Clarkey

21 minutes ago, Dan_Paris said:

It is the Newton fault, but rather the filter fault, or a a shared responsibility between the filter and the corrector

I was not really suggesting it was down to the newtonian (other than the fast optics). The reflection was between the coma corrector and the filter as far as I could tell. It was just another reason why I gave up on the scope - ever mounting costs. I think a newtonian design that is intended for imaging is not a bad proposition - hence my comment about looking at the Sharpstar hyperbolics. I actually got some good images from it - and pretty quickly. However, I spent a lot of time in processing removing halos. Eventually, I just decided it was too much work and I would look at other options. If I had the OSC camera at the time it may have changed my mind, as the filter reflections would no longer be a problem.

On 25/08/2023 at 18:01, Simon Pepper said:

but for the price of say a SW quattro at F3.45 will be fast enough I believe.

I can't comment on the Quattro specifically, but I did get a 6" f4 TS Photon - mainly for the speed. However, by the time I had brought a new focuser and decent coma corrector it ended up costing me near to £1000. Also, I got horrendous reflections from the OIII and Ha filter and which were a nightmare to remove. See below for the worse version - this is Ha only. (I could have brought new filters but this would have added another £1000). I ended up selling the extra's and now have a redundant f4 scope. I guess the buy cheap, buy twice is correct in this case. For now, I have gone back to refractors and the RC8. I would like a RASA when funds permit (or possibly the F2.8 Sharpstar) - but that may be a while. 

On 26/08/2023 at 13:19, iwols said:

Indeed the 23911 was the new antlia filters luckily 😁

I assume this is the 3nm version - I am looking at these myself. What was the old filter?

My phone refuses to work at all with the Starsense app, despite being on the 'approved' list. Not sure if it focus or anything else. It has never plate solved, just keeps saying it is unable to locate it's position. Looking at the screen I cannot see any stars. Shame as it is the only reason I bought it. I certainly did not need an 80mm achro. Unfortunately, I modded the mount to work on a standard finder bracket so I can't even return it....

Is this not the same principle as night vision kit (and other similar sensors). Very high gain but very noisy. I remember covering this at college 30 years ago. Not sure how it would affect well depth and bit depth though.

@iwols C'mon - time to let on......

My earlier comment was assuming the scope was a 200P, not a PDS. If it is a PDS version, then working with the scope you have is obviously a sensible option. However, for the 1000mm FL you will really need to guide for longer exposures which will be an additional cost and complication. Starting with the smaller scope, although an additional cost, might save a lot of pain in the long run.

Yes, AP is a rabbit hole......

As @Budgie1 says, you need and heq5 as a minimum with the 200mm reflector, but even that will be near its limit, especially if you start guiding. As a 200p owner I would recommend getting something smaller to start 'serious' imaging. The 200mm newt is a bit of a wind-sock and is not really designed for imaging.

I would agree with @RT65CB-SWL that the Baader zoom is very good and I would also recommend it. If you are on a tight budget, there is a Svbony version. Although not not as good as the Baader, it is much cheaper and still gives reasonable views.

I'm not sure what mount you have, but you could consider a small widefield scope instead of eyepiece upgrades. The Mak is always going to have a fairly limited field of view so a small refractor or reflector could be an option. They can be picked up pretty cheaply second hand on SGL and Astro Buy and Sell. Most second hand kit is in excellent condition as Astronomers tend to look after their kit.

Another option would be to see if there is a local astro club near you. Get a chance to look through a few scopes and talk to some like-minded folk.

Surely for a Tak, it's a hot water bottle and a blanky 🤣🤣

Looks very much like the amp glow on my 1600mm pro, but slightly more balanced. As said, if it calibrates out - don't worry about it🙂

I'm still running well after 50+ years. What does that say about my build quality🤣

Seriously though, it is great to hear about good quality kit lasting so well in a world where nothing is really built to last.

You could try a bespoke cover such as these:

https://www.bagsandcoversdirect.co.uk/category/500/Garden-Chair-Covers

I have no idea about them, but the prices seem reasonable and they can be made to measure.

Mmmmm. Clearly I am over doing it. I have a large cupboard and set of shelves for my 'bits and pieces'. The rest is in the observatory.

Any clues yet? Don't say Chroma, I'll have to sell body parts.

To be honest, because you have steel in the tube and an alloy of some sort for the mirror cell, trying to prevent galvanic corrosion completely is tricky. One or other will be affected. Chrome plated mild steel is probably as good as anything - which I believe is what SW normally use. SS is probably the worse choice.

Not sure how strong they are, but you could try nylon.

I'm not allowed to forget about any scope I buy. SWMBO makes sure of that🤣

1 hour ago, Budgie1 said:

I'm not one for details analysis of an image but there is a definite decrease in noise and an increase in detail in 23911

Agreed. Also, given the 1/3 of the average signal which suggests a much narrower band pass.

@iwolsI wish you hadn't done this; I keep telling myself that the filters I have are fine and I do not need to buy new ones..... I can feel my wallet groaning already🤣

3 hours ago, GTom said:

Would not go much larger with sensors though.

Interesting that it quotes 'suitable for APS-C' but also says a 21.7mm image circle. Slight contradiction in my book. But I agree that larger sensors will not be good. I actually considered one of these for imaging but was put off by the small imaging circle (to pair with an IMX571). I do have a 150mm TS Photon F4 which I pair up with a 1600MM pro. I would certainly advise against this scope as it needs too many modifications to be acceptable for imaging - not least a new focuser.

3 minutes ago, vlaiv said:

kipper on banana pi

?? You've lost me already. Fish and fruit??

I would second a couple of the points above. I use a Powerline adaptor for my internet connection into the observatory - this is just for the remote desktop. It's still not too quick, but I collect the subs on the PC and transfer in the morning as suggested by @ONIKKINEN. I use a fanless mini PC which generate enough heat to keep dew off.

There are plenty of small scopes that would fit the brief, depending on your budget and requirements. As long as you get an ED doublet as a minimum to keep CA at bay. I would add that pushing the focal length too far will probably be a stretch for your mount.

The SW 72 ED is a good little scope, but will only only add marginally to the FL. However, beyond this you are probably looking at a new EQ mount.

I think imaging can be done relatively cheaply these days, especially with the lightweight trackers that are now available. It all depends on what you want to achieve. I have spent a fortune (for me) on my imaging kit - but that is largely by choice. I am now in a position where I have too many options and it is difficult to decide what to use!

However, a small telescope or long FL lens with a star tracker and give excellent results.

Assuming the same rules apply as for an achromat, the amount of CA will increase with aperture. Therefor the 125 will show relatively more CA than the 80mm scope. However, good doublets still give good results if well corrected. There is also the option of using something like an Astronomik L3 to reduce any bloating.

Another option would be the AA 115 Starwave. Slightly less aperture but an FPL-51 triplet with good correction.

If you are looking to expand into deep sky AP at a later date, then make sure you invest in a decent mount. The newer harmonic mounts are certainly good for portability and load carrying. In terms of scope, I would not put a 9.25 in the 'portable' category. In reality there are loads of options including Maks, SCT's, CC's all of which would be usable. In general, the SCT's seem to be the 'goto' choice for most planetary imagers.

I think the real choice is how portable you want it to be. The larger the set-up, the more effort is required to get it moved and running. With the exception of the suggestion by @AstroNebulee which is genuinely a portable set-up, the others are simply 'moveable'.