Adam J

It uses FPL-51 but don't let that put you off in this case its an excellent bit of kit that performs very well for astrophotography,. Having said this through there are there seems little reason to chose this scope over the TS-optics version which is cheaper, FLO might be able to get you one as it seems that they are importing TS scopes at the moment. Its out of stock because its a total bargain. Adam

The first thing I would say is that this is a valid imaging scope and I would not consider it a stepping stone rather simply a tool in your box for working at this focal length / FOV. I own an Esprit 100 and lots of other very expensive accessories and I still enjoy imaging with this scope as part of my mobile / wide feild imaging rig. I use it on a AZ GTI in EQ mode for GOTO. So personally i would go with all those things guiding / good mount and then when you get a larger scope I would keep this for wider views. In terms of 3. nothing really helps for RGB imaging vs LED lights you will just have to live with them or get a duel narrow band filter if your camera has been modified. I would get the adjustment rings especially for a full frame sensor as you will need to get it spot on. Remember that nothing ever really covers a full frame no matter the claims unless you spend some very serious cash. Hence be prepaired to crop. Personally I would chuck a little more cash in and get and AZ GTI with a wedge and counter weights bar to use the scope in goto even as a interim step as if your current tracker is not coping I doubt that chanigng to the FMA180 will help too much over the canon lense combinations that you have been using. If you are not going to use a auto focusing solution then i think that a bahtinove mask is avaliable for the FMA180 and that it has been discussed earlier in this thread, for me that would be an essential purchase. Finally I would say get a 2 inch dew strap and 12 volt power source as designed for use on 2 inch eyepeices. It will fit the FMA180, I would not image without one. You will not need a dew controller for such a low power strap just run it all the time at full. Adam

Yes the pattern is indevidual to each IMX294c and can have extremes. Some people dont have issues at all because they lucked out and got one when the pattern is less strong. Some cant calibrate at all it would seem in the worst case. Adam

Well I was worried about astigmatisum but you will be glad to know that the scope itself looks ok, although you do have slightly pinched ppitics causing the four gaps in your star halo, but I dont think this would be causing the effect you are seeing on the mask spike. As the effect is only present on the Lum channel I think that we can atribute it to chromatic aberation in the lens. If you have ever used a mask with a OSC camera you would have seen a rainbow effect progressing along each of the diffraction spikes. Like this: You will notice that the same pattern is present here as in your mono image, but here we see the RGB elements,, your lum shot still contains those elements its just not apparent in mono that this is the case non the less. Green in the middle and Red / Blue either side. The degree of lateral spread in those i.e how twisted they appear is relative to the amount of Chromatic aberation within the imaging scope. You are essentially seeing that the green is in the centre and that the blue and red are shifted slightly away from perfect focus to either side green. In contrast in a better corrected scope you may see something more like this: Despite this I would not say that this means the scope is badly corrected its just not fully corrected. Adam

I dont think its the ASI1600mm pro sensor cover glass. Never seen anything like that before. What exact filters and scope are you using? Also would be useful to see a stack of a completed Lum filter and RGB as seperate channels if possible. I have a feeling about what it may be but I dont want to say without more evidence. Adam

RGB are really quite close in this scope as demonstrated by others using OSC cameras (assume this is an OSC?), once you have used a L3 filter its virtually perfect correction between 420 and 680nm. So its nothing to do with the filter you are using. I would take a look though your subs. Adam

Looks more like a stacking issue to me, as if you have includrd some out of focus stars in the stack with some in focus subs too. Adam

I have had no issues getting a near perfect polar alignment with the SW wedge. Better astro gear to spend that money you will save on that will do more for your imaging.

Just don't make it more than about 2 inches long.

It threads onto the front of the scope in front of the objective onto the same thread you used for the lens cap. To be honest its the best place for it you should not get reflections and you should not get any issues with pass band shift. Clearly its exposed to the elements though so I use a dew shield i made myself to protect it in use. Finally it wont cause any flats issues with dust on it etc from that location. Adam

Really nice image! I do like the dust seen here that you don't normally see in pure duel channel narrow band, great work all round. Adam

Watch the mount to ensure that it doesnt bind in the cold, any lipo batteried will need to be pre heated and ideally insulated. You dont say what scope you are using but the glass may pinch as such a low temperature. Also think about thermal shock on the glass especially if its flurite. Adam

This was about 5 years ago now, my memory is not the best but I looked into it quite extensively at the time. Also it was a 1000D so not exactly a modern processor.

Despite Canon calling it RAW it is not, they apply a different multiplier to each channel prior to readout. Hence boosting to the R and B pixels. Not well documented but if like me you have removed the Bayer matrix from one of their sensors you would know that a checker board pattern in the RGGB form is still present in flats despite all the pixels now being physically identical with no Bayer filter. Some experimentation leads to the conclusion that they do not process the pixels identically. Adam

Generally having the filter reversed will cause reflections as opposed to altering the underlying filtering performance. So not sure it would effect calibration to have it reversed. Adam

Yes from that it looks like a standard 3/8th inch thread. Adam

yes I wonder that too. Also the other way around. @FLO do you know what the thread on the bottom of the mount is? I rather like the tripod that i already have. Adam

Really very nice wish i had the time for 20 hour integrations these days, I take it that this is at F5.6 without the reducer then? Adam

Three hours of RGB with the ASKAR, no luminance. Dont get to do the long 40 hour intergrations I used to these days but I was quite happy with some of the fainter dust starting to come in even without any luminance. Adam

You are correct that is a big ask for a DSLR, but its a fantastic image as a result considering this, i applaude you for your tenacity in gathering the data, lots of hard work. Adam

The ST102 will work it's just not really a good match to the capacity of your mount and the quality of the optics is low. I use an askar FMA180 and I get good results. I managed to fit an autofocuser to the helical. But to be honest I am not sure the 50ed focuser is as smooth in operation.

I have not been understanding correctly and thought you where looking at the cooled versions (pro) and not the uncooled versions. I would actually agree about the ASI183mc especially if its not a cooled pro model. The ASI485 is much better suited for uncooled imaging as it has no amp glow and you need cooling to calibrate sensors with amp glow. Astro photography on the EQ3 pro is a challange even without small pixels. The AZ GTI is a better budget bet. This is the type of starter setup I would usually suggest on a low budget. He uses a ASI178mc and thats essentially a smaller ASI183mc would work with this kind of setup but the newer ASI485mc is a better bet as it has no amp glow and is more suited as above, but is smaller than the 183mc. What i would do is keep the EQ3 Pro, buy a 50ED and get that 183mc, or if you can afford it the much better 485, as the real problem in your proposed setup is the ST102. If the EQ3 pro does not deliver you can then sell it and grab a AZ GTI instead. Adam

Nina is better, you always feel like you are fighting a new program at first, but its worth while sticking with it.

It calibrates fine, but I have often noticed a zone of lowered signal to noise in the area under the most intense part of the burst in the images of others. Adam

The main issues is not that people don't look after their stuff its that there is a lottery every time you buy equipment as not all equipment is made equal off the production line. In my time I have purchased new equipment and had to send it back twice due to imperfections (optical and mechanical), not a problem if you buy new. The main culprits in terms of this in my view are triplet refactors and flat field refactors. They are very precise bits of kit that too often have optical issues. All this is fine assuming that the individual that you purchased from is reasonably knowledgeable as if they received a poor scope then they would have sent it back for a exchange. However, in many cases people just starting out in the hobby do not notice optical issues until after they have run out of their warranty period or sometimes not at all. They then sell you the scope and you have inherited their issue. The way to combat this in terms of image is to ask to see some of their raw stacked images so that you can inspect them for aberrations. Mounts are the other big offender, they usually need tuning and some just track better than others. Not many ways around this, best way is to fire it up when you collect it and listen to it, how does it sound to the ear when it moves, are both axis smooth. It also seems that filters are starting to be more hit and miss now too. With some of the budget makes trying to move into the ultra narrow band filter market its not been going well as you really do need some precision in applying coatings and rigorous testing to ensure that they product delivers especially in the case of fast F-ratio optics. Electronic goods such as autofocusers, filter wheels, cameras etc. Are much less of a gamble and you will generally see very little variation between examples. One thing that has always gotten me worried is people who advertise the kit as "new and unused" or only used a couple of times. Often this is for very expensive items and I always ask myself why they are selling it so soon. One tip is to always buy from an known member (not someone who just pitched up to sell and has one post) or in the case of astrobuysell always have a chat with them before hand. For expensive equipment and perceptually OTAs always collect in person. If you look in the small print of any of the major delivery companies they will either specifically tell you that they do not insure telescopes or they will say they do not insure glass items of which a telescope is one. Never buy from overseas. If it looks too good to be true it probably is. Despite the above post I would never buy a solar filter second hand. So how reliable is second hand kit? I would say that if you go in with your eyes open and take the required precautions then its normally a safe bet, but I have has some lemons in my time and had to send one item back to the vendor. It was a filter wheel and the threads on the scope side had been cross threaded and stripped, no chance that they would not have know about this I sent them a message and they refunded me. I know of others that have not been so lucky. In the end if you want zero risk buy new but it will cost you. Adam