beka

On 29/10/2020 at 16:06, Pixies said:

Hi,

The 114 AZ is a Bird-Jones design, with a focal length (1000mm) longer than the actual tube itself. This is achieved by using a spherical (not parabolic) mirror and an associated correcting lens placed in the focuser.

This means that the collimation process is much harder - but correspondingly, precise collimation is not as essential with a spherical mirror.

However, as it effectively already has a barlow lens installed, I'd avoid investing in a new one (or using the one supplied).

I agree with @jonathan's suggestion of BST Starguiders or Celestron/SW plossls. If you ever upgrade your scope, you can take these with you.

Hi All,

I have used the NexStar 114 which is also a Bird-Jones 1000mm FL 114mm diameter scope and it seems the collimation is critical for getting a good image. Though the primary is spherical it has a short focal length and my guess is that there is a lot of off axis aberration - so the mirror has to be aligned to the lens in the draw tube.

Best

Hi PATRIOT SKYNET,

Your scope is not the most ideal for planets. You will have to use your highest power eyepieces to get good views of the planets and you should be able to see some detail on Mars, Jupiter and Saturn when the conditions are favorable. Uranus and Neptune will be tiny disks with no detail and you would be lucky to see Pluto at all. However you will have to learn how to collimate the scope to get the best views as this instrument is quite sensitive to misalignment. It is an excellent scope for wide field low power views of star clusters and the Milky Way so I would suggest you try this aspect of as astronomy which you may find to be very interesting. The kit eyepieces (assuming they are from the Celestron kit) are not really too bad. I used them for a long time before purchasing better quality eyepieces. The 6mm and 8mm may be difficult to use because of there low exit pupil so I suggest you use the longer focal length ones with the barlow. You can buy better eyepieces later if you decide you want to get more serious with the hobby.

Best!

On 18/10/2020 at 19:17, Silent Running said:

Hi, Geetings from Saudi Arabia. I just came across your post. Did you ever go ahead with the Pyxis LE field rotator?

Hi Silent Running, no I didn't get the field derotator. So far I have just taken short up to 30 second exposures and stacked them with the software doing the derotation. I would like to hear from someone who as experience with the device to know how practical and easy it will be to use.

Best

On 18/10/2020 at 19:22, andrew s said:

I have one I use for setting PA but not field derotation.  It works well. If you have a specific question I may be able to help.

Regards Andrew 

Hi Silent Running, no I didn't get the field derotator. So far I have just taken short up to 30 second exposures and stacked them with the software doing the derotation. I would like to hear from someone who as experience with the device to know how practical and easy it will be to use.

Best

Meant to quote Silent Running's post...

On 16/10/2020 at 20:52, beka said:

O

Yes same on my phone, but it did not seem so on my laptop. I will try to improve them.

Well now I can see that while the colors on my laptop are faded as compared to my Samsung phone, they actually do appear pink here as well. I adjusted the color curves with Gimp and I think they are improved.

O

2 hours ago, tooth_dr said:

Nice images, well done.  Both have a pinkish/orange tone on my screen, how do you see them?

Yes same on my phone, but it did not seem so on my laptop. I will try to improve them.

I played with the curves for Saturn a little in Gimp to bring out the cloud bands. I think the Encke gap is not a processing artifact - I believe that I had seen it visually at 400X some time back. 

Best!

Hi All,

I took the following images of Jupiter and Saturn with my CPC 1100 scope and my NexImage planetary imager (old no. 93712 640 x 480 model). Seeing was generally bad with the planet dancing all over the place but there were brief sharp moments. I took about 10000 frames at 15 fps. using oacapture.  When I first tried to stack using AS!3 (AutoStakkert 3) using Wine on Linux, I found that it would not open compressed AVI files so after some Google searches and reading through forums, I found that I could use ffmpeg to convert the AVI file to a series of jpg images. Unfortunately AS!3 crashed when I tried opening maybe 100 or so images, but I later found I could convert the compressed AVI to uncompressed AVI which it opened and stacked (with basically just the default settings and about 25% of the frames) without problems, I deconvoluted with rawtherapee ,and finally used the unsharp mask of Gimp a little. While I am not unhappy with the results I think I could have done better had I used my Bahtinov mask for focusing and initially captured to an uncompressed AVI.

Thanks for looking!

Deciding to take another crack at planetary imaging since my last and only attempt about 7 years ago, I started setting up my CPC 1100 on the 5th floor deck of a childhood friends hospital building. He helped me carry it up a couple of flights of stairs and to place the OTA assembly on the tripod. While he curiously looked at his reflection through the corrector plate, worrying me with the prospect of a nose print, I collected the accessories I needed to start the imaging session. My friend who was in the meantime fumbling around with something on the deck, found a signboard thing which he happily declared would be his next canvas (he paints on all kinds of things) and went downstairs leaving me alone with the scope. I soon found that the power extension cord was too short and would not allow me to connect the power adapter - so I did a very foolish thing. I tried to lift the scope tripod on all supported by my body and decided it was doable. I slowly moved along the deck to place the scope nearer the power outlet... and then disaster! The azimuth clutch being loose, the OTA swung around and hit me on my left brow. I staggered thinking that was the end of my telescope but I somehow managed to maintain my balance and placed the scope down safely. I put my hand to the place where I had been struck by the OTA and it came away bloody. Looking in a mirror I was alarmed to see the left side of my face covered in blood. I washed my face and saw that luckily I just had a tiny superficial cut just below my left brow. I pressed some tissue to it and it stopped bleeding in a few minutes, and I continued setting up and imaging for a couple of hours. Recently someone asked on this forum about how manageable a CPC 1100 was to handle and I posted that I managed to set it up alone which was the case most of the time, but I have to admit it is was not the best advice. In the end I was not unhappy with the results which I will post in the imaging section.

Thanks for reading!

Hi NovaeSci,

I am enrolled currently in the UCLAN BSc course. I would agree that it is excellent and challenging (the latter maybe because I am a MD). I can't say how well it will prepare you for the MSc and PhD levels. Regarding math you will need something a bit more than IGCSE level - some basic calculus is required even for the level one courses. If you wish to get the degree in a reasonable time you will need to do two or three courses a year. Part time I have found two courses a year my limit. 

Best

Hi George Jones, 

I am of similar height and weight to yourself and 52 years old. I just about manage to assemble the CPC 1100 on my own. I keep it on the tripod in the house, to use it I take the OTA assembly off the tripod and place it on a waist high table. Then take the tripod out, then come back in for the OTA assembly. It is fiddly placing the OTA back on the tripod outside but manageable.

Best

Hi Tharsus55,

You need an  Celestron SCT T-Adapter and a Canon T-Ring or equivalents. You will not need spacers or extentions. If you don't already have it a Focal Reducer/Field Flattener  would be useful.

Best

On 16/05/2020 at 02:25, Star101 said:

OK, After a great debate and discussion with folks here and with myself...yes, I do think to myself....Not yet started talking...but who knows

Tonight, after a lot of thought, calculations and procrastination. and Knowing Olly is right. Thanks Olly and sorry. .I, could not let it go, went against advice and pulled the trigger on the 16" RC. with FR, Expected ETA Mid June...perfect for those summer nights lol. Expect lots of clouds, in the UK, for at least 3 months.

At least I will have something to look at when drinking my beer 🍻 Thanks to all and Cheers

Congrats on your decision.

I am at about 2300m altitude and judging from the discussions on this forum the seeing at my location seems to be better than most folks in UK have, so I am in favor of larger apertures and pushing my equipment to get the best resolution and to pull in the faintest objects. While by no means scientific I tried to look at images I had done with a Canon D700  (30sec subs) on Celestron 102SLT and C11 scopes to compare to faintest stars captured and it was 15.95 and 17.95 mags respectively - which also appears to align roughly with theory.

On the exoplant observing, this reference A Practical Guide to Exoplanet Observing basically says that size matters - fainter and therefore more stars will be observable. 

All the Best!

On 19/04/2020 at 17:04, Star101 said:

My reason for this thread is due to looking for a better scope to help capture the smaller distant galaxies that don't get much attention. Talking it through, its looking like the UK is not the best place to do this....but then again, the UK is not the best place for AP anyway.  So, it is what it is! lol.  I'm still on the fence, trying to find the best solution. 

I have scopes and cameras, so its not urgent. I am still looking at mid August to purchase a new scope and probably a new camera to go with it.

Olly and others have put a good case up for why I should chose an APO. But I still like the idea of a 16" CR Truss. 

 

If it maybe interests you now or in the future you can also do serious science with the 16" like exoplanet transits... 

Hi All,

My two cents, the larger aperture should capture fainter point sources like stars regardless of seeing - so for example clusters will be better the larger the aperture. Although I have not tried it there is also deep sky lucky imaging where the resolution of the larger aperture will be an advantage. I guess it depends how much imaging of these kinds of objects are of interest to you.

Best.

14 hours ago, Mike JW said:

 

...Using the 15" Dob means I get a result very quickly - in about 6 x 5 sec stack or quicker. This shot I used a stack of 7 seconds...

 

Very interesting shots, what was your camera?

Best

Hi Science562h,

Nice widefield image and thanks for the tips. Feels like a lifetime is required to learn and try the different features and options available in all the software packages! So what exactly does the "Pick all black points for all channels" option do to the image. Maybe one trade off is between an aesthetically pleasing image versus one in which you try not to lose any detail.

Best

44 minutes ago, alacant said:

Hi

Lovely shot. I like it.

Are you sure that you correctly produced a master flat frame? If you did then each light frame would have the master flat frame removed. Only then (after Siril's pre-processing) should you register -where the rotation is done- the -now flat corrected- frames. Remember also that the master bias should be removed from the flat frames before they are stacked.

Cheers and HTH

I had a master flat from some time back and it seemed to work correctly for a picture of the lagoon Lagoon Nebula I had posted then. I used the workflow on Siril so I imagine it applied the master flat to each light before the stacking and derotation. I did not take any bias or dark frames but that should probably be the next step. Another question that came to mind is, do I have to match the ISO setting on the camera for the flats and lights. If this is the case I have to do another set of flats.

Thanks for the tips.

Hi baggywrinkle,

Nice pictures. The one of Andromeda shows a number of small trails when viewed at full size. Are they all satellite trails - maybe Starlink?

Best

On 27/01/2020 at 15:01, Science562h said:

Where's the color, did you desaturate & loose it? That's good data. I did 100 lights x 30 sec & 10 darks. 

 

I stretched and adjusted curves separately for each channel then my mistake was to just merge down the layers for each color channel in Gimp.  Here is a version where I recomposed properly I hope - but it brought our the chromatic aberration in the stars. I am still kind of a novice when it comes to astrophotography and processing. I prefer this version because it has some color and the central bulge looks more natural, as does M32.

Cheers.

7 hours ago, wimvb said:

Very nice. You still have very dark corners. Did the flats do their job properly? 

Maybe the flats didn't work but I am thinking it might be due to the derotation that Siril does resulting in the corners not stacking. You can see some of this in the lower left though I tried to crop it out.

Hi BiggarDigger,

You must have a seriously dark sky. What would you estimate you naked eye limiting magnitude to be?

Best

Hi All, 

Was just thinking that it should not be that hard to put a Nasmyth focus on some of the bigger alt-az mounted SCT's.  It would have the advantage of have a fixed viewing height and you could say, have one side for visual and the other for astrophotography with a flip mirror. I imagine some would not mind the additional cost - considering that people are buying the Celestron RASA's. Any ideas?

Cheers

Hi george7378,

While doing lot of subs, hours of processing and expensive gear will of course get you better images, I am also in favor of doing quick imaging like these you have done because you do get to "see" things you wouldn't at the eyepiece and you also have some  record of your observing sessions.

Best

Hi All,

Having had to move to an apartment where I could not use my CPC 1100, I decided that I have to see what I could do with my NexStar SLT 102 (alt-az achromatic 102mm f6.47 refractor). Setting up on my narrow balcony was challenging and the altitude bearing was so loose that it almost moved from the weight of the Canon 700D. I could not see M31 in the estimated 3.5 magnitude sky so I did a two star alignment and used the live-view to focus on a bright star. I then took a 15 second exposure after slewing to M31 which allowed me to see that I had it in the field of view. After a few more 15 second exposures and playing with the motion controls I managed to get it centered. The resulting picture is from 39 subs of 30 seconds at ISO 1600, 9 flats. The images were stacked and stretched with Siril and then I played with the curves on Gimp, cropped and scaled. Not too unhappy.