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Seanelly

Help analyze M81-M82 1x180s vs 37x180s

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9 hours ago, Seanelly said:

Thanks for taking time to respond.

I'm living in Bortle 7 skies just outside the city (Ottawa), with no streetlamps, and city glow to the north and west, which would interfere somewhat with M-81 and M82 imaging, but overall pretty decent dark skies, using an IDAS LPS D1 clip-in, and in this case at 800iso. I read the article, which leans toward helping those taking short exposure images because of less than exemplary tracking mounts without autoguiding, but it was nevertheless helpful. I was not aware that so many calibration frames were necessary (the thought crossed my mind that I was adding too many, which was contributing to dulling the final image. Hey, I'm new to this!), and I will have to experiment further with increasing these, but the number of subs will definitely have to be increased in this case to draw out more detail. My original concern was that compared to the single 180s image shown, the 37 180s light frames stacked in DeepSkyStacker (with ten each of darks, lights and bias) seemed to show poorly in the finished product before processing. I don't mind spending the time getting the images, I just want to be sure I'm wasting as little time as possible because clear skies are as rare here in Ottawa these days as they seem to be over the British Isles, which is a surprise to me. Thanks again.

It's still true what Samir says re sky fog - he gives a link to a page to measure your own with a dslr. That can then help to optimise your exposure length. I imagine you'd have to do sky fog measurements in different directions if you know certain directions are more light polluted than others. In some ways Samir was ahead of his time in that, since he created his web page, a new breed of high sensitivity (high qe) cmos cameras have come on the market which actually prefer many short exposures. If you have lots of money you could invest in a sky quality meter though it doesn't seem worth it unless you image at lots of different places.

It's also a good idea to dither, if you can.

Louise

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If you want to upload all the subs including calibration frames I will happily process them for you in APP to see if that helps?

But given that it’s totally free, why not try the trial of APP?

 

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11 hours ago, Thalestris24 said:

Going from 32-bit Windows 10 to 64-bit requires a clean install. It's probably only worth doing if you have a decent spec computer or are willing to upgrade the hardware. Otherwise it may be better to simply by a new one.

Louise

I was considering buying a dedicated laptop for my imaging/processing, and this just may push me over the edge, it's just the darn $$$!!! at every turn, it seems. But I'm not happy with dragging the only computer I have out of the house for sessions (thus far) in 5C to -15C conditions and then back in again covered with dew or frost, so...bite the bullet. Which reminds me, I'll have to hide the gun from my wife, as I told her Xnumber of dollars ago that yes, this last purchase is all I will need, at least until my birthday! Thanks for the input.

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9 hours ago, tooth_dr said:

If you want to upload all the subs including calibration frames I will happily process them for you in APP to see if that helps?

But given that it’s totally free, why not try the trial of APP?

 

I definitely will take advantage of the free trial offers, including Adobe PhotoshopCC, though I've read that this program, and so assume others as well, don't supply with the trial period all the apps you might want or need for processing astrophotos. I was waiting to try APCC until I was more familiar with my gear and imaging proper, and also to obtain more quality data to work, or play, with, as the trial is only a month. My main goal will be to bank as much good data as I possibly can, which is why I was concerned with the results from DSS.

Thanks for offering to give the data a go-round, but I think I'll do as mentioned above and have a crack at it myself once I've compiled more to work with. If I run into difficulties or find the results wanting, however, I may get back to you.

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9 hours ago, Thalestris24 said:

It's still true what Samir says re sky fog - he gives a link to a page to measure your own with a dslr. That can then help to optimise your exposure length. I imagine you'd have to do sky fog measurements in different directions if you know certain directions are more light polluted than others. In some ways Samir was ahead of his time in that, since he created his web page, a new breed of high sensitivity (high qe) cmos cameras have come on the market which actually prefer many short exposures. If you have lots of money you could invest in a sky quality meter though it doesn't seem worth it unless you image at lots of different places.

It's also a good idea to dither, if you can.

Louise

Absolutely the link provided will be helpful as you say. I will be imaging exclusively from my home for what may turn out to be a year or more, as I have so much to learn there is no point in trying different locations until more experience is acquired, which is why I excluded a power tank with the original gear purchase for the time being to cut total cost. There are superb dark skies starting about 100k north of us here in Ottawa, however, up in the province of Quebec, and in future, new power tank in tow, I definitely will be heading there for sessions when possible.

Speaking of dithering: PHD2 guiding, in the Brain/Global page, has a Dither Settings section, and one of the options is Random, which is selected. Would this be adequate for the suggestion you make about dithering being a good idea? (Sorry to jump the gun, I'm assuming you use PHD2?) Thank you for yout time.

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1 hour ago, Seanelly said:

Speaking of dithering: PHD2 guiding, in the Brain/Global page, has a Dither Settings section, and one of the options is Random, which is selected. Would this be adequate for the suggestion you make about dithering being a good idea? (Sorry to jump the gun, I'm assuming you use PHD2?) Thank you for yout time.

Hi

Ideally you want to use an image capture program that supports PHD2 dithering eg APT. But failing that you can use the PHD2 dithering app - I've no experience of it, though. Afaik, which dither pattern you use isn't important. You can even dither manually i.e. just shift the scope x-pixels between subs, but that's obviously a bit of a pain to do.

Louise

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The biggest problem that you have when starting out in astrophotography is knowing what equipment to buy.

When you buy a car you can have a test drive, so you have a good idea about what you are getting for your money.

I would caution against buying anything until you really know what it is going to do for you.

The only thing wrong with the images that you posted was that they were not processed as best as they could be.  You don't need to spend anything at all to fix this.

I hate to think about all the bits and pieces that I have only ever used a couple of times.  If my wife knew, she would probably kill me.  I even have an IDAS 2" light pollution filter that I cannot remember using at all!

 

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1 minute ago, don4l said:

The biggest problem that you have when starting out in astrophotography is knowing what equipment to buy.

When you buy a car you can have a test drive, so you have a good idea about what you are getting for your money.

I would caution against buying anything until you really know what it is going to do for you.

The only thing wrong with the images that you posted was that they were not processed as best as they could be.  You don't need to spend anything at all to fix this.

I hate to think about all the bits and pieces that I have only ever used a couple of times.  If my wife knew, she would probably kill me.  I even have an IDAS 2" light pollution filter that I cannot remember using at all!

 

Hi

I think the op already has a fair bit of gear - from his sig :)

Louise

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20 minutes ago, Thalestris24 said:

Hi

Ideally you want to use an image capture program that supports PHD2 dithering eg APT. But failing that you can use the PHD2 dithering app - I've no experience of it, though. Afaik, which dither pattern you use isn't important. You can even dither manually i.e. just shift the scope x-pixels between subs, but that's obviously a bit of a pain to do.

Louise

I do have APT downloaded but have yet to use it because I have a battery-operated digital controller for the DSLR and it is just a matter of a few steps to program it, but I have heard it spoken of here quite highly so this is another app I will eventually have to make myself aware of more than superficially to consolidate my imaging sessions.

To be clear about dithering, are you say that PHD2 random dithering is not adequate? I've downloaded the dithering app you linked me to, but I think, from attempts to execute the app with the PHD2 guiding open, that I actually have to be guiding to use it (?). The next session will tell. I will have to dig further into this PHD2 Brain/Global/Dither Settings, because if I can reduce, or at least not increase, the number of steps necessary to image, it would be beneficial, though I suppose using APT would be the way to go in that case. So much to learn! (Manual dithering is out of the question, at least through the winter months!) (Thanks for sticking with me, here.)

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2 minutes ago, Seanelly said:

I do have APT downloaded but have yet to use it because I have a battery-operated digital controller for the DSLR and it is just a matter of a few steps to program it, but I have heard it spoken of here quite highly so this is another app I will eventually have to make myself aware of more than superficially to consolidate my imaging sessions.

To be clear about dithering, are you say that PHD2 random dithering is not adequate? I've downloaded the dithering app you linked me to, but I think, from attempts to execute the app with the PHD2 guiding open, that I actually have to be guiding to use it (?). The next session will tell. I will have to dig further into this PHD2 Brain/Global/Dither Settings, because if I can reduce, or at least not increase, the number of steps necessary to image, it would be beneficial, though I suppose using APT would be the way to go in that case. So much to learn! (Manual dithering is out of the question, at least through the winter months!) (Thanks for sticking with me, here.)

I assume you're pulse guiding the heq5? Best way to go. So you could, in principal, 'manually' dither from eqmod or the manual phd2 guide controls. However, APT is so much better (there was just a new update, I think) though you have to learn your way around it. APT has become quite complex over the years though I find it easy enough to use. I would recommend reading through the documentation for both packages. Either random or spiral dithering is fine, as far as I know. Dithering involves moving the mount automatically (as specified) between subs and in sync with PHD2. So you need to get the dithering distance right and the timeouts. It's great once it's all running smoothly...

Louise

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16 minutes ago, don4l said:

The biggest problem that you have when starting out in astrophotography is knowing what equipment to buy.

When you buy a car you can have a test drive, so you have a good idea about what you are getting for your money.

I would caution against buying anything until you really know what it is going to do for you.

The only thing wrong with the images that you posted was that they were not processed as best as they could be.  You don't need to spend anything at all to fix this.

I hate to think about all the bits and pieces that I have only ever used a couple of times.  If my wife knew, she would probably kill me.  I even have an IDAS 2" light pollution filter that I cannot remember using at all!

 

I hear you, and thanks for the input. I've owned a dob for 20 years and never spent a dime beyond the original purchase (two eyepieces included) plus several quality eyepieces and a barlow and a few filters. This new imaging venture cost me only time and effort for the first couple of months while I waded through as much info as I could read until I was dizzy with facts, comparisons, numbers and opinions. But I finally had to make choices and so far I have no regrets, nor has it cost me any more than the original kit price except for a digital programmer and an A/C powered battery for the DSLR, both relatively cheap. But I'm facing some harder choices now. When I bought the IDAS LPS D1 clip-in for the DSLR for prime focus imaging, I did not know that it would not accomodate the EF-S lenses I have, which I was counting on for wide-field exposures (the scope being 900mm minus the x85 reducer/flattener). So I believed that I needed to abandon the wide-field option (never!), get new EF lenses (which accomodate the clip-in filter and which I know are better lenses for the purpose of astro imaging), or purchase a second filter that fits the DSLR lenses. But I'm now slowly coming to the realization (or am being coerced into it) that adequate processing of the data will go further to produce a quality image than an LPS filter. Other than that, I don't believe (but could be wrong) that I mentioned any other expense in this thread except for processing. When I have enough quality data to play with, I will download the one-month free trials of several processing programs I've heard about, maybe try out some of the freeware that has been suggested, and decide which direction to take.

You say "The only thing wrong with the images that you posted was that they were not processed as best as they could be." The original intent of this thread was to find out why the 37 DSS stacked unprocessed images (2) didn't look any better (in fact, minus the cleanliness, worse, to me) than the single 180s image (1), and to discover if something was wrong. The third image (3) was processed with a generic photo editor, and I can see that there is rather decent data to work with, and that a quality astrophoto editor could do it justice, but I just couldn't (still don't) understand how a single 3minute unprocessed image can look better (or at least show more colour and contrast) than the 111minute stacked unprocessed image.

What I've taken from this thread, from you and others, is that there is nothing wrong with the data a good processing program couldn't deal with, and that is pretty much what I was hoping to hear. As a side benefit, there's plenty more info here for me to mull over, even if some of it is conflicting. Because as far as I'm concerned, the more I hear of this pastime the better off I'll be in the long run. Thanks again for taking time to respond.

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52 minutes ago, Thalestris24 said:

I assume you're pulse guiding the heq5? Best way to go. So you could, in principal, 'manually' dither from eqmod or the manual phd2 guide controls. However, APT is so much better (there was just a new update, I think) though you have to learn your way around it. APT has become quite complex over the years though I find it easy enough to use. I would recommend reading through the documentation for both packages. Either random or spiral dithering is fine, as far as I know. Dithering involves moving the mount automatically (as specified) between subs and in sync with PHD2. So you need to get the dithering distance right and the timeouts. It's great once it's all running smoothly...

Louise

Yes, the mount is pulse-guided. (I had some difficulty at first with calibration but was coached through it by someone here with as much patience as you seem to have!) I think my mind is now set on consolidating my sessions with APT, as I keep hearing nothing but good about it. (It's just so darn cold out now, I shudder (literally, haha) to think of having to learn a new program outside (the forecast is clear skies this entire weekend, but -17C Saturday night and -15C Sunday!) just when I thought I was reaching the point where a 45 minute set-up and go was getting me back into the warm house! But one thing I've always known and that this new pastime is reinforcing is that I have a lot of patience and fortitude when it comes to doing what I set my mind to, so your advice and time will not be wasted, and is much appreciated.

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Hey Sean. You seem to quite reluctant to actually go out and try out the suggestions such as APP and APT? These programs are fully functioning trials unlike your PS, and APT is not even time limited.

PS is a post processing program. If you don’t acquire (APT and PHD2) and stack (APP) good data then you are feeding suboptimal data into PS.  (Rubbish in rubbish out). I used DSS for quite a few years, APP is just better IMO. 37 frames is more than enough to do a decent comparison.

 

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7 hours ago, don4l said:

When you buy a car you can have a test drive

Hi. Equally for astro equipment and processing software; go along to an astro-club meeting near you. They'll go out of their way to give you a demo and between them are sure to have the combination in which you are interested. IMHO, buying blind and hoping for the best is not the way to begin. HTH.

Edited by alacant

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Have you tried startools for post processing? They offer an unlimited trial version, you just cannot save the image but it allows you to use everything else.  It is also a reasonable price to purchase.

Edited by spillage
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8 hours ago, Seanelly said:

Yes, the mount is pulse-guided. (I had some difficulty at first with calibration but was coached through it by someone here with as much patience as you seem to have!) I think my mind is now set on consolidating my sessions with APT, as I keep hearing nothing but good about it. (It's just so darn cold out now, I shudder (literally, haha) to think of having to learn a new program outside (the forecast is clear skies this entire weekend, but -17C Saturday night and -15C Sunday!) just when I thought I was reaching the point where a 45 minute set-up and go was getting me back into the warm house! But one thing I've always known and that this new pastime is reinforcing is that I have a lot of patience and fortitude when it comes to doing what I set my mind to, so your advice and time will not be wasted, and is much appreciated.

I don't envy you! Those sort of temperatures would rapidly give me hypothermia 😲. It doesn't often drop below zero here and I'm bound to do my imaging from my 2nd floor flat through an open window. Not ideal, but at least I can have a cup of coffee whilst I'm imaging and watch tv :). If I were you, I'd set up a long connection to your mount and cameras, if that's a possibility? Lots of people on here have done that using active usb cables, control via a second computer, or other means. Can you leave your equipment set up and ready to go? Covered, obviously! That would be good if you can.

Louise

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If you are able to access the internet from the pc near your mount and have another pc in the house you could always use teamview or vnc. Leave your laptop in a plastic box and sit indoors at you other pc with a nice cup of tea or cold beer...

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On 11/01/2019 at 02:50, tooth_dr said:

Hey Sean. You seem to quite reluctant to actually go out and try out the suggestions such as APP and APT? These programs are fully functioning trials unlike your PS, and APT is not even time limited.

PS is a post processing program. If you don’t acquire (APT and PHD2) and stack (APP) good data then you are feeding suboptimal data into PS.  (Rubbish in rubbish out). I used DSS for quite a few years, APP is just better IMO. 37 frames is more than enough to do a decent comparison.

 

Not reluctant to try the software, exactly; I'm just getting my feet wet (or cold!), and finally have all the gear functioning adequately for the first time, though not 'prime' time, so I want(ed) to produce a few images to keep the confidence and spirits up before attempting anything new. We have clear skies all weekend here in eastern Ontario and I was out again last night (Fri), but I started set-up in -17C and at midnight teardown it was -21C, so you can probably understand my present reluctance to jump into anything that will keep me out in the cold any longer than necessary.

That said, I've built up a tolerance for the cold from a lifetime of outdoor activities and twenty years of winter visual observing, and as I stated earlier, I definitely willl be experimenting with these programs. The difference with hiking or skating, etc. in winter, compared to observing or this new venture, however, is that you are constantly on the move, whereas standing around connecting cables and cold hardware, or worse sitting in front of the laptop, with thin gloves, despite the hand-warmer pouches, is not my idea of a good time!

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On 11/01/2019 at 04:51, alacant said:

Hi. Equally for astro equipment and processing software; go along to an astro-club meeting near you. They'll go out of their way to give you a demo and between them are sure to have the combination in which you are interested. IMHO, buying blind and hoping for the best is not the way to begin. HTH.

Yes, I'm aware of our local (Ottawa) astronomy club and have attended several meetings, parties, etc., but they break for the coldest stretch of winter and the next meet is not until February 1. I certainly will not be buying or paying any fees for processing until I am as informed as possible, and will just use as much freeware as I can until I achieve this goal, plus pick the collective brain of this great forum, and Google whatever strikes me. I'm rather computer illiterate (I had to Google your acronym IMHO, haha), which is a real drawback to this new pastime of mine, but I'm confident I'll work through it all eventually. I really wish I'd bought this imaging gear a few months earlier to take advantage of warmer weather for the break-in period! Thanks for the input!

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On 11/01/2019 at 05:01, spillage said:

Have you tried startools for post processing? They offer an unlimited trial version, you just cannot save the image but it allows you to use everything else.  It is also a reasonable price to purchase.

This is interesting, thanks. I will jot down this program and look into it. When you say 'cannot save the image', I assume you mean that you just can't save the raw image and/or the processed image to the program, but must transfer it elsewhere? 

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3 minutes ago, Seanelly said:

This is interesting, thanks. I will jot down this program and look into it. When you say 'cannot save the image', I assume you mean that you just can't save the raw image and/or the processed image to the program, but must transfer it elsewhere? 

So startools is fully functional except for the minor detail that you cannot save the final image at all. It lets you see what can be done and you have to pay to save it 

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On 11/01/2019 at 06:57, Thalestris24 said:

I don't envy you! Those sort of temperatures would rapidly give me hypothermia 😲. It doesn't often drop below zero here and I'm bound to do my imaging from my 2nd floor flat through an open window. Not ideal, but at least I can have a cup of coffee whilst I'm imaging and watch tv :). If I were you, I'd set up a long connection to your mount and cameras, if that's a possibility? Lots of people on here have done that using active usb cables, control via a second computer, or other means. Can you leave your equipment set up and ready to go? Covered, obviously! That would be good if you can.

Louise

Hi Louise. Unfortunately, I can't image from my backyard as there are too many trees-which at most other times is preferable to too few-so I have to set up beside a large field next to the house that has clear skies from Polaris to perhaps 40% overhead, and while the property is mine, the neighborhood reasonably safe, and we live on a remote crescent with only five other houses outside the city proper, I would probably need to build a shelter to guard it from prying eyes on the main road about 70 meters away. Come to think of it, that's not a bad idea, and would certainly save me a ton of time and a pile of cold fingers and toes next winter. I'm feeling warmer, already!

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17 minutes ago, tooth_dr said:

So startools is fully functional except for the minor detail that you cannot save the final image at all. It lets you see what can be done and you have to pay to save it 

Okay, I get it. A drawback, but understandable, and I do see the benefit of being able to experiment with all the tools. Actually, this sounds really good. Thanks for the tip!

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8 minutes ago, Seanelly said:

Hi Louise. Unfortunately, I can't image from my backyard as there are too many trees-which at most other times is preferable to too few-so I have to set up beside a large field next to the house that has clear skies from Polaris to perhaps 40% overhead, and while the property is mine, the neighborhood reasonably safe, and we live on a remote crescent with only five other houses outside the city proper, I would probably need to build a shelter to guard it from prying eyes on the main road about 70 meters away. Come to think of it, that's not a bad idea, and would certainly save me a ton of time and a pile of cold fingers and toes next winter. I'm feeling warmer, already!

Oh ok. I wouldn't advise taking a risk with your gear!

Louise

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19 minutes ago, Seanelly said:

Okay, I get it. A drawback, but understandable, and I do see the benefit of being able to experiment with all the tools. Actually, this sounds really good. Thanks for the tip!

I wouldn't bother trying to run Startools on a 32-bit Windows machine. I think you can get a 32-bit version of gimp and it's free and fine for basic processing - levels, curves etc.

Louise

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