretty good image for essentially 50 minute of integration time.
I've got an unmodified a7s. It's low noise up to ISO6400, reasonable up to 56000 and tops out at 409600 (yes that is four hundred and ninety six thousand) which lets you shoot handheld in almost complete dark and is excellent for frame-and-focus.
I've got a mate who has a modified one. I can ask him what mods his has.
Rod, the mate doesn't use darks. He is an experienced astrophotographer and reckons the a7s doesn't need them at 6400.
I know next to nothing about imaging with a DSLR. I'm looking to purchase a good DSLR and this one has had my attention for a while. I've hesitated only because I hasd been thinking that the Canons seem better suited to astronomy.
Is there software to control astro imaging with this A7 camera?
How is focusing achieved? I suppose one would need a driver/CCCDSoft, TSX or MaxIM to use something like FocusMax. Is focus done using a mask. Is ROI possible?
I've looked around for examples of A7 use on a telescope but until now hadn't seen anything.
Peter, it might take awhile for the camera control software programmers to support Sony, but the more that request support, the more they'll listen.
Having only just started using backyard EOS for focusing, I can say that focusing using the cam screen is pretty easy, esp if you zoom into a star. I hear the Sony is even easier to focus, as you just boost ISO temporarily and focus off video live!
Mark said:
""the photographer is an old customer of ours. We have a special
deal on at the moment for this camera, we are selling it for below the
RRP and also modified for astro use!""
The RRP in Oz is about $2400 body only but I got a couple of discounts. I've got the correct T adapter for mine but haven't had a chance to try it on my scopes. Through the cloud from the last Lunar Eclipse with a Sigma 500mm f6.3, 2.5 sec, ISO25600. I can put up the RAW if you are interested.
Is there software to control astro imaging with this A7 camera?
Very funny. Sony seem to have no plans to release a proper SDK for the alpha series so you can do the sort of automation you can with Canon. You can control if over wifi so it might be possible to reverse engineer the datastream.
The photographer in question is Fritz Hemmerich and he's using a 14" Hyperstar (F/1.9), so it's not just a 14" telescope, it's a super-speed astrograph. It was also shot in Tenerife at 1200m, so I'd wager the sky was as black as black.
Please in future post all the details, especially the name of the original photographer.
-Cam
"
Fritz Helmut Hemmerich
November 4 at 9:38pm · Edited
Orion Nebula complex, DSLR (only IR-block-filter) exposed over an hour, no calibration (no darks, flats, bias or bad pixel mask), 65 x 1/3 sec (for the center) and 200 x 15 sec (!!) for the outer structures, Hyper star 14 ", Sony A7s (modded), ISO 3200, no cooling, no guiding. This is just a quick-and-dirty processing. I don't like the halos of the brighter stars. I will next weekend, when I have time, edit it thoroughly.
Location: Tenerife, 1200 meters altitude
Time: November 3, 2014 between 4: 30h and 5: 45h"
Even with the same camera, I reckon that 1 hour under cold dark skies (say mag 22/arcsec^2) at F/1.9 would need around 240 hours under suburban skies (mag 19/arcsec^2) at F/7.5 to get the same SNR on the wonderful outer dust.