[DrMindbender]

No astrotracer? No EQ mount? No problem.

Just stack.
And stack.
And stack some more.
Then you stack.
And stack again.

Neowise with 300 exposures taken with a Pentax-A 50mm 1.7.

[geo444]

No astrotracer ? No EQ mount ? No problem.
Just stack.
And stack.
And stack some more.
Then you stack.
And stack again.
Neowise with 300 Exposures taken with a Pentax-A 50mm 1.7....

Wow ! Congrats for that Huge Job, DrMindbender !
- At which F/ - ISO - SS were they shot ?

If ISO-setting was just a Preset...
... I would suggest you to re-build this stack at lower ISO-setting...
I bet you would get less noise in the final picture...

I think the K-5 is at it's best at ISO~800...
... many users say beyond that, its just Digital Gain...
so it's better applying the Digital Gain by yourself, after stacking ?

ie: when the SNR is Maximised ?
Don't you think so ?

K5s don't fear Under-Exposure at all :
Photos tagged "ISO-80": Galleries: Digital Photography Review
- the First ISO-less DSLRs

[VoiceOfReason]

I prefer to use my tracking mounts

[DrMindbender]

Wow ! Congrats for that Huge Job, DrMindbender !
- At which F/ - ISO - SS were they shot ?

F2. ISO 400. 3/5s.

Unfortunately, I started getting a handle on stacking as Neowise was pulling away. (This was taken on the night of July 24-25th.)

[blues_hawk]

Wow ! Congrats for that Huge Job, DrMindbender !
- At which F/ - ISO - SS were they shot ?

If ISO-setting was just a Preset...
... I would suggest you to re-build this stack at lower ISO-setting...
I bet you would get less noise in the final picture...

I think the K-5 is at it's best at ISO~800...
... many users say beyond that, its just Digital Gain...
so it's better applying the Digital Gain by yourself, after stacking ?

ie: when the SNR is Maximised ?
Don't you think so ?

K5s don't fear Under-Exposure at all :
Photos tagged "ISO-80": Galleries: Digital Photography Review
- the First ISO-less DSLRs

I found mine performed best with noise reduction and in body darks off and operating long exposures of ten minutes or more guided at 200iso. 400 and up showed aberrations that I couldn't remove with stacking despite running the square# vs. of the gains.
A comprehensive test of different gains with the same setup showed the sweet spot. I would note however that Indilib/gphoto doesn't have the special deep well iso 80 enumerated. I was just curious about dynamic range vs gain initially.
Everything above unity is applied off sensor and so stores as a lower bit count by the factor given by the digital amplification.

[geo444]

Sorry, I just forgot 5 words here :
.

Wow ! Congrats for that Huge Job, DrMindbender !
K5s don't fear Under-Exposure at all :
Photos tagged "ISO-80": Galleries: Digital Photography Review
- the First ISO-less DSLRs

.
The Closer to Base-ISO 80, the More it's True...

... F2. ISO 400. 3/5s....

.
I think I understand where the Noise comes from :

F/2 is Good, it's the aperture I would have choosen too...
ISO 400 is Good too... I think you can go until 800...
3/5 sec. is way Too Short Exposure given the 3 other Parameters

Camera Simulator, Exposure Calculator, Light Value -49 to 69 Ev.

Please go to this page... then select 1/3 Ev Steps...
then select 02 Ev Dark Streets at Night, Dark indoor...
then select F/2... then select ISO 400... then select 1/1.6 sec.~3/5
then click on CalcSLV = Compute Scene Light Value an you get 0.7 Ev !

The whole Range of my Astro-Photos is within - 3.5 Ev down to - 6 Ev !
Photos tagged with "nx-mini": Galleries: Digital Photography Review
Photos tagged with "iso-80": Galleries: Digital Photography Review

I would have choosen at least 2 to 4 sec. for the Exposure duration :
4 sec at ISO 800 at F/2 click CalcSLV that gives - 3 Ev !
given the downsizing you applied to your pic.

...This was taken on the night of July 24-25th....

.
So this was shot within the Hottest and shortest Nights ?

What was the " Camera Temperature " recorded in Exif Datas ?
if ExifTool is on your PC, the Command Line is :

" Exiftool -T -FileName -T -CameraTemperature *.PEF "

Thanks DrMindbender

[cobbu2]

Cap Rock at Joshua Tree National Park

A first quick attempt with a K-5 with the SMC-DA 18-55mm WR. A simple 30-second one-shot exposure at ISO 3200, no special processing. A first step, I'll refine the process as time goes on!

Cheers, Allan

Attached Images

View Picture EXIF

File Date

 

[PhotosbyV]

Beautiful!!

How could you make this any better?

[cobbu2]

Beautiful!!

How could you make this any better?

Thanks! I suppose I could take multiple low-ISO exposures and stack, or use the Astrotracer for the sky and superimpose the foreground from a separate exposure. But for this I just wanted to keep everything simple and see how it worked.

[cobbu2]

I finally updated the firmware on my K-5 to use the O-GPS1 and the Astrotracer. Here's my first attempt this past Tuesday night. ISO800, 2-minute exposure, HD 10-17mm DA-Fisheye ED.

Taken at Cedar Breaks National Monument, Utah just barely in time between full sunset and moonrise.



Cheers, Allan

[geo444]

Here's my first attempt this past Tuesday night. ISO800, 2-min. exposure, HD 10-17mm DA Fisheye ED.
Taken at Cedar Breaks National Monument, Utah just barely in time between full sunset and moonrise. Cheers, Allan

.
A successful first attempt, Bravo !

Love the inimitable rendering of the sky with the Pentax 6x7 and the Fujichrome film :
- Angel Terrace, Mammoth Hot Springs, Yellowstone & Grand Teton 4/21, yer Album.
.

Hi all !

More Easy & Efficient than editing autosave.tif in L*a*b mode ?

I am now testing a new way to boost Pentax K5's performance at base ISO-80 :
- 8 RGB .PEF files stacked through DSS to a Color picture as usual
- 1/ these Raw files are exported one color plane at a time, each to a B&W .fits or .tiff file -or-
.. 2/ these Raw files are converted to B&W .fits / .tiff files (1/ to Super-Pixel 2/ to match Bilinear Color stack)
- the best B&W results from these are stacked
- result's levels are pushed to make a High Contrast B&W mask
- the Color picture and the High Contrast B&W mask are blended together in Elements, Gimp, Photoshop, etc.
- you can even try several ways to blend them together thus getting the best result to your taste...

Here is my 1st " Pink prototype picture " using this process :
it is the Rosette Nebula from 8 .PEF files, each is a ~15 minutes long exposure...
... resulting in a Second place in DPR's Challenge named "Edited.." :
Rosette, Ngc-2237 nebula, 2nd place in "Edited" Challenge of DPReview

RosetteMCCou60.jpg - Right Click, View image :
.

.

Now let's Compare this to the original picture, a simple stack from 6 .PEF files in 2015 :
https://g3.img-dpreview.com/2364ADE4B8904B8197CD1BD7DAB375DE.jpg
... the 2 Raw files added to get the picture above are not the best !

And my 2nd " Red prototype picture " using this new process :
= the Rosette Nebula from 7 .PEF files, each is a ~15 minutes long exposure...
blended in another way w/ its High Contrast mask

RosetteMCLC50.jpg - Right Click, View image :
.

.

Which one do you prefer, the "Pink" or the "Red Rosette" ?

the whole story of these Long Exposures of Rosette nebula since feb. 2013 :
Pentax me voila : mon K5 arrive juste, p. 8
- winter's appalling weather conditions in a well lit city at sea side...

the story of this New Process starting from the 2015 original picture w/o use of it :
Pentax K-5 : vos Photos ( fil ouvert )... page 47
Pentax me revoila : mon K-5 arrive juste, page 12

I'll post a page on my site dedicated to this process as soon as it's reliable & easy to use
Easy DiY Mod for Pentax Samsung ILC for Astro, IR Landscape

[cobbu2]

.
A successful first attempt, Bravo !

Love the inimitable rendering of the sky with the Pentax 6x7 and the Fujichrome film :
- Angel Terrace, Mammoth Hot Springs, Yellowstone & Grand Teton 4/21, yer Album.
.

Hi all !

More Easy & Efficient than editing autosave.tif in L*a*b mode ?

I am now testing a new way to boost Pentax K5's performance at base ISO-80 :
- 8 RGB .PEF files stacked through DSS to a Color picture as usual
- 1/ these Raw files are exported one color plane at a time, each to a B&W .fits or .tiff file -or-
.. 2/ these Raw files are converted to B&W .fits / .tiff files (1/ to Super-Pixel 2/ to match Bilinear Color stack)
- the best B&W results from these are stacked
- result's levels are pushed to make a High Contrast B&W mask
- the Color picture and the High Contrast B&W mask are blended together in Elements, Gimp, Photoshop, etc.
- you can even try several ways to blend them together thus getting the best result to your taste...

Here is my 1st " Pink prototype picture " using this process :
it is the Rosette Nebula from 8 .PEF files, each is a ~15 minutes long exposure...
... resulting in a Second place in DPR's Challenge named "Edited.." :
Rosette, Ngc-2237 nebula, 2nd place in "Edited" Challenge of DPReview

RosetteMCCou60.jpg - Right Click, View image :
.

.

Now let's Compare this to the original picture, a simple stack from 6 .PEF files in 2015 :
https://g3.img-dpreview.com/2364ADE4B8904B8197CD1BD7DAB375DE.jpg
... the 2 Raw files added to get the picture above are not the best !

And my 2nd " Red prototype picture " using this new process :
= the Rosette Nebula from 7 .PEF files, each is a ~15 minutes long exposure...
blended in another way w/ its High Contrast mask

RosetteMCLC50.jpg - Right Click, View image :
.

.

Which one do you prefer, the "Pink" or the "Red Rosette" ?

the whole story of these Long Exposures of Rosette nebula since feb. 2013 :
Pentax me voila : mon K5 arrive juste, p. 8
- winter's appalling weather conditions in a well lit city at sea side...

the story of this New Process starting from the 2015 original picture w/o use of it :
Pentax K-5 : vos Photos ( fil ouvert )... page 47
Pentax me revoila : mon K-5 arrive juste, page 12

I'll post a page on my site dedicated to this process as soon as it's reliable & easy to use
Easy DiY Mod for Pentax Samsung ILC for Astro, IR Landscape

Many thanks, I'm happy you paid a visit to my album!

As for the Rosette Nebula, I have to vote for red; a subjective opinion, but it's what I think I'm more familiar with. Excellent images at any rate! These techniques are above my skill level for now, but maybe I'll be able to figure it out at some point.

[XLXW]

I personally prefer looking at photos of that nebulae in black and white because that's how it appears in the eyepiece of the telescope. I'm always mind-boggled by that 130 light year diameter of this stellar object. That being said, congratulations on the spectacular images of it which you have imaged. I have immensely enjoyed theses images. I would suggest that you submit the images to Sky and Telescope magazine and Astronomy magazine. They may wish to pose your question to their magazine readership. Thanks for posting the images.

[geo444]

As for the Rosette Nebula, I have to vote for red; a subjective opinion,
but it's what I think I'm more familiar with. Excellent images at any rate !
These techniques are above my skill level for now, but maybe I'll be able to figure it out at some point.

.
I like the Red too ! Especially with its highlighted stars that I didn't get on the Pink one...
but, the only way to improve the Perceived Contrast is to add more Blue & Green to the Red, hence the Pink !
Many Thanks for appreciating !
I'll try to make it simple to use for everyone...
.

I personally prefer looking at photos of that nebulae in Black and White because that's how it appears in the eyepiece of the telescope. I'm always mind-boggled by that 130 light year diameter of this stellar object. That being said, congratulations on the spectacular images of it which you have imaged. I have immensely enjoyed theses images. I would suggest that you submit the images to Sky and Telescope magazine and Astronomy magazine. They may wish to pose your question to their magazine readership. Thanks for posting the images.

.
Especially for you, a Black and White reworked version !
Thanks for your kind appreciation !
.
RosetteMCCou67B&W.jpg - Right Click, View image :
.

.

enjoy !

[geo444]

.

what else is Dynamic Range that the ability to highlight NoiseLess Details...
... even from the Deepest Shadows of a dark night !
.


.
shot in a very well lit.city ~Bortle-99 rated
A few satellites Astrophotography Talk Forum Digital Photography Review

I can compare dozens of measurements... the Pentax K-5 is still...
... the Absolute Master of Astro-Photography and Long Exposures in very Low Light :
Best Cameras for Astro Photography, Long Exposures in Low light

I'll try a used Nikon D7500 one day, but it's more a High-ISO & Short-Exposure camera than the K-5
- and Shorter Exposures at Higher-ISO mean much more Noise in each sub-frame...
... so you'll need Stacking much more subs with Dark-Frames !

The Pentax K-5 also benefits from an exceptionnally low Dark-Current level :
Best Cams 4 Long Exposures in Low light, Astro Photography#K5=LowestDarkCurrentLevel
I never hesitated to go until 16 minutes Long Expos. to get Clean PEFs

Remember it was the first camera (+ the Nikon D7k) with the new Sony Exmor Sensor inside :
Best Cams 4 Astro Photography, Long Exposures in Low light#ConversionNoise
and thus, the Lowest Conversion Noise level of that time !

Even compared to the High-End most expensive FF cameras around years 2008-2012 :
Best Cams 4 Long Exposures in Low light, Astro Photography#K5=DR-Master
2010 Pentax K-5 is still the Champion of the Dynamic Range !

/!\ you have to compare in Screen Mode : your Favorite Telescope will Not...
give you a wider on-sensor image of the DSO you're shooting !

And now that one can find used Pentax K-5 for $250€ or less
... everybody could shoot Astrophotography

The ASI071 imx071 camera is still priced at $1500€...
with a not useless... but Not Mandatory Cooling !

Enjoy that Pentax K-5 !