783 replies to this topic

[astrshdr]

Venus + Jupiter through my telescope this evening with the AstroShader app on my phone, 4 0.066s exposures at ISO ~400 (I think). 

 

There’s a reflection in the middle which is repeated 4 times, because the app aligned the planets.

 

This was taken with the eye guard extended. If I collapse the eye guard and put the phone closer, I get a big reflection with a “hole” in the middle. See other attached pictures. Looks like the primary mirror shape with s dark reflection of secondary in the middle? Any idea why this appears and how it could be avoided?

I sometimes see a similar thing when out of focus in a certain direction—may be worth playing with the focus slightly and seeing if it makes a difference.

 

One other suggestion would be to try dropping your ISO a little say 100-200 and exposure time to 0.02-0.05s.

This was Jupiter last year on iPhone13 with ISO 120 and exposure to 0.018s (x200 exposures).

 

[Domdron]

Thanks will try that

[GeezerGazer]

I was out last night with my phone mounted to a stationary tripod, using a 1.7x supplemental lens in front of the 2.5x lens (for 4.25x) on my iPhone 12 ProMax.  I took two photos using Nocturne for one image and AS for the other.  In all regards, the AS photo was a better image... sharper, with tighter, brighter stars and very nearly no star trailing.  Both images were post processed to brighten exposure, while darkening the sky with increased contrast and a small bit of black point.  Nocturne took 94s to complete the image of Orion's Belt with no control of focus, stacking or exposure.  AS was a stack of 20 x 3s (60s total) exposures at ISO 640.  Focus point for my phone was at 87 on the 1-100 focus scale, which is the same for 1x photos with no supplemental optics.  Both images taken from my red zone, Bortle 7-8.

 

You must click on this image to open for much better detail: 

 

Edited by GeezerGazer, 07 March 2023 - 02:23 PM.

[Pinac]

Still experimenting, but the seeing conditions weren't helping, many clouds and a bright sky, but I found the image somehow attractive anyway, so shwoing it here fwiw (iPhone 11 Pro, magnification, 10 exposure @ 1 secs, edited slightly with ColorSyncUtility, exported with reduced size to allow uploading here)

Attached Thumbnails

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Edited by Pinac, 11 March 2023 - 11:45 AM.

[lwbehney]

Hello astrshdr. What a wonderful app! Post #53 really shows its superiority with the use of its aligning capabilities compared to some other low light camera control options. 

I know a great many people on CN are in love with all things photography, but there are a larger number of people, who just take photos of things or people they like and prefer this to be an automated and easy task. Personally, I like the ability to control exposure duration, but I am not a photographer and have no enjoyment other than just simple experimentation in fussing with ISO and white balance settings. I have the NightCap App and it has a feature called Stars Mode, which is fully automated. It provides a 10 second exposure and the ISO is set by the program for the conditions of the shot. For my Nikon DSLR, I have the Backyard Nikon camera control program. This has a feature to help you focus, where you select a bright star and adjust the focus to the lowest FWHM number you can reach, which depends upon your local seeing conditions. Then you lock your focus and proceed. That is a nice feature. 

So, I am wondering if it would be possible for the AstroShader App to have some automatic features added to it?  I would be very happy to spend money on your App if it could have an automatic function, where all I have to do is focus and select an exposure time. You could call this "Telescope Mode" and you could break it down to subsections such as Planet Mode and Deep Sky Mode etc. A simple algorithm of questions on the screen could put the phone camera into the perfect settings for the shot. Such as, what is the visual magnitude range of your target? What is the aperture of your telescope? What is the magnification? What exposure duration do you want (or what is the visual magnitude of your target?) All of these answers could be saved later in the settings as a default selection to speed matters up for the next night's targets, so the user would not have to repeat the process unless they wished to do so. 

IMHO, you have already done the most important and the most difficult work. The ability of your program to align the exposures and add them without having to do any photo processing is fabulous.  All you have to do now is make the package easier to use for people not really into AP. 

 

Best Wishes,

 

Laurence Behney

[Leafus]

Ditto the last post.

iPhone AP is solely about easy to do otherwise you’re down the Astro camera route. Autofocus on dates would be great. Especially if a filter is on the scope because then I can’t see if stars are focussed or not. And without a filter it’s a pain

[astrshdr]

Hello astrshdr. What a wonderful app! Post #53 really shows its superiority with the use of its aligning capabilities compared to some other low light camera control options. 

I know a great many people on CN are in love with all things photography, but there are a larger number of people, who just take photos of things or people they like and prefer this to be an automated and easy task. Personally, I like the ability to control exposure duration, but I am not a photographer and have no enjoyment other than just simple experimentation in fussing with ISO and white balance settings. I have the NightCap App and it has a feature called Stars Mode, which is fully automated. It provides a 10 second exposure and the ISO is set by the program for the conditions of the shot. For my Nikon DSLR, I have the Backyard Nikon camera control program. This has a feature to help you focus, where you select a bright star and adjust the focus to the lowest FWHM number you can reach, which depends upon your local seeing conditions. Then you lock your focus and proceed. That is a nice feature. 

So, I am wondering if it would be possible for the AstroShader App to have some automatic features added to it?  I would be very happy to spend money on your App if it could have an automatic function, where all I have to do is focus and select an exposure time. You could call this "Telescope Mode" and you could break it down to subsections such as Planet Mode and Deep Sky Mode etc. A simple algorithm of questions on the screen could put the phone camera into the perfect settings for the shot. Such as, what is the visual magnitude range of your target? What is the aperture of your telescope? What is the magnification? What exposure duration do you want (or what is the visual magnitude of your target?) All of these answers could be saved later in the settings as a default selection to speed matters up for the next night's targets, so the user would not have to repeat the process unless they wished to do so. 

IMHO, you have already done the most important and the most difficult work. The ability of your program to align the exposures and add them without having to do any photo processing is fabulous.  All you have to do now is make the package easier to use for people not really into AP. 

 

Best Wishes,

 

Laurence Behney

Hi Laurence,
 

I completely agree. Really my aim was to make things easier for beginners and for more advanced users are out and about, e.g. trekking. So anything that can automate this process seems like a win.

I'm just about to release a new version (another post to follow but is related to automation in the editing phase), then have second release with a few more minor fixes and suggestions from users. Once this is done I'll do an "auto-settings" release where I try to tackle as many of these as possible.

I really like the idea of just choosing the exposure and hitting go. I think there's probably a way to achieve this where the first part of the image capture is actually a just calculating the optimal settings. The focus mechanism and autofocus on iPhone is problematic so will be giving this some thought too.

Also don't worry about paying, this will be free as long as I'm still making it. Really Apple did all the hard work with the camera and GPU capabilities anyway, I just combine them in a certain way.

[astrshdr]

OK new release coming soon 1.0.4.

 

The major new addition is calibration without the calibration frames (...almost). It's a new slider on the editing screen called "Smart Image Calibration".

 

Why was this added?

- When really stretching images from AstroShader they tend to get ruined with distorted colour and loss of detail. A large part I believe is thermal noise/dark current effects from the long exposures.

- Calibration frames (darks, flats, bias, etc) are likely going to be the biggest improvement in image quality if you are already stacking.

- However, calibration frames are a pain to do and didn't feel very mobile friendly.

 

What does this slider do?

- Inspired by an (old) blog from a Durham University astrophysics professor.

- AstroShader attempts to calculate the image contribution from thermal noise, light pollution, etc and remove this using the slider.

 

Below shows a first image of M42 where I stretched the image to pull out the detail but this ruined the colour. In the second image the only difference in settings is the "Smart Image Calibration" slider being applied.
 

 

[astrshdr]

Some more examples of Pleiades, Andromeda and Flame+Horsehead (top to bottom).

 

These were all images where I thought I couldn't recover the detail without ruining the image. However this new approach seems to improve things.

 

 

All these images and Orion above were shot without specialist AP equipment; iPhone, 8x42 monocular, phone-tripod from Amazon—as it's all I could carry when travelling. Which is why they look a bit weird, but was also a good test.

 

 

(Also in the next release will be a few bug fixes and improvement to the exposure slider).

[astrshdr]

Version 1.0.4 is now live.

 

Anyone doing any deep sky or wide-field let me know how the calibration tool works out for you!

[Pinac]

Thanks - will do, and thank you for version 1.0.4

 

Pinac

[Pinac]

Still experimenting a bit.

 

In the link below, I have loaded 4 photos into Microsoft oneDrive to show them in the original size and quality.

 

First image shows Orion with Astroshader (26 exposures @ 1.2 sec. each) unedited (phone used: iPhone 14 Pro, main camera).

 

Second image is the same, but edited with slight change in brightness and full use of the smart image calibration lever; the improvement is substantial.

 

Third image: for reference, iPhone 14 Pro single shot at night mode (about 10 sec. exposure), unedited.

 

Fourth image: for reference, Leica Q2 single shot, all settings on automatic, unedited.

 

Question: did the iPhone 14 camera just get so much better, or how can the single iPhone shot almost compete with Astroshader's stacked images?

 

https://1drv.ms/f/s!...LMOMv8?e=hqFDlv

Edited by Pinac, 19 March 2023 - 05:52 AM.

[GeezerGazer]

Hey Pinac, 

Nice photos!  About differences between your Night Mode and AS photos, they are being produced with different parameters.  

 

AS is taking 26 separate images (over about 29 seconds @ 1.2s/image) and using only the stacking mechanism to align and average them.  Night Mode is taking 10 or more images that it is averaging for a single image.  I can't open your photos to see what the EXIF info reveals, but I'd guess that Night Mode was using a higher ISO for its 10 images.  

 

To see a direct comparison between Night Mode and AS, take your Night Mode photo first.  After it is complete, open that image and click on the "I" in a circle to see information (specifically, the length of exposure and the ISO.   If it was 1s at ISO 2000, use those parameters when you set up AS for the same shot.  But instead of taking individual images to stack, make it a single image at the same length of time as was used by Night Mode.  That would be a direct comparison.  

 

A problem might crop up if Night Mode used a 1/2s or 1/3s exposure, because AS will not permit a single, averaged exposure of 10 or 20s using a sub-second exposures.  In that case, use the 1s exposure for 10 seconds or whatever timeframe Night Mode used.  I hope that makes sense. 

Ray

[Pinac]

Thank you so much, Ray!!

[Leafus]

That auto-calibration looks very good. I’ll be downloading that latest version.

Would be good to have a gap in the clouds so I could try it out.

[astrshdr]

Still experimenting a bit.

 

In the link below, I have loaded 4 photos into Microsoft oneDrive to show them in the original size and quality.

 

First image shows Orion with Astroshader (26 exposures @ 1.2 sec. each) unedited (phone used: iPhone 14 Pro, main camera).

 

Second image is the same, but edited with slight change in brightness and full use of the smart image calibration lever; the improvement is substantial.

 

Third image: for reference, iPhone 14 Pro single shot at night mode (about 10 sec. exposure), unedited.

 

Fourth image: for reference, Leica Q2 single shot, all settings on automatic, unedited.

 

Question: did the iPhone 14 camera just get so much better, or how can the single iPhone shot almost compete with Astroshader's stacked images?

 

https://1drv.ms/f/s!...LMOMv8?e=hqFDlv

Ray’s answer is a great explanation.

 

Unfortunately I can’t see the image on the link - but the gist from your message.

 

In terms of a direct comparison of image quality of AstroShader vs the iPhone camera app - I would expect the images to be very similar if they are both shot using the same parameters. The processing may result in some differences.

 

Really where AstroShader will go further is shooting beyond the 30 second limit in the iPhone camera app and aligning and stacking - say 150 exposures at 10 seconds so you can then really stretch the image to bring out detail.

[Pinac]

Thank you - yes, that is what I expect and will try out next.

By the way, the smart calibration of verson 1.0.4 works well indeed.

Edited by Pinac, 21 March 2023 - 03:55 PM.

[GabeRossi]

Wow, I just came across this post and i have been desperately trying to find a better app for my Iphone 14 pro max and this hits the nail on the head. I cant wait until I can give it all a try. I thought I have been getting great photos with the phones camera app but this will take it to the next level. Thank you. 

[FredOz]

For the deep sky targets like Orion nebula and Pleiades if you have a tracking mount you can do >10s subs. If no tracking mount you may need to do <1s subs or whatever the max you can achieve without blurring.

Hi All,
I hope to try AS in a few days after the moon is out of the way.  My interest is for deep sky objects untracked.

For estimating max. exposure, use the MFN Rule (see attached screenshot w/notes in blue).  The website is written in French but Google can translate (except "yarn" means star trails).

https://sahavre.fr/w...f-rule/#content

 

For your iPhone, you need to look up some specs.  I had trouble finding some of them.  For my iPhone X, here is what I think they should be (not sure of crop factor but it is not needed for MFN):

iPhone X: Wide: 4mm (28mm equiv), ƒ/1.8, crop fact 7.0, 4032 x 3024 px, Px sz: 1.22 μm
iPhone X: Tele: 6mm (52mm equiv), ƒ/2.4, 4032 x 3024 px, Px sz: 1.0 µm

 

The MFN Rule gave: Wide:11.9 sec,  Tele: 9.1 sec

Thanks to astrshdr for providing AS and to Ray (GeezerGazer) for telling me about it.

--- Fred

Attached Thumbnails

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[FredOz]

Rather than waiting for the moon to leave the evening sky, I made a quick 'n dirty attempt tonight on our favorite target with the 2x camera on my iPhone X.  The MFN Rule as described in msg. 69 above, suggests a max. exposure length of 9.1 sec.  I had some trouble adjusting the slider so I settled for 9.3 sec. with 8 stacked exposures and then made a crude attempt to enhance the photo.

 

The AS photo is much better than my attempt on Orion two months ago with Nocturne: https://www.cloudyni...sts/?p=12569602

 

I also made a photo with a much longer exposure of 27 sec (what MFN calls "Visible trail" or "visible yarn")  At bottom is a 1:1 zoom on the belt stars to compare the two exposures.  Note, it was rather windy and this may have blurred the 27 sec exposure.  Also, I typically have difficulty in focusing.

 

When I copied these photos to my Windows laptop vi a cable, the software I have could not read either the TIFF or HEIF formats (I did not try PNG).  So I emailed the HEIF photos to myself.  Perhaps Photoshop on my desktop will read them.

Attached Thumbnails

• 
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Edited by FredOz, 03 April 2023 - 01:45 PM.

[Fred76]

Hi

 

The NPF rule (and not MFN which is a strange artifact of Google's translatation) available of the page linked in a previous post is valid for any sensor and focal length. The page shows 2 calculation sheets, one in french and one in english. They both use the same formulas.

 

The "accuracy" box allows you to set the available star trailing, whether no trail (1), light trail (2) or visible trail (3).

 

The full formula is explained in detail in this page :

 

https://sahavre.fr/w...-la-regle-npf/ 

 

The "4-crop" rule has been calculated for :

- µ4/3, APS and FF sensors ONLY. It is therefore definitely not valid for bigger or smaller sensors like iPhones, or PhaseOne cameras

- common nightscape resolution sensors, i.e. in the range of 15-30 MPix, definitely not the sensors with 60 MPix ! 

- common nightscape-imaging aperture, i.e. from f/1.8 to f/3.2, not f/0.9 nor f/8 !

 

The 4-crop formula is equivalent to (using the real focal length, not the crop focal length) :

- rule of 300 for full frame sensors

- rule of 250 for APS sensors (Nikon, Sony)

- rule of 240 for APS-C sensors (Canon)

- rule of 200 for µ4/3 sensors.

 

Note that smartphones images may be oversampled from the real sensor's dimension. Also, there is a strong internal noise reduction, before the image is saved (whether in RAW, HEIF or JPG). This oversampling and internal noise reduction may give strange colors in point-sizes details, like stars that may be considered as noise or unwanted signal. Therefore I would recommend you to leave some star trail so that the stars are not considered as artifacts by the internal AI algorithm.

 

Note also that in a near future, the AI of the smartphones will analyse the image, recognize what part of the sky you are framing, and replace it automatically by a computer generated sky... 

 

Fred

Edited by Fred76, 03 April 2023 - 07:18 AM.

[astrshdr]

Rather than waiting for the moon to leave the evening sky, I made a quick 'n dirty attempt tonight on our favorite target with the 2x camera on my iPhone X.  The MFN Rule as described in msg. 69 above, suggests a max. exposure length of 9.1 sec.  I had some trouble adjusting the slider so I settled for 9.3 sec. with 8 stacked exposures and then made a crude attempt to enhance the photo.

 

The AS photo is much better than my attempt on Orion two months ago with Nocturne: https://www.cloudyni...sts/?p=12569602

 

I also made a photo with a much longer exposure of 27 sec (what MFN calls "Visible trail" or "visible yarn")  At bottom is a 1:1 zoom on the belt stars to compare the two exposures.  Note, it was rather windy and this may have blurred the 27 sec exposure.  Also, I typically have difficulty in focusing.

 

When I copied these photos to my Windows laptop vi a cable, the software I have could not read either the TIFF or HEIF formats (I did not try PNG).  So I emailed the HEIF photos to myself.  Perhaps Photoshop on my desktop will read them.

Thanks for sharing.

 

It might be worth editing to see if you can push some more stars out. Try opening the tiff in AstroShader and then pushing the brightness, adding some sharpening and pushing the midtone curve. (Using the tiff allows you to edit in more detail without wrecking the image, although the file is much larger).

 

The HEIF is an Apple format that windows might not like. The tiff is 16bit which is not compatible with all software to open and a large file—the reason for using this is that it's lossless so you can stretch the image much more to bring out detail.
...But I've had some feedback from a few people about the image formats so will be changing this soon to add JPEG and make it a bit easier to choose which one you want to save.

[astrshdr]

Hi

 

The NPF rule (and not MFN which is a strange artifact of Google's translatation) available of the page linked in a previous post is valid for any sensor and focal length. The page shows 2 calculation sheets, one in french and one in english. They both use the same formulas.

 

The "accuracy" box allows you to set the available star trailing, whether no trail (1), light trail (2) or visible trail (3).

 

The full formula is explained in detail in this page :

 

https://sahavre.fr/w...-la-regle-npf/ 

 

The "4-crop" rule has been calculated for :

- µ4/3, APS and FF sensors ONLY. It is therefore definitely not valid for bigger or smaller sensors like iPhones, or PhaseOne cameras

- common nightscape resolution sensors, i.e. in the range of 15-30 MPix, definitely not the sensors with 60 MPix ! 

- common nightscape-imaging aperture, i.e. from f/1.8 to f/3.2, not f/0.9 nor f/8 !

 

The 4-crop formula is equivalent to (using the real focal length, not the crop focal length) :

- rule of 300 for full frame sensors

- rule of 250 for APS sensors (Nikon, Sony)

- rule of 240 for APS-C sensors (Canon)

- rule of 200 for µ4/3 sensors.

 

Note that smartphones images may be oversampled from the real sensor's dimension. Also, there is a strong internal noise reduction, before the image is saved (whether in RAW, HEIF or JPG). This oversampling and internal noise reduction may give strange colors in point-sizes details, like stars that may be considered as noise or unwanted signal. Therefore I would recommend you to leave some star trail so that the stars are not considered as artifacts by the internal AI algorithm.

 

Note also that in a near future, the AI of the smartphones will analyse the image, recognize what part of the sky you are framing, and replace it automatically by a computer generated sky... 

 

Fred

Hi Fred,

 

interesting point on the use of AI. This relates to the app used to capture the image, as you say the default camera apps have a very heavy processing pipeline with noise reduction which I think is the cause of the water colour paint style artefacts in photos taken with the iOS camera app.
AstroShader (and other apps like Halide etc) avoid the AI processing that the native camera app adds. In the case of AstroShader the main processing is around aligning and stacking multiple exposures, then I keep everything else pretty light, I use a different image processing pipeline specific for the app.

 

I was reading recently about the Samsung camera app that adds crater detail to the moon using AI after detecting a moon in the scene. I couldn't help feeling there's something a bit fake or cheating about that, but on the other hand some people just want a nice picture without caring how it's made.

[astrshdr]

version 1.0.5 just released.

 

Major changes...

1. In response to feedback from Ray and others the save image flow has been rebuilt. It now includes JPEG and will prompt for a choice of image format—no longer automatically saving a TIFF.
2. Telescope view correction. Go to settings; "Rotate camera 180". "Flip horizontally" provided for anyone with a diagonal. These options will flip the preview and the resulting image.
3. Temporarily removed ultra-wide camera option from certain devices as the hardware doesn't support raw sensor output.

 

 

I'm pausing new features in the next release to try and improve the alignment process.

 

Then following this will take a look a some automatic settings options, autofocus, etc. 

Edited by astrshdr, 08 April 2023 - 08:30 AM.

[GeezerGazer]

version 1.0.5 just released.

 

Major changes...

1. In response to feedback from Ray and others the save image flow has been rebuilt. It now includes JPEG and will prompt for a choice of image format—no longer automatically saving a TIFF.
2. Telescope view correction. Go to settings; "Rotate camera 180". "Flip horizontally" provided for anyone with a diagonal. These options will flip the preview and the resulting image.
3. Temporarily removed ultra-wide camera option from certain devices as the hardware doesn't support raw sensor output.

Screenshot 2023-04-08 at 14.15.59.png

 

 

I'm pausing new features in the next release to try and improve the alignment process.

 

Then following this will take a look a some automatic settings options, autofocus, etc. 

Wow, you are working fast!  Thank you.  Weather here in N. California has been awful for observing.  But we do have some clear weather forecast in the next two weeks, and I'm very much looking forward to using AS.