Sorry, folks! No A77 ghosting (60 minutes Pleiades)!

This evening I got the chance to make a 60 minute exposure of the bright open star cluster The Pleiades under clear skies. If ghosting was a problem, this image would have revealed it. So sorry, people! No ghosting issue to discuss!

The total exposure is 60 minutes (12 frames, each exposed for 5 minutes and stacked). ISO was set to 800. 530 mm focal length at f:5.

The Pleiades, A77:



100 % crop:

Nice shots, guess we'll have to live without the supernatural in our camera's, but who knows, you might find some extraterrestial with that telescope attached

--
Shamelessly promoting my favourite painters website (my wife's )
http://EdithsArt.nl

Nordstjernen said:

This evening I got the chance to make a 60 minute exposure of the bright open star cluster The Pleiades under clear skies. If ghosting was a problem, this image would have revealed it. So sorry, people! No ghosting issue to discuss!

Click to expand...

Nordstiernen

That is certainly good news. To totally reveal my lack of astronomical knowledge, I have a question. Is the cluster of bright stars in your Pleiades shot what we, in North America, call the "Big Dipper" ? It certainly is similar.
Bert

Maybe no ghosting, but what about all the light that is lost by being diverted for focusing? Does that mean there are only half as many stars in the sky? Only kidding of course! Very nice shots, by the way, I assume you used a tracking device.
--

• May the good light always be with you! - Karl: A77 - (8/10-20/18-250/50-500mm)

They're the "seven sisters", which is a star cluster in Taurus, so not the big dipper, which is Ursa Major.

If you see a "V" in the sky, that's Taurus, and the Pleiades are a bright cluster of stars to the right of the "V" about 2/3rds of the way up if I remember correctly.

Glad to hear about the (lack of)ghosting.
--
http://www.pbase.com/jprny

No, it is not Ursa Major (the Big Dipper). The Pleiades is a Star Cluster and reflective nebula that is generally visible to the human eye as a very small blob of stars. Certainly much, much smaller visually than the Big Dipper.

BertIverson said:

Nordstjernen said:

This evening I got the chance to make a 60 minute exposure of the bright open star cluster The Pleiades under clear skies. If ghosting was a problem, this image would have revealed it. So sorry, people! No ghosting issue to discuss!

Click to expand...

Nordstiernen

That is certainly good news. To totally reveal my lack of astronomical knowledge, I have a question. Is the cluster of bright stars in your Pleiades shot what we, in North America, call the "Big Dipper" ? It certainly is similar.
Bert

Click to expand...

--
Rick Krejci
http://www.ricksastro.com

and the a77 passes with flying colors. I'm very impressed with that piece of beamsplitter work! Thanks for posting these!
--
Steve W
weather photos: http://home.comcast.net/~scwest/atmo/

Hi, I thought the star is 'moving'. So how could you have 5min exposure without the sign of it? Then when you stack 12 pictures, do you align it manually?

Beautuful image! Great to see they've dealt with the ghosting to put that minor issue to rest.

Do you think the very faint vertical diffraction-type spikes on the brightest few stars is an effect of the mirror? I've had these before on my own images, but I usually attributed them to some small screw or something in the pathway. Even if it is the mirror, knowing full well how extreme astro images are stretched, it's an absolute non-issue...just more of a curiosity.

--
Rick Krejci
http://www.ricksastro.com

He has a tracking mount taking many 5 minute exposures and aligning them and stacking them. An untracked 5 minute exposure would indeed be just star trails.
--
Rick Krejci
http://www.ricksastro.com

n/t

--
Rick
http://www.flickr.com/photos/fjbphotos/

This is a minor thread hijack and some semi-coherent ramblings. Sorry.

That there simply isn't any sort of ghosting gives me great hope that the next generation of camera (think a99) will be even better as Sony continues to do it's R&D and makes the newer cameras better and better.

According to rumor, a FF camera will be the next big deal introduction, and it should be a killer camera, but I'm also anxious to see what a second generation a33 and a55 might be like.

Sony has never been very good at advertising their products (in the USA anyway) but if they should somehow get it together and do a proper job of getting the message out about their new cameras they could leap frog Nikon and just bury Pentax and Olympus.

Let's go for the Trifecta: Here's a rant as well.

Come on Sony, give us some new "G" lenses to go along with with our new Alpha cameras. Please don't tell me about all the other mounts you've been fleshing out, I don't care. I want "a" mount lenses! Can we start with some sort of a Bigger, Better, Newer, Faster, 16-105mm lens? A SSM focus motor and F/2.8 up to about 35mm would be a good starting point. How about a high quality 12-36mm UWA?

Thanks for reading all this drivel.
--



Tacoma, Washington, USA

Thanks Nordstjernen for posting, and great image!

I was wondering about the vertical lines as well. I know nothing about astro photography though, so I've got no idea if they're 'normal' or not.

Either way, it's great to see that Sony's squashed the ghosting bug!! Thanks for the test!

Great result, thanks very much for posting.

It seems that with a great EVF and no ghosting the only downside to the SLT design in the A77 is the half a stop of noise, which overall does not impact in real world shooting as much as some would like to pretend.

Thanks again.

--
IQ is not judged exclusively by high iso noise performance

OK, thanks I am not astrophotographer so I have no idea that such gadget exist.

RicksAstro said:

Beautuful image! Great to see they've dealt with the ghosting to put that minor issue to rest.

Do you think the very faint vertical diffraction-type spikes on the brightest few stars is an effect of the mirror? I've had these before on my own images, but I usually attributed them to some small screw or something in the pathway. Even if it is the mirror, knowing full well how extreme astro images are stretched, it's an absolute non-issue...just more of a curiosity.

Click to expand...

I've seen those before with pictures taken with conventional cameras. I think they look cool!!

--
Tom

Look at the picture, not the pixels

http://www.flickr.com/photos/25301400@N00/

It's a very nice image (and super clear skies). For comparison, this is a photo taken with a 57,600mm focal length lens at f/24 which, despite it's rather high cost, was originally delivered with less than perfect optics.

http://www.spacetelescope.org/projects/fits_liberator/fitsimages/danny_lacrue_7/

Splendid - then I have to go for the A77 - my wallet is already crying!

Amazing how quickly and well Sony solved the ghosting issue - this is obviously a company listening to its customers - but then they had to: ghost stories like the A55 story might end as a nightmare if not applying the new spooky coating on the A77 translucent mirror...

Now I would like to see a guided exposure taken with your CZ 85mm at aperture 5.6 to see if there is any trace of ghosting with wider lenses than your wonderful TAK.

Anyway - this is amazing and wonderful news!