Uranium235
-
Posts
7,253 -
Joined
-
Last visited
-
Days Won
25
Content Type
Profiles
Forums
Gallery
Events
Blogs
Everything posted by Uranium235
-
Heh heh Im not really a member of an AS, as SGL is the community I known since day 1. I'll be down at the next SGL star party in October if youre coming. This years topic for my processing workshop is likely to be mosaics. But, I digress.... as this thread is supposed to be about the 130pds - so come on, lets see another image folks!
- 4,169 replies
-
- 1
-
-
- skywatcher
- 130
- (and 1 more)
-
Not always mate, there are plenty of occasions where its just a misty patch with the exception of the Veil, crescent, M42 and a few others (where there are definite separate structures), other common targets have a good 90% of its structure in Ha (IC1396 for example), so OIII isnt really buying you that much in terms of detail. Same deal for Sadr region, and countless other Sharpless objects where Ha dominates. Horses for courses And its highly doubtful that anyone would notice minor OIII structures that are missing in a Ha rich image.... its an approach Ive used for years, and not once has someone stopped me to say... "hang about, theres a bit missing!" - but that has been when Ive imaged OIII at the same FL as the Ha, not sure I'd get away with it if resizing an OIII layer to nearly 300% its original size.
-
hmmm, thats got me thinking..... I wonder if I could use the Star71+DSLR at the same time as the 200pds (in Ha) to collect OIII data. Its not like you need a super clean OIII image becuase all youre looking for is a misty patch of OIII with no structure. All of the structure and detail would come from the Ha layer. Though it would probably need to be rescaled to death... 350mm and 1000mm is quite a focal length difference!
-
Thats good, and its confirmed my suspicions that a DSLR would operate on two portions of the bayer matirx in OIII. I just never got around to trying it myself! (as I soley use the DSLR for RGB infilling of CCD luminance data now). lol... and youre probably just up the road from me I guess it aint too bad around here, I've lived in worse places for LP.
- 4,169 replies
-
- 1
-
-
- skywatcher
- 130
- (and 1 more)
-
Missed this one.... and for only your first proper outing... a good result. Good corners, but... the background is clipped slightly. If you are using photoshop, try to ensure the back point starts at about 15 on the histogram - ie: avoid having it hard left, and leave a bit of a gap. You can shave small values off, but you cant put it back a bit like having your hair cut (if you have any!).
- 4,169 replies
-
- 2
-
-
- skywatcher
- 130
- (and 1 more)
-
Its as expensive as you want to make it Steve But the basis for a good setup is firstly the mount, you could start with the EQ5 or AVX but that would limit your future options should you ever want to get a larger or heavier telescope. So with that in mind, I would suggest an HEQ5. Next, you would need some autoguiding - a simple setup like a 9x50 finder with a guidecam attached (QHY5) would be perfect for that telescope. After that, you can either stick with your current camera - or take the leap into CCD imaging.... which is like stepping out of reliant robin and getting into a formula one car But having said that, StamosP is getting some great images with his DSLR.... very impressive. Also you may want to get an LP filter, especially if living in London (which is pretty much LP hell). Eventually, you can move to narrowband imaging and bypass the LP altogether by shooting in glorious Ha with a CCD.
- 4,169 replies
-
- 1
-
-
- skywatcher
- 130
- (and 1 more)
-
Welcome aboard! In regard to the NB filters, if you are only using a DSLR then just get the Ha - as the DSLR isnt really the camera of choice for for bicolour (or hubble format) narrowband work... not unless its been modified and had its bayer matrix removed (a very difficult job indeed!). Im guessing Jordan must have some pretty dark places, so you will be able to take full advantage of the lack of LP and kick out some really good RGB images.
- 4,169 replies
-
- 2
-
-
- skywatcher
- 130
- (and 1 more)
-
Now thats the milliion dollar question! It depends on how much you can afford, and what pixel size and resolution you want to work with. Also, you will need a guidescope that is up to the task - possibly an ST80 or a barlowed finderguider.
-
If you already have the Edge, and a mount capable of supporting it - then your next step is a CCD. You wont be doing big targets with it, but you can concentrate on the smaller galaxies or PN's.
-
Its pretty easy to test the colour correction properties of both correctors by placing a b-mask on the scope, focusing in Ha - then flicking the FW round to OIII. The SW corrector gives a noticeable shift in the diffraction pattern, while with the Baader it is a lot less (in fact it barely moves).... so much less in fact that I normally didnt bother refocusing between filters when using the Baader.
- 4,169 replies
-
- 1
-
-
- skywatcher
- 130
- (and 1 more)
-
Getting bored of no darkness and loads of rain.
-
Guiding tonite!
-
AstroImageJ tutorial and macros
Uranium235 replied to Astrofriend's topic in Imaging - Image Processing, Help and Techniques
Thanks for taking a look at this. The above image is just under 9MP (8300 camera, which is 16bit), but ive used it on images that are ~60MP+ (3x3 mosaic), and Im using the 64bit version of AIJ. When you zoom out to view the whole image, the labels remain the same size (and so look too big). Whats needed is a way to save it all off as a TIFF (or id be happy with a jpg), while keeping the object labels the same size as they would look when the image is viewed at pixel scale (100%). ie: the lable font size needs to scale in relation to the image zoom setting, so if you zoom out to something like 20% - the text follows suit and becomes quite small. Or alternitavely, when using the option to save the current view - instead of saving just what is displayed, it also saves was isnt currently being rendered (the rest of the image, plus its overlay). I'll take a look at the overlay options next time im at the PC. -
AstroImageJ tutorial and macros
Uranium235 replied to Astrofriend's topic in Imaging - Image Processing, Help and Techniques
Ive been using AIJ for a while to WCS solve and annotate images via SIMBAD, its only downfall is that you have to save the image off in chunks (if its large) and stitch them back together in order to keep the object labels uncluttered. This image had to be saved off in 24 chunks before stitching back together with ICE: If you could write a function that would avoid me having to save off in so many bits, that would be incredibly useful for a lot of people as it would provide a free alternative to much more expensive options like PI. -
Looks clear.... but it aint really. No good for imaging anyway!
-
Firstly, dont use brushes! If you can use a rocket blower to dislodge them, give it try. But unless the secondary is absolutely filthy its probably best left alone.... however, cleaning it would require you to remove the secondary and clean it properly using warm water with a drop of washing up liquid in it. Use cotton balls (like make-up removal ones) soaked in the warm water, and lightly drag them across the mirror surface - using fresh one for each pass. When satisfied, rinse the surface with distilled or de-ionised (distilled is better) water from a squirty bottle (I use a new, unused sports drinks bottle for that).
-
Maybe.. just maybe, the sky will improve enough to get out tonite (looking a little fuzzy @ the mo)
-
Hope you got the chance old chap! Forecast here was clear from 10pm to 7am.... shame the sky didn't agree. Not too disappointed as the moon was bright and there are so few hours of real darkness these days... think I might have to retire for a month or two from imaging and practice my processing... and maybe get a scope for visual to pass the time! :-)
-
-
-
The 150 secondary is midway between the two, so youre correct in your thinking. I think the main issue would be the amount of obstruction involved and whether it has an impact on the image quality. An alternative is to keep the existing secondary and lower the height of the focuser, but that also involves either moving the primary back and/or moving the spider foward so the focus point is shifted inwards.
-
I got it im my 10x50's about 4pm, pretty small... but definitely there!
-
I spent yesterday afternoon making a baader solarfilm filter for my 10x50's..... works quite well! Just given it a test drive and it can make out a sunspot, the only downside is there being a bit of CA on the edges of the sun - which is to be expected since theyre quite an old pair of Prinz 10x50's.
-
In that case it would be easier to move the vanes forward. Its difficult to tell if its been a success until you get it out under the stars to see what effect it has had.
-
The only way I can think of is to move your spider vanes forward a little, but I cant imagine there being much room to do that.
