Listening for Pulsars

[Phil Hart]

On the Friday afternoon before the CWAS Astrofest/Malin Awards in Parkes, Greg Gibbs and I met up out at 'The Dish', despite the fairly ordinary weather. Having stuck out a cloudy couple of hours (and light rain), we waited for a clear gap on the horizon visible at sunset and were treated to a short sucker hole, just as the skies got dark, which lasted all of 15 minutes. Can't exactly remember but I think it started raining again after that so we gave up.

After dinner in town, I stuck my head outside again later and was surprised to see what looked like clear skies so I went back to the dish (a well traveled road) and manage to capture this one. I'm still a relative newbie at night sky panoramas, but have to admit I like the couple of results I've tried recently.

You can see a larger version here, but this holds up very well even in much larger format than this:
philhart.smugmug.com/ (http://philhart.smugmug.com/Night-Sky-Photography/Rural/29434551_tm4MDm#!i=2689190794&k=5KsswnJ)

I took some of my own advice and shot this at lower ISO (400) to reduce the amount of blown-out highlights (which is still tough). I can't see any difference in the sky detail compared to shots I take at ISO3200. So gotta say the 6D is a damn impressive camera.. this is a straight four shot pano with 24mm lens at f2.8, 30 secs each.. no HDR/compositing etc.

Enjoy :-)
Phil

[Larryp]

Nice shot, Phil

[gregbradley]

Good shot there Phil. That is impressive dynamic range as you could've easily expected the Milky Way to be too dim with the lights on the dish dominating the image.

Higher ISO of course is simply amplification so it makes sense you can stretch 400 to emualate 3200 whilst protecting highlights. Interesting though no difference in quality at ISO3200 which shows how well sensors and supporting electronics have become.

I take it you shot in RAW as jpeg would not be the same from ISO400 to ISO3200 due to noise reduction being done internally.

Greg.

[Phil Hart]

Thanks Greg. Def shot in RAW. Not much I do JPG these days.. except maybe a quickie timelapse but even then mostly RAW. You're right of course.. no way I could have pulled out detail from a JPG file.

[CapturingTheNight]

Awesome shot Phil. Really surprised that this is ISO 400. I have not even looked at the quick pano I did during that "sucker hole" yet. I suspect that if I ever do something with them it wont have the great composition of this one. The Dish was not well placed for my shots.
Regretting not doing the same and heading back later, but I still enjoyed the weekend regardless.

[StephenM]

Looks great Phil! Sounds like you hade a bit of the same weather as last year.

Cheers,
Stephen

[Bassnut]

Most excellent Phil, you've handled the dynamic range very well. Composition is tops too, impressive.

[Phil Hart]

Thanks Mr Everpresent Larry! ;)



Worth experimenting with ISO.. makes less difference than many people think and you definitely gain dynamic range when you need it.. I tell people this all the time on my workshops but it's only when I was standing there figuring out how to make the shot work that I decided to do it. 400 on 5DII also achieves almost identical to 3200, but maybe not quite as good as same settings on 6D.

It was certainly helpful that the dish had moved around later on.. i was surprised that it stayed clear.. i thought by the time i got back out to the dish that it would cloud out again. my pano experiments recently have been partly inspired by your sweet shots so thanks for that too!



thanks Stephen.. yes.. typical winter weather pattern but still better in Parkes than Melbourne!



Thanks Fred. I know you wouldn't say it unless you meant it ;).

I'm very happy (even a little surprised) with how well it worked out. Now I'm just frustrated to be missing out on a clear winter Saturday night in Vic.. too many other commitments!

Phil

[Paul Haese]

Nice natural looking shot. Colour of the Milkyway and sky is as it should be in my opinion. Well done.

[gregbradley]

Worth experimenting with ISO.. makes less difference than many people think and you definitely gain dynamic range when you need it.. I tell people this all the time on my workshops but it's only when I was standing there figuring out how to make the shot work that I decided to do it. 400 on 5DII also achieves almost identical to 3200, but maybe not quite as good as same settings on 6D.


I did some experimenting on this point last night with D800E. The results I got I PMed you. I was surprised. I think in some cases there would be a gain using a lower ISO and boosting in post processing. It may be a good strategy in light polluted areas and probably not as needed from a dark sky site is my initial conclusion but I intend to check it out more next time I am at my dark site.

In a way when you are imaging at ISO400 and boosting in post processing it would depend on how loseless of DR your post processing boost is as well. Plus the assumption is your processing will be better than the camera engineers implementation of high ISO boost incamera.
Perhaps that is true that camera engineers are limited by amplification in a way post processing is not. That would be a question for a camera engineer. Hmm , I know one so I think I will ask!

Greg.

[redomatic]

Phil, Greg - I'm enthralled, in general I suppose it makes sense.
Can you keep us posted on your findings!!

Oh, I suppose the photo is okay too :thumbsup:.

[Camknox]

Absolutely incredible! You've captured so much sky, with awesome detail and at such a low ISO!

[astronobob]

Far Out, Thats a ripper photo, Totally envious of the scenery with the two Dishes. Very Nice work with them exposures Phil :thumbsup:

[Phil Hart]

Thanks Paul, redomatic, camknox and astronobob :)

No doubt Greg will have more to say on ISO at AAIC..

[RB]

I agree with Paul and the other comments.
Well done a this lovely shot !

[rustigsmed]

Hi Phil,

Fantastic shot. I too am surprised by the ISO setting. Do you think that this gives some extra hope to those with lesser quality DSLRs?

Cheers,

Rusty

[Phil Hart]

Thanks Andrew!



What it shows is how over-analysed the ISO setting is. We don't compare CCD cameras by talking about the gain setting which is a user setting.. we talk about read noise, quantum efficiency etc.. the fundamental performance characteristics of the sensor.

Likewise, what matters with your DSLR is the signal/noise ratio of your sensor.. older cameras are not quite as good in this respect as newer cameras, regardless of what ISO setting you use them at. Having said that, a lot of the over-hyped gain in high ISO performance is just better noise smoothing algorithms and only partially due to better sensor performance.

I don't believe there's any advantage in using ISOs above ~800 (when shooting RAW) with just about any DSLR aside from very helpfully being able to see your shots better on screen at the time you take them. At very low ISOs there is a difference in dynamic range (with read noise being the limiting factor) where the newer cameras are doing a bit better than older ones.

Phil

[dutch2]

Love this one, Phil.
Also gives me motivation to keep trying to get that elusive shot. :)

[Ross G]

A beautiful photo Phil.


Ross.