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

Equipment letting me down... Where should I go from here?

  • Please log in to reply
51 replies to this topic

#1 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 03:44 PM

Hi friends!

 

Like many people, I took up the hobby of astrophotography this year during the pandemic and got instantly hooked. In my day job I'm a software engineer, so the technical challenges were exciting to me, and I like to think I progressed quickly in learning, moving from using a telephoto lens to shoot the moon, to a skyguider pro and some very blurry nebula photos, to a redcat51 and a sony a7 that helped me get to some pretty sharp andromeda and NGC7000 captures.

 

During the summer I plotted an upgrade and have been slowly assembling the following into my "real rig":

* HEQ5 mount

* Explore Scientific ED127CF scope

* William Optics 50mm guidescope with asi290mm camera

* asi6200mc pro

* ASIair to control everything

* various other dew heaters, power cables, adapters etc.

 

It has taken me many, many sessions of tinkering to get to a point where I can operate it all, but I have the hang of everything and I'm still not getting good images. I actually think I may have a fundamental problem here - the scope is slow, and with the size of the camera I'm using I will need long (5m+) exposures to get any usable dynamic range. The mount doesn't seem to be able to provide stable enough guiding for that length, though. Even worse, with all the extenders I need to get focus to the camera from that scope, the imaging train is very long and pretty often the camera will come into contact with the legs of the mount, messing up EVERYTHING (focus, mount alignment, loosening connectors and extender tube connections... everything)

 

Did I screw up? I have yet to get great images from this setup and I've had every frustrating problem over the past two months. But maybe I should keep trying with this equipment

 

Any advice welcome


Edited by spiantino, 01 October 2020 - 03:47 PM.


#2 erictheastrojunkie

erictheastrojunkie

    Viking 1

  • *****
  • Posts: 845
  • Joined: 15 Jul 2016
  • Loc: Salt Lake City

Posted 01 October 2020 - 03:47 PM

Your mount is under "powered" for your scope, you either need a more robust mount or a more reasonable scope. With a scope like that the minimum you should be looking at is an EQ6-R level mount. Also, look for a focal reducer for the scope to get a faster aperture if you aren't already using one. 


  • mikefulb likes this

#3 randcpoll

randcpoll

    Mariner 2

  • *****
  • Posts: 279
  • Joined: 20 Jul 2013
  • Loc: New York

Posted 01 October 2020 - 03:52 PM

Ditto with erictheastrojunkie. Your 127mm should be a 102mm max on that mount. 


  • SilverLitz likes this

#4 RJF-Astro

RJF-Astro

    Viking 1

  • -----
  • Posts: 674
  • Joined: 13 Aug 2018
  • Loc: Zeist, Netherlands

Posted 01 October 2020 - 04:03 PM

Besides upgrading the mount you could also get a smaller, faster scope. Unless you are aiming for specific targets, an 80mm triplet can keep you buisy for a few seasons.
  • nebulasaurus, SilverLitz and ThatsNoMoon like this

#5 rgsalinger

rgsalinger

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 7,187
  • Joined: 19 Feb 2007
  • Loc: Carlsbad Ca

Posted 01 October 2020 - 04:07 PM

I think that I'd make a different set of cheaper recommendations.

 

You may well be under mounted, but you've provided no evidence of what the problems actually are. A good way to do that is to post a picture of your system along with some indication of where you image. Do some guiding and share the guiding log to see if you've got everything set up properly. The next thing to do is to simplify the setup as much as you can and see how long you can go unguided. Eliminate as much cabling as possible so that you're seeing the mount performance more clearly. Learn how to do a PEC run to reduce the periodic error. (Are you using EQUASCOM?)

 

 The first thing that I would recommend is to see if there's an astronomy club locally that you can join. It's not that hard to mentor someone from a few feet away. Every club that I know of will have experienced imagers available who would love to show you the ropes. The second thing to do is to buy some books about astrophotography and read them carefully. There are two that I recommend. The Deep Sky Imaging primer is my favorite closely follow by Chris Woodhouse's The Astrophotography manual. So, far this is much cheaper than buying a new scope or mount. 

 

Once you've posted some results and some more information it will be possible to give you much better advice. I really doubt that at F7.5 you need 5 minute exposures to get really nice results so more about that would be interesting. Are you familiar with this calculator and how to use it? 

 

I wouldn't spend a lot of money yet, there's probably more that can be done with what you have. 

 

Rgrds-Ross


  • Dynan likes this

#6 Peregrinatum

Peregrinatum

    Surveyor 1

  • *****
  • Posts: 1,518
  • Joined: 27 Dec 2018
  • Loc: South Central Valley, Ca

Posted 01 October 2020 - 04:11 PM

imo your mount is your weak link, you need a beefier one, and possibly better image acquisition software

 

frustrated, and many nights getting it all to work?  ...welcome to AP it's par for the course


  • DRK73 and charlieb123 like this

#7 Pauls72

Pauls72

    Mercury-Atlas

  • *****
  • Posts: 2,868
  • Joined: 28 Oct 2007
  • Loc: LaPorte, IN USA

Posted 01 October 2020 - 04:16 PM

Your mount is rated at 30 lbs for visual use. That would put it around 15 lbs for AP. Your OTA is 22 lbs, finder scope 1 lb 2 oz, guide camera 4.2 oz,  image camera 1.55 lbs, then add in the spacers guide scope bracket, dew heaters and all the cables hanging. Your up to someplace around 27-28 pounds. It's not that it can't be done with that mount, but it's going to be a huge challenge.

 

Second, a reducer or flattner will reduce the the amount of extenders you need to get the camera in focus.

 

As Ross suggested, try and find a club or someone local to mentor you. First post or put in a drop box with a link back here some images for us to look at.

 

Throwing more or different equipment won't help unless it's the right equipment.


Edited by Pauls72, 01 October 2020 - 04:24 PM.


#8 SilverLitz

SilverLitz

    Apollo

  • -----
  • Posts: 1,179
  • Joined: 17 Feb 2018
  • Loc: Louisville, KY

Posted 01 October 2020 - 04:49 PM

I agree with everyone that you have too little mount and too much scope.  I would also add that you camera (although excellent) is probably too much as well, as full-frame sensors will be a challenged for very experienced imagers, as the large sensor will greatly exaggerate sensor tilt, and most scopes (Tak FSQs excepted) cannot cover full-frame sensors very well.



#9 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 04:49 PM

I think that I'd make a different set of cheaper recommendations.

 

You may well be under mounted, but you've provided no evidence of what the problems actually are. A good way to do that is to post a picture of your system along with some indication of where you image. Do some guiding and share the guiding log to see if you've got everything set up properly. The next thing to do is to simplify the setup as much as you can and see how long you can go unguided. Eliminate as much cabling as possible so that you're seeing the mount performance more clearly. Learn how to do a PEC run to reduce the periodic error. (Are you using EQUASCOM?)

 

 The first thing that I would recommend is to see if there's an astronomy club locally that you can join. It's not that hard to mentor someone from a few feet away. Every club that I know of will have experienced imagers available who would love to show you the ropes. The second thing to do is to buy some books about astrophotography and read them carefully. There are two that I recommend. The Deep Sky Imaging primer is my favorite closely follow by Chris Woodhouse's The Astrophotography manual. So, far this is much cheaper than buying a new scope or mount. 

 

Once you've posted some results and some more information it will be possible to give you much better advice. I really doubt that at F7.5 you need 5 minute exposures to get really nice results so more about that would be interesting. Are you familiar with this calculator and how to use it? 

 

I wouldn't spend a lot of money yet, there's probably more that can be done with what you have. 

 

Rgrds-Ross

Thanks for the advice - let me provide some of the details you mentioned:

  • I'm attaching a guide log from my must successful night. I was stabilizing around 1.4" during guiding, and it's hard to get good data, but that sounds like it might actually be what the mount is capable of
  • I haven't done a PEC run, but will try that next time I go out. I'm using the USB cable directly connected from ASIair to hand controller port (not sure if that's EQUASCOM)
  • I'm not familiar with that calculator, but plugged in my values and got 0.67 e/pixel/s. I assume that tells me something about how long of an exposure I'd need to get a reasonable signal but I'm not sure how to interpret then umber.
  • One thing I neglected to mention is that I'm using an Optolong UHC 2" filter which may impact how much light I'm able to capture.

Attached Files



#10 SDTopensied

SDTopensied

    Viking 1

  • *****
  • Posts: 849
  • Joined: 25 Apr 2011
  • Loc: Atlanta

Posted 01 October 2020 - 04:54 PM

I’ll echo what others are saying.  A carbon fiber 102 mm or an aluminum tube 80 mm refractor are about the heaviest scopes I would put on an HEQ5 for imaging.  Everything else is fine.

 

I image with an ED127CF FCD100 on an NEQ6 Pro with the counterweight shaft upgrade and larger counterweights as well as a tripod spreader kit.  Without those modifications, the NEQ6 Pro doesn’t handle the weight and length of the 127 very well for imaging.

 

You have a nice mount and a nice scope.  You can either get a more robust mount or a smaller scope and you’ll be in better shape.  Explore Scientific has a good trade in program and great customer service.

 

-Steve



#11 Stelios

Stelios

    Voyager 1

  • *****
  • Moderators
  • Posts: 10,276
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 01 October 2020 - 04:55 PM

Your scope (as already pointed out) is too much for your mount, plus you opted for a CF tube which leads to thermal expansion problems (CF tubes are great for reflectors where rigidity is paramount, they are NOT a good idea for refractors). 

 

Also, at that F/L (952mm) you will do much better guiding with an OAG than a guidescope. 

 

If you had a beefier mount, you could add riser blocks to lift the scope so as to avoid it hitting the tripod legs. You could also perhaps move the OTA forward in the saddle (you may need a longer saddle and/or longer dovetail bar). The downside of riser blocks is increase in moment arm, but using an OAG would mitigate that. Something else that would help is a pier, or a pier extension (not sure if they sell one for the Sirius/HEQ5 domestically--they are available in the UK).

 

As for the "long exposures"--you don't need long exposures, you need long total integration time. At gain 100 and up, the 6200MC-Pro has very low read noise, so you could probably swamp it in two-three minutes. 

 

Bottom line though: It all starts with the mount. It is an extremely common mistake to spend more on other stuff (scope, camera) than on the mount. This does not work, as you're finding out. I would recommend a Losmandy G11 or an iOptron CEM70 (not the G) for your scope. This (and the other recommendations in my post) will let you maximize your scope and camera and get some *beautiful* images out of them. 



#12 Stelios

Stelios

    Voyager 1

  • *****
  • Moderators
  • Posts: 10,276
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 01 October 2020 - 05:00 PM

One thing I neglected to mention is that I'm using an Optolong UHC 2" filter which may impact how much light I'm able to capture.

 

This is a visual filter. The best thing you can do is put it away for visual use and nothing else. 

 

Although there are cases where filters (such as the Triad or the L-Enhance/L-Extreme) can be beneficial *for emission nebulae* with OSC, in general you are better off without them till you have a very solid understanding of both acquisition and processing. 



#13 bjulihn

bjulihn

    Mariner 2

  • -----
  • Posts: 226
  • Joined: 19 Jan 2019
  • Loc: Langley, BC. Canada

Posted 01 October 2020 - 05:02 PM

Hey spiantino;

 

Where do you live? City, suburbs, or country? What capture software and what are you post-processing with? And show us both some raw frames and a completed image good or bad. You need good data from your equipment, but post-processing is another big part of the equation.

 

Brad



#14 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 05:08 PM

Your mount is rated at 30 lbs for visual use. That would put it around 15 lbs for AP. Your OTA is 22 lbs, finder scope 1 lb 2 oz, guide camera 4.2 oz,  image camera 1.55 lbs, then add in the spacers guide scope bracket, dew heaters and all the cables hanging. Your up to someplace around 27-28 pounds. It's not that it can't be done with that mount, but it's going to be a huge challenge.

 

Second, a reducer or flattner will reduce the the amount of extenders you need to get the camera in focus.

 

As Ross suggested, try and find a club or someone local to mentor you. First post or put in a drop box with a link back here some images for us to look at.

 

Throwing more or different equipment won't help unless it's the right equipment.

I was worried about weight, but I did get the carbon fiber version of the scope. So it's quite a bit lighter, I think. I just weighed the whole setup and it's 18.1 lbs - probably pushing it but hopefully not the main source of my problems. Here's an image of the scope where you can see the long tubes i need to get an image

 

I didn't know that about reducers/flatteners - that sounds promising. Any advice on what kind I need? Ideally I'd find a flattener since the whole point of splurging on this scope was to exploit the long FL

Attached Thumbnails

  • IMG_1098 (1).jpeg


#15 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 05:14 PM

Hey spiantino;

 

Where do you live? City, suburbs, or country? What capture software and what are you post-processing with? And show us both some raw frames and a completed image good or bad. You need good data from your equipment, but post-processing is another big part of the equation.

 

Brad

I'm in the country, though pretty close to New York City so I get a lot of glow in the southern sky. Happy to post subs - is there a preferred way to attach large files? I know the limit on the forum is 500kb.

 

I assume I'm underexposing because the histogram shows averages in the couple hundred range. I use DSS or sometimes I let the ASIair do the stacking for me, and then I postprocess in Photoshop. When I try to stretch the nebula they show up as a single quantized region with no detail.

 

Now that you mention it, I must be doing something wrong because I have gotten a few decent images but only when I let the ASIair do the stacking/stretching itself. Here are a few

Attached Thumbnails

  • IMG_1074.jpeg
  • IMG_1077.jpeg


#16 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 05:16 PM

This is a visual filter. The best thing you can do is put it away for visual use and nothing else. 

 

Although there are cases where filters (such as the Triad or the L-Enhance/L-Extreme) can be beneficial *for emission nebulae* with OSC, in general you are better off without them till you have a very solid understanding of both acquisition and processing. 

 

Okay, let me try skipping the filter on my next session. Didn't realize this was a visual filter



#17 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 05:20 PM

I’ll echo what others are saying.  A carbon fiber 102 mm or an aluminum tube 80 mm refractor are about the heaviest scopes I would put on an HEQ5 for imaging.  Everything else is fine.

 

I image with an ED127CF FCD100 on an NEQ6 Pro with the counterweight shaft upgrade and larger counterweights as well as a tripod spreader kit.  Without those modifications, the NEQ6 Pro doesn’t handle the weight and length of the 127 very well for imaging.

 

You have a nice mount and a nice scope.  You can either get a more robust mount or a smaller scope and you’ll be in better shape.  Explore Scientific has a good trade in program and great customer service.

 

-Steve

I don't have any issues with balancing, but I am using both of the included counterweights. 

 

I think my plan is going to be to try some of the suggestions from folks on here, but if that doesn't stabilize things to trade in the scope with ES for something in the 80mm range. 


Edited by spiantino, 01 October 2020 - 05:21 PM.


#18 rgsalinger

rgsalinger

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 7,187
  • Joined: 19 Feb 2007
  • Loc: Carlsbad Ca

Posted 01 October 2020 - 05:34 PM

Apparently I'm the only one who's actually bothered to look at your guide log. The problem you are having with guiding seems immediately obvious, if you've included the correct file. You never even once got a successful calibration that night. The mount only moved in one axis. So, the first thing to do is to figure out why the mount won't calibrate. I can tell you with 99 percent probability that until you do that it's impossible to get decent guiding. 

 

This is why I suggested getting a book and a mentor. Until you understand how to get a good calibration it's impossible to get exposures longer than 30 seconds with the equipment. 

 

Check the read noise on your camera at your gain setting. Now square it and multiply it by 20. Now take the number of photons/second that the calculator gives you and divide that into the first result. That's roughly how long an exposure needs to be. (Check my math please- all of you). I think that's going to come out quite a bit less than 5 minutes.  

 

So,  now I'd add in giving the PHD 2.x manual a long careful read before going out again. Some of the parameters don't look correct either. That's small beer - getting a good calibration is 90 percent of getting good guiding. 

 

Rgrds-Ross 


  • happylimpet likes this

#19 Gary.McK

Gary.McK

    Viking 1

  • -----
  • Posts: 516
  • Joined: 29 Jan 2009
  • Loc: Geelong, Australia

Posted 01 October 2020 - 05:48 PM

After sorting out your guiding calibration, you should also consider fitting a belt drive kit from here to your mount.:

 

http://www.rowanastr...htm#heq5beltkit

 

I have an HEQ5 that was guiding poorly, after fitting this, my guiding went to superb. (12 arc secs total smooth PE) .You are  overscoped for the mount though ( I know from experience !!)

 

FWIW

Gary


Edited by Gary.McK, 01 October 2020 - 05:49 PM.


#20 nimitz69

nimitz69

    Mercury-Atlas

  • *****
  • Posts: 2,692
  • Joined: 21 Apr 2017
  • Loc: A barrier island 18 miles south of Cocoa Beach

Posted 01 October 2020 - 06:20 PM

Trying to learn AP by posting questions on CN is like trying to compile computer programs back in the 1970s where you’d spend hrs typing out your program onto punch cards, then trudge across 2 miles of snow covered campus and give the card deck to some geek behind a counter and come back the next day only to discover your program didn't run because you messed up some commas somewhere ...
If you don’t want to continue to struggle do what Ross said & get that book at the minimum but way better would be to get a mentor at a local club. You will learn more in one night than weeks of posting on CN .....

Edited by nimitz69, 01 October 2020 - 06:21 PM.

  • charlieb123 likes this

#21 Stelios

Stelios

    Voyager 1

  • *****
  • Moderators
  • Posts: 10,276
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 01 October 2020 - 06:29 PM

Trying to learn AP by posting questions on CN is like trying to compile computer programs back in the 1970s where you’d spend hrs typing out your program onto punch cards, then trudge across 2 miles of snow covered campus and give the card deck to some geek behind a counter and come back the next day only to discover your program didn't run because you messed up some commas somewhere ...
If you don’t want to continue to struggle do what Ross said & get that book at the minimum but way better would be to get a mentor at a local club. You will learn more in one night than weeks of posting on CN .....

Mentor at a local club in COVID-19 times is not likely to be a practical (and certainly not a risk-free) option. 

 

He's got some good advice here. As usual, there are a ton of things to improve, and not everyone has the time to address *all* aspects of what may be wrong. 


  • happylimpet likes this

#22 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 07:06 PM

Trying to learn AP by posting questions on CN is like trying to compile computer programs back in the 1970s where you’d spend hrs typing out your program onto punch cards, then trudge across 2 miles of snow covered campus and give the card deck to some geek behind a counter and come back the next day only to discover your program didn't run because you messed up some commas somewhere ...
If you don’t want to continue to struggle do what Ross said & get that book at the minimum but way better would be to get a mentor at a local club. You will learn more in one night than weeks of posting on CN .....

 

I hope I didn't come across as trying to learn by posting questions on this forum! I've done a lot of research, I'm just focusing here on the pieces I don't already know. Anything I can find good information on I have found, but there is certainly a dearth of info on some elements.

 

 

Mentor at a local club in COVID-19 times is not likely to be a practical (and certainly not a risk-free) option. 

 

He's got some good advice here. As usual, there are a ton of things to improve, and not everyone has the time to address *all* aspects of what may be wrong. 

I've heard of some local clubs, but yes it does seem like it will be tough to get together at the moment



#23 idclimber

idclimber

    Viking 1

  • -----
  • Posts: 581
  • Joined: 08 Apr 2016
  • Loc: McCall Idaho

Posted 01 October 2020 - 07:07 PM

Don't get discouraged and be proud of what you have accomplished so far. Obviously you have learned how to polar align, focus and get some images to start working with. Add a few more pieces and your images will improve, even with the mount you have. 

 

Get the best mount you can afford. Seriously, it is more important than anything else and is the literal foundation of your imaging. You can easily sell the one you have for most of what you paid for it. These relatively inexpensive mounts last less than a day in the classifieds at CN if priced reasonably. 


Edited by idclimber, 01 October 2020 - 07:07 PM.


#24 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 07:15 PM

Apparently I'm the only one who's actually bothered to look at your guide log. The problem you are having with guiding seems immediately obvious, if you've included the correct file. You never even once got a successful calibration that night. The mount only moved in one axis. So, the first thing to do is to figure out why the mount won't calibrate. I can tell you with 99 percent probability that until you do that it's impossible to get decent guiding. 

 

This is why I suggested getting a book and a mentor. Until you understand how to get a good calibration it's impossible to get exposures longer than 30 seconds with the equipment. 

 

Check the read noise on your camera at your gain setting. Now square it and multiply it by 20. Now take the number of photons/second that the calculator gives you and divide that into the first result. That's roughly how long an exposure needs to be. (Check my math please- all of you). I think that's going to come out quite a bit less than 5 minutes.  

 

So,  now I'd add in giving the PHD 2.x manual a long careful read before going out again. Some of the parameters don't look correct either. That's small beer - getting a good calibration is 90 percent of getting good guiding. 

 

Rgrds-Ross 

 

That was probably a bad log to post - that night I was playing with settings and recalibrating over and over, so the log is probably a mess. Here's a log from a night where I wasn't messing around with the settings that much.

 

The mount definitely moves in both axes. It does seem to move appropriate amounts east and west, but then when calibrating dec it moves north correctly but the south steps don't move nearly as far and it ends up far from the original location. After that it starts so far away that it never settles and that makes the calibration fail with "timed out waiting for guider to settle". I thought this might be backlash, but there is no detectable wiggle when I'm moving either axis manually, and I believe the calibration should do a backlash clearing step that would mitigate this.

 

Part of the problem is I'm not using PHD, I'm using the ASIair software (which has a lite version of phd included). So I have to manually set some of the parameters PHD would be automatically suggesting and I don't get quite as much control.

Attached Files



#25 spiantino

spiantino

    Sputnik

  • -----
  • topic starter
  • Posts: 40
  • Joined: 24 Jun 2020

Posted 01 October 2020 - 07:17 PM

After sorting out your guiding calibration, you should also consider fitting a belt drive kit from here to your mount.:

 

http://www.rowanastr...htm#heq5beltkit

 

I have an HEQ5 that was guiding poorly, after fitting this, my guiding went to superb. (12 arc secs total smooth PE) .You are  overscoped for the mount though ( I know from experience !!)

 

FWIW

Gary

 

I've looked into the belt kit but in the spirit of working with what you have I've avoided cracking open the mount until I'm sure it's not me doing something silly. If I rule everything out then this is definitely an upgrade I'll consider


Edited by spiantino, 01 October 2020 - 07:17 PM.



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






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics