cfpendock

It certainly does make a difference. Quite noticeable. There is still some noise from somewhere though. I don't know if PI has a noise reduction feature which you can use selectively? It does also seem to me that the noise has a definite green tinge. These are highly critical comments, by the way, and aren't meant to detract from what is actually a fine image. Chris

Nice tight stars, and nice framing. I agree with you about the "noise". Does uploading as a .png file help? Chris

Good one. It's not so easy, this one.... Chris

I think that I have made the error of assuming that all CPC1100 s have mirror locks. Mine is an Edge, and came fitted with mirror locks. On my CPC1100 there are three knobs on the rear. One of these is for focussing. The other two are mirror locks. I focus through the visual back, so that I don't need to unlock the mirror during an imaging session. I also bin 2 x 2, and sometimes for RGB even 3 x 3 - otherwise the sampling rates become ridiculous - especially for the UK.. But to capture the image in your post without mirror locks....Well, I take my hat off to you! Chris

I think you may be right. I find that blue is more usually more of a problem with a refractor so I was surprised to see your blue from the C11. The mirror on my C11 is always locked and I use a visual back for imaging (and focussing). This completely removes any problem of mirror movement. I cannot afford a focal reducer, so I am actually quite jealous! Have you tried imaging at f10? Need to watch out for any wind.... Nevertheless, you have produced a fine image. Chris

This seems to me to be an excellent image of what I find to be a pretty tricky target. Chris

Nice one, Bob. A touch of blue on the topside of the stars? I like these images of far away places. Chris

Like Richie092 above, I use a Lakeside motor. This works very well for me on my C11. I presume you are intending your set-up for astrophotography, in which case the Pegasus system sounds ideal. I also presume that your C11 has a "visual back" - so that you don't move the mirror when focussing. I use a Moonlite focuser fitted to a visual back, and I keep the mirror locked. It works a treat. Chris

Hmmm.....Dangerous talk. But an absolutely stunning image in all respects. This has got to be as good as it gets. Chris

Very nice. I like the colours. I also have a sneaky suspicion that you quite like Taks. Chris

Well, I see no one else has answered your questions, so I will suggest one or two things based on my experience. 1. A. - You certainly won't need a guide camera for visual. Provided that the mount is reasonably polar aligned, then it should have absolutely no problem in following any target. B. - From memory, these screws are different lengths. Be very careful to use screws that will not interfere with the mirror mounting, but yes, you can use the screws to mount accessories. Normally, if the accessories have been purchased specifically for this model of scope, then appropriate screws and instructions should be provided. C. - See A above. D. - I would certainly use the manual focuser for visual - at least until you are very familiar with how the focuser works. Visual and photographic use of this scope are very different. For example, you will almost certainly want to use a "visual back" attachment for photography. E. No idea. F. No idea 2. - The setup for visual and photography are so different, that personally I would not even consider a quick change-over. For me, it would be reasonably quick to revert to visual, but then to reset everything for photography would take me several hours - recalibrating focuser, re-aligning target etc etc etc.. Doesn't mean it can't be done....... Chris

I would be very surprised if they were. My image is comprised of 16 combined Luminance exposures each of 300 seconds, i.e. a total exposure time of 80 minutes. And even then, the quasars are only just visible. Eyes just don't work like that. Chris

I agree with Martin regarding imaging time and star colour. It may be my screen, but it seems to me that both images have a slight green tint???? I also agree that Craig Stark's paper illustrates very well the effect of signal to noise ratio. In very simple terms, I always assume that this S/N ratio increases roughly according the square of of the image time, i.e. 4x image time gives 2x signal to noise. I know it is not 100% correct, but it works for me. So it is a law of diminishing returns. 16 x 300 seconds exposures will be twice as good as 8 x 300 seconds. But to get twice as good as 16 exposures, I need 32 exposures, and frankly this can sometimes take too much time for me. I choose the individual exposure time based on the longest time I can get a reasonable image with my sky conditions, and this is around 300 seconds for my colour Baader filters. Longer exposure times tend to saturate some stars and picks up too much sky background "noise", and shorter exposure times sometimes doesn't appear to do justice to some of the fainter things. Having said that, there is a good argument that twice as many exposures at half the time give good results. However, I think that other sources of noise from the camera etc become too great. Confused? Me too.... Chris

Thanks, Steve. I know, obviously it was the excitement of actually being able to see the quasars. And to think that those photons started out on their jouney so many billions of years ago, eventually finding their way to my village, my telescope, and then landing on my camera sensor. Makes you appreciate the enormous power of these things. One day I will finish the image of NGC 1073, although it is rather small - somewhat less than 5' of arc, but weather etc..... But pretty incredible all the same, for the reasons I gave above. Chris

I did try the Hubble test from April 2015 using my C1100 setup, but without success. However, last year I did start a project on NGC1073, and in the attached (very heavily cropped) image I reckon that I have captured three quasars. I find it almost impossible to ascertain their distance, but from various research papers, their distances range from 6 to 15 billion lightyears (15 billion lightyears equating to around 10.3 billion years in time because of the expanding universe.) Perhaps someone could enlighten me further??? But as Nicola Hannah Butterfield pointed out above, those smudges of light really do have a wow factor - for me, anyway....... Chris

I would have a look at some sort of dew protection. I see that you have already considered a dew shield, but I would also consider an electric heater tape. Also, if you eventually go down the astrophotography route, then a "visual back" adapter is useful. Chris

What does EEVA mean? According to Google it is something to do with embryo viability. Are you sure you have the right forum? Chris

I use one of these. Works a treat although it doesn't have a heater, but costs next to nothing..... https://www.amazon.co.uk/gp/product/B07CP2GX9P/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 Chris

Nice job for a difficult target. Chris

On the other hand, I find this eminently transportable: Chris

I bought a CPC 1100 Edge. It was very heavy, and although it is superb for visual, eventually I wanted to do some astrophotography. So I took it off the mount to make it into an OTA. It is now much more manageable, and I use it mounted onto an EQ mount. In this way, it remains a first class visual scope, but even in my amateurish hands, it can produce the goods for photography - you can see what it can do in some of the images in my album - https://stargazerslounge.com/gallery/album/2996-dso/ . Some of the images were taken with my Tak 106, but the others all with the Edge. So in my opinion, better to get an OTA only - it is much easier to handle, and one day you might want to do some astrophotography. For ease of use, unless you are comfortable with an EQ mount, perhaps get an alt-az mount, and change this when you want. But for astrophotography, don't even think of using a wedge...... Chris

Very very nice. Chris

Very nice. I like these kind of images. What are the spikes on the two bright stars in the last image caused by? Chris

As others have indicated, the Celestron is pretty good for visual - i.e. moon, planets, clusters etc. But for astrophotography, in the long run, it seems to me that a Porsche will be far less expensive, and nothing like the hassle - unless you like that of course..... Chris

I think that this is a very good image, although I'm not sure from where you found the time with clear skies. I like the OIII very much - certainly well worth the 11 hours! Chris