catburglar

Welcome. I don't know if this sight might be worth a look: https://www.slooh.com/about/about-slooh

I think I saw a comparison between one of the canon L series lenses and a WO Redcat- the results were similar....I'd expect a similar situation here...with some important things to note....they are both 400mm FL and therefore will have the same image scale if used with the same sensor. As you note this means that the RASA will be faster. But, I would also expect the lens to be slightly less sharp if used at it's maximum aperture- this is typical of many camera lenses even good ones. So to get comparable sharpness, you'd probably need to stop the lens down, which would make the RASA speed advantage even more significant. In which case the lens will produce diffraction spikes when you stop it down because the aperture blades aren't circular...You can get around this by using a round aperture mask. So- if you want to operate at 400mm and you want to do it quickly, I think the RASA is a better option than the canon lens, unless you also want something for conventional daytime photography... But I've never used either of these, so I have no practical experience

I started with a 60mm Tesco refractor telescope on a wobbly altaz mount...apparently it was exactly the sort of telescope that you shouldn’t start with according to some.....but it showed me lots of detail on the moon, Saturn and it’s rings, double stars a plenty as well as the Hercules globular cluster, dumbbell nebula and ring nebula...your scope will be fine, and give you lots of things to look at. Like nialk above, I’d also recommend the book Turn Left at Orion- it’s got a nice selection of things you can see with easy to follow instructions showing how to find them as well as a guide to what it should look like...You can get all of this from the internet, but I find it easier to use a paper guide like this to start with...An alternative might be the Celestial Sampler by Sue French, but that’s less beginner oriented in my view...

I was surprised I didn’t have any significant interference for a couple of days to see this so suddenly....but as of about 11:30 it seems to have disappeared....not sure what it was, but will see if it reappears.

I decided to have a try at meteor scatter detection- using a 3 element yagi based on the S@N design and using a nooelec SDR....following this guide: https://www.popastro.com/main_spa1/meteor/radio-meteor-observing-2020/ The antenna went into the loft on Sunday evening- bearing approx 160 degrees with approx 10 degreees of elevation. All seemed to be working OK- could pick up local FM radio stations so the connections and driver and SDRSharp software must be OK. SpectrumLab was installed and seemed to be getting a few real meteor detections, many short (< 1 second), but other longer and with SNR >15dB according to the log(see the first capture)........Note the caption is incorrect the central frequency is 143048 (not 143028) So this morning I thought I'd install colourgramme- all went OK, got it to look at my live RMOB log file and everything seemed OK, but when I went back and had a look at SpectrumLab, I've got a spurious signal that I can't track down. I've checked all the connections, unplugged/restarted the PC and it's a permanent feature. The last image shows the difference in signal with the antenna pointing in the usual position (first part) compared to approx due west (second part)....but I need to point south to get the scatter from Graves..... The system was running for 2 days before this appeared, so don't know if it's something more local that's generating it, although I can't think what it might be. Any clues as to how I should troubleshoot?

I think you need to come back to the ‘diminishing returns’ point made by Olly- if there’s only 60mins of data in that image, then adding another 60mins will likely make a noticeable difference. However, if you’ve already sunk 6 hours of data, then another hour or two won’t add much....How patient do you feel? Have you u got a wish list of autumn targets that you’d be missing out on if you go after this. But to counterpoint the above- most of the targets will still be there next year if you don’t get around to them this season.

I think you’ve just pushed the processing a bit too far- there are dark haloes around many of the stars suggesting that the deconvolution is a bit too fierce or your star mask wasn’t quite generous enough...The image is also stretched quite hard so you get white cores and accentuate the haloes.... Startools has a nice ‘fringe killer’ filter that allows you to selectively reduce these blue haloes, but the best first step might be to go gently with the post processing...

No....you suggested windsk32... I suggested win32dsk..... Yours would create a mirror of the SD card😁

Don’t you just love detailed instructions like that... I suspect the troubleshooting guide is equally helpful....If the green light isn’t on, check that the power is plugged in....if the problem persists contact technical support.....

I suspect the drive letter issue is because the ASI Linux OS is installed in a compressed or EXT4 (I think) partition which windows can’t read. use win32dsk imager (a free download) to backup the sdcard and all will be Ok. on the WiFi front....does the phone support 5GHz WiFi networks, most modern ones do, but older ones may not....I suspect you can switch the ASI air to use the 2.4GHz band for WiFi, but not sure on the details....

You can use astronerry via a vnc app or web browser (astroberry shops with 'novnc' enabled by default I think. But the interface isn't optimised for phones so you're left trying g to use a standard linux desktop on a small screen touch device...you can do it but I don't find it enjoyable....a tablet is much better in my view, but it's still harder work than using a laptop....However, one of the key benefits of astroberry is that you can be almost fully automated, so you only need to connect to set your run off, so you may fi d it works OK

If I remember correctly the guide cam has 3.75micron pixels and the mini guidescope is f4- so 120mom focal length... so your guiding resolution is 3.75x206.265/120 = 6.4 arcsec per pixel. Guiding software computes the centroid of the guide star image- and it should be able to spot deviations of approx 1/6 - 1/8 of a pixel- so your focal length is a bit short for high res DSO imaging but probably OK if you aim image at about 2-3 at seconds which is more typical for most DSO images anyway... There are a few things to consider- 1. For long exposure DSO imaging the maximum resolution possible is governed by the atmospheric seeing- unless you are at high altitude this likely places a limit of around 2 at seconds on a good night. 2 The guiding system and mount need to be able to guide at 2x higher precision than your final image resolution (an extrapolation of Nyquist sampling theory) So your guiding errors need to be in the region of 1 arcsec if your final image is going to achieve 2arcsec resolution 3. The guidescope resolution needs to be sufficient to ‘identify’ guiding deviations significantly smaller than this and t he n apply just the right correction to the mount which must then respond quickly and precisely to the going input... putting all this all together..... I don’t know the specifics of your mount, but it usually takes a well tuned high spec mount machined to precise tolerances to reliably guide at better than 0.5arcsec RMS- it’s a tough ask for your typical HEQ5 the ioptron may well be better the the HEQ5, @ollypenriceis half way (or more) up a mountain, has oodles of experience, some really high spec kit and no small amount of talent- I seem to recall that he’s happy with his images at approx 0.9arcsec per pixel.... if I were you starting out with DSO imaging I’d bin the pixels to get a sensible image scale or even better- get a scope with a focal length shorter than 1metre

I wouldn’t use a barlow- at the native 1500mm focal length you’ll be imaging at approximately 0.5 arcsec per pixel- I’d be surprised if you can get your auto guiding setup to get the best from that sort of scale. I’d keep the native resolution and bin the pixels 3x3 (or 2x2 if you have really good seeing and excellent guiding)

You don't say specifically, but I assume your doing planetary imaging if you're using a mak and a Barlow. The link given above seems to be based on DSO imaging where for the relatively long exposures used, image resolution may be seeing limited... However, for fast frame rate planetary imaging, the situation is somewhat different- here you want to sample at approx 1/2 to 1/3 of your max resolution. So you can get an idea of the optimum pixel size for any specific focal ratio (irrespective of focal length) you should aim for the situation where focal ratio is between 3.5 x pixel size and 5.3 x pixel size. In your case, I'd be tempted to ditch the Barlow and image at f15 with a camera that has pixels between 2.8 and 4.3 micron. There are a few chips in this range- ASI290 series @ 2.9 micron or ASI224 @ 3.75 microns. If you particularly want the 174, then with the 2x Barlow you're still in the right ballpark for critical sampling. Clearly there are other factors that also come into play, and I'm not a planetary imager, so these may not be the best overall match for your setup, but in terms of critical sampling I think the maths is correct.

I have both Pocket Sky Atlas and the Cambridge double star atlas. I prefer the scale of the Cambridge atlas, and the double stars are a nice addition, however I prefer the layout of PSA- so I took the liberty of scanning each page to a PDF and printing out at A4. Put them all in poly pockets in and A4 ring binder....dew proof, convenient if any pages get lost/damaged I can reprint them and now my original PSA doesn’t need to go outside at all.

I picked up a Solar Scout from FLO a couple of weeks ago. To date I’ve managed about half a dozen sessions and been quite happy with the prominence details. There’s been nothing much to see on the disk apart from granulation - which is visible, but more subtle than I thought it would be (but I guess that’s what happens when you compare images with visual). In terms of eyepieces I’m using a 16mm Nirvana for the most part- which gives a good full disk view, with reasonable control of scatter and sufficient magnification to see detail in larger prominences. But I also have a scan around the limb with a 10mm BCO to check for smaller proms- but the view is quite dim- I need to get a better hood to block out ambient light. Overall, I’d have no problem recommending one as a first solar scope- the price is V good in comparison to new Lunt and PST options....but this is my first solar scope so I don’t have any experience of these other options to compare the quality of the view.

Tico If you’re struggling to decide, you probably don’t need another option, but here goes.... I sat on the fence about getting a solar scope for a couple of years...a few weeks ago I bit the bullet and bought a Daystar Solar scout SS-60DS....At about half the price of a PST-DS- It seems like a good buy. Had a few short sessions with it and I’m pretty impressed- although I don’t have anything to directly compare it with. It’s quick to set up, simple to use and the view seems pretty good- I’ve been able to see good details in prominences along with solar granulation (there’s not a lot of activity on the disk at present).

Unless you choose carefully barlows can make getting the right level of magnification at higher mags because it effectively doubles the ‘gaps’ between your various fl’s. E.g- if you’ve got. 1200mm fl scope with 10 & 7mm eyepieces plus a 2x Barlow- you get 120x, 171x, 240x and 342- that’s a big jump between 240 & 342- so if you want something around 300x you’ve either got to go for an 8mm native with the 2x Barlow or a 12mm with 3x Barlow- either way you end up with an eyepiece that’s pretty close to one you’ve already got....you could go for a 2.5x Barlow...but you’ll almost certainly end up with some duplication....It’s almost certainly possible to get a good spread of mags but it makes my head hurt trying to avoid duplication, so I’ve not gone down the Barlow route

I have a really old Freecom DVB-T USB dongle that I’m trying to repurpose to radio astronomy. I’ve tried a Windows 10PC with the winusb driver and a raspberry pi with the rtl-sdr driver and neither seem to work. In both cases the application fails to detect the device. In raspbian dmesg reports the device as an rtl2830 chipset but in all my googling the rtl-SDR docs don’t mention this version- nearest is 2832u- so am I out of luck?

Received my Daystar SS60 from FLO on Friday and had a chance to get first light with it today. There was a bit of thin cloud but with patches of clear blue between- so thought I'd give it a quick try. Paired it up with a SW Heritage Virtuoso mount, Amazon Basics (badged Ravelli) tripod and a SW dielectric diagonal. I plugged the power pack in to the SS60 before heading outside. I pointed the OTA roughly North and set altitude to 53 degrees and switched on to get the tracking going and then swung around to the general direction of the sun. Bag inside to get the eypeice case, popped in a 25mm plossl and within 30 seconds had my first ever view of the H-alpha sun. The bullet finder, though small made it easy to find the target and the eyepiece gave a nice full disk view with plenty of dark sky around it, so it didn't matter if the tracking was slightly off. I waited a few more minutes for the etalon to get up to temperature and then set about "observing"... but that's when it started to get a bit tricky. Focusing was much more difficult than I thought it would be.....the helical focuser is a little stiff but the main issue was that there was almost no detail to focus on....tweaking the etalon temp up / down didn't seem to make a great deal of difference.....I was a little underwhelmed- but then again- we're only just past solar minimum., so perhaps I need to be patient..... Then I noticed a small prominence at the limb around the 1 o'clock position (not sure of my solar orientation yet), so I moved that to centre of the view and tweaked focus on it- to say I was chuffed is a bit of an understatement.... there were bits of cloud moving through the view so the detail was coming and going, but when the cloud cleared I could see real structure in the prominence- and it had only taken about 15 minutes from noticing that the early morning clouds were clearing until I was able to be outside taking in the view. After a few minutes with the 25mm plossl, I realised I was finding it quite tricky to hold a clear view- I sometimes get blackout issues using the same eyepiece at night, but it seemed much trickier in daylight. I thought I'd up the magnification and popped in a 10mm BCO....this was much easier to use, a few seconds finding focus again and there I was, back on target and able to see the appearance of the prominence change almost minute by minute....sometimes it was a wall of vertical streamers rising up from the limb and a few minutes later there were "holes" in it and the outer edge was more feathered..... Tried upping the power again with a 7mm Fujiyama HD ortho but this dimmed the view a bit and didn't seem to add much detail, so I switched back to the 10mm. Then I took a tour of the limb to see if there was anything else of note- at times it looked like there were tiny "spicules" radiating out from the limb but they seemed to come and go, so not sure if I was imaging them or if they were real.....I also got hints of solar granulation towards the limb, but couldn't see it towards the centre of the disk, so again might have been imagining it. There wasn't a lot else to see today, but I think I've learnt a couple of important things and also got a few questions. 1. The detail that's available is much more subtle than I'd expected. I assumed because there's so much light on offer, that it would be easy to detect, but the brightness difference between the disk and the prominence means you have to work reasonably hard to get the most from it- and I quite like that. 2. I'd expected granulation to be more evident- perhaps it's just I need to get my eye in- but the fact that I could see or suspect it more at the limb makes me wonder if the central portion of the disk is just a bit too bright.....does anybody use a polarising or neutral density filter for H-alpha? 3. I thought that the seeing might be a bigger problem than it turned out...I've got a south facing patio, but setting up so I viewed over the lawn and then out onto open fields seemed OK. It wasn't the hottest day today, but with the 25mm (approx 37x) the view was sharp and very little shimmer was seen and even at 93x with the 10mm BCO the view was mostly steady with just a bit of shimmer at the limb. 4. The eye relief of the plossl was a bit too much and seemed to make it quite difficult- I thought this would be my "go to" eyepiece. I tried a light shroud which helped a bit, but I'll need to think again. The 10mm was nice, but the narrow field of view meant I couldn't get a whole disk view...So any opinions for optimum eyepiece- thinking that a 9 or 10mm - 60-68 degree eyepiece should give me enough magnification to see the details and still enough field to get the full disk..... Overall, this was a great first light for me.....I'm happy to cut my teeth when there's not too much going one, and can't wait to get out again to get a little more experience under my belt.

A cheaper option would be one of the 6inch f9 RC scopes- with a reducer/flattener. You'd have the pption of 1370 mm or 1000mm focal length- with the edge it's 2m or 1.4m with reducer. Both are a tough ask for the HEQ5. At 1m with your camera and 2xbinning your image scale is around 0.9arcsec per pixel and at 2m it'd be half that. If you can guide at 0.5arcsec per pixel rms then Imaging at over 1m focal length could give good results- but I'd check my guiding stats before investing in the Edge.

Thanks to both- might take a trip to my local Halfords to get a can or ArmorAll and see how it goes.

My circa 10 yr old Canon ISB’s have developed a sticky outer coating. Is there anything I can do to fix it- short of trying to physically remove it. They’ve always been kept in their case when not in use, so also wondering if there’s something I could do to prevent it happening to my other binos. Any ideas?

Definitely want a modded camera on this in my view, and the 250mm FL on the RedCar could catch you the pelican at the same time- even with the crop sensor

I know what you mean- I had a go at the veil nebula last year with a DSLR (unmodded) and Samyang 135mm. Initially all looked good in the subs but as you process for the nebula the stars end up dominating the field. Not sure that there’s much you can do at acquisition. All comes down to post processing/masking before stretching the different aspects of the images.