Date   

Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Jeny@
 

"Instrument specifications are payload capacity for astrophotography is 28lbs + counterweights and for visual use, the instrument payload capacity is 40 lbs + counterweights"

I think it should easily handle 200mm Newt.
--
EXOS2-GT PMC8
Orion150 Mak, Polemaster, ZWO ASI178MM


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Dave Cherry
 

I have a SW 200PDS , no problems, pretty much always under 0.5 average in PH2

Dave
--
Scopes: Sky Watcher 200PDS, Skywatcher 72ED
Mount: Explore Scientific PMC8 EXO2
Cameras: ASI 294MCPRO Coooled, Altair guide cam + 50mm scope
Software: Sharpcap Pro ,PH2, Stelarium Startools


Re: #astrophotography #goto #iexos-100 #astrophotography #polaralignment #astrophotography #goto #iEXOS-100 #polaralignment

Wes Mcdonald
 

Why would you think not?

--
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


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Wes Mcdonald
 

I have always thought that more mass on the load would be better.  Yes you will during slew experience more tortional twisting of compliant shafts etc.  but the increase in mass will decrease resonant frequencies.  In a spring mass system the period is proportional to the square root of the mass.  So one lowers the frequency as one increases the mass.  I wonder if guiding happens better.  External disturbances might also have less influence, even wind if the mass goes up faster than the sail area.  

When we are guiding we are tracking along at a nice pace and issuing slight corrections.  Unfortunately the response of mount will be longer given greater mass... pesky time constants to final value gonna be proportional to the inverse natural frequency which higher mass decreases thereby increasing response time.  But if these times correspond to intervals lots smaller than the guide interval the advantage more mass gives for resistance to disturbances might just be a positive  overall.

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


locked Re: What Platform Do You Use To Run ExploreStars? #poll-notice #poll #ExploreScientific #ExploreStars

James Ball
 

I use ExploreStars on Android tablet only because it doesn't work on W7. 


--
James Ball
Dawson Springs, Ky
Mounts: iEXOS-100
Scopes: Meade ETX90RA(deforked now) Sky Watcher 150MCT
Camera: ZWO ASI 120MC-S
Software: Explore Stars Android, ASCOM, Stellarium Scope, Stellarium, AS!3, SharpCap, RegiStax6.


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Dan Kahraman <dkahra213@...>
 

Bill:

Please post pictures of your cable management. It is a very important yet challenging topic.

Dan Kahraman

On Thu, 25 Jun 2020 at 16:35, Bill Black <wcblack1020@...> wrote:
Totally agree on the cable management. It can make all the difference for refining your guiding/drift.
I route all of my cables to the center of the mount and then straight down, with enough slack all at the center.
--

Bill
Location: Dallas, GA
Scopes:
 Celestron C8, AstroTech 80mm APO

Mounts: EXOS II PMC-Eight, LXD75

Cameras: ZWO ASI294MCPro, ASI385


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

jrichard333 <jrichard333@hotmail.com>
 

Good day all,

 

I don’t know about the EXOS-2GT, but the IEXOS-100 does J.

 

JR

 

From: MAIN@ESPMC-Eight.groups.io [mailto:MAIN@ESPMC-Eight.groups.io] On Behalf Of Robert Hoskin
Sent: Thursday, June 25, 2020 4:00 PM
To: MAIN@ESPMC-Eight.groups.io
Subject: Re: [ESPMC-Eight] Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

 

Bill / Dan

 

I'm starting to wonder if the EXOS2 doesn't like a bit more weight... :-)


Question:  What's your tolerance limit for wind?  

 

- Bob  (who keeps hearing the siren song of small Newts...)

 

--

Mounts: ES PMC-8 EXOS2

Scopes: SV 102EDT, ZWO 60/280 Guide

Cameras:  Nikon D5300, Altair GPCAM2 290M

Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

 

Bill / Dan
 
I'm starting to wonder if the EXOS2 doesn't like a bit more weight... :-)

Question:  What's your tolerance limit for wind?  
 
- Bob  (who keeps hearing the siren song of small Newts...)
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2 290M
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Bill Black
 

Totally agree on the cable management. It can make all the difference for refining your guiding/drift.
I route all of my cables to the center of the mount and then straight down, with enough slack all at the center.
--

Bill
Location: Dallas, GA
Scopes:
 Celestron C8, AstroTech 80mm APO

Mounts: EXOS II PMC-Eight, LXD75

Cameras: ZWO ASI294MCPro, ASI385


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Dan Kahraman <dkahra213@...>
 

Bill:

I meant yes not "yet".

Dan Kahraman

On Thu, 25 Jun 2020 at 16:18, Dan Kahraman via groups.io <dkahra213=gmail.com@groups.io> wrote:
Bill:

The answer is yet but the other challenge will be good cable management...shifting cables are a no-no so they should be held in place yet allowed "slack" within those constraints.

Dan Kahraman

On Thu, 25 Jun 2020 at 16:08, Bill Black <wcblack1020@...> wrote:
Hi Zernike Polynomial (nice!)
I have no problems using this mount with my 8" SCT. It sort of looks like a 200mm newt with the dew shield on it.
On top of the SCT, I have my 80mm APO riding piggy back plus cameras on both scopes.
My total equipment weight is 27 lbs and I have 27 lbs of counterweight as well.
If the seeing is good, I can guide to about 0.5" RMS in PHD.
--

Bill
Location: Dallas, GA
Scopes:
 Celestron C8, AstroTech 80mm APO

Mounts: EXOS II PMC-Eight, LXD75

Cameras: ZWO ASI294MCPro, ASI385


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Dan Kahraman <dkahra213@...>
 

Bill:

The answer is yet but the other challenge will be good cable management...shifting cables are a no-no so they should be held in place yet allowed "slack" within those constraints.

Dan Kahraman

On Thu, 25 Jun 2020 at 16:08, Bill Black <wcblack1020@...> wrote:
Hi Zernike Polynomial (nice!)
I have no problems using this mount with my 8" SCT. It sort of looks like a 200mm newt with the dew shield on it.
On top of the SCT, I have my 80mm APO riding piggy back plus cameras on both scopes.
My total equipment weight is 27 lbs and I have 27 lbs of counterweight as well.
If the seeing is good, I can guide to about 0.5" RMS in PHD.
--

Bill
Location: Dallas, GA
Scopes:
 Celestron C8, AstroTech 80mm APO

Mounts: EXOS II PMC-Eight, LXD75

Cameras: ZWO ASI294MCPro, ASI385


Re: Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

Bill Black
 

Hi Zernike Polynomial (nice!)
I have no problems using this mount with my 8" SCT. It sort of looks like a 200mm newt with the dew shield on it.
On top of the SCT, I have my 80mm APO riding piggy back plus cameras on both scopes.
My total equipment weight is 27 lbs and I have 27 lbs of counterweight as well.
If the seeing is good, I can guide to about 0.5" RMS in PHD.
--

Bill
Location: Dallas, GA
Scopes:
 Celestron C8, AstroTech 80mm APO

Mounts: EXOS II PMC-Eight, LXD75

Cameras: ZWO ASI294MCPro, ASI385


Re: M24

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


Re: #astrophotography #goto #iexos-100 #astrophotography #polaralignment #astrophotography #goto #iEXOS-100 #polaralignment

brian skinner
 

Hi, I have now mastered my recently purchased ES iEXOS 100 polar scope. I've used it a couple of times now without any real difficulty. Last evening I managed a 600second exposure without any obvious trailing, without the polar scope around 120seconds was around my useable limit, so am well pleased.
One question I do have is wrt collimation. I have tried to collimate the polar scope using the three small cross head screws provided but found this basically impossible practically speaking. Thinking about it, provided I place polaris correctly in the reticule having previously aligned the reticule with either Ursa Major or Cass. Is collimation strictly necessary?
Thankyou, Brian


Can EXOS2-GT PMC-EIGHT handle 200mm diameter f/5 newt? #EXOS2

zernikepolynomial
 

Many have a better understanding of the mount now, and I am seeing astrophotography payloads up to 28 pounds. Do you think this mount can handle a 200mm f/5 newt? With both the usual weight (maybe 20 pounds with a camera) and length? Do other users have too much trouble keeping PHD under 1"?


Re: M24

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


Re: M24

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


Re: M24

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


Re: M24

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


M24

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

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