Flats trouble?

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Stuart
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Re: Flats trouble?

#61

Post by Stuart »

Yep. I looked, and that was the difference. My default has the pure raw turned off and instead has just VNG checked. I clicked on pure raw and I got your results. My guess is that the way I have it set it scales it like I was saying before. Go to the settings, uncheck the four things on the top box, and check VNG. Open the file and you'll get my results. Anyway, now we've figured it out and you can do what works for you.
Personal equipment: TEC 140 F7 on Astro-Physics Mach 1 mount. Camera QSI 683ws7. Guide with Vario guiding scope
Shared equipment through Star Shadows Remote Observatory through PROMPT/ CTIO/Chile 16" RCOS 16803 chip
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Re: Flats trouble?

#62

Post by Baskevo »

Good to know! So my flats are okay then? So what happens if flats are too bright? I’m having trouble with trying to get in between like 45% and %60, as I move the exposure composition one step
-James W.

Telescope: Explore Scientific 80mm FCD100 Triplet APO Refractor
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Re: Flats trouble?

#63

Post by Juno16 »

JayTee wrote:
Wed Nov 06, 2019 12:00 am
Have you guys tried a piece of software called Astrophotography Lab? It is freeware and was promoted by the author over on AF about 2 years ago. It is a very powerful title for image and sensor analysis as long as you have your sensor detailed specs. Give it a try and see what you think.
http://lars-frogner.github.io/Astrophot ... index.html

Cheers,
JT
This software is really amazing. Has anyone else looked into it?

Took me a bit to figure out what values it needed, but it looks like it is producing some pretty amazing values.

Maybe I am easily impressed!

If i look at a flat that i have shot with a histogram at midway, i get an adu value of about 1800 which is about 1/8 or 1/9th of what i need for 50% full well.

I wish that i had my camera so that i could compare the values to the ccd flats wizard in APT.

Extremely interesting! Thanks again JT!

Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
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Re: Flats trouble?

#64

Post by fatboy1271 »

Downloading APLab now. I want to say I say the original post on AF years ago but I honestly don't remember... And it doesn't really matter anyway :)
OTAs: Explore Scientific ED80 Essential Edition / The Little Guy (Celestron 90SLT)
Mount: Celestron Advanced VX
Gear: Canon 70D / Hutech LPS-D1-48 / ES 2" Field Flattener / QHY PoleMaster / Celestron GPS / ZWO ASI120MC / Orion 50mm Guide Scope / ZWO EAF
Software: CPWI / PHD2 / N.I.N.A / Stellarium/StellariumScope/Remote Control / PI / RegiStax 6 / AutoStakkert!2 / PIPP | Retired? BackyardEOS Premium
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Re: Flats trouble?

#65

Post by Juno16 »

fatboy1271 wrote:
Fri Nov 08, 2019 12:02 am
Downloading APLab now. I want to say I say the original post on AF years ago but I honestly don't remember... And it doesn't really matter anyway :)
Patrick,

If you get time to get APLab set up, let meknow how it reads your flats and how it compares to Pixinight.

Thanks,
Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
Dog: Jack
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Re: Flats trouble?

#66

Post by fatboy1271 »

Juno16 wrote:
Fri Nov 08, 2019 12:09 am
fatboy1271 wrote:
Fri Nov 08, 2019 12:02 am
Downloading APLab now. I want to say I say the original post on AF years ago but I honestly don't remember... And it doesn't really matter anyway :)
Patrick,

If you get time to get APLab set up, let meknow how it reads your flats and how it compares to Pixinight.

Thanks,
Jim
Hey Jim,

So I'm still confused but I think it's becoming clearer with APLab! Hopefully this all makes sense... For one, I'm finally seeing imperfections in my Flats!!! That makes me happy. It looks like my optimal exposure time/setup is between 2 and 3 seconds, double t-shirt, and LED panel on lowest brightness level.

300sec saturated Flat for PI ADU reference:
APLab Flat at 300sec - Histogram.PNG
3sec; it has some weird "banding" issues but you can see the Histogram is "flat:"
APLab Flat at 3sec - Histogram.PNG
2sec; dust motes can be seen but I'm not sure how the Histogram fits the ADU value I'm looking for:
APLab Flat at 2sec - Histogram.PNG
1.75sec; dust motes can be seen but I'm not sure how the Histogram fits the ADU value I'm looking for:
APLab Flat at 0_1_75sec - Histogram.PNG
OTAs: Explore Scientific ED80 Essential Edition / The Little Guy (Celestron 90SLT)
Mount: Celestron Advanced VX
Gear: Canon 70D / Hutech LPS-D1-48 / ES 2" Field Flattener / QHY PoleMaster / Celestron GPS / ZWO ASI120MC / Orion 50mm Guide Scope / ZWO EAF
Software: CPWI / PHD2 / N.I.N.A / Stellarium/StellariumScope/Remote Control / PI / RegiStax 6 / AutoStakkert!2 / PIPP | Retired? BackyardEOS Premium
EPs: Stock Celestron 9mm and 24mm / Celestron Omni 32mm (I love this one!) / Celestron X-Cel LX 3x Barlow (I think 2X would have been smarter...)
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Re: Flats trouble?

#67

Post by Juno16 »

fatboy1271 wrote:
Fri Nov 08, 2019 12:32 am
Juno16 wrote:
Fri Nov 08, 2019 12:09 am
fatboy1271 wrote:
Fri Nov 08, 2019 12:02 am
Downloading APLab now. I want to say I say the original post on AF years ago but I honestly don't remember... And it doesn't really matter anyway :)
Patrick,

If you get time to get APLab set up, let meknow how it reads your flats and how it compares to Pixinight.

Thanks,
Jim
Hey Jim,

So I'm still confused but I think it's becoming clearer with APLab! Hopefully this all makes sense... For one, I'm finally seeing imperfections in my Flats!!! That makes me happy. It looks like my optimal exposure time/setup is between 2 and 3 seconds, double t-shirt, and LED panel on lowest brightness level.

300sec saturated Flat for PI ADU reference:

APLab Flat at 300sec - Histogram.PNG

3sec; it has some weird "banding" issues but you can see the Histogram is "flat:"

APLab Flat at 3sec - Histogram.PNG

2sec; dust motes can be seen but I'm not sure how the Histogram fits the ADU value I'm looking for:

APLab Flat at 2sec - Histogram.PNG

1.75sec; dust motes can be seen but I'm not sure how the Histogram fits the ADU value I'm looking for:

APLab Flat at 0_1_75sec - Histogram.PNG
Very interesting Patrick!

I see what you are seeing in your images.

When i enter a light frame, darks, bias, and flats, i am seeing a very realistiv skyglow of 19.05.

I am seeing a really low adu of 1800 on my flats. Does that correspond to your earlier flats?

Thanks,
Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
Dog: Jack
Sky: Bortle 7
Astro Photos https://flickr.com/photos/157183480@N07 ... 7681236785
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Re: Flats trouble?

#68

Post by fatboy1271 »

Juno16 wrote:
Fri Nov 08, 2019 12:43 am
Very interesting Patrick!

I see what you are seeing in your images.

When i enter a light frame, darks, bias, and flats, i am seeing a very realistiv skyglow of 19.05.

I am seeing a really low adu of 1800 on my flats. Does that correspond to your earlier flats?

Thanks,
Jim
Sorry Jim, I'm not understanding your question; it's me, not you :)

Let me know if this is what you asking about; I will say PI has added so much frustration by not producing an image like what is seen in APLab...
APLab Flat at 2sec - Histogram with PI Statistics.PNG
OTAs: Explore Scientific ED80 Essential Edition / The Little Guy (Celestron 90SLT)
Mount: Celestron Advanced VX
Gear: Canon 70D / Hutech LPS-D1-48 / ES 2" Field Flattener / QHY PoleMaster / Celestron GPS / ZWO ASI120MC / Orion 50mm Guide Scope / ZWO EAF
Software: CPWI / PHD2 / N.I.N.A / Stellarium/StellariumScope/Remote Control / PI / RegiStax 6 / AutoStakkert!2 / PIPP | Retired? BackyardEOS Premium
EPs: Stock Celestron 9mm and 24mm / Celestron Omni 32mm (I love this one!) / Celestron X-Cel LX 3x Barlow (I think 2X would have been smarter...)
Support Staff (Loved Ones!): CeCe, Ro, and Geno
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Re: Flats trouble?

#69

Post by Juno16 »

fatboy1271 wrote:
Fri Nov 08, 2019 12:51 am
Juno16 wrote:
Fri Nov 08, 2019 12:43 am
Very interesting Patrick!

I see what you are seeing in your images.

When i enter a light frame, darks, bias, and flats, i am seeing a very realistiv skyglow of 19.05.

I am seeing a really low adu of 1800 on my flats. Does that correspond to your earlier flats?

Thanks,
Jim
Sorry Jim, I'm not understanding your question; it's me, not you :)

Let me know if this is what you asking about; I will say PI has added so much frustration by not producing an image like what is seen in APLab...

APLab Flat at 2sec - Histogram with PI Statistics.PNG
Hi Patrick,

Sorry for not being clear.

I was just curious how the adu values in Pixinsight compared to the values that you see for the same flats in APLab.
I see the adu values in APLab for my flats being very low and i am trying to see if you had a chance to do any comparisons with the adu values in Pixinsight.

Yeah, APLab is pretty impressive.

Thanks,
Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
Dog: Jack
Sky: Bortle 7
Astro Photos https://flickr.com/photos/157183480@N07 ... 7681236785
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Re: Flats trouble?

#70

Post by fatboy1271 »

Juno16 wrote:
Fri Nov 08, 2019 1:06 am
fatboy1271 wrote:
Fri Nov 08, 2019 12:51 am
Juno16 wrote:
Fri Nov 08, 2019 12:43 am
Very interesting Patrick!

I see what you are seeing in your images.

When i enter a light frame, darks, bias, and flats, i am seeing a very realistiv skyglow of 19.05.

I am seeing a really low adu of 1800 on my flats. Does that correspond to your earlier flats?

Thanks,
Jim
Sorry Jim, I'm not understanding your question; it's me, not you :)

Let me know if this is what you asking about; I will say PI has added so much frustration by not producing an image like what is seen in APLab...

APLab Flat at 2sec - Histogram with PI Statistics.PNG
Hi Patrick,

Sorry for not being clear.

I was just curious how the adu values in Pixinsight compared to the values that you see for the same flats in APLab.
I see the adu values in APLab for my flats being very low and i am trying to see if you had a chance to do any comparisons with the adu values in Pixinsight.

Yeah, APLab is pretty impressive.

Thanks,
Jim
That's what I thought you were asking but I guess I don't know how to get an ADU reading in APLab…? Is this it?
APLab Flat 2sec Sensor ADU - Histogram.PNG
APLab Flat 2sec Sensor ADU - Histogram.PNG (28.81 KiB) Viewed 522 times
OTAs: Explore Scientific ED80 Essential Edition / The Little Guy (Celestron 90SLT)
Mount: Celestron Advanced VX
Gear: Canon 70D / Hutech LPS-D1-48 / ES 2" Field Flattener / QHY PoleMaster / Celestron GPS / ZWO ASI120MC / Orion 50mm Guide Scope / ZWO EAF
Software: CPWI / PHD2 / N.I.N.A / Stellarium/StellariumScope/Remote Control / PI / RegiStax 6 / AutoStakkert!2 / PIPP | Retired? BackyardEOS Premium
EPs: Stock Celestron 9mm and 24mm / Celestron Omni 32mm (I love this one!) / Celestron X-Cel LX 3x Barlow (I think 2X would have been smarter...)
Support Staff (Loved Ones!): CeCe, Ro, and Geno
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Re: Flats trouble?

#71

Post by Juno16 »

fatboy1271 wrote:
Fri Nov 08, 2019 3:12 am
Juno16 wrote:
Fri Nov 08, 2019 1:06 am
fatboy1271 wrote:
Fri Nov 08, 2019 12:51 am


Sorry Jim, I'm not understanding your question; it's me, not you :)

Let me know if this is what you asking about; I will say PI has added so much frustration by not producing an image like what is seen in APLab...

APLab Flat at 2sec - Histogram with PI Statistics.PNG
Hi Patrick,

Sorry for not being clear.

I was just curious how the adu values in Pixinsight compared to the values that you see for the same flats in APLab.
I see the adu values in APLab for my flats being very low and i am trying to see if you had a chance to do any comparisons with the adu values in Pixinsight.

Yeah, APLab is pretty impressive.

Thanks,
Jim
That's what I thought you were asking but I guess I don't know how to get an ADU reading in APLab…? Is this it?

APLab Flat 2sec Sensor ADU - Histogram.PNG
Actually, I am still learning this application too.

I believe that this data (or at least the adu data) is static based on your sensor and iso.
I tried loading a flat, then right clicked on the image and viewed the statistics for that image.
Take your time and play with the software some.
I hope that you are having a chance to image tonight.
Rain here, but my camera is still in transit to Lifepixel anyway.
Have fun and Good luck tonight!

Thanks,
Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
Dog: Jack
Sky: Bortle 7
Astro Photos https://flickr.com/photos/157183480@N07 ... 7681236785
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Re: Flats trouble?

#72

Post by fatboy1271 »

Juno16 wrote:
Fri Nov 08, 2019 3:23 am
Actually, I am still learning this application too.

I believe that this data (or at least the adu data) is static based on your sensor and iso.
I tried loading a flat, then right clicked on the image and viewed the statistics for that image.
Take your time and play with the software some.
I hope that you are having a chance to image tonight.
Rain here, but my camera is still in transit to Lifepixel anyway.
Have fun and Good luck tonight!

Thanks,
Jim
Got it! Very odd but if you do a 'Fit to Window' on the image then the Statistics is greyed out...? That's why I missed it. Looking at Green value to Green value they are pretty darn close! I like it 🤘

APLab 1.75sec
APLab Flat 0_1_75sec - Statistics.PNG
PI 1.75sec
PI Flat at 0_1_75sec.PNG
OTAs: Explore Scientific ED80 Essential Edition / The Little Guy (Celestron 90SLT)
Mount: Celestron Advanced VX
Gear: Canon 70D / Hutech LPS-D1-48 / ES 2" Field Flattener / QHY PoleMaster / Celestron GPS / ZWO ASI120MC / Orion 50mm Guide Scope / ZWO EAF
Software: CPWI / PHD2 / N.I.N.A / Stellarium/StellariumScope/Remote Control / PI / RegiStax 6 / AutoStakkert!2 / PIPP | Retired? BackyardEOS Premium
EPs: Stock Celestron 9mm and 24mm / Celestron Omni 32mm (I love this one!) / Celestron X-Cel LX 3x Barlow (I think 2X would have been smarter...)
Support Staff (Loved Ones!): CeCe, Ro, and Geno
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Re: Flats trouble?

#73

Post by Juno16 »

fatboy1271 wrote:
Fri Nov 08, 2019 3:55 am
Got it! Very odd but if you do a 'Fit to Window' on the image then the Statistics is greyed out...? That's why I missed it. Looking at Green value to Green value they are pretty darn close! I like it 🤘

APLab 1.75sec

APLab Flat 0_1_75sec - Statistics.PNG

PI 1.75sec

PI Flat at 0_1_75sec.PNG

That is really awesome Patrick! Look like a really close comparison.

Thanks for taking the time to do this comparison. When i get my camera back, i will also compare the values to the APT ccd flats tool.
Great application JT!

Thanks,
Jim
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Stuff: ASI EAF Focus Motor
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, Adobe Photoshop 21.1.3
Dog: Jack
Sky: Bortle 7
Astro Photos https://flickr.com/photos/157183480@N07 ... 7681236785
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Re: Flats trouble?

#74

Post by bobharmony »

Thanks for the info on getting flat ADU values out of APLab, Jim. I now am an independent person, and won't have to rely on the mercies of you kind folks to measure my ADU. It looks like 1/20 is a tad high, and 1/30 is a bit low.for me. I will get a 1/25 and see where that puts me. Thanks for all your help on this, especially Stu and James, who have measured many of my flats along the way.

And yes, Henk, I will try and do some reporting on my findings here, when I figure out what they are :). As always, processing images is a somewhat subjective exercise, and can be difficult to quantify.

Bob
Hardware: Celestron C6-N w/ Advanced GTmount, Baader MK iii CC, Orion ST-80, Canon 60D (unmodded), Orion SSAG
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Re: Flats trouble?

#75

Post by Stuart »

Baskevo wrote:
Thu Nov 07, 2019 8:47 pm
Good to know! So my flats are okay then? So what happens if flats are too bright? I’m having trouble with trying to get in between like 45% and %60, as I move the exposure composition one step
If your flat is too bright then it might not correct. I would shoot from 40-50%.
Personal equipment: TEC 140 F7 on Astro-Physics Mach 1 mount. Camera QSI 683ws7. Guide with Vario guiding scope
Shared equipment through Star Shadows Remote Observatory through PROMPT/ CTIO/Chile 16" RCOS 16803 chip
Shared equipment through San Diego Astronomy Society 14" RC with 16803 chip on a paramount
Software (for my stuff) PemPRO, SGP, PHD, Focus Boss, ASCOM, and Pixinsight on the other end.
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Re: Flats trouble?

#76

Post by bobharmony »

I have been experimenting with all sorts of things on the "flats front" and finally realized I was just confusing myself more, so I stopped and did a straight process comparison between my AV exposure flats and the latest iteration of brighter flats, which are 1/20 seconds, light panel at minimum level and a sheet of paper covering the light source. I did a Kappa-Sigma stack in DSS of the lights and each set of flats, and used the library master bias and master dark I created for this image.

My initial goal when I started this thread was to try to reduce the amount of noise in my finished images, and my thought was that increasing the brightness of the flats would give them a better SNR, and reduce the amount of noise they contribute to the final image. I used the StarTools process outlined here: https://astro.ecuadors.net/processing-a ... startools/. I excluded the Contrast module as I felt it removed too much of the dark nebulosity in this particular subject (the Iris nebula). I didn't change many defaults along the way, and I used the same Color saturation values for both images.

My findings were a bit of a surprise to me, based on these images. Both sets of flats did a good job of removing the vignetting and ant dust donuts in the train. Both images resulted in very similar noise-reduction requirements at the end of the process, which was a bit of a disappointment to me, given my initial reason for going down this path. On the plus side, the longer flats provided a much richer color result than the original AV flats, so on the whole it was worth the effort in my eyes. Also, reducing the brightness on the lightpad reduced the color imbalance significantly. The longerflats are still biased toward the blue, but they are paler than the originals and closer to gray than the AV flats.

Here are the two images after post-processing:

AV flats:
Iris KS AV flats ST.jpg
Longer duration flats:
Iris KS 1-20 flats ST.jpg
Comments and questions are welcome.

Bob
Hardware: Celestron C6-N w/ Advanced GTmount, Baader MK iii CC, Orion ST-80, Canon 60D (unmodded), Orion SSAG
Software: BYE, APT, PHD2, DSS, PhotoShop CC 2020, StarTools, Cartes du Ciel, AstroTortilla

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