Adam J

True but the spot diagram has changed. Make of that what you will. Although still only goes down to 430 nm OLD NEW Crossings are different too. Adam

Looks like this is the end of the road for the original FMA180 as the FMA180 Pro has now been released with some upgraded features and potentially upgraded optics too although thats not 100% confirmed in my view. https://www.firstlightoptics.com/askar-telescopes/askar-fma180-f45-ed-apo-v2-astrograph-lens-reducer.html However, its lost the modular construction which was a attraction. Would be nice to try one out but am not sure that I can justify an upgrade. Wonder if they improved correction in the blue. Adam

It would bot tempt me, I would let someone else take the dive first, so you should 100% try it. Adam

I will be able to "get away with" the 1.25" Baader filters that are already in said wheel. That will depend entirely on F-ratio of the imaging scope. I doubt that the auto focus issues are anything to do with the sensor your using. The ASI294mm is a relative pain in the bum to calibrate in comparison to the 694, it can suffer from some of the same calibration issues as seen on the 294mc version, probably sample dependent. Its the reason I have decided to stick with the ASI1600 until such time as a better 4/3 sensor is available. I assume you are binning the 694 with that scope? I think the bigger performance advantage of the 294 is in narrow band imaging due to the lower read noise but for LRGB I am not sure that you will see such a big advantage. Adam

Lovely scope with a nice report, its not all about Strehl though, its also important that PV is below 0.2 which it is in this case, although more important for imaging than it is for visual use. I like these RVO scopes much more than the WO equivalents, WO dont give you a report and WO don't use a colimatable lens cell., both important setting points. Adam

More to the point 80% power is a indication of high temperature differential, higher temperature differential = more likely that dew will form. Adam

Trying to process an image to look correct on multiple different monitors is a one way ticket to a padded cell mate. Second version is much better, great image. Adam

Its not designed to work at F2.8, if you own one try it, but if you dont own one then you will need to invest in a preshifted filter instead. Its not so bad a situation as with a scope that has a central obstruction as in those cases you can litterally end up with nothing, but most likely you will not be truely getting the full benefits of imaging at F2.8. https://www.firstlightoptics.com/idas-filters/idas-nbz-uhs-dual-band-nebula-boost-filter.html Above is that I would recommend. See the reviews and you will note comment on the SharpStar 15028HNT with L-extreem with Adam

It's not really hardware binning. It can't do real hardware binning. It's a firmware read mode thing. By the time you soft bin it, then it's post stacking so 16-bit or even 32-bit depending. Always bin in software unless it's true hardware binning.

Don't bin during capture in lots of Sony sensors binning during capture will result in 10bit A/D instead of 12bit bin after in software, it's no different.

Anything on the images will not be from the objective lens those are simply too far from focus to ever show up. Any problems you are seeing on flats are from the the corrector backwards. But the most likely location is from the sensor itself. If you can post a flat frame and let me know the F-ratio of the scope I can actually work out were they are located mathematically. Adam

Yep not like it would take long. Problem is that the manufacturer needs a reason to start turning stones over and looking for expensive issues.

The trouble with filters is that 1) it's really hard to achieve fine tolerances. 2) most amateurs customers would never know if the specification of their copy was off. For those reasons I think it's good that consumers are starting to question performance claims, it can only lead to good things.

Honestly just mix some blue and green into the Ha data it will give an IDE tical result. All the lines come from the same hydrogen and tend to be found in exactly the same place as the Ha emission just dimmer.

It is an object that I have not often seen drawn out in images of this area if at all. Being most strong in SII it's certainly not going to show up in images taken with OSC cameras and Ha / OIIi duel band filters. There is also a tendency for people to clip that area, seeing the north America shape relies on it been dark.

Yes it will work, not sure what you think that there will not be sufficient room??

I would drop down to 50-60mm for a scope to take on holiday as opposed to the 70mm range. https://www.firstlightoptics.com/askar-telescopes/askar-fra300-60mm-f5-petzval-astrograph.html Adam

Best to put up a jpg so that it's displayed in the thread. That way more people will be able to view it. 🙂

You will want 2 inch so that you can use it with the larger sensor later. The problem with flats is as much related to the Ha wavelength as anything else and so will likely still manifest in any duel narrow band filter, for that reason I would go with the L-Extreme or the IDAS NB1 filter if you want to reduce reflections. Either way you will still need to run it at gain 200 and not 120 unless you have a lucky copy of the 294mc pro (some do exist). Next step up is the Antlia or the L-Ultimate and they are outside your budget. Adam

My point is that the 450D will be much worse than the 6D for everything except emission nebula. I started out with a 1000D, then a 450D and then a 550D. I modified them all myself and as a result was able to sell them at a profit once I had gotten a dedicated astro camera. Honestly, even for emission nebula I dont think that it will as bigger jump as you might hope for. . My 550D was in my view significantly better than the 450D. Adam

It's one of those things that everyone should own.

Yes because ideally you need quite long flats or the shutter movement effects them. Adam

Gorann of course I have already seen this fantastic image and commented on it at the time. Along with many other examples of your work with the RASA. But I would essentially say this is in line with my comments. In that it's an excellent tool for going after very faint structures. What we do see here is a very faint structure in terms of the SN reminant next to a very bright object in the form of the fish head / heart in the linked image. Adam

So imagine two scopes. 1) Triplet 80mm aperture with flattener @ 400mm focal length giving F5. 2) Triplet 80mm aperture @500mm focal length, but now using a 0.8x reducer to give 400mm effective focal length. Scope #2 will not only out perform scope #1 in terms of correction / spot size quality being equal. It will also be cheaper to make. Hence why most optically fast scopes archive this using a reducer instead of just a faster objective. That final point was less about the 'myth' and more about the usefulness of reducers. Adam

and so is the Altair triband... I recommend a UV/IR cut for broadband targets like M45 and the triband on emission nabula, honestly I would not find much use for a L-eNhance. Adam