M24


Edwin <esanc001@...>
 

Jennifer, Tim
Thank you for your input! I will follow workflow as I just started at this crazy amazing hobby.
I found a youtube video that all it is Is white light for an hour, I used it with my tablet and it worked great as when I check the histogram its a solid line in tue middle.

Jennifer, I noticed you use APT, I just started using and at times plate solving has a hard time. I installed the 3 apps that it uses but I have noticed that only 2 are used. When I am having issues, I manually try the same image in All Sky Plate Solver and it does solve it but I am not sure if/how I can make APT use that one at those times when the other 2 fail.
do you know or have any other solution?

thanks you!
--
Edwin Sanchez
Iexos-100
ed-80 triplet
canon T6i


Jennifer Shelly
 
Edited

Edwin:

Flats can be done the next day as long as you leave your focuser and lens untouched.  If your focus changed throughout the night it does not matter as long as +/- change was minimal.  You can use something like an iPad with a white screen  placed on the dew shield when the telescope is pointing straight up. My ES refractor’s dew shield tends to walk it’s way down on with the weight of an iPad, so I use a large rubber band directly behind the dew shield to keep it from moving.  You can sometimes get away with using a set of flats multiple times as long as any dust on the lens an/or camera sensor has not moved.  

Sincerely,

Jennifer Shelly
AstroPorch, VA

Mounts
: ES PMC-8 G-11, ES PMC-8 EXOS-2
Scopes: ES ED127 FCD-100, ES Levy Comet Hunter, ES N208CF, QHY Mini Guide Scope, Solomark F60 Guide Scope
Cameras: QHY600M, QHY128C, QHY168C
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance, QHY CFW3-L, Baader 2” LRGBSHO CCD
Imaging Software:  NINA, APT, SharpCap Pro
Processing Software: PixInsight, Lightroom, Premiere Elements


Timothy Myers
 

I always make it part of my night to capture darks, flats and dark flats at the end of every imaging session. You really don't need the darks if you have a set at the same gain/ISO, exposure time and temp but I find it just as easy to do them every night and place them with my lights for the night.

I must admit though that taking flats and dark flats with the wizard in NINA makes it much easier to do than it was with Sharpcap. But that is just my experience.
--
Tim Myers

Telescopes:     Celestron 4SE, Celestron 8SE, SkyWatcher 100ED Pro
Mounts:           4-5 SE, 6-8SE, EXOS-2GT with PMC-Eight
Cameras:        ASI1600MC, Cooled
Tablets:           Asus Nexus 7, Amazon Fire 7
Laptop:           Lenovo


Edwin <esanc001@...>
 

Wes, Or someone in group,
speaking of flats, I do have a question.  I saw somewhere that you need to do your flats the same night or next morning. I made a bunch of them that I always use, dslr - iso 400, 800, 1600 etc. but i heard that they have to be the same position, focus, etc. as your lights.

what is the recommended or best practice for flats?

thanks!
--
Edwin Sanchez
Iexos-100
ed-80 triplet
canon T6i


Jeff Snell
 

Thanks for the feedback Wes.  Yes, all guided with PHD2.  My FOV is all south out over Ogden UT and then on to the Salt Lake City area.  Pretty high light pollution and all the targets I wanna shoot at this point are fairly low in the south.  I have a couple of dark sky areas within an hour so just need to get out and away to eliminate that as a factor.  PHD tracked well last night with total remaining around .5 all evening.

I find this target fascinating with such a dense star field.  Guess I’ll drop some coin on a ES field Flattener soon😎

Thanks again.
Jeff


On Jun 24, 2020, at 6:43 PM, Wes Mcdonald <wesmcd6@...> wrote:


Jeff:

Nice pic!

1.  If stars are displaying comma in all four corners then yes, a field flattener will address that.  
2.  If you have comma in pne corner and not others then that might be an alignment issue with the camera focal plane relative to the line of sight.  This will certainly cause focus error, as part of the focal plane is further away from the center and part is closer than the center to the objective.
3.  Vignetting is pretty much always present which is why we do flats.  Flats basically are used to correct the transfer function of light passing through the optical system as a function of radial distance from the center.  If you have light somehow entering off axis and getting scattered around I wouldn't try to eliminate it by a flattener.  Taking a series of flat images won't help either as these are done with a uniformly illuminated aperture. 

Image looks nice.  Great focus  Tracking obviously good enough to render nice round stars.  The star field is very dense around there, and after looking at other images I think what you might be thinking of a sky glow might well be faint nebulosity that appears in all other photos I inspected. 

It seems clear for your 80mm, the PMC8 guiding is doing just grand.  If you were not guiding, then Bully Bully.  240 secs is amazing.

Wes.

 



--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


Wes Mcdonald
 

Jeff:

Nice pic!

1.  If stars are displaying comma in all four corners then yes, a field flattener will address that.  
2.  If you have comma in pne corner and not others then that might be an alignment issue with the camera focal plane relative to the line of sight.  This will certainly cause focus error, as part of the focal plane is further away from the center and part is closer than the center to the objective.
3.  Vignetting is pretty much always present which is why we do flats.  Flats basically are used to correct the transfer function of light passing through the optical system as a function of radial distance from the center.  If you have light somehow entering off axis and getting scattered around I wouldn't try to eliminate it by a flattener.  Taking a series of flat images won't help either as these are done with a uniformly illuminated aperture. 

Image looks nice.  Great focus  Tracking obviously good enough to render nice round stars.  The star field is very dense around there, and after looking at other images I think what you might be thinking of a sky glow might well be faint nebulosity that appears in all other photos I inspected. 

It seems clear for your 80mm, the PMC8 guiding is doing just grand.  If you were not guiding, then Bully Bully.  240 secs is amazing.

Wes.

 



--
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


Jeff Snell
 

To be clear, the FF to correct for the trailing/edge distortion only.  Not the light issues.

Jeff

PMC-Eight w/Explore Stars
ES ED80mm APO
Celestron 8" Edge HD
Canon Ti-5 w/ Spencer Camera Astro-mod


On Wed, Jun 24, 2020 at 4:51 PM Jeff Snell via groups.io <Jeffery.snell1=gmail.com@groups.io> wrote:
Folks,
Took this last night.  Very little processing at this point just levels.  31 light (240s/800ISO), 20 darks, 20 flats with my Canon and the ED80 APO PMC Eight.  I'm getting what appears to be trailing around the edges and some vignetting and possible sky glow in upper right corner (Bortles 5/6 looking directly over the city at about 30 degrees elevation).  I assume this is what a field flattener would fix???

Any critiques welcome including what to add to the imaging train to correct.  Core of the star cloud tracked very nicely so PMC-eightdoing great.

Jeff

PMC-Eight w/Explore Stars
ES ED80mm APO
Celestron 8" Edge HD
Canon Ti-5 w/ Spencer Camera Astro-mod
CdC, APT, Polemaster, PHD2


Jeff Snell
 

Folks,
Took this last night.  Very little processing at this point just levels.  31 light (240s/800ISO), 20 darks, 20 flats with my Canon and the ED80 APO PMC Eight.  I'm getting what appears to be trailing around the edges and some vignetting and possible sky glow in upper right corner (Bortles 5/6 looking directly over the city at about 30 degrees elevation).  I assume this is what a field flattener would fix???

Any critiques welcome including what to add to the imaging train to correct.  Core of the star cloud tracked very nicely so PMC-eightdoing great.

Jeff

PMC-Eight w/Explore Stars
ES ED80mm APO
Celestron 8" Edge HD
Canon Ti-5 w/ Spencer Camera Astro-mod
CdC, APT, Polemaster, PHD2