Adam J

It's the sort of thing I would be happy to do myself...but would the op?

Yes, but in this case it's not a warranty repair. If you have managed to work out the OPR let me know how it's done as I read and read online and could not find any instructions that made sense.

He either ends up with £299 for a broken camera that was worthless or he ends up with a fixed camera that is now worth ~£650 on the used market. Also if its lost or stolen on the way to ZWO then he wont be having to pay the repair cost? I would guess minimum £200. So actually 299 + 200 gets us back to £499 and so in fact in that situation he has only lost about £150 and once you pay the inevitable £50 customs processing fee that then looks more like £100 pounds. That £150 has to then be balanced against the likely cost of getting tagged by customs which could easily be that amount if you put down the new replacement value which is much more than that £50 processing fee. If its lost on the way back to him that would be ZWOs issue in my opinion and they need to sort it. So worst case he has £299 to put towards another used ASI183 when one comes up and they do quite often. As I say its all balance of risk / reward, others will see the balance differently to me as its all about perception. But if I had a bricked 183 and someone offered me 300 for it....I might be tempted. After all I have 300 pounds towards a working new / used camera and I dont have to wait 6 months to get it back or deal with any pain with customs / postage. That would go out the window though if I could return it via a UK retailer. If ZWO say its causing issues if you put down a higher price...well I would take them at their word. Those problems probably involve ZWO getting charged on import to china which I am sure they will add to the repair cost of the camera. It could all easily snowball. Adam

Basically you need to pay a processing fee and you also need to pay VAT on the cost of the repair when not under warranty. If it was me I would do it exactly as ZWO told OP to do it. You can assume that they do this allot. Its a paper weight right now so you need to send it and if something goes wrong then you are only back to square one. Adam

If you want the highest probability of trouble free imaging then I will second the choice of a ZS61 an F6 doublet is a really safe bet. On the other hand its not fast either. The I love my ASKAR 180 and the ASKAR230 seems to be of similar optical quality at F4.5 ish, hence not quite fully APO unless you use a L3 filter with it or a L-Pro filter. But then its much cheaper than a redcat isnt it. For that reason I could live with it but could you? Then you have the redcat, a more complex optical design than the above and so still has some sample to sample variation, you pay for it but if new you can send it back cant your. I would have thought that the original could be colimated though I assume from this line of questioning that was not possible? Adam

I would actually think that if you are doing 10mins now it might be as low as 2 mins with the 533 depending on gain and F-ratio of your scope. Adam

Honestly I would not think about that, just take the number of pixels and multiply by the pixel size if you want to understand relative sensor size. Adam

This is an obvious one for one replacement for the Atik 460EX, you would likely see more advantages in terms of much shorter narrow band exposures and slightly higher QE. It shares properties of the 460EX such as no darks being required due to low numbers of hot pixels and no amp glow, its a very clean sensor. But having said all this the delta in terms of real word image quality, while noticeable is not going to be mind blowing. Adam

Well my 1.1k prediction was spot on (£1080).

Some place between the two. The star to the 4 o'clock of the cluster should appear white with a very slight blue tint from its spectral class. I personally dont like it when people push it to be a bright blue star. On my monitor yours is looking ever so slightly green tinted and so i think you could stand to boost the blue channel a little. Adam

I would say that this is likely your problem as there will be a consistent direction of drift on top of the dither.

Are you dithering in both axis? There is an option for RA only that could potentially cause issues. Adam

NII imaging is not my aim, more wondering if it might be a useful side effect that would push me to get a 3nm instead of a second 5nm. Adam

Second one no contest. First looks clipped to me.

Personally i would need to know the price first before biting FLOs hand off. lol I asked if it was available without the ipolar and they don't think it will be so that is bound to push up the price a bit.

sent you a pm.

Not sure its user adjustable (push pull screws on the front lens cell) but you should check that the front cell is not loose as a first step. Adam

Honestly i would be trying to get your money back from the seller as this scope has obvious coma across the entire image. ES reed may be able to help, if you cant get your cash back. Not sure if the redcat has user accessible collimation screws on the front element? Is so then you might be able to fix it yourself using a Cheshire collimator. Adam

So have been thinking about doing a duel imaging rig and one of the things i was mulling over is a second Ha filter to go with that (on paper at least) So if I have a Astrodon 5nm Ha in one scope and a Astrodon 3nm Ha in the other could I take the difference between the 3nm and 5nm and in effect extract the NII channel from that delta? Any thoughts? Adam

Yes this is why I ask OP who they purchased it from originally. For example FLOs policy is here: From above link: "I bought it from First Light Optics but it is outside the warranty period. Please contact us, we can probably help. If it needs repair or a replacement part we normally charge you only what it costs us. " Adam

533 has my vote for sure. You are never getting 1.37arc seconds per pixel from a ZS61 anyway. Just won't happen. Adam

Who did you originally purchase the camera from?

UK seeing is not ok in my experience. I know people that make the 294 work but its can be a pain to calibrate and some people seem to never get it to work for them. In all honesty I think that the only OSC options I would consider are the 533 and the 2600 (but probably the rising cam version of the 2600 (IMX571)). Adam

and that is the problem isnt it, my mobile rig is kept cheap for just this reason, I dont want to pay out my nose for something that is not my main imaging kit and only used for travelling. The AZ GTI is not perfect but it works in that role, a little more performance is nice but £600...huum. To put it another way thats two thirds the cost of a HEQ5 Pro and that comes with a tripod and a hand controller.....£600 and no tripod no hand controller....common. Adam

Conditions can make a massive difference. Personally I would say that I have seen a step change in images quality that people are producing since the latest generation CMOS has been released so I would not be persuaded to purchase a 8300 these days unless second hand and on a very limited budget. Also it is worth remembering that the biggest performance difference will be in narrow-band when its harder to bury that 8e of read noise. Adam