First night's viewing - some setup issues/questions.

[tehmac]

Hi all,

 

So I had my first attempt at using my new equipment (and first time ever using a telescope) last night. It’s still not dark enough here until very late and cloud cover has been an issue, but I’ve been desperate to use it for days now, so I saw The Moon clearly and quickly ran out to set it up. Here are my questions based on my first attempts. Hopefully you can answer.

 

1. Without using a GOTO (also not tried yet) on my HEQ5 for tracking, it was a devil of a job to keep even the moon in the eyepiece for more than a couple of minutes. I was shocked how quick things move. I found it very difficult to use the RA and DEC clutches on the mount. When I would release one and find The Moon again and then tighten the clutch to lock it in position, the action of tightening the clutch would often cause it to move The Moon out of frame again, so I’d return to the eyepiece and see nothing again. The clutches seemed to do this constantly, even when I tried to tighten them very gently but tightly, and was very frustrating. Any tips? Is this normal?

 

2. The 15mm eyepiece gave the best view as I could see the whole Moon in view. I tried it with a 2x Barlow and the detail was great, but it was perhaps too close and then with my issues with following it in frame, it became a pain to find it again, I also tried a 28mm eyepiece, but for some reason, this would not focus, no matter what I did. I could see the The Moon as a fuzzy ball through the eyepiece, but at both extremes of focus and everything in between, it just remained a blur. Why would this happen?

 

3. I was wanting to use my DSLR for some photographs, and obviously I wanted sharp images. I have a Bahtinov Mask, which I put over the end, but I’m confused as to how it should work. I have watched all the tutorials and read about it, but I never saw the star shape or an easy way to focus when using it on the The Moon. Instead, it was as if I were viewing The Moon without the Bahtinov and I just had to gauge focus with my own eye like I had been doing all night. Is The Moon just too big/close an object to be useful when using one of these?

 

Many thanks for your time.

 

Gary

[Demonperformer]

Hi, Gary, and welcome.

(1) As long as your mount is polar aligned (and switched on!) objects should stay within the eyepiece. But polar alignment can be a beast! Your instruction manuel should give you advice on how to achieve this for your specific model. Alternatively, there are a lot of threads on SGL about polar alignment. [This should not be confused with doing a 1- 2- or 3-star alignment of the scope. This is a process which you will do after polar alignment to enable the onboard computer to find objects you want to GOTO.]
(2) Don't know about this - assuming the eyepiece is not defective.
(3) A bahtinov mask works well on point sources (stars), but not on extended objects like planets or the moon. The moon should not be a problem, as there are lots of craters - just adjust the  focus until their edges are crisp.

These answers probably generate more questions, but I thought it best to start with an overview. Any issues they raise, please let us know and we will try to help.

Thanks.

[ronin]

Sounds as if you have not done the poalr alighment or an approximate polar alignment?

For visual you should be able to get away with simply levelling the mount, I always suggest thsi for the hell of it, and then setting the Latitude to your location and then perform a fine adjustment so that Polaris is central in the polar scope. The mount will be about a degree off but should be reasonable.

One aspect is does the mount drive if it is not aligned, I guess it does but not sure. They are now intended to be aligned for goto and I half guess that if not doen they don't always move. They are getting too "intelligent" these days.

DSLR's need the focal plane of the scope to alter. Usually it has to move outwards. If your scope came with the words "Cana ttach a DSLR", that is only half correct. You can attach a DSLR but it will not sit at the focal plane so you do not get sharp images. Sneaky bit of wording.  Also if you move the mirror to move the focal plane then the eyepiece will not work and you will need a short extension tube.

Simple answer i sto use the DSLR and the lens it came with, for now forget the scope. Set the exposure for about 1/100 sec and go click. The moon is bright so you can use a DSLR as "normal" on it. Easier to set manual focus and say 1/100 sec and ISO 400 or 200.

Think bahtinov masks need a bright star not a bright moon.

[tehmac]

Hi all,

Thanks. I did not want to bother with the GOTO tracking etc setting up as I just wanted to quickly look at the Moon through the telescope for 15 minutes then go back inside. I didn't do any sort of polar alignment (though I know how to do this), but I just thought it would have been easier to track it manually than it was. As mentioned, the clutches tended to move the whole thing off position when trying to tighten them. I also couldn't do a polar alignment as there were no stars visible, only the Moon.

Good to know about the Bahtinov Mask. I guess I need to use it on a star first and get focus, then use that focus of the planets. The reason I don't want to trust my eyes is because I can't trust them when I don't have my glasses on. And obviously if it is incorrectly focussed, even though it might look like it to me, the camera will pick up sharp images.

Below was my very first attempt at a shot last night with my DSLR in the scope with only a little sharpening after in photoshop. It came out alright, but I still wasn't happy with how sharp it was when I zoomed in (pre-processing) in photoshop. Could have been a lot better. Plus, when looking in the eyepiece, since it wasn't an extreme close up, seeing sharpness in the craters wasn't as easy for me.

Thanks,
Gary

[MarkyD]

This is the same OTA as I have

1}  You can set a rough polar alignment by using a compass (or smartphone compass) and pointing the mount (not the scope) to north and setting the Lat to roughly what latitude you are at.   If you want to track the moon set the tracking mode on the handset to Lunar and it will roughly follow the moon.  Don't try to follow using the clutches - always use the arrows on the handset

2} You will need an 2" extension for the 28mm to achieve focus

3) A DLSR will focus on this OTA.  Point to a bright star - Arcturus is a good one as it's bright and fairly high up atm - and use the Bahtinov on that.  As said it doesn't work on apparent large object

[Demonperformer]

8 minutes ago, tehmac said:

Below was my very first attempt at a shot last night ... Could have been a lot better.

It's a great deal better than my first attempt to take a photo at the scope. Come to think of it, it's a lot better than many of my subsequent attempts as well ...

Also, many people think that a full moon is the worst phase to try and image it, because the light is falling on it directly, making everything look flat. This time next week you will get much more "depth" with the light hitting it at an angle.

[tehmac]

1 hour ago, MarkyD said:

This is the same OTA as I have

1}  You can set a rough polar alignment by using a compass (or smartphone compass) and pointing the mount (not the scope) to north and setting the Lat to roughly what latitude you are at.   If you want to track the moon set the tracking mode on the handset to Lunar and it will roughly follow the moon.  Don't try to follow using the clutches - always use the arrows on the handset

2} You will need an 2" extension for the 28mm to achieve focus

1). Can you tell me how to use tracking on the SynScan handset? Once it has slewed to a set object, does it begin tracking automatically or do I need to tell it to do so? The manual doesn't specify anything about tracking. It only mentions that you can set Lunar rate etc as you mentioned. Any information on the best way to do all that would be appreciated.

2). I had a rummage in the my equipment box I got with the telescope and I found a 2" eyepiece adapter. It seems to be composed of two pieces that attach. I presume the top bit not labeled as the adapter is the extension tube? What is the purpose of the small mushroom end that would go in first into the focuser?

3). Regarding the DSLR, for the image I took above, I just put the Nikon D50 in Manual mode, tried my best with the telescope focuser to get the Moon in focus when I was looking through the Nikons viewfinder (I don't have live view on the back of it), then messed around with shutter speeds until I got one that was neither too bright nor too dark. Is there any other way to do this that is easier or more effective? I presume once I get the Bahtinov Mask focused on a star, I lock the focuser in position and put the DSLR in and that is the best way to focus in the future i.e. no need to keep manually adjusting it. Just set and forget. I also wasn't sure if I should be trying any other settings on my camera exposure wise or trying to get it to focus on the secondary mirror in someway or something like that. Any tips since I don't have the Making Every Photon Count book yet?

 

[baggywrinkle]

When I lived in WA the Southern Pole Star (Sigma Octans) was a faint beast.

I had an EQ5 then and I used a compass to get a southern pointing and an inclinometer to get the altitude setting.

If you use a piece of wood across the back two legs of the tripod and place the compass on that (at right angles to the wooden batten) then you can nudge the legs around to get a fairly reasonable setting for your North.

I had a long spirit builders spirit level which I used across the back legs, but a batten would do.

Once you have the moon in view just set the tracking to lunar. It should hold the view reasonably well.

[D4N]

Once you polar align mark the ground where the tripod legs are, this will make future sessions quicker to set up.

 

The lack of live view will make focusing harder but not too much so.  Rough focus as you have been doing through the view finder then use the bahnitov mask and take an exposure, zoom in on the preview to see what side of the Stars the line falls on then adjust focus and take another exposure.  You should soon get the knack of this and be able to focus with just a few exposures.

 

When imaging always shoot in RAW, jpg will ruin you images.

 

If you tell your mount to slew to an object it should start tracking automatically.

 

[tehmac]

27 minutes ago, D4N said:

... zoom in on the preview to see what side of the Stars the line falls on ...

 

Can you tell me what you mean by this? Thanks.

[D4N]

When you take a picture it should appear as a preview on the LCD screen, you can then use the cursor button to zoom in.

When the bahnitov mask is in place the will be a cross over the star and unless perfectly focused there will be a line crossing one side of it that you want to centre.