Astrophotography Telescope

[Stub Mandrel]

The thread has been linked, from experience the EQ3-2, with an upgraded tripod and patience can work and can guide as accurately as an HEQ5.

This was 5-minute guided exposures on an EQ3-2 with a 130P-DS

That said, having gone from EQ3-2 to HEQ5, I would not go back.

Why - reliability. With the HEQ5 you get  a higher ratio of successes to failures; also the HEQ5 can take more weight.

[Adam J]

On 20/03/2019 at 08:02, masjstovel said:

@Knight of Clear Skies ive decided to go for the 150 PDS with EQ5 and then add the synscan goto st another time. I made a post on the equipment beginner  forum, and were told it then would be exaclty the same performance as a EQ5 pro synscan goto. Correct?

With 9 kg limit on the mount i guess that would be stable enough with a 988grams nikon d810 added. 

No i havent even considered that. Thank you! What is a coma corrector? 

I also wonder what adaptor(s) i need to mount a Nikon full frame

Two things come to mind with this plan,

1) I have a friend who uses a 150PDS on a HEQ5 Pro and it works but will struggle with a small amount of wind, as a result I don't see that mount guiding a 150PDS. The SW 72ED is your very best bet in that price range with an EQ5. You really dont want to start AP at that longer focal length at any rate. 

2) You will not get a nice stars across the entire sensor with a 150PDS / 130PDS and a full frame camera like the D810. 

3) Don't get hung up on aperture for Astro Imaging its not factor. F-ratio is the thing you need to look at. F5 - F7 being the sweet spot for a beginner. 

 

Do you already own the D810? If not then its not one I would recommend for AP. If you already have one though its not terrible either. 

[masjstovel]

@Uranium235 Thanks for the input!

Well unfortunately it's too late now, i ordered the package with an EQ-5 a little over a week ago :S I would love the HEQ5, but for me this "adventure" started out like;
"I would love a telescope. Couldn't cost more than a couple of hundred dollars, could it?"
"Ok, I need an equatorial mount. Couldn't cost more than a couple of hundred dollars more, could it?"
"OK, the eq-mount isnt heavy enough……… And so on. 

So i had to set a limit somewhere. 
I will likely spend another $1000 dollars on a HEQ5 and sell my EQ5 for half the price i bought it for in the future, but its at least a calculated risk i am aware of:) I will look for for sale-adds for the HEQ5 mount, and go for it if the price is right!

 

@Icesheet Wow, thanks, that's a really great offer! PM sent. I started thinking im the only one in Norway interested in this field. 
 

@Adam J As i mentioned to Uranium235, i've already ordered the 150PDS and the EQ-5. 150/750  will be F/5 so im in the right range at least?
I do already own the D810 as i'm mainly doing photography from beforehand. You dont reccomend it because its full frame, or is there some other reason? 

[Stub Mandrel]

I suspect people who struggle with wind live in windy places. I have no trouble using a 150PL on a HEQ5 and a mate uses a 200P on his, but we are in the midlands, not on the coast.

neil

[masjstovel]

Update: 
The 150PDS is in tha house now. I bought a "used" Synscan Goto Upgrade kit for approximately 220$ which i installed tonight. 
The neighbours must think i've gone mad if they saw me do the polar alignment, luckily its dark.
 

I tried taking some shots (light frames) of the Pinwheel Galaxy, M101 just for testing. Tried 30sec exposures, 800, 1600 and 4000 ISO but i couldnt see the Galaxy at all. I thought i would see at least some traces of it. Was I off, or is it because of the light-pollution? I Attached some unedited jpeg's here. I would be impressed, but does anyone know if M101 would be in this frame, or which star this bright one is? I was on the porch stepping around, so they are alittle blurry.

 

[Knight of Clear Skies]

Hi, if you upload your pictures to http://nova.astrometry.net/ it will plate solve them for you and tell you what you're looking at.

[Stub Mandrel]

Doesn't look right to me, plus M101 is quite challenging even without the moon around.

Compare the stars in this pic:

Ah Astrometry.net solved it:

You are about three frames too low and about a frame too far to the right.

Did you do a three-star alignment before doing the GOTO?

[masjstovel]

Ok I AM impressed:) Thanks again for the replies guys.

I did a 2-star alignment. First i checked if the mount was leveled, and did a polar alignment as best i could. after the alignment it said i was 1 and some degrees off East, and 4 and some degree off North , which i dont understand why. I find it difficult to know if its Polaris i'm looking at or something else. Also my app puts it at about 2 o'clock in the "Polar-Wheel", but i dont how it is in the polar finder since the image is "mirrored" and all that. I copied what i saw on my app.

I used Mizar and Vega for the 2-star alignment. When i chose Vega at first, the Scope went veeery far off. Like 130 degrees off, pointing down to the ground. This got me thinking of probably a very stupid question, but is there a right way and a wrong way to attach the scope, directionaly? i mean you have 2 options 180 degrees.

After centering Vega, it moved to what i at least think was very close to Mizar, just had to calibrate it a little bit closer.

But then when you say im 3 frames too low and to far to the right, then there must be something I'm doing wrong?

Another thing that made me worry. If i released the RA and DEC locking knob, and turned on the scope, at some point the scope would crash in the tripod legs. It didn't happen but if i continued turning it would. The Synscan doesnt "know" this and stops and goes the other way around if its obstructed? Is this a common thing, or am i doing something wrong here too? 

[Stub Mandrel]

You need two stars about 30 degrees well away from the pole star. Mizar is too close to the pole star to give a really good alignment.

You should start with the scope parked which normally means on top of the mount and pointing at Polaris. Best way to do this is check mount is parked, if not park it, then manually slew it to point at polaris and on top. Unpark and it now ought to slew to approximately the right spot.

[don4l]

I used ASTAP on your image, and it solved it immediately.  It's very easy to use, and is completely self contained.    http://www.hnsky.org/astap.htm

I popped the result into Cartes du Ciel and this is the result (your image is the lower box).

Platesolving seemed complicated at first, but it saves hours and hours.

 

[Stub Mandrel]

Looking at that I bet your second star alignment was on the  lower star circled in yellow, rather than Mizar (circled above).

That would explain the short move ending up exactly where it did rather than on M101.

If it was on Mizar it should have been an obvious wide double with Alcor.

[Knight of Clear Skies]

Stub Mandrel could well be right, it's easy to align on the wrong star. Sometimes I use a laser pointer to check the scope is pointing where I think it is, if I can find a straight edge on the mount to rest it against.