pushrod

On ‎19‎/‎12‎/‎2017 at 13:14, Galen Gilmore said:

Anybody know what is causing these pacman shaped stars in my images? They always go the same direction, not increasing towards the outside.

I can't really see the image too well. Is it a constant or occasional problem? Things to check might be collimation and focus; also are you getting any 'clicking' sounds from your mount - it could be that a gear is jumping, particularly if your mount is heavily loaded or  the worm spindles needs regreasing or your rig is not very well balanced.

If you have the slow motion controls for your eq5 check that they turn easily when your imaging set up is all in place.

8 minutes ago, mikey2000 said:

 

pushrod - It looks good for a one-shot.  The darkening towards the edges could be fixed with flat files.  If you dare go back to stacking try 'DSS' then use a cheap bit of software called Startools to get the most out of the pic.  As ever, expect a bit of a learning curve but Startools is definitely simpler than PixInsight (my free pixinsight trial ran out before I understood anything at all.  The startools trial in time-unlimited but you can't save the end result except for by screengrabbing)

Hi Mikey, I am ok with DSS it is the post processing that used to get me a bit cheesed off. Yes i would agree that the vigneting should be fixed and i have never really got to grips with flats when i have stacked - usually just sticking with lights, darks and biases. The unlimited time of star tools sounds interesting - i might just give that a go

On ‎17‎/‎12‎/‎2017 at 12:47, Peco4321 said:

My latest Pleiades, 60 x 50 sec ISO 1600 darks and bias. New year resolution is to master the art of flats!!

Hi Peter, Newbie on this forum but have been messing with AP for a year or two and was interestingly reading this thread as i image with an EQ3 synscan when i came upon your image - and thought how similar it is to my recent attempt but from a totally different approach. Recently i have given up on stacking images and just gone for single long exposures - this is a  SINGLE 407s exposure, 130 pds scope with CC through a modded dslr with a cls ccd clip filter fitted, guided with phd, and then about 30seconds worth of tweeking of the raw image in an old adobe elements. I got a bit fed up trying to learn pixinsight(trial) and gimp as i'm not the quickest learner on a computer!

I would be very interested to hear what people think of my attempt - criticism gladly accepted

Took the focuser apart today, small hands are definitely useful when reassembling so you can hold the 2 furthest back  internal nuts  in place without having to dis-assemble the spider. 

Took the chance to inspect the Crayford mechanism and regrease the ball bearings in the focuser. Looks a very straightforward job to shorten the tube and the only tools needed to take it all apart are a good set of fine metric allen/hex keys and a phillips screwdriver. A junior hacksaw should be more than capable of cutting the tube. Looks like 3cm could easily come off the internal side of the focuser tube without any affect at all on the mechanism.

I have reassembled it and will mark the protruding tube with a felt pen when focused, (with CC in place) with my camera and a variety of lenses so that i don't cut too much off! If you are ever going to use it without a coma corrector i suspect you will need to leave more tube but then without a CC the projecting tube is less of an issue anyway.

When i do it, hopefully in a day or two, i will take the opportunity paint the remaining tube black as its present silver colour could contribute to stray reflections.

This single cropped image of Alnitak in Orion shows the issue i am trying to avoid in about the 9 o'clock position on the star  

Hi, apologies as have only read the first 17 pages ! of this amazing thread . I have a 130 pds , with the skywatcher CC and am looking to shorten the focusing tube  - at focus so much of it protrudes inside the tube that images of bright stars really show a lop sided effect. It is mentioned a few times up to page 17 but no details are given. Is it discussed in detail anywhere? Are there any problems/pitfalls/special precautions needed/disadvantages in doing this. Anyone got a pic of their shortened focuser? How much was considered safe to cut off? Many thanks in anticipation