Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

best focal length for beginner?

beginner astrophotography equipment
  • Please log in to reply
49 replies to this topic

#26 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,220
  • Joined: 03 Mar 2018

Posted 10 July 2020 - 08:03 AM

I've grown to love my F4/F2.8 Newt.  I struggled a lot with collimation initially, mainly because I got obsessive compulsive about getting perfect stars out to the corners that I usually ended up cropping out anyway. 

 

But speed covers a multitude of sins. 

 

No more fighting with the 1000 variants of "why isn't my autoguiding tighter?", "How do I afford a premium mount?", "Why does PhD2 not recognize my mount, and then after I reboot, it recognizes the mount but won't recognize the guide camera?".  Or "There is flex between my guide camera and my OTA, so I'll need to find a guide star within a 30 arc second FOV using an OAG from my light polluted back yard".

 

No more driving 3 hours to a dark site and having the clouds roll in 3 hours into an 8 hour exposure.  When things go badly, for whatever reason, I've wasted 1 or 2 hours and not an entire night.

 

Flaming Star Nebula, single 90 second exposure. I much more commonly use 15 to 30 second exposures, and you can see that some of the stars are burned out in this one. Everything is easy when you're only exposing for 15 seconds per sub.

 

I'd argue that speed is a more important simplifying factor than short focal length, and one that is vastly underappreciated in the usual Advice to Newbies posts.

 

 

Capture.JPG


Edited by John Tucker, 10 July 2020 - 08:22 AM.

  • kisstek likes this

#27 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 10 July 2020 - 09:55 AM

Calibrating light pollution? As far as I know calibration takes care of vignetting and amp glow, but not LP. You do this in post processing.

You're right, I should not have said calibrating and rather processing. I use APP for my stacking and calibrating, and it includes a great light pollution removal tool, so before the data is even taken out of there for stretching it's already been cleaned. Hence my brain probably just automatically was like "it's in my calibration/stacking step!" 



#28 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 10 July 2020 - 10:07 AM

I'd argue that speed is a more important simplifying factor than short focal length, and one that is vastly underappreciated in the usual Advice to Newbies posts.

 

I feel like speed and shorter focal length kind of go hand in hand for simplifying the things you mentioned like guiding tbh. You are right in that more people tend to focus on the shorter focal lengths, however I also don't see people mentioning like f/10 scopes as beginner friendly. Most of the friendly ones I see suggested (or suggest myself) are in the f/4-6 range. Is it a fast RASA style scope? Nope. Do those bring about extra issues that may also throw off a beginner? Yep. 

 

It's about finding a balance and trying to explain things like collimation, the way light can shift at higher speeds through filters, etc just adds another layer on things. Meanwhile you can get focal reducer/flat combos to help squeeze some extra speed and FoV out of the more common beginner scopes if needed... (and yes I know Hyperstar is a thing for the SCTs and I can't imagine there aren't reducers for Newts)



#29 Peregrinatum

Peregrinatum

    Apollo

  • *****
  • Posts: 1,294
  • Joined: 27 Dec 2018
  • Loc: South Central Valley, Ca

Posted 10 July 2020 - 12:20 PM

good calibration makes removing any LP gradients easy



#30 RJF-Astro

RJF-Astro

    Viking 1

  • -----
  • Posts: 549
  • Joined: 13 Aug 2018
  • Loc: Zeist, Netherlands

Posted 10 July 2020 - 01:07 PM

Hm well I like to think my calibration and processing skills are ok, but I have serious issues getting rid of these gradients. Could be me though, or some other variable in my setup.

#31 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 10 July 2020 - 01:38 PM

Hm well I like to think my calibration and processing skills are ok, but I have serious issues getting rid of these gradients. Could be me though, or some other variable in my setup.

How are you trying to remove them? By far the easiest method I've found is using the remove light pollution tool in APP. I hear good things about Gradient Exterminator also, then I think there is some option inside PI that does it too however not sure what that is called. 

 

Once I'm home from work later today I'll try popping that image from earlier in APP and see what it makes of it really quickly though.



#32 RJF-Astro

RJF-Astro

    Viking 1

  • -----
  • Posts: 549
  • Joined: 13 Aug 2018
  • Loc: Zeist, Netherlands

Posted 10 July 2020 - 03:10 PM

I use DBE in linear PixInsight, and/or Astroflat Pro in Photoshop in non-linear. I have less issues from my backyard beyond 300mm and none with narrowband. But with wide angle RGB, especially below 45 degrees, things get complex.

#33 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 10 July 2020 - 07:31 PM

I use DBE in linear PixInsight, and/or Astroflat Pro in Photoshop in non-linear. I have less issues from my backyard beyond 300mm and none with narrowband. But with wide angle RGB, especially below 45 degrees, things get complex.

Will not lie, when I tossed that image in APP like I said I would it did not really improve much. Still had some weird things going on and almost like gradient banding or pockets of black sky. Not sure if this is due to the data, using a stretched image, etc.

 

For me personally I did not have any issues with my images, including the one I was talking about that was mostly nebula. That was shot on a crop sensor DSLR at 250mm, though I did have a broadband light pollution filter in to try to help some. Still had some gradients, but maybe that filter knocked some of the stuff out that's impacting that image?

 

Either way you should normally be able to process them out however of course YMMV.



#34 klaussius

klaussius

    Viking 1

  • *****
  • Posts: 608
  • Joined: 02 Apr 2019
  • Loc: Buenos Aires

Posted 10 July 2020 - 09:33 PM

I gave that image a shot with my own tool and with some quick parameter tweaks I got something almost clean. It's got an artifact in the center that I think may be some kind of reflection or light leak, because it doesn't look like part of the gradient.

 

post-298773-0-54673300-1594365489-abr.jpg

 

So... surely, the starting point looks bad, but it can be cleaned.

 

BTW, that's a lovely image. A point for the short FL team I'd say.


Edited by klaussius, 10 July 2020 - 09:37 PM.


#35 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 6,410
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 10 July 2020 - 10:48 PM

I've grown to love my F4/F2.8 Newt.  I struggled a lot with collimation initially, mainly because I got obsessive compulsive about getting perfect stars out to the corners that I usually ended up cropping out anyway. 

 

But speed covers a multitude of sins. 

 

No more fighting with the 1000 variants of "why isn't my autoguiding tighter?", "How do I afford a premium mount?", "Why does PhD2 not recognize my mount, and then after I reboot, it recognizes the mount but won't recognize the guide camera?".  Or "There is flex between my guide camera and my OTA, so I'll need to find a guide star within a 30 arc second FOV using an OAG from my light polluted back yard".

 

No more driving 3 hours to a dark site and having the clouds roll in 3 hours into an 8 hour exposure.  When things go badly, for whatever reason, I've wasted 1 or 2 hours and not an entire night.

 

Flaming Star Nebula, single 90 second exposure. I much more commonly use 15 to 30 second exposures, and you can see that some of the stars are burned out in this one. Everything is easy when you're only exposing for 15 seconds per sub.

 

I'd argue that speed is a more important simplifying factor than short focal length, and one that is vastly underappreciated in the usual Advice to Newbies posts.

 

30 minutes total exposure in 40mph winds with a $550, 65mm f6.5 APO....and a dSLR...

49376906012_c995ae56de_b.jpg

 


Edited by 17.5Dob, 10 July 2020 - 10:56 PM.


#36 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 6,410
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 10 July 2020 - 10:56 PM

I've grown to love my F4/F2.8 Newt.  I struggled a lot with collimation initially, mainly because I got obsessive compulsive about getting perfect stars out to the corners that I usually ended up cropping out anyway. 

 

But speed covers a multitude of sins. 

 

No more fighting with the 1000 variants of "why isn't my autoguiding tighter?", "How do I afford a premium mount?", "Why does PhD2 not recognize my mount, and then after I reboot, it recognizes the mount but won't recognize the guide camera?".  Or "There is flex between my guide camera and my OTA, so I'll need to find a guide star within a 30 arc second FOV using an OAG from my light polluted back yard".

 

No more driving 3 hours to a dark site and having the clouds roll in 3 hours into an 8 hour exposure.  When things go badly, for whatever reason, I've wasted 1 or 2 hours and not an entire night.

 

Flaming Star Nebula, single 90 second exposure. I much more commonly use 15 to 30 second exposures, and you can see that some of the stars are burned out in this one. Everything is easy when you're only exposing for 15 seconds per sub.

 

I'd argue that speed is a more important simplifying factor than short focal length, and one that is vastly underappreciated in the usual Advice to Newbies posts.

 

Single 60" shot, dSLR, ISO 200, f6.5 with a $550 APO, $800 mount

49466312243_93343748d4_b.jpg


Edited by 17.5Dob, 10 July 2020 - 10:57 PM.


#37 klaussius

klaussius

    Viking 1

  • *****
  • Posts: 608
  • Joined: 02 Apr 2019
  • Loc: Buenos Aires

Posted 10 July 2020 - 11:12 PM

Single 60" shot, dSLR, ISO 200, f6.5 with a $550 APO, $800 mount

49466312243_93343748d4_b.jpg

 

Now you're just showing off your bortle-0 skies tongue2.gif



#38 RJF-Astro

RJF-Astro

    Viking 1

  • -----
  • Posts: 549
  • Joined: 13 Aug 2018
  • Loc: Zeist, Netherlands

Posted 11 July 2020 - 07:44 AM

I gave that image a shot with my own tool and with some quick parameter tweaks I got something almost clean. It's got an artifact in the center that I think may be some kind of reflection or light leak, because it doesn't look like part of the gradient.

 

attachicon.gifpost-298773-0-54673300-1594365489-abr.jpg

 

So... surely, the starting point looks bad, but it can be cleaned.

 

BTW, that's a lovely image. A point for the short FL team I'd say.

Nice attempt Klaussius. Here is the original stacked tiff if anyone wants to have a go at it.

 

When I started AP I used the 100ED with reducer, giving me 750mm f/7.5 on a full frame camera. It is kinda slow, but easy gradient wise. I only started using widefield when I already had mono, narrowband and the like. Maybe I am spoiled and give up too fast wink.gif

 

Now this picture below is also widefield (105mm) but with narrowband h-alpha. There were zero gradients in de stacked tiff. Processing was easy and very rewarding:

20200707 NGC700 Ha 105mm.jpg

 

Getting back on topic for a beginner: maybe it is just a matter of choosing a path. Look at what appeals to you. Widefield can be very tempting if done right, and if you have nice dark skies it can be even more rewarding.


Edited by RJF-Astro, 11 July 2020 - 07:46 AM.


#39 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,220
  • Joined: 03 Mar 2018

Posted 11 July 2020 - 07:45 AM

30 minutes total exposure in 40mph winds with a $550, 65mm f6.5 APO....and a dSLR...

49376906012_c995ae56de_b.jpg

 

Picture I took of the sun in just 10 msec with an F14 Cassegrain. 

 

I guess there are a handful of objects in the sky that are bright enough that optical speed is of no consideration whatsoever, but the broader point I was making was that 4x faster is, well, 4 times faster, and there are some advantages to that.

 

I've seen you post these same pictures to other discussions in which the merits of a fast Newt are discussed, but in the final analysis you're arguing with basic optics.  A scope with a 6 inch objective is faster than a scope having the same focal length and a 4 inch objective. And a whole lot faster than one with a 3 inch objective.

 

There are reasons to own a small refractor instead of a reflector with a much larger objective, but "its just as fast" isn't one of them.

 

Capture.JPG


Edited by John Tucker, 11 July 2020 - 08:15 AM.

  • kisstek and RJF-Astro like this

#40 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,220
  • Joined: 03 Mar 2018

Posted 11 July 2020 - 08:12 AM

I feel like speed and shorter focal length kind of go hand in hand for simplifying the things you mentioned like guiding tbh. You are right in that more people tend to focus on the shorter focal lengths, however I also don't see people mentioning like f/10 scopes as beginner friendly. Most of the friendly ones I see suggested (or suggest myself) are in the f/4-6 range. Is it a fast RASA style scope? Nope. Do those bring about extra issues that may also throw off a beginner? Yep. 

 

It's about finding a balance and trying to explain things like collimation, the way light can shift at higher speeds through filters, etc just adds another layer on things. Meanwhile you can get focal reducer/flat combos to help squeeze some extra speed and FoV out of the more common beginner scopes if needed... (and yes I know Hyperstar is a thing for the SCTs and I can't imagine there aren't reducers for Newts)

Agree with all of the above except that I don't think I've ever seen anyone  other  than myself recommend an F4 scope in one of these "advice to beginner" threads, and when I do, I am usually "corrected" by a least one person restating the "small refractors for beginners" dogma. And invariably at least one person posts the really really great picture of some exceptionally bright celestial object they took in just 15 minutes with their F6.3 refractor.

 

Collimating an F4 Newt is not for the faint of heart.  But for some I think its a viable path.  Once you drop down from 2 minute subs to 30 second ones, you can pretty much dispense with guiding.  So many other challenges disappear that I think some would find the pathway a reasonable alternative.


Edited by John Tucker, 11 July 2020 - 08:14 AM.

  • kisstek and Ryou like this

#41 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 11 July 2020 - 01:06 PM

Agree with all of the above except that I don't think I've ever seen anyone  other  than myself recommend an F4 scope in one of these "advice to beginner" threads, and when I do, I am usually "corrected" by a least one person restating the "small refractors for beginners" dogma. And invariably at least one person posts the really really great picture of some exceptionally bright celestial object they took in just 15 minutes with their F6.3 refractor.

 

Collimating an F4 Newt is not for the faint of heart.  But for some I think its a viable path.  Once you drop down from 2 minute subs to 30 second ones, you can pretty much dispense with guiding.  So many other challenges disappear that I think some would find the pathway a reasonable alternative.

I will admit that the f/4 scope suggestions are rare, however I feel like I've probably seen a f/4-ish (maybe with reducer) refractor being suggested before. Or at least in theory you could depending on things. I think the Stellarvue SVX70 reduces down to like f/4.8 so not super far off of f/4, maybe about 1/2 an exposure stop photographically speaking. Granted I don't know if I'd call that scope beginner friendly due to the price tag... 

 

Either way I don't think anyone will (or can) argue that f/4 is going to be faster than f/6 which can definitely help just ease the exposure times down and help the guiding requirements. The bigger thing is really the overall exposure time though, so whether your subs are 2min or 5min if you expose for 15min the results are going to be fairly similar. 



#42 klaussius

klaussius

    Viking 1

  • *****
  • Posts: 608
  • Joined: 02 Apr 2019
  • Loc: Buenos Aires

Posted 11 July 2020 - 02:30 PM

Nice attempt Klaussius. Here is the original stacked tiff if anyone wants to have a go at it.

 

When I started AP I used the 100ED with reducer, giving me 750mm f/7.5 on a full frame camera. It is kinda slow, but easy gradient wise. I only started using widefield when I already had mono, narrowband and the like. Maybe I am spoiled and give up too fast wink.gif

 

Now this picture below is also widefield (105mm) but with narrowband h-alpha. There were zero gradients in de stacked tiff. Processing was easy and very rewarding:

attachicon.gif20200707 NGC700 Ha 105mm.jpg

 

Getting back on topic for a beginner: maybe it is just a matter of choosing a path. Look at what appeals to you. Widefield can be very tempting if done right, and if you have nice dark skies it can be even more rewarding.

 

Not meaning to hijack the thread, but here's my result with a bit more effort (not too much though) based on your linear stack:

 

markarians_20200328_abr_bn.jpg

 

After finishing, I realized that maybe I stretched it too much. It's noticeably flatter. I could have dialed down on the HDR stretch to retain some dynamic range. Also, there was a lot of walking noise that's very hard to deal with, and I think I can see some CA that's kinda bothersome and is begging to be fixed. But I'd say the gradients are under control, although not totally gone. That's about the best I can do without manual touchups.

 

I think this is relevant to the thread. Gradients are perhaps the bane of beginners, myself included, and it takes some experience and patience until you get to a point where you know how to attack them. They should not be feared, but it is true that wider fields suffer from more pervasive gradients. At the same time, wider fields have smaller features, making gradient reduction actually easier. The hardest gradient to remove is that which has the same feature scale as your target. At 750mm FL, your target may very well encompass the whole shot, and removing gradients under those conditions without nuking the target itself is hard. At 50mm, there's no such thing, so you can go nuts on ABR without remorse.

 

Shorter FL are thus only hard on beginners because they haven't learned how to approach gradients yet. But that's good. Short FL imaging is easier in other respects, like tracking, so you can focus on learning how to deal with gradients, calibration and all the other problems.

 

And yes. Narrowband, especially H-alpha, is amazing. It's pleasant to work with, because the data tends to be so much cleaner. Gradients are there, but a mere fraction of what they are in broadband, and you get much better SNR from the start as well. But narrowband imaging requires longer exposures, and beginners may have a hard time getting consistent tracking to expose for 5-10 minutes per sub. I've recommended H-alpha imaging to beginners, with the caveat that they should get their guiding straight before attempting it.

 

I will admit that the f/4 scope suggestions are rare, however I feel like I've probably seen a f/4-ish (maybe with reducer) refractor being suggested before. Or at least in theory you could depending on things. I think the Stellarvue SVX70 reduces down to like f/4.8 so not super far off of f/4, maybe about 1/2 an exposure stop photographically speaking. Granted I don't know if I'd call that scope beginner friendly due to the price tag... 

 

Either way I don't think anyone will (or can) argue that f/4 is going to be faster than f/6 which can definitely help just ease the exposure times down and help the guiding requirements. The bigger thing is really the overall exposure time though, so whether your subs are 2min or 5min if you expose for 15min the results are going to be fairly similar. 

 

F4 may be tricky, but F5 isn't. I was merely starting, although I had some experience with a 70mm achromat, when I upgraded to an F5 150/750 newt that I still use today. It was an automatic step-up. Sure, tracking was less forgiving, but optically I had few issues. Zero at first. Collimation was only a problem when I forgot to check it and, luckily, the scope arrived in good collimation so I didn't have to worry about it at first. Still, the first time I tried to collimate, it was a breeze. It was done in under a minute, and wasn't particularly hard. It just takes a bit of reading to know what not to do (like not messing with the secondary unless absolutely necessary) and how to use the tools.

 

I'd say an F5 is a good starter scope.


  • John Tucker likes this

#43 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,220
  • Joined: 03 Mar 2018

Posted 11 July 2020 - 02:38 PM

I will admit that the f/4 scope suggestions are rare, however I feel like I've probably seen a f/4-ish (maybe with reducer) refractor being suggested before. Or at least in theory you could depending on things. I think the Stellarvue SVX70 reduces down to like f/4.8 so not super far off of f/4, maybe about 1/2 an exposure stop photographically speaking. Granted I don't know if I'd call that scope beginner friendly due to the price tag... 

 

Either way I don't think anyone will (or can) argue that f/4 is going to be faster than f/6 which can definitely help just ease the exposure times down and help the guiding requirements. The bigger thing is really the overall exposure time though, so whether your subs are 2min or 5min if you expose for 15min the results are going to be fairly similar. 

I'm not sure I follow.  Are you arguing that total acquisition time will be similar at F4 and F6?  My total acquisition times at F3 are routinely 25% of what they used to be.



#44 Stelios

Stelios

    Cosmos

  • *****
  • Moderators
  • Posts: 9,559
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 11 July 2020 - 03:13 PM

Please stay on topic.

 

This thread has totally derailed. None of this discussion is of any value to the original poster. 



#45 John Tucker

John Tucker

    Apollo

  • *****
  • Posts: 1,220
  • Joined: 03 Mar 2018

Posted 11 July 2020 - 05:03 PM

Please stay on topic.

 

This thread has totally derailed. None of this discussion is of any value to the original poster. 

Does it really matter?  The original poster received 22 pertinent responses, which is far more than most people posting questions here get. 

 

What has ensued is a different conversation, but one that is clearly of value to the participants.

 

Is the purpose of the site to serve the interests of the users, or is it to strictly follow a set of arbitrary rules? 

 

This note will no doubt be deleted, which will settle that question to my complete satisfaction.


Edited by John Tucker, 11 July 2020 - 05:04 PM.


#46 eddykhan993

eddykhan993

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 26 Jun 2020

Posted 11 July 2020 - 09:20 PM

Does it really matter? The original poster received 22 pertinent responses, which is far more than most people posting questions here get.

What has ensued is a different conversation, but one that is clearly of value to the participants.

Is the purpose of the site to serve the interests of the users, or is it to strictly follow a set of arbitrary rules?

This note will no doubt be deleted, which will settle that question to my complete satisfaction.



I have had a lot of answers which have answered most and lead to many other questions which I will no doubt ask this wonderful community in the very near future. im actually really happy and surprised to see how many people are sharing their work on my question. I honestly don't mind that it has gone a little off subject but I dont know what the guidelines are for posts?

id love to see more work with maybe break downs on: telescope/FL/Focul ratio/ iso/ exposures etc. it would be amazing.

#47 17.5Dob

17.5Dob

    Fly Me to the Moon

  • ****-
  • Posts: 6,410
  • Joined: 21 Mar 2013
  • Loc: Colorado,USA

Posted 11 July 2020 - 09:39 PM

Simple answer...somewhere between 375mm and 500mm..........

If you want plug and play, get a refractor.......

If you like the challenge of never ending fiddling around, each  every time you go out, to save a few minutes of total exposure time, get a reflector...



#48 dan_hm

dan_hm

    Viking 1

  • *****
  • Posts: 564
  • Joined: 31 Dec 2012
  • Loc: New Jersey

Posted 11 July 2020 - 09:51 PM

id love to see more work with maybe break downs on: telescope/FL/Focul ratio/ iso/ exposures etc. it would be amazing.

I encourage you to go on astrobin.com and type whatever piece of gear you are interested in into the search bar. This will generally show you all the pictures that people have posted with whatever the equipment is. So let's say you want to see how the Orion 80ED does; you can see likely hundreds and hundreds of pictures that people have taken through the telescope. 

 

The important caveat to remember is that there are many variables that can make any individual picture good or bad. Some people are just very skilled at acquisition and processing and can make excellent pictures with fairly modest equipment. A given piece of gear often does not necessarily produce bad pictures. It's often the driver of the car, not the car itself.


  • Ryou likes this

#49 Ryou

Ryou

    Ranger 4

  • -----
  • Posts: 343
  • Joined: 10 Apr 2020

Posted 12 July 2020 - 11:14 AM

I encourage you to go on astrobin.com and type whatever piece of gear you are interested in into the search bar. This will generally show you all the pictures that people have posted with whatever the equipment is. So let's say you want to see how the Orion 80ED does; you can see likely hundreds and hundreds of pictures that people have taken through the telescope. 

 

The important caveat to remember is that there are many variables that can make any individual picture good or bad. Some people are just very skilled at acquisition and processing and can make excellent pictures with fairly modest equipment. A given piece of gear often does not necessarily produce bad pictures. It's often the driver of the car, not the car itself.

I will basically second this whole post. Astrobin is a great resource for finding example images and seeing other people's work with details about the gear used. Very good starting point to see what cameras CAN do and any issues that may be present across a wide number of them like the ASI1600 Microlens thing.

 

It is still very important to remember though that there are lot of factors outside of gear that make an image great or not. See for example the light pollution gradient thing we were discussing. With my skills/software I was not able to do much to that image (admittedly I did not try on the un-stretched image provided) however someone else was able to really clean up even the stretched.

 

There is also personal taste, artistic liberty, etc to consider too. You can have person A take data and give it to persons B and C to process and both B and C will come up with totally different results. Maybe person B likes the deeper reds on nebula with huge contrast and doesn't care as much about some noise in the image, where C wants completely noise free and is willing to loose some contrast and deepness on the reds if it means achieving that. I've seen a few threads like this actually before where someone will toss their data out there to see what others come up with and it is fairly interesting actually. 

 

To even further muddle it, and move back towards the gear side of things, you could have someone come over and use my exact equipment/location to image who has more experience and still likely have some differences in the image. For example maybe they take better calibration frames than I did or more perfectly balance the signal to noise ratio than I do. Etc. This despite the gear being (literally) the same. Now this is probably going to be a smaller difference than the processing, however there can still be one there.


  • dan_hm likes this

#50 eddykhan993

eddykhan993

    Sputnik

  • -----
  • topic starter
  • Posts: 27
  • Joined: 26 Jun 2020

Posted 13 July 2020 - 05:00 AM

any body have any personal opinions on BRESSER MESSIER AR-102XS ED


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: beginner, astrophotography, equipment



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics