Seanelly

6 hours ago, Dave_D said:

The worst thing about having astrophotography as one of your favourite hobbies is being stuck somewhere where you can't do it... stuck in a 1st floor flat in a heavily light polluted area and having weekends almost totally taken up with family, and not having the finances to afford the extortionate rent charges of finding a decent house (at 53, i really doubt i'd get, or be able to afford a mortgage), i've all but given up on imaging

I've been toying with the idea of a remote obsy, where i can store the majority of my gear without having to worry about carting delicate (and heavy) gear up and down stairs and subjecting it to a longish drive.

So, i've been pondering getting in touch with farmers/ land owners round the north cheshire area about renting a small bit of land.

Has anyone here done anything like this?

I feel for you. During the twenty years I've owned my Meade Dob, six of the earlier years were spent with it idling in the bedroom closet because our growing family forced (please don't tell my wife I used the word forced) us to find larger, city accommodations, which were great for the kids, but terrible for my observation needs. I almost gave it up. I can't begin to count the times over those six years my wife said I should just sell it. A 10" Dob takes up a lot of closet space. I'm glad I didn't, as time worked to my advantage.

Finding a place to store/use gear away from a family home sounds so impractical. My totally unsolicited advice would be to store your gear in the bedroom closet (haha) and wait for the Heavens of the future to favour you. Perhaps I'm overstating it, but at 53 you've still got a lot left in the tank, and despite your gloomy (for astrophotos) outlook, you never know what's around the next corner.

6 hours ago, DaveL59 said:

Bigger problem is the swarm? of slugs that seem to come out of nowhere every night and the wee hedgehog has gone walkabout so there seems to be more of them around lately  

Okay, glad (that's not the right word) to hear the slug population is not entirely just on my property.

I've finally succeeded in squeezing ten+ decent hours out of six sessions into this image, with my first NGC showing satisfactory detail, and overall what I think is a pretty picture.

10h 37m of 3m subs, with 75 calibration frames each, from DSS to PS, taken with the modded T6i and gear listed below.

Please, suggestions or comments would be most helpful for this rookie. 

A marvelous image.

No tips, no critiques, just admiration for a job well done.

On 18/06/2019 at 17:54, vlaiv said:

Sorry Rodd for being so harsh on your first processing, but reality is, second one is major improvement (again to my eyes ).

I too preferred the second image without knowing why, and now I do know why.

You've presented this very well.

How do you like the Ioptron mount? I almost bought one to start off my imaging venture with the DSLR, but in the end decided to go with the HEQ5, et al, mainly because of my experience with upgrading my Dobs several times until I was finally satisfied with the 10".

Well, i'all can offer a warm welcome to SGL from one settled North American to another on the go, and can say from experience that this is definitely the place to satisfy your curiosity and any tech problems that may arise with your gear.

This came out very well.

It's been all Messier so far since this fascinating photo-venture began for me 11/18, and I really like the colours in this M29. I had three hours of data to work with, but I found that rather than enhance the object, the total data did little to bring out the cluster and rather washed it out somewhat with the more vivid surrounding star field, so I settled on eighty minutes. This is the first time I've found less to be more, but it's only my impression.

1h 20m of 2m exposures at 800i, taken with the modded T6i and gear listed below, with 50 each of darks, flats and bias from DSS to PS. My PS skills are slowly coming around, I believe.

5 hours ago, toxic said:

its a nice M57 but i think you may have clipped the black just a bit to much but it may just be my monitor 

 

You could be right. I spun together about ten versions and probably went too far on this one. I'm such a fan of this pretty little gem.

Originally a test subject for my guiding issues, I collected about twelve hours of subs on this and thought I'd throw a few hours of the better ones together.

 Total 3h 46m of 3m subs with 50 each of dark, flat and bias with no stretching in PS, only level and contrast, taken with the Canon T6i and gear listed below.

 My goal was to get both central stars noticeable to some degree and some details in the ring, and this at least was accomplished.

4 hours ago, Paul73 said:

Only 10%! Well done. You are truly a man who researches well and has a will of steel! 

I accidentally bought a scope on eBay that is suited to imaging. The Bank balance has been declining steadily ever since. The moral of the tail? Research, read, ask, more research; only then, buy.

Paul 

Originally 10% 'and it continues to grow', haha. 

Six months ago I was in the position that you now find yourself (though without any imaging scope to start off with). For what it's worth, the most important advice I can give you is reflected in some comments above and can be some of the toughest words of advice to follow in the entire process: don't be hasty. Read up on the subject until you are reasonably sure what your priorities are and can fit them into your budget. In my case, even after three months of homework, I fell short of realizing the entire monetary cost of my start-up venture by about 10%, and it continues to grow (there will often be something forgotten and always something out there better than what you have), and entirely disregarded the time and effort imaging entails (loss of sleep, social life revolving around the weather, etc.). I in no way want to dissuade you from this venture, I personally find it extremely rewarding, in part because my efforts to nail down my priorities pre-purchase have left me reasonably happy with my choices. I only wish you the same. Check out the reference book(s) suggested above, and good luck! 

My Meade Starfinder Dob has teflon pad bearings. I use a dry lube teflon spray to ease friction and wear on the tube saddles and base; separate the base and clean it, spray on the teflon pads and the runway, wait until dry (not long, but don't rush it) before reassembly. Been good for me for 20 years.

A very pretty sight.

I'll note this down and take the cover off the mount for a look. This hands-on physical stuff is more my style. From the description and the photo, it looks like the intermediate gear is the one above the one being adjusted? Is the int. gear mesh position adjusted in this way or is this just an example photo to show the gears? If the int. mesh position is adjusted by altering the larger gear position as this photo indicates, should it be adjusted clockwise or other, or might it be either and checking the Analysis section of the Log Viewer will show which way is better? I'd love to get my hands a little dirty here but the more I can narrow down the variables before hand the better, or perhaps there's a tutorial that would explain it thoroughly? (Maybe I should just shut up and Google it.)

Calibration: I set up the parameters again that you mentioned, HFD, minus Star mass detect, and then on a whim rotated the guide camera slightly back and forth in it's mount, and it turns out I cannot always get ideal focus on the stars unless I pull the camera out a few millimeters, which may have been part of the guiding problem, I don't know, though I don't recall in the past selecting stars or having them selected that looked out of focus. Anyway, once I had ideal focus on what I knew were actual stars, Auto select grabbed the first one and away it went no trouble. I'll just have to keep an eye on this procedure in future, maybe make a spacer for the guide camera.

Ya, again, guiding just blew me away. Once I got into that second session and tinkered a bit and saw the results, I sat back and held my breath a while but other than the odd spike or short meander, it kept on beautifully. I captured a couple of screen shots but silly me I can only find the text documents and not the photos, which are probably lurking around with those subs I was looking for earlier, haha.

I'll certainly do my best to return the favour of help to anyone I can.

I'll check out the Canon CD (I didn't know anybody actually looked at the CD's that come with most electronic devices these days). When I am absolutely certain my issues are behind me I will look into the Utilities or try APT or some such to consolidate my sessions, if only for more precise focus, and download the latest PHD2 version, which I hesitated to to jump into until things had settled down. I still hesitate, now that it seems my guiding is where I want it. No rush, at any rate, I'm going to enjoy a few nights of solid imaging without headaches, or without those specific headaches.

I'd hug you without reservation if I could, Michael, but you'll have to settle (whew) for a big thank you.

Canon Utilities, I will look into this. Are you able to get focus with dim stars around your object or must you locate a fairly bright star nearby?

I have seen the tutorial in the link you've supplied, and now that I know more than I did about PHD2 I'll keep it handy to reference, but having initially looked through it a few times it can be intimidating to the uninitiated. I have better aptitude for hands on teaching rather than being supplied off the written page, sort of like being shown rather than being told, if that makes sense, and retain the lessons better this way, which is why I've leaned so heavily on your advice. To which I am stoked to tell you has paid wonderful dividends!

4 hour imaging session last night: Having to rely on a bright star (for now) for focus, and keeping in mind your warning about possible flexing after slewing the heavy DSLR to a distant object afterwards, I went straight from focus (Vega) to M92, a less unpredictable slew than M51, and having applied all the GA suggestions (1s Drift-limiting exp suggested, which was already in use from the pre-GA setting you mentioned to change), I fired off twenty 2m subs of M92, then having M57 clearing the treetops around 11:30P., slewed there and got calibration again, then let the scope really do it's works with 72 3m subs.

Results: Fantastic! Conditions were much better, though seeing was still rated rather poor, and after minor fiddling on a hunch (finally taking some initiative in this), in which I reduced the aggression on changes to Dec and RA to control initial sporadic spiking, guiding was so good it brought tears to my eyes. It only occasionally climbed beyond 1" either way all night. What a difference! I kept creeping out to the laptop as time dragged on (I couldn't help myself and sacrificed some sleep over it) to check and see if the other shoe was going to drop but it remained excellent all night.

Subs came out great, most better than I've ever captured, and I didn't lose a single one of the 20 M92's, all stars pinpoint with no hint of stretching. Out of 72 M57 subs I lost 7, which were only 'bad' when compared to the good ones, which were so crisp and clean the central star showed nicely in each 3m sub, with the occasional hint of the second. Another 8 of these 'good' subs showed minor variations, but again only compared to the excellent ones, and most I will try at least once in a stack to see if the results are better or worse than just the best ones.

PHD2_GuideLog_2019-05-26_220049.txt

I supply the log for you verify the results, and perhaps it may be seen that I've exaggerated somewhat, but I believe not much, as my subs do not lie. I may have seen the improvements from M92 and M57, but I'm over the moon about it all!

I can see...that my gear will never equal the image seen here, which is why I appreciate you sharing this so much!

My opinion is you should find that pin you heard drop and stick with it.

I love that enthusiasm, Greg!

2 hours ago, michael8554 said:

HFD 1.5 might be inappropriate for your setup, I still think it's the best way to avoid autoselecting hot pixels:

"Minimum star HFD' - specifies the minimum half-flux-diameter (roughtly the 'size') of a suitable guide star.  This is probably the best way to prevent PHD2 from mis-identifying clumps of hot pixels as usable guide stars.  You can determine a suitable value for your system by manually selecting some small stars that you know are not just hot pixels, then use the star-profile tool to see the HFD values of those stars.  You'll want to specify a minimum HFD value that allows selection of legitimate faint stars but not hot pixels."

Star Profile is in the Tools menu. A saturated star will have a flat top to the profile, and you'll get a red SAT message on the bottom of the PHD2 window.

 (You can refine your guidescope focus by getting the lowest HFD figure in the Star Profile window as you focus.)

I don't believe you can have too high a snr, but you can have too low, the SNR message at the bottom of the PHD2 window should be green, it goes brown if getting too low.

I noticed the other night you focused on Vega, then slewed over to M51. Remember my concerns over micron moves in your guidecam mount ?

Well  the same applies to your dslr, I always set focus on or near the target because the heavy dslr will sag differently after a slew to a different position. 

Worth doing if you're picky about star shape 🙂

You should continue with your sub rejection process because you are the best judge of what's suitable.

But you should aim to improve your guiding to lower that reject rate.

Michael 

Okay, Michael, I will familiarize myself with HFD settings and guidescope focus to find a value that works for me.

As to focusing on Vega before slewing to M51, I have no choice at present but to focus using the Bhatinov mask on a bright star because even in the 10x DSLR box the cross-hairs and floating focus bar are still quite dim and focus tricky. I've tried the B-mask on dimmer stars around the objects I'll be imaging but they are too dim unless a luckily positioned bright star is nearby. I realize that using APT or similar app (I assume this is how you get focus with your DSLR) to control my sessions is optimal and focusing is easier but I had no problem without it, really, using a digital remote shutter release as I do. I avoided using APT (I already have it on the laptop) right off when I started into imaging this past winter because I wanted to concentrate on the basics and getting things up and running before jumping into another set of parameters. Once I've got things under control here I'll definitely look into setting it up.

Yes, it seems I am at the stage of refining the tools at my disposal to limit bad subs and reduce unwanted egging. Perhaps the new suggestions to be implemented tomorrow night will do the trick!

I like a speeding bandwagon.

12 minutes ago, johninderby said:

I thought Marmite came from scaping out the contents of old engine oil pans. 😺

Not your engine oil pans, I hope, else I'll never buy a used car from you!