The Admiral

Well of course you shouldn't be able to see a cw signal direct from Graves, only a meteor scatter signal as and when it occurs. Outside of meteor showers you may have to wait many minutes before getting a 'ping'. As wxsatuser suggests, one normally sets the 'tuned' frequency 1-2kHz away from Graves in order to make the scatter audible. You are a long way from Graves as well, so it will be interesting to see what can be detected. Ian

Well Starsense with it's associated hc seems to be able to do it, no additional computing power necessary. It identifies stars in each image and builds a model of the night sky. Of course, the Starsense is there for alignment, but it can be used in Polar alignment when Polaris isn't visible. I've never tried that feature as I've only ever used it with an Alt-Az mount, so I can't vouch for its success, but possible others can. And given the price of the Starsense, I think it would fulfill your smartphone comparison! Ian

I read a new post on the CN forum: "Contacted iOptron about the iPolar and it will need a computer to work, so pretty well built in polemaster. It will be available for retrofit on other iOptron mounts though. " That's disappointing, I was rather expecting that as it's using the iOptron branding that it would have been integrated into the handset, rather than requiring subsidiary computing power. If Celestron can do that with the Starsense, then in theory it ought to be possible. I guess it comes down to intellectual property rights. Ian

Best to keep an open mind until we have more information and user reviews I think. But it is true that Polemaster is also licensed to iOptron to market under their own brand. Ian

The major mount manufacturers do have polar alignment routines for when Polaris isn't visible, and it might be worth sounding out users of this feature, and whether it is sufficiently close for AP. I noticed also when reading the limited information currently available for the new iOptron CEM40, that: "This mount also has an integrated electronic polar finder scope known as the iPolar. This tool ensures the accurate alignment of a telescope, even when the pole star is obscured." Now, whether this tool is actually better than the other routines I wouldn't like to say (and it'd be too early to tell), but it does use it's own built-in polar scope, much like Polemaster I guess, but at least that's not one extra accessory you should need to buy. Does Polemaster only work when Polaris is visible? I've no experience of that, but someone will know. Ian

Currently I have only used an Alt-Az mount ;<). If I decide to invest in an EQ mount then I should need to compromise a bit and move away from the house a little, but at least my garden is on the level. Probably not the answer you wanted to hear! Of course, if you are loaded you might care to look at the TTS-160 Panther mount, an Alt-Az mount with the facility to rotate the scope and thus allow imaging without field rotation! Ian

Yup, my problem too! Ian

To be honest, I don't know! I was wondering too, but the site does warn that the data for different cameras shouldn't be compared. Ian

Yes, indeed that would be interesting to check out. I assume that the X-A3 has no anti-aliasing filter in front of the sensor, like the X-T1. That is something I believe helps enormously in astro-imaging, and I've never been dissatisfied with the acuity of my images. Ian

Personally, I'd be inclined to convert them to DNGs using the free Adobe DNG converter. I would imagine that converting to TIFFs would involve a non-linear transfer curve, which can be a problem with subsequent processing. Yup, storage can be an issue! Astroart sorted that one though. I had myself wondered about the X-A series; should be fine. I've always regarded the red response of the Fuji sensors to be quite good, and I don't know how much you'd gain by conversion. If you check out my album there is an image of the Horse's Head nebula, and that shows a decent amount of H-alpha. Certainly see how the X-A3 performs in that regard before spending money. The photons to photos site shows a slightly different noise curve (http://www.photonstophotos.net/Charts/RN_ADU.htm#FujiFilm X-A3_14), but it is still nice and linear. Ian

When I imaged M45 I used ISO400. No colour in the brightest stars though. I couldn't make DSS work with my Fuji RAFs without converting them to DNG, but I switched to Astroart and it ceased to be a problem. Technically, though, the non-Bayer array of the X-Trans does cause potential issues with processing, but I've not found it to make a noticeable difference, to my relatively untrained eye. Be careful with darks though, as they need to be taken at the same temperature as when you were imaging. And if you do them, do a good number. If neither of that can be attained they can add more noise to the image rather than reduce it. There is a school of thought with DSLRs, because they are not temperature controlled, that better results can be obtained by substituting bias frames (or a previously produced generic bias) in place of the darks. That may not be practical where there is significant amp glow, because the bias won't compensate for that, though I've not found that to be a problem with these short exposures. That's what I do and it seems to work. It's easy to do with Astroart, but I think in DSS you'd need to re-name the bias frames if you want to substitute them for the darks, because DSS won't accept identical file names, IIRC. Ian

Well that's come out rather well! Nice round stars, and good that an X-T1 has been used! What ISO did you use, and what processing software? Your background looks a little black, and if you could make it a fraction lighter you might reveal more nebulosity, and more noise of course ;<) Ian

May be that's a bit too high. If you look here you'll see that there is some indication that gain ceases to be analogue above about ISO1600 with the X-T1, and a little higher with the X-A1. You need to avoid getting into the digital gain region for astrophotography. I generally used ISO 1600 with mine, though when I had bright stars in the field and I wanted to minimize the degree to which they were over exposed, I dropped it down to ISO400. A high ISO, contrary to what it may seem, just amplifies the noise as well, so as long as your histogram is well off the bottom of the range you should be exceeding the read noise, and there is nothing to be gained by increasing the ISO. At least, that's my take on it. Ian

Welcome to SGL, and I'm pleased that you find it to your liking. Well that's a very good start to your imaging, well done. Am I right in saying that the XA-1 has a conventional Bayer filter array, rather than the Fuji X-Trans? If so, then that will allow software like DSS to work as it should. I have the Fuji XT-1, which has the X-Trans array, and that adds complication. But if yours is anything like mine, then it will have a decent deep red response so will be reasonably sensitive to the H-alpha light. You will find that the more subs you take, the lower the noise levels. You will see from this thread that 100 or 200 or even more short exposure subs are routinely taken. Of course, it doesn't help having a light polluted sky. You may also find that doing darks with a non-temperature controlled camera can introduce more noise, and if you do them you need a decent number. Incidentally, what ISO value are you using? Ian

Or, you could leave it on the table and take the flats by putting a laptop/tablet, displaying a plain white screen, directly in front of the objective. I think you'd still need to diffuse it though, and don't have the screen brightness too high so that you can get a reasonably long exposure (i.e. tenths of a second rather than hundredths or less). Those images are a good start! But galaxies are hard in the sense that they are generally small in the FoV, which makes them susceptible to tracking errors and field rotation, which will smear their tiny details. Also, as Filroden indicated, it is useful to be able to remove gradients 'easily', and not being a user of Gimp, I don't know whether the Photoshop plugins work with it. It might be worth looking at the range of specialist astro processing software that there is available. Not all are expensive. Ian

Just to add my thoughts to this old thread. I think all the points raised above are valid. I started using a mirrorless system camera simply because when I first got my telescope I hadn't even thought about imaging, and the camera is what I already had and I thought I'd give it a go. For me though, the over-riding consideration is that it is self contained and stand-alone. Like others here I would need to set up and strip down the kit every time I carted it all into the garden, so simplicity was the key. No need for a separate processing capability to be wired up. I have a few potential upgrade paths available to me in terms of mount and camera, but to be frank, I found I could not justify the expense given the infrequency with which I am able to image. Even so, the time spent imaging with such a camera has been a very valuable learning opportunity without spending money. It's time not wasted. So, do you buy a dedicated astro camera or a DSLR? If you are starting imaging and have a DSLR to hand, I'd say wring the most you can out of that and pick up some experience along the way. If you haven't a camera of any sort, then I guess it'll come down to what you can afford, but be aware that astro imaging can be a big hill to climb and you might want to keep things as simple as possible to begin with. But I'd certainly not decry anyone going for a cheap DSLR to start off, even if the imaging purists would say otherwise. Within it's limitations and advantages you can make some really nice images, so don't be put off. If you are buying a new high performance DSLR, then just be wary of some of the gotchas that these cameras can throw at you, like the star-eating noise subtraction that some of the Sony's have, and (?) some of the Nikons. Whatever you choose, have fun while you're doing it! Ian

Pretty sure I didn't . In fact, the current offerings from FLO don't include either batteries or mains power supply. Ian

Welcome to the forum. I use this https://www.firstlightoptics.com/power-accessories/baader-outdoor-telescope-power-supply-128v-15a.html Works fine. Ian

Can you link to it please? All I can see on the November news are pictures. Ian

This has all been a very interesting read, and the perceived trajectory of imaging cameras becoming more affordable CMOS astro cameras. But would I be correct in thinking that the price change that you are envisaging would result from the switch from CCD to CMOS? In other words, you wouldn't expect a price fall for the likes of ZWO cameras which already use CMOS? Or are you saying that you see the prices of all astro cameras, in general, falling? Also, it strikes me in my naivety that one of the consequences of the take up of CMOS cameras for astro is that they'll be through a re-purposing from existing applications, so there might not be such ready availability of mono cameras, to wit the ASI071 AP-S and ASI094/128 full-frame cameras being only available in colour versions. I hope I'm wrong! Ian

This bit is intriguing: "Forget quirky handpads and software installation. Control your AstroTrac 360 from your familiar browser environment out of the box." "Future software updates will include GOTO and support for popular 3rd party software such as SkySafari and TheSkyX." (My emphasis) So exactly how does it work? Still an unfinished product then. Ian

There is a paucity of technical info, just pretty pictures. I see that there are now pictures of the dovetail clamp in use, but there needs to be more than just 'newspaper headlines' accompanying them. A downloadable manual would be of use, not least a review or two. Who would cough up a grand deposit on the basis of this? The 10kg capacity is claimed to be the imaging capacity, so it may be better than taking most mounts' capacities and dividing by 2 . Ian PS. Odd website! https://www.astrotrac.com/ I've just discovered a bit more information by continuing to scroll down. Doh!

http://deepskystacker.free.fr/english/index.html Try it! Ian

Jpeg doesn't really cut it when you come to astro imaging. Being only 8 bit, they fall apart too readily with the stretching that is required. RAWs are the way to go, and as LOL221 says, DSS is a capable freeware that you should be able to run. If your laptop can run in 64 bit, then the 64 bit version of DSS would be preferable. But in any event, the processing won't be quick and letting it do its thing, even if it takes half an hour or more, so go off and have a coffee! Ian

I think you've done well with those. I found M42 to be the harder of the two, because there is such a brightness range that it's difficult to to get the feinter bits without losing detail in the highlights. What many do with that target is to take two or three sets with different length exposures, one optimised for the brighter regions and the other(s) for the feinter regions, and then they're blended together. There seems to be plenty of data there, which is good. The background looks very black; is it being clipped or is it just a 'dark grey'? If it is clipped then you'll possibly lose some feinter parts of the nebula; any noise will need to be separately dealt with. I'm not sure about M31. You've got plenty of detail in the dust lanes but the core region appears to be blown out. I don't know whether your individual subs have blown out, or whether it's the processing. Have you looked at other astro processing software besides GIMP? StarTools is worth a look. There is a fully functioning trial, other than you can't save, but is very reasonably priced anyway. Also, can I check, you are stacking the RAW files? Ian