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View Full Version here: : Observing session (highlights and frustrations!)


04Stefan07
16-11-2013, 11:08 PM
I just went outside for about an hour and a half. Saw that the Moon was up and wanted to get some shots. I run Windows XP in Parallels on my Mac using my NexImage 5. As usual when I start to capture I run into problems! Will list below.

Problems:
- My new table is unstable! I need to find out how to make it not shake :lol:
- The stupid iCap software that comes with the NexImage 5 that doesn't work properly! You cannot capture the entire Moon in one single frame (which is fair enough) so I was trying to take video of different sections of the Moon therefore I used the x and y axis to move around. Lined it all up, adjusted my exposure and started to record then all of a sudden it defaults back to the original x and y values?!:mad2: No idea why the hell it does it and thought my camera was stuffed. I then downloaded and installed SharpCap, gave that a go (adjusted my x and y axis) and it worked perfectly! It didn't default to the original settings :). One problem solved!
- Next...my tracking on my computerised mount doesn't seem to track properly. Once I align the Moon and track it, it locates and locks on fine but then slowly you can see the Moon moving out of the picture over 15-20 secs then stops therefore which I need to align the Moon lower then when it stops it should be dead centre. Anyone know why this is happening???
- I accidentally stepped on a snail :(

Highlights:
- Using my brand new Late 2013 October MacBook Pro Retina 13". The battery life on this thing is amazing! It started off with 88%, watched 2 American Pickers episodes on it (90mins) then used Parallels XP capturing video on the NexImage for an hour and a half and they battery is now only down to around 58% (still says I have 5hrs left!).
- A possum scared the crap out of me which made me turn on all the lights. :lol:

Lessons Learnt:
- Using SharpCap over iCap from now on. Just want to run through the program and get familiar with it.

Now hopefully the video I captured is alright and will be processing it.

I am hoping tomorrow morning is nice and clear so I can use my PST!

:D

Camelopardalis
17-11-2013, 11:52 AM
Stefan congrats on the MBP, was looking at them in store the other day and they're beautiful :)

Regarding your tracking, I have a Nexstar also and here's a couple of tips I've picked up along the way...
* Perform either a 2- or 3- star alignment with a high-ish magnification eyepiece (reticle better) to centre/align the stars as accurately as possible. I've had some success with planetary viewing with only a solar system align on the subject, but the Moon is least good for this because it moves so fast
* check your goto approach settings - you want your final goto approach to an object to be the same as the direction of motion of the object to minimise the effects of slackness in the gears. Check in your scope setup that the azimuth goto approach is negative. The best setting for the altitude approach would depend on the balance of your scope - my SCT is back heavy, so I use negative approach
* to minimise the effect of slack in the gears, adjust the object in the view manually with the direction keys depending on the objects real direction of motion... for example, if the object is in the north and east of the meridian then move the object away so that to centre it again you need to move the scope with an up and left motion (note this is actual motion, not through the eyepiece), or down and left for west of the meridian. The left and right will need to be reversed if you want to track an object in the south.

Apologies if you've tried all these already, in which case I'm stumped :sadeyes:

04Stefan07
17-11-2013, 12:05 PM
Thank you for the tips I will try these tonight if it is a clear night :).

I always do a Solar System align because it is easier and quicker than finding stars but I will try a 2/3 star alignment. Once I can get the Moon to lock on and stay with it then I should be able to capture some decent video. If you touch the OTA it does move a bit so even though it is securely tightened underneath the mount still moves a tiny bit.

Mate the MBPR is fantastic. The Read/Write speed of 700MB/s! The early 2013 MBPR got around 350MB/s write and I think 500MB/s read. Has the Haswell processor which OMG lasts forever! As I said below after watching videos and using a VM with XP recording video with the Mac not even initially fully charged I still got half the battery left! A bit pricey but so worth it.

Camelopardalis
17-11-2013, 12:42 PM
For a quick alignment, try Auto 2-star align. You will have to guide it to the first star but once you select the second star it will slew there itself and should get pretty close, and then you just correct it and it's aligned! This should be much better for goto accuracy and tracking as it had a better model of the sky.

Also careful selection of alignment stars can make a difference too...pick the two alignment stars so that they're between 20 and 70 degrees in altitude and around 120 degrees apart (give or take) in azimuth. For tracking solar system objects, pick alignment stars that satisfy these criteria and are in the north.

The SLT mount is not known for its overwhelming robustness, but you should still be able to get some decent results. Have you tried hanging some weight from the spreader? After you've touched the ota the vibration should damp after a few seconds, but I'm not 100% sure as the weight distribution of the 130 newt vs the little SCT is a bit different. I have a Nexstar 6SE/8SE which has a thicker, heavier tripod and even then the lighter ota makes a noticeable difference to its stability. If you're observing on a hard surface that can make things worse too, so I use vibration suppression pads when not on grass.

The ssd in the new Macs is really impressive, I use the last gen (Ivy Bridge) iMac with fusion drive and the machine is very quick and excellent for multitasking, but it's obvious when it's accessing the hard drive :(