How long?

[ZiHao]

Hi everyone,

Anyone has an idea of how long a SW 750/150 scope with an eq3 pro mount can track? I did drift alignment with the sidedreal rate on but I am getting maximum of 20 seconds tracking only ( with no star trails). Or I expect too much h on this setup? Thanks.

[ollypenrice]

1 hour ago, ZiHao said:

Hi everyone,

Anyone has an idea of how long a SW 750/150 scope with an eq3 pro mount can track? I did drift alignment with the sidedreal rate on but I am getting maximum of 20 seconds tracking only ( with no star trails). Or I expect too much h on this setup? Thanks.

I think you probably are expecting too much. A 750mm focal length is quite long and you may well be using a small pixel camera like a DSLR, making a high resolution setup which will show errors mercilessly.

Olly

[astrosathya]

14 hours ago, ZiHao said:

Hi everyone,

Anyone has an idea of how long a SW 750/150 scope with an eq3 pro mount can track? I did drift alignment with the sidedreal rate on but I am getting maximum of 20 seconds tracking only ( with no star trails). Or I expect too much h on this setup? Thanks.

Recently someone got 10min tracking with EQ3-PRO with guiding. 20s is very less especially you've mentioned drift aligning it. Its quite obvious something is wrong somewhere. Try to do drift alignment by software assistance like using PHD2 or Astrophotography Tool DARV method. EQ3 mount is not really as bad as it seems. Can you see the pole star correctly from where you are? Sometimes from a dark location its also quite easy to "polar align" on another star close by. 

I'd highly recommend you use APT for drift align. It doesn't get easier than that. But you need to have EQMOD connection for this. You could also do a manual DARV method.

[ZiHao]

47 minutes ago, astrosathya said:

Recently someone got 10min tracking with EQ3-PRO with guiding. 20s is very less especially you've mentioned drift aligning it. Its quite obvious something is wrong somewhere. Try to do drift alignment by software assistance like using PHD2 or Astrophotography Tool DARV method. EQ3 mount is not really as bad as it seems. Can you see the pole star correctly from where you are? Sometimes from a dark location its also quite easy to "polar align" on another star close by. 

I'd highly recommend you use APT for drift align. It doesn't get easier than that. But you need to have EQMOD connection for this. You could also do a manual DARV method.

Thanks for your reply. No, I cannot see Polaris from my location (which is close to equator), I can only perceive Kochab and Pherkad here. Perhaps due to the heavy light pollution and thick atmosphere on the horizon, Polaris is imperceptible. I do my drift alignment using the DARV method by picking a star 30 degrees above the Eastern horizon and a star near the intersection of the meridian and celestial equator. And I press the right ascension key on the syncan controller to drift the star across the screen and look for any north south drift. But the problem is I am still getting 20 seconds even though the drift alignment is perfectly done. Also, I did the GOTO alignment, it slewed to the object chosen accurately, but the result is still, 20 seconds of tracking  

[wxsatuser]

How long is you DARV, at 30dgrees above horizon make it a lot longer than the default.
The further you deviate from the CE the longer you need to DARV.

As Olly pointed out you are expecting a lot from the mount so you need everything on your side.

[ollypenrice]

1 hour ago, astrosathya said:

Recently someone got 10min tracking with EQ3-PRO with guiding. 20s is very less especially you've mentioned drift aligning it. Its quite obvious something is wrong somewhere. Try to do drift alignment by software assistance like using PHD2 or Astrophotography Tool DARV method. EQ3 mount is not really as bad as it seems. Can you see the pole star correctly from where you are? Sometimes from a dark location its also quite easy to "polar align" on another star close by. 

I'd highly recommend you use APT for drift align. It doesn't get easier than that. But you need to have EQMOD connection for this. You could also do a manual DARV method.

I assumed the OP was not guiding. Perhaps he could let us know.

Olly

[Alien 13]

I would have thought that 20 seconds is about right for that scope, the EQ3-2 is better suited to sub 400 mm focal length scopes or camera lenses where you can achieve unguided subs of 90-120 seconds or 5 minutes or more if you are shooting widefield with something like a 50mm lens. 

The EQ3-2 should be looked at as a lightweight tracking mount similar in performance to the Star Adventurer but has the advantage in that it can take a bigger scope for a bit of Lunar/Planetary imaging where tracing accuracy is not critical.

Alan

[ZiHao]

2 hours ago, ollypenrice said:

I assumed the OP was not guiding. Perhaps he could let us know.

Olly

I was not guiding, what I was using is just the DARV, sidereal rate, and the GOTO function only.

 

2 hours ago, wxsatuser said:

How long is you DARV, at 30dgrees above horizon make it a lot longer than the default.
The further you deviate from the CE the longer you need to DARV.

As Olly pointed out you are expecting a lot from the mount so you need everything on your side.

125 seconds, is this adequate? I am using a DSLR, Nikon d5300

[ollypenrice]

20 minutes ago, ZiHao said:

I was not guiding, what I was using is just the DARV, sidereal rate, and the GOTO function only.

 

 

Then I think that quite a large scope with quite a long focal length on quite a small mount is doing reasonably well at 20 seconds. Your temperatures are going to be high in Malaysia, I assume, so uncooled cameras won't benefit from very long exposures anyway.

Olly

[wxsatuser]

29 minutes ago, ZiHao said:

I was not guiding, what I was using is just the DARV, sidereal rate, and the GOTO function only.

 

125 seconds, is this adequate? I am using a DSLR, Nikon d5300

Most likely not, may be add another 60secs per leg and see.
If it still looks good go for it.