rnobleeddy

I'd guess it'd depend on the UHC. The easiest way to compare filters is to ignore the name and look at the chart of wavelength vs transmission %!

Is it the MPCC ii ? I had the same issue with the mark ii, which was fixed by getting a mark iii.

The extreme has to be better - with a narrower band pass you get more of the signal you want. Of course, that may not make a noticeable difference to the final image, but it's bound to be measurable if you compared them side by side with the same sky/equipment.

In terms of ISO, http://dslr-astrophotography.com/iso-values-canon-cameras/ has a solid list of recommendations.

Keep the load as light as possible, balance it as well as possible and ensure the backlash is adjusted as well as possible. Are you intending to guide?

If you've already got the motors then if you can find a second handset I'd start there. Astroboot used to be good for that kind of thing, but Brexit appears to have killed it. The main difference in the the handsets is that the advanced red one allows guiding via an ST4 cable. I thought long and hard about upgrading my un-motorized EQ5 to GoTo but in the end I went with a second hand Skywatcher upgrade kit, because there wasn't anything else that seemed particularly cost effective.

I think you'll find a few opinions but.... - I'd be surprised if light pollution is your issue in Bortle 5. More likely, an unmodded DSLR is better suited to galaxies that nebula due to the fact that a lot of red light is being filtered out. - The narrow band filters work well in areas of high LP but probably best if you don't consider them as just a LP filter. They fundamentally change what you're imaging as you're only capturing 2 emission lines. - For general LP you can also consider something like https://www.firstlightoptics.com/light-pollution-reduction/idas-d2-light-pollution-suppression-filter.html which passes much more light, but tries to remove common pollution sources like street lights. Mainly. I've seen some people add Ha data from galaxies to good effect but always in addition to LRGB or RGB data. As best I can tell, the tri-band label is just a marketing trick, and the dual band is strictly better, but costs more. I know these filters really come in to their own in areas with more LP, so the cheaper tri band would probably produce good results. Ha maps to red. O maps to G/B. So you can get bi-color images. My experience was that the veil nebula produced stunning dual color images using this type of filter, but that most nebulae just ended up red. But the increase in contrast was very noticeable. The red data was far less noisy and much more detailed for the same exposure times. They'd work well with color cameras. I'm not sure I've seen anyone use them with mono cameras. The concept could work, but if you've got a mono camera, you're almost certainly going to use a filter wheel and it'd be much easier to stick with the usual SHO + LRGB filters.

I was about to say the same. With a Ha filter, there will be no signal in G/B, so all that can add is noise.

I was gonna suggest this. It works very well and doesn't limit you to certain products (in as much as it supports everything that Indi supports). Astroberry has most of the same software.

I've used both a baader mpcc mark ii and mark ii with sensors up to and including aps-c and they've performed fine. I'm not the pickiest imager, but I can't see any coma remaining. I know it's used by a few people and I've not heard any particularly bad reviews, but it probably depends how much you stare at the stars in the corners! I heard from someone I purchased a 2nd hand scope from that the aplanatic cc worked well too.

Slightly different take from me. If the OTA has a large enough image circle, a second hand 5D could be a decent option. You could pick up an umodded one for £250 for eBay, although I'd assume that the only reason you're after such a wide field would be for nebulae, and so modding may be essential. To make it viable cost wise, I think you'd need to do the mod yourself, as the full frame sensors tend to command a premium with the modders.

The 1600 is old, but perhaps the 414 is older? Either way as far as I know, the newer CMOS are larger and more expensive. I may be wrong - I just picked a popular model at a comparative prove - so obviously do your research! By real estate I mean the surface are of the chip!

Not sure there's anything better for the price.

New or second hand? It'll be a noticeable upgrade from a DSLR in terms of noise, but also has a much small sensor size. Personally, if I was buying new, I'd go with a cmos from zwo or qhy (such as the zwo asi 1600) as they're cheaper and have more real estate.

I got similar results last night, where as the night before I'd been at 0.4" in RA/DEC. I attributed that to the fact it was rather windy outside. Otherwise the existing advice seems solid. As the issue is in RA I'd try purposefully unbalancing a little. Otherwise I'd be interesting to know if the behavior in consistent across the sky - I realize some level of deviation is normal, but my ageing EQ6 appears to perform quite differently depending on where in the sky it's pointing and the orientation - to the point where guiding is often markedly better one side of a meridian flip.

I don't see this as surprising. Yes, it sucks, but it's not going to change anytime soon. - It's very unlikely there's any collusion. The usual rules of supply and demand apply. There are many equipment manufacturers and many retailers. I may pay a small premium to shop at my preferred retailer(s) but like most people, I'll be lead by price. - The large increases in costs for shipping freight from China is well publicized, as is the issue caused by Brexit. Astroboot was still closed last time I checked. No hobby is immune to covid and the choices the country has made. - eBay tends to be more expensive for new astro stuff, but no one's forcing anyone to buy there. This is true across many markets on ebay. The specific increases in prices recently were almost certainly just the front edge of the prices rises we're now seeing everywhere.

I achieved focus with a dmk21au04 (or very similar model) and a 130PDS. I don't have the camera any longer, but worth posting a picture. I always find it easier to check focus on a distant tree branch or chimney during the day - as it can be hard to find focus on a star in the dark if you have no idea which part of the travel you need to be in.

Lots of this is personal preference, but if cost is a concern, you can definitely get started more cheaply if you're prepared to buy second hand and can wait a while to build up a collection of kit. I actually think a modded 2nd hand DSLR (for <£200) is a superb camera to get started with. To echo other advice, don't be tempted to try to save money on a mount. Some people obtain good results with cheaper mounts, but most of those people know how to tune their mount - for a beginner, get a HEQ5 and you'll do fine! Finally, treat image processing as a first class part of the hobby. I was very excited to capture my first set of data, only to realize I had no idea what to do next. It's a topic in itself, but there are numerous tools, with numerous pros and cons, at various price points. People obtain good results with many of them, but it's worth working out what your priorities are and finding something you're happy with and can spend some time mastering.

I had the color version of this (which in comparison to the mono, receives terrible reviews), but in general - expose for as long as you can, as it has a relatively high read noise, and longer exposures mean that isn't the dominant factor in your noise - flats need to at least 2s to work around the mechanical shutter. For exposures much lower than this the shutter distorts the flat. I've got a very DIY approach to flats, using an old tablet screen, so I just stuck some more A4 paper sheets in front of it to create a dimmer light

+1 for this setup. It's cheap and cheerful but works very well, and I'd be amazed if this was ever the thing that limited guiding performance with the popular affordable mounts.

I got a 250 to try on my EQ6 but I haven't used it yet, and have already decided that it's probably univiable just due to its massive size. I'll give it a go, of course, but don't underestimate the importance of being able to setup with one person and safely carry it through the door.

I found this video very interesting. It suggests the eq3-2 can guide very well, however, I'm not convinced that the tuning service is really cost effective on the lower cost mounts. My advice would be: - try it! Work out how long you can expose for and just stack lots of images - if you aren't guiding consider it. Even if you upgrade later, the guidescope + cam should be transferable

I'd guess the differences are more likely to be felt in skies with worse light pollution. The pass bands on the extreme are much smaller so that must make a difference somewhere!

I'm sure this would work. If it's just for use as a guide scope then I'd certainly consider it overkill - it's unlikely it'll guide any better than a much cheaper guide scope. If you have other uses for it, then it's a probably a good multi-purpose OTA.

Just so when the next person comes here in a few years time and wonders what happened.... I decided that the easiest/most cost effective/most likely to work option was to change coma corrector. Due to covid/brexit, availability wasn't great and I wasn't keen on spending a massive amount of money. I ended up getting a MPCC mark iii as I was happy with the MPCC mark ii in terms it's ability to correct coma. The mark iii is supposed to have better anti-reflective properties but otherwise appears to be similar. The good news is that the issue is much reduced. The bad news is that because I know to look for it, I think it's still there, just much less intense. Or maybe it's just my eyes. Either way, this almost calibrated out before the change, so I'm not too worried about it impacting the final result now. Below are side by side comparisons of single flats taken with exactly the same settings, except for swapping coma corrector, keeping the exact same spacing. Not saying that changing the coma corrector was the only way to fix this - but it has certainly helped. Ha - left mark 3, right mark 2 S - left mark 3, right mark 2