Stars
Posted 07/03/2011 - 22:07
Link
18mm you say? How much were they cropped?
I particularly like that you can make out some nebulosity in Orion. And you exposure times are just enough to capture the dimmer stars without showing too much motion.
Well done!
I particularly like that you can make out some nebulosity in Orion. And you exposure times are just enough to capture the dimmer stars without showing too much motion.
Well done!
Getting there! Thanks to you guys
Pentax K3ii, Pentax K10d, Kit lens ( 18-55mm ), 50mm f1.7 lens, Tamron 70-300mm lens, Prinzflex 70-162 manual lens, Various old flashes.
Pentax K3ii, Pentax K10d, Kit lens ( 18-55mm ), 50mm f1.7 lens, Tamron 70-300mm lens, Prinzflex 70-162 manual lens, Various old flashes.
Posted 07/03/2011 - 22:18
Link
Thanks, Ted.
The Plough wasn't cropped at all.
Orion is about 25% of the original size.
I did set the lens to 18mm when I started & that's what the exif states.
But I've looked & it's set @ about 30.....?
Can you tell from the images what's what, or is the exif always right?
Roger.
The Plough wasn't cropped at all.
Orion is about 25% of the original size.
I did set the lens to 18mm when I started & that's what the exif states.
But I've looked & it's set @ about 30.....?
Can you tell from the images what's what, or is the exif always right?
Roger.
The more I look, the more there is to see!
Posted 08/03/2011 - 14:45
Link
Thanks Will.
Yes, I used a tripod(!)
I was after, as near as I could, points of light as opposed to trails.
Would lowering the ISO not have increased the exposure time?
The stars are already just beginning to trail anyway, @ 15secs.
Keeping the exposure time down, with lowISO, would also have meant recording only the brighter stars & I was keen to record as many as poss.
Does all this make any sense?
Roger.
Yes, I used a tripod(!)
I was after, as near as I could, points of light as opposed to trails.
Would lowering the ISO not have increased the exposure time?
The stars are already just beginning to trail anyway, @ 15secs.
Keeping the exposure time down, with lowISO, would also have meant recording only the brighter stars & I was keen to record as many as poss.
Does all this make any sense?
Roger.
The more I look, the more there is to see!
Posted 08/03/2011 - 15:13
Link
coker wrote:
Thanks Will.
Yes, I used a tripod(!)
I was after, as near as I could, points of light as opposed to trails.
Would lowering the ISO not have increased the exposure time?
The stars are already just beginning to trail anyway, @ 15secs.
Keeping the exposure time down, with lowISO, would also have meant recording only the brighter stars & I was keen to record as many as poss.
Does all this make any sense?
Roger.
Ah, I see now! Makes sense.
Thanks Will.
Yes, I used a tripod(!)
I was after, as near as I could, points of light as opposed to trails.
Would lowering the ISO not have increased the exposure time?
The stars are already just beginning to trail anyway, @ 15secs.
Keeping the exposure time down, with lowISO, would also have meant recording only the brighter stars & I was keen to record as many as poss.
Does all this make any sense?
Roger.
Posted 08/03/2011 - 15:37
Link
Hello Roger
Really nice images.
I think you probably struck the best compromise ISO versus exposure time...always compromises.
The only way to record more stars while lowering your ISO is to increase exposure time slightly by mounting your camera on an astronimical motor drive of some description ...but the compromise ...well you house & trees would suffer motion blur.
In the good old days of film your fixed camera exposure could have ran another 5 to 10 secs without showing too much trailing as the star were hidden within the bloated halated star image but because DSLR sensors resolve so much better than film there is no room for error.
To record the red colour (hydrogen wavelength) in the Orion nebula a DSLR sensor needs to be modfied which is better done with an old inferior camera like a Canon 450D than a K7 as the process is not reversible
Unfortunately Canon are the only manufacturer supported by astronomical filter manufacturers because relatively few have used Pentax & Nikon for astronomical photography.
Mike
Really nice images.
I think you probably struck the best compromise ISO versus exposure time...always compromises.
The only way to record more stars while lowering your ISO is to increase exposure time slightly by mounting your camera on an astronimical motor drive of some description ...but the compromise ...well you house & trees would suffer motion blur.
In the good old days of film your fixed camera exposure could have ran another 5 to 10 secs without showing too much trailing as the star were hidden within the bloated halated star image but because DSLR sensors resolve so much better than film there is no room for error.
To record the red colour (hydrogen wavelength) in the Orion nebula a DSLR sensor needs to be modfied which is better done with an old inferior camera like a Canon 450D than a K7 as the process is not reversible
Unfortunately Canon are the only manufacturer supported by astronomical filter manufacturers because relatively few have used Pentax & Nikon for astronomical photography.
Mike
Posted 08/03/2011 - 16:02
Link
Thanks, Mike.
Compromises all the time!
Do you have any of Orion, taken with your kit, i.e. telescope?
Roger.
Compromises all the time!
Do you have any of Orion, taken with your kit, i.e. telescope?
Roger.
The more I look, the more there is to see!
Posted 08/03/2011 - 17:27
Link
Hi Roger
Nothing taken with the K5 & scope yet but hope to do so before Orion slips away for another season.
Just trying to get to grips with the K5 limitations using the 18-135mm lens before going up the focal length.
Mike
Nothing taken with the K5 & scope yet but hope to do so before Orion slips away for another season.
Just trying to get to grips with the K5 limitations using the 18-135mm lens before going up the focal length.
Mike
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1547 posts
16 years
Wiltshire
Orion
[IMG]http://i1021.photobucket.com/albums/af340/rogerhlane/Stars4001Orion_filtered.jpg[/IMG]
The Plough
[IMG]http://i1021.photobucket.com/albums/af340/rogerhlane/Stars4002Ploughcolour_filtered.jpg[/IMG]
Both images:
K7, 18-55 @ 18.
ISO 800, f3.5.
Orion 15.35 secs.,
The plough 14.61secs.
C&C welcome.
Coker