>
>> I hate my *ist D. I stayed up until 5:15 AM taking eclipse photos. The
>> first several within 20 minutes of when the eclipse started look OK,
>> though
>> that was not the fabulous part of the evening(morning). However, the
>> camera
>> quickly became noisy (electronic noise), even at short exposures ISO 400
>> and
>> 1/500 sec. All with Tokina 500 f/8 mirror lens.
>>
>> Of course it was at its absolute worst during totality. One shot for some
>> reason was less noisy than the others, though still ruined by noise (next
>> to
>> the last as presented).
>>
>> http://photo.net/photodb/presentation.tcl?presentation_id=355756
>>
>> Most shots looked good on the LCD, even when magnified to check focus,
>> with
>> orange hues and turquoise tones at the edge of earths shadow. All lost to
>> noise.
>>
>> Some taken during totality didn't make muster because 8 - 10 sec exposures
>> were too long and exhibited too much tracking across the frame.
>>
>> I'm not sure if I have a hardware problem with the camera... may be time
>> to
>> throw it in the trash. I've taken other aurora shots with the same body
>> that were virtually noise free at exposures of 15 - 20 seconds. The newer
>> *ist DS with less than 1000 shots on it was even worse, however, at ISO
>> 800
>> and 2 secs. Images (not shown here) were absolutely obliterated. Looked
>> like a Photoshop effect.
>>
>> Still amazing to watch.
>>
>> Tom C.
>>
These looks to me like not a noise problem, but a *signal* to
noise problem. Again, without a useful histogram, it's difficult to know
if you got the bright parts exposed to the right. By default, the RAW
converters I've seen will gain up the entire image until the brightest
part is "bright." Some even ignore the top 1% or so of what's brightest
and make the 99th percent "white" and blow out the top 1% For stars and
such that is definately unacceptable.
A good example is your
http://photo.net/photodb/photo?photo_id=6356709
Re-convert from RAW so that the white part of the moon isn't blown
out (assuming it wasn't in the original RAW). That'll reduce the black
back down to the noise floor where it belongs. If the moon is still too
bright to make out the detail in the more dimly-lit parts (but isn't blown
out in the brightest), then sorry, Charlie... not enough dynamic range to
capture in one shot.
-Cory
--
*************************************************************************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
*************************************************************************
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