cfpendock

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

Very nicely done, Martin. I think you've got the blue absolutely right, and I like the star colour. Personally, I think I would dial the red back a bit, but really this is an excellent image. Chris

Nicely done for a difficult target. I like the processing, and you've managed to reduce the stars very well. What scope was this? Chris

Keep going and eventually you will get there! I frequently image at 2800mm focal length and although it is true that SCTs do produce rather larger "wooly" stars, this can be overcome with careful setting up and processing. I have found the following helps: Use of an off axis guider - almost essential for long FL work, and you should be able to guide at around 0.25 secs. But in order to achieve this, attention to balance is critical - I usually balance slightly off so the mount is always pushing slightly - I find this helps with overcoming backlash. With my C11, any significant wind ruins everything. As has been pointed out, round stars are no indication of good guiding. When focussing the SCT, I always make sure that I am focussing so that the for the final adjustment the mirror is being pushed upwards ( I do use an auto-focus system), but I find focussing at F10 anyway is not too difficult compared to short focal lengths. To keep the stars from bloating, I always re-layer a less stretched version into the final image as Olly suggests above. It seems to me that your subs are quite short. Do you have a lot of light pollution? I normally have average rural light pollution, but I do use subs of around 5 minutes. For your information, my sampling rate is just over 1"/px using my Atik 4000 and binning 2x2. I stack in DSS and process in Photoshop. My version taken at 2800mm FL is in my album: https://stargazerslounge.com/gallery/image/33396-ngc-891png/. Hope this helps. Chris. (No, seriously!)

Thank you very much, Martin. Your comments always very encouraging! Chris

Thank you very much Hallingskies. Yes, the tracking from my EM200 is pretty good - around 0.3 arcsec, but I take care under-balance slightly so that the mount is always pushing. Yes, I think you are right - the noise reduction is excessive, but because of the light pollution, the image was otherwise horribly blotchy.... But I did cheat on the core by using some selective sharpening which absolutely did not work on the outer areas....I shall try again when I have a moment. It is exactly these kind of comments which I find extremely useful - I get blinded by looking too much at the same thing! So once again, thanks. Chris