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Long Exposures on teh a900

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Shelby Lewis

Guest
Hey Guys... not shooting sony anymore (still), but may be making a move back to it as my personal 35mm system after the new year. Anyone who knows me knows that I know the system cold...

with one exception.... long exposures.

I have a landscape/fine art project that's going to call for exposures in the 20sec to 10min range.

At Low ISO, how do the a900 files hold up? A little "texture" is just fine with me... but I've just never seen any long exposure work with the a900.

Care to share?

Thanks!
Shelby
 

douglasf13

New member
I've done some long exposure stuff, but I'm not near them to post, and I can't really compare it to anything else, because I had only done long exposures with APS-C in the past. You may want to PM Hardloaf about it, as I remember him making a comment or two about it (positively, I believe.) Since the A900 is geared towards low ISO noise, I would imagine it stacks up pretty well.

p.s. i just remembered that you may also want to contact "Nordstjernen." His astrophotography is cool. http://www.dpreview.com/members/?User=hhivikiwhxig

a couple of his shots with the a900:
http://www.astroweb.no/a900/Orion-and-Sirius.jpg
http://www.astroweb.no/astro-2009/Orion-longexpo-1.jpg
 
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dhsimmonds

New member
Hi Shelby. It's good to see you posting here again.

No problem with the A900 with long exposures. I suggest that you set the "Long exp.NR" to ON. in the menu.

This tells the camera to do a dark frame subtraction on any exposures of over one second. It takes a little longer to write to card using this feature but it is well worth it! Note though that this will not work if you are using continuous Advance or Bracketing, as it is already taking two images, one a black image and then interpreting the noise from the black image and automatically removing it from the subject image.

Set the ISO to no more than 160 would be my advice. I have never seen any problems with the Zeiss lenses when stopping right down to either F18 or F22 either. Otherwise the usual caveats apply when using a tripod. You will "walk it" with the right camera!!! Good luck.
 

gilgameshist

New member
Hi Shelby,

I agree w/ What Dave wrote before. I only tried once and went well.
I used MLU and cable release. Long Exposure NR was on. ISO 125

A900, 135/1.8, ƒ/16, around 20s. (I can't remember exact time because RPP didn't not retain the exif data and my screenshot only showed the aperture). Obviously developed w/ RPP.



lower right corner crop:


upper left corner crop:


MG
 
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Shelby Lewis

Guest
Thanks for the sample...

Wow... what great detail. With the WB pushed so hard towards blue, it's hard to tell if the excess noise (even though it doesn't look "bad") is just from the overabundant presence of the blue channel, or if that's just "how it is".

I'd be interested in seeing this with the WB a bit more towards "accurate", even if it's not nearly as neat (color-wise).

As it stands, I think it's a fantastic shot.
 

dhsimmonds

New member
The problem is that the blueness is often natural if taken shortly after sunset, say within 45 minutes or so. If you adjust WB to correct for this then the night time colour detail gets lost. If you need to avoid this for the look that you need perhaps it might be better to wait until totally dark (black) so that there is no trace of natural after glow from the sunset. Best to practice before the shoot!

Have Canon DSLR's finally gone over to MLU?
 

gilgameshist

New member
Well, not pushed WB, It was already blue at that time of the day(08:42 PM).
Pushing WB to get this blue would kill the reds. I enhanced the colors selectively, not only blues.

Anyway, I revisited the PSD file and removed the color enhancement layers. The new crops:

lower right corner crop:



upper left corner crop:


MG
 
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Shelby Lewis

Guest
Ah... thanks for the clarification. I totally understand the blue light at twilight, just not that blue, lol. Makes sense now. Like I said before... fantastic shot. I think the noise is respectable given that the entire shot is essentially in the shadow range.

Canon and MLU?... I just switched to using live view and stopped worrying about the mirror :) Live view is something, now that I'm getting more into landscape work, that I'm only now beginning to really appreciate. Before, the only time i used it (usually) was for macro ring shots during wedding work... and then it was mostly used for focus and also to give me the ability to shoot with a slower shutter speed in yucky light.

I LOVED intelligent preview on the sony, especially for portrait and wedding work... but now I see why some bemoan the lack of live view... especially in landscape work.
 

Terry

New member
Hi Shelby,
I did a bunch of pre-dawn and night shooting in Iceland this summer. Unfortunately I don't have my Drobo hooked back up yet (I just moved). As soon as I do I will check the exif to see how long the exposures were.
 
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affoche09

Guest
Hi there

Ive been playing around with long exposures lately typically 1-15 seconds. I am finding in the "dark" areas of the shot that there is a lot of "noise" - typically for the exposures from 1 - 5 seconds. At about 10 seconds, I dont see it anymore. BTW, I am using ISO 200 and 400 for these shots.

Is this "normal"?
 

dhsimmonds

New member
Hi there

Ive been playing around with long exposures lately typically 1-15 seconds. I am finding in the "dark" areas of the shot that there is a lot of "noise" - typically for the exposures from 1 - 5 seconds. At about 10 seconds, I dont see it anymore. BTW, I am using ISO 200 and 400 for these shots.

Is this "normal"?
Have you set the Long exposure NR to "ON" in the menu? I would normally keep the ISO low and I normally use ISO 160 for long exposures at night.

In fact ISO 160 is probably the best setting for quality all round on the A900.
 

gilgameshist

New member
I take it that the Moon is pasted in the shot?

(Not a criticism, just askin')
David...Shelby,

Yes, the moon was borrowed from another shot of mine of NYC Skyline that was taken on July 4th celebrations in the 90s. Camera was a Minota 9xi, 200/2.8 APO, ƒ/11, 2 min and Velvia pushed +1 stop, processed accordingly. :D

MG
 
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