David_Scotland

Hi,

Just received my 2600MC to go with my RASA 8, first light was last night and the first couple images (between clouds) produced some promising results. On closer inspection it looks like i may have tilt/backspace/focus issues, one corner has donuts(bottom left), and star trailing top left and right, and bottom right.

I ran the stacked image through CCDI and got the following 2 results. 

So my question is, is this just a tilt issue, will fixing the tilt also fix the curvature, or at least reign it in a bit. I am using a starizona filter holder (with the 5mm spacer) and the RAS8 clear glass removed. I am also using a ZWO EAF for auto-focusing

I am not looking for perfect stars, but the only donuts i like are in ma belly

Any help/advice is appreciated.

Cheers

Dave

Wasn't too happy with the previous image so gathered more data and reprocessed.

468x15second exposures - total integration 1hour 57minutes

4 hours ago, Stargazer33 said:

Nice! Andromeda looks a bit magenta to me. You've controlled the core well in your processing. Nice placement in the frame too. A 0.7x or 0.8x reducer would give you a nice amount of space (do you see what I did there 🙄) around the galaxy. 

Yeah, not enamoured with the processing, going to capture another couple hours and spend some time processing this. For some reason i find galaxy processing hard.

18 minutes ago, assouptro said:

Great images for such short subs! 
what’s your sky like for light Pollution? 
 

cheers 

Bryan 

Bortle 6 normally, there is a petro-chemical plant usually in that direction which burns of excess gas, but no output last night which helped.

Another clear night and some of that astronomical darkness.

Started off with Narrowband imaging, some technical issues later.

17x2m subs for a total integration time of 34 minutes, darks from the library and no flats

IC1396 - Elephant Trunk Nebula

RASA8

Altair 183C Pro

L-Enhance filter

Processed in Pixinsight

When i finsihed the above noticed M31 was in my FOV between the 2 big trees at the bottom of my garden

Managed to get 182 x 15sec for a total integration of 45 minutes, no darks or flats

Same hardware as above, just with an L-Pro instead of the L-Enhance.

Happy with the data, nice and clean. Bit unsure of the processing, i'll need to get more data and re-process. Current image looks a bit washed out

1 minute ago, Lee_P said:

Worth the 4-month wait I'd say!

Was a looooooong 4 months, think the weather gods were being sympathetic, weather during them 4 months was poor, slowly getting upto speed with the scope and mount just in time for astronomical darkness starting at the end of this week

7 minutes ago, peter shah said:

love the colour ....a super shot

Thank you, was a bit unsure that i over saturated the red a bit much and wanted to keep as much of the dark lanes and dust as much as possible,

Hi,

So at the beginning of the year decided to upgrade my setup from a redcat and a dodgy eq5 mount to a RASA 8 and a CGX mount, had to wait 4 months as it was on backorder.

Here is my first real image taken with this scope (have done some test shots to guage exposure times, FOV, etc

This is 2.5 hours with an Altair 183C Pro camera.

Stacked in DSS and processed in Pixinsight

I do have some tilt mainly bottom left and bottom right, hardly noticeable so far as i tend to crop the edges.

Cheers

i see lots of celestron boxes, any rasa 8's and CGX mounts in there?

So again its been awhile since i posted any images, Scottish weather sucks  Had a fair amount of tracking issues also, but a bit of tweaking and hitting my head against a wall, managed to fix it so am now able to guide 10m subs, probably never need 10m subs but at least the mount is working.

First image NGC7000 North American Nebula
45X120sec subs
Darks and Flats from the library
Filter used - L-Enhance

Second image NGC6992 - Eastern Veil Nebula
38X180sec subs
Darks and Flats from the library
Filter used - L-Enhance

Hi,

Couple new targets added to the album.

North American nebula and Eastern Veil nebula, both taken from my spare room as unable to access this portion of the sky from my normal location due to trees, so no polar alignment on these, just a rough guess as to where it is, used stellarium to slew to a bright star, adjusted RA and DEC until centered then slewed to the target.

North American - 40x3m subs, my framing for this was well off, will have to go back and spend some more time on this
Veil Nebula - 65x3m subs, happy with this image, yes the colors are a bit off and processing could be better, but i think this is my best image yet, i look forward to capturing the rest of this nebula before the summer nebulas start coming up from the south.

Clear skies

2 hours ago, DavM said:

How can the Optolong filter affect the darks?

Dave

I have no idea, but whenever i take a dark with the optolong in i get loads of issues, i take it out and no issues at all. I dont think theres an issue with the filter, the above images are testimont to that (if you can see past the crappy processing  )

I am happy that something works, though i would like to understand why darks without the filter work with darks with the filter dont. I have time this week i will attempt to take more darks with the filter in to see if it works.

Dang what a great picture, i can only dream of reaching this level, /runs to delete his crappy pictures before anyone sees them 

Posted these in another section, but probably better in here. Been having issues with processing due to amp glare issues and processing with darks, finally figured out that my system dont like darks with the filter installed.

So with that fixed, pointed my scope to the only nebula within my field of view from my garden. Excuse the poor attemp at processing, still learning that side of things.

Soul Nebula - 42 x 3m subs, gain 400, dark 24

Heart Nebula - 13 x 3m subs, gain 400, dark 24

Both images captured with Redcat 51 with Altair Hypercam 183C Pro Tec with an Optolong L-enhance filter.

Cheers

Okay finally got to the bottom of the problem, for some weird reason it didn't like me taking a dark with the filter installed. Since i got that fixed grabbed a quick couple of images to test.

One of the Soul Nebula and Heart Nebula, only 2 nebulas in my field of view in my garden. Soul was 42x3m subs, heart was 13x3m subs

Not the greatest of images (basically my processing still sucks, still learning), these were processed in APP and touched up in photoshop, apparantly the weather for the rest of the week is sort of promising so going to try for 5-6 hours on the heart to try and bring out more data, plus capture some RGB of the stars

So there is light at the end of the tunnel....

Prior to the Optolong l-enhance i was using a cheap nasty moon and sky glow filter, and when i meant previously, i meant without the dark file attached

So ran the files through DSS and aligned the RGB, before i started, this is what the RGB looks like, doesn't look normal to me

So lined them up saved with adjustments and ran in PS, screen glow is gone, but so is all the color... i did save as a 16bit tiff

So obviously i assume its the dark that is the problem as apart from the screen glow, i had no issues with color previously, albiet some processing was required

Hi,

So managed to capture some data with my new filter after a week of poor weather, filter was great, really pulled out the nebula from the Heart Nebula in relatively short time. When processing through DSS with no calibration frames, i can see the nebula along with the lens glare of my Altair Hypercam 183C. These are stills taking from Sharpcap Livestack.

So i spent all morning making a dark file with the same exposure, temperature, and gain value from last night. When i add this dark file into the stack the red channel does not have a peak no more, see image, cant really explain  No matter what i do, stretch does not bring the red channel over enough to make a difference to the image

This is my first time processing with this filter, am i missing something? Do i process these images any different from normal images, special software, etc.

Cheers

Light pollution is a big part of my query but not just that, my main interest in the night sky is nebula which is why i went for the optolong to focus more on Ha, OIII and Hb. Obviously nebulas are not up all year round, right now is a good example, nebulas are at a preminum and with the dwindling hours at night looking to at least get some galaxies and clusters to add to my image collection, so i suppose my answer would be something that allows me too capture the other stuff in the night sky without having to worry about light pollution too much, i know you can never get rid of it all, but every little helps. The example you gave above is probably more than i would like to spend, just spent 166 on the optolong, so possibly i will look for a little bit cheaper, bout 100-120. Eventually i will be going mono imaging, probably next year or the year after. Will this filter be usuable with mono imaging?

5 minutes ago, RayD said:

The RedCat is a Petzval design so almost certainly adding the filter will mean you need to refocus, but I'd be surprised if it was by enough to cause your issues.

The Optolong L-enhance is a NB filter so not only will you need to select the right targets to see anything (M81 is probably not one of the best) you will also probably need to take much longer subs than you would be without the filter in (this would account for the banding).

I'd try to pick a good emission nebula and try again with a sub of about 2 minutes, then see if you have anything.

Thanks for that, makes sense, due to the clouds and the less than bright stars i was taking short exposures just to test the filter, will increase the exposure length next clear night i get (at a premium at the moment). 

What would you consider a good filter (bortle 6 sky) for non-emission nebulas and galaxies?

5 minutes ago, david_taurus83 said:

Hi Dave. It was me on FB that was saying the filter is in the correct position and you dont need to worry about back spacing on the Redcat. Can you post up a couple of fits files as they come from from the camera? One for the image above with no filter and another one with filter and banding so we can have a look?

Hi Dave,

Thanks for sending me here, fun friendly place

i deleted all the images from the night i tried the filter, more in anger than from anything else, next night i'm out i'll try get some images if what RayD says doesn't work.

So basically bought a filter holder for nothing, oh well at least i can take my filter in and out now without touching the filter too much.

Cheers

I can get focus on my stars, with or without the filter, that is definately not an issue, granted when testing the filter it was partly cloudy and the stars where not as bright as normal, but still woulod have thought sharpcap would have been able to livestack some of them

2" extention long tube (the one that comes packaged with the Hypercam), i have ordered a filter holder for my filter, if this is not the issue then at least i will have an easy way to take the filter in and out.

The image i posted was taken with the exact image train (without the filter) so definately not a focus issue, unless the filter does weird stuff with your focus.

I would test it again but people keep buying astrophotography gear

Cheers for the replies.

Hi,

Captured 60 x 1m subs with the Altair Hypercam 183C and stacked with a previous image taken with my Canon DSLR Rebel S1 (unmoddified), stacked in DSS and processed in Photoshop.

On show, Bodes Galaxy and Cigar Galaxy.

Clear Skies

Welcome to SGL, so i can blame you for the poor skies lately then

Hi,

Any redcat51 users out there that have an optolong l-enhance filter in there image train.

I currently have my filter in my scope, the place where WO suggest, a 2" extension tube, then my camera (Altair Hypercam 183C Protec), so far all i've managed to capture is unstackable images and horizontal banding noise. Without the filter i have no issues capturing images, see below.

My question is, is the filter (2" Optolong L-enhance)  in the correct location in the train, does it need to be close to the camera sensor (as someone on social media had said) and do i need to worry about backfocus as i can easily get focus on the current setup i have.

Kind off at my wits end, in the past i would buy stuff willy nilly and get nowhere, i'm afraid my pockets are starting to get very lean and cant afford just to buy what i think i need anymore, i need results

Cheers

3 minutes ago, Marvin Jenkins said:

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Marv

Sadly i had to put her to sleep 3 years ago due to a brain tumour, i did get 13 completely mad years with her though, luckily she never ate anything in the house, she was too busy sliming everything in the house. Brilliant dogs, i am now the proud owner (companion) of a Rottwieler/German Shephard cross, affectionatly called Kaylar, my 2 previous dogs Kess (west highland terrier), and Seska (the boxer) anyone get the naming convention here?