vineyard

Hello, I took advantage of the beautiful sunshine today to get the Lunt out again. It was wonderful seeing the Sun, the Ha features, and some really nice prominences and filaments. Just wow. I could look at this stuff all day. I grabbed a few shots - one just by putting my iPhone over the eyepiece, and the other by threading the ASI in and taking the nose out (now that I know where it should sit 😀). I still haven't gotten the chance to sink my teeth into stacking so the two photos below are Lightroom tweaks of a single image each. Not great by any means (but it actually helps to see the image and then realise what I could have done differently even at the time of taking them - hindsight is 20/20 but that's how you learn!). Cheers, Vineet (PS - I know the photos could both be in better focus. With the iPhone one, I just couldn't get my hand to stay rock steady long enough, and with the ASI one, trying to dial in focus on the laptop screen with the glare of the ambient light while just crouched down was eye-opening: now I understand why people use the boxes and blankets etc!)

Thanks all 3 of you! Can PMs be like WhatsApp group messages (ie have more than 2 people on the PM)? If not, thank you for the offer Peter - your kindness gets you the short straw :) I'm going to call the scope maker first just to figure out a few factual things and then there'll be a message incoming 😀 This could be the beginning of a great adventure (for me anyway!). Cheers, Vin

Hello, With the ZWO sale that's now running, I'm thinking about possibly dipping my toe in to guided imaging. And so was wondering whether SGLers had any view on the ZWO 30F4 miniguider scope. I've run that on astronomy.tools against EvoGuide50 and Altair Astro 60 miniguiders, and it seems to have a nice big FOV (all the better for getting a good guide star in light polluted skies?). Its nice and small and light. What is it like to focus in practice - and can its focus be locked for future use (I don't think so guessing from the photos)? My main scope is a 102mm f8.6 - is that miniguider too small for that? I suspect the Evo or the Altair would be better, but just in case... Thank you! Vin

Hello, I'm not sure whether this is better in the Equipment forum or not, so I thought I'd start here. I'm slightly intrigued by the idea of doing a PST mod to allow Ha through my normal refractor. I've come across various references to it having been done (including this useful article). But since I don't want to use a donor scope but my existing scope (which is my baby), I wanted to see if that might be possible (b/c I'm not physically altering my baby in any way ). My current scope is 102mm aperture, 880mm focal length (ie f8.6). I've seen references to the donor scope needing to be f/10 (I guess the PST is geared for f/10 optical lengths) and then also seen references to people cutting about 12cm off their donor scopes. Which would take 1000mm optical path to...880mm give or take! So, I'd be v grateful to those with experience on this mod (or better knowledge than me about light paths) if they could shed [sun]light on whether it would work if I took the black section of the back of the PST and attached it into the drawtube of my refractor? I'm guessing I wouldn't be able to view the full disk with just a stage 1 mod, but I don't mind tbh - I'm more interested in looking more closely at features (and I suppose I could always use a reducer if needed as I know some SGLers have done to get full disks on bigger aperture with stunning results)? If that is possible, then (just as an aside) could the front bit of the PST that's been taken off also be used to construct a guide-scope as a separate project (albeit in a v garish gold colour...)? I'm hoping its possible (esp as that article has photos where the author has attached the PST mods to TEC140s which I'm sure they wouldn't have chopped, unless they were oligarchs!). If so, then what are the things I should keep in mind about getting a used PST (eg: the article says how the penta prism can move out of alignment - how do I guard against that before buying, or is that correctable?). Thank you! (And btw, if this is path of madness & frustration that I'm intrigued by, pls feel free to say so!). Cheers, Vin

Thanks both! That's really kind of you & both of those definitely improve the original Agreed the focus could have been sharper still & thank you re the gamma tip. I played around a bit w exposures (I think that one was about 5000us) and haven't even gotten my head around gamma & gain etc yet, but reading up about things like that is what cloudy days are for, right Unfortunately Immpg doesn't seem to be on Mac - I've found SiriL & already have access to Lightroom so will play with those a bit, but I suspect I may have to bite the bullet on Pixinsight if I really get into AP! Cheers both, Vin

Hello all. SUCCESS! I had another quick stab before heading to work, and managed to get the sun to focus (see attached sample single shot, no processing). Lots of thin, high clouds and I didn't try and pressure tune it, just wanted to see if I could focus. Its not an interesting photo by any stretch of the imagination, but I think it shows focus on the disk edge? So, to get it done I took off the 30mm EP holder that comes out of the diagonal, and threaded the ASI body straight into that. And then started to take the diagonal nose out of the helical focuser slowly. Got to 14mm out, and was able to get the focus (I'm sure I could have micro-focused it more but time was running). So by my maths, I needed 16mm of inward travel when switching from the EP to the ASI. And the helical focuser only has 10mm so that seems consistent with not being able to find focus using it alone (and in practice depending on where the EP finds focus with the helical, there may be much less than 10mm of remaining travel available). Out of curiosity, I then swapped back from the ASI to the EP (with the EP holder). Thinking that would add 30mm back and so I'd have to push the diagonal nose back in - I tried that to see how far I'd have to go to find focus on the EP, and there was about 4mm sticking out (vs the original 14mm). So a net movement of 20mm (ie, around the 16-20mm range). Now, as I write this, I realise my maths is off b/c the comparison should be to the movement of the focal plane of the EP. Maybe I will try and sit with a towel on my head to figure that just out of curiosity (or maybe I'll pass on that!). I'm just glad to have gotten it to focus (unless you tell me no that's not in focus! 😂) What a palaver. Thank you all so much for the help & feedback. Now to just practice all the other skills for taking good solar AP 🤣. (Part of me does wonder whether it might have been easier - albeit perhaps marginally more expensive - just to get a Quark to stick on my normal refractor, which has much more draw!). Thank you all again - what a great community this is & you all are stars to take so much effort to help a newbie. Cheers, Vin

Hello, thanks for this both. Nigella, I have a helical focuser with the princely amount of 10mm travel back & forth. I can find focus with an EP but there isn't enough inward travel for the camera. Yes I think the Lunt 60 seems to be better equipped (although I guess even you have had to use work-arounds with reducers etc). Pete, thanks for that link - v helpful. I did see it earlier in my internet trawls but then had lost it. I remember being equal parts impressed at the ingenuity & also appalled that rubber bands would be needed for kit like this! 😂 Chapeau. Upon re-reading it, and carefully looking at the photos, you're giving me ideas & hope. In particular, the first photo in that thread. I notice you've got the nose piece of the diagonal out a bit and that that worked with your ASI120. I think the 178 & 120 have v similar bodies. I was starting to try that systematically last time but then the clouds arrived. So I'll keep persevering with that. I'm guessing the DMK has different dimensions than the ASI if that worked for you with the nosepiece all the way in, and the thinner adapter than the stock Lunt 30mm after the diagonal (photo 6 in the thread)? One Q for you. Did you try putting the 2.5x powermate after the diagonal and then attaching the ASI (either with or without nosepieces) to it? I've been toying with whether that would work (perhaps by placing the powermate in at different depths into the eyepiece holder after the diagonal, so that the optical image it makes parallel has different dimensions (to match the chip size) depending on how deep the powermate is sitting, but have no powermate to try it with! Cheers both - now to wait for the sun (again). Vin

Thanks both. Re the ZWO extender, I've found all the different formats in astro kit just too confusing at times so I thought I'd stick with the OEM for the camera. When I looked at the link you shared Rusted, I thought "what's T2" and then googled it and saw that T2 is M42 with a thread pitch of 0.75mm (along with a warning to be careful as conventional M42 has a pitch of 1mm and ne'er the twain should meet). Then I went back and looked at ZWO and their M42 camera connections are indeed with a pitch of 0.75mm, ie T2...its like the tower of Babel🤷🏽‍♂️ On the camera, no I wouldn't keep both! It was more the arithmetic of trading into an ASI290MM mini which could also be used for guiding eventually in the future. No rush there anyway as I don't see myself doing guided night-time imaging for quite a while (just not worth it where my scope lives), so will chew on it a fair bit more - your arguments are both compelling & reassuring Rusted. Nigella re the reducer/barlow, this is where I get confused with the extender. I can see the logic for a reducer - it contracts the focal length and so if inward focus was a challenge, then it makes perfect sense. (And for zooming in on prominences, the magnification of a Barlow also makes sense). Where I'm left scratching my head is how an extension spacer would fix things if the problem is with inward focus, since after the extension, the CMOS chip is further away not closer to the objective. (Unless it's about getting the chip sensor somewhere between where the EP focal plane and the EP objective would be). Anyway, nothing venture nothing gained - I'll try a spacer & report back. Cheers both for all your help - it's always good for your own insanity to have someone to use as a sounding board! Vin

Thanks both. Nigella, I looked at ImPPg after your reply - unfortunately it seems to be Windows only and I'm a Mac user (just to make things more complicated🧐). Rusted, I have a BP400 but that shouldn't affect the focus should it (from what I can tell, the difference is the size of the gap the remains around the viewed image - BP600 has more space so the image doesn't get potentially clipped?). I have tried the ASI178 w terrestrial targets on a larger refractor (4" 880mm) with more focuser travel and it worked with that to find sharp focus - I also tested it quickly with white light solar on that same scope and attached is a single shot image I was able to take. I'm glad I can ignore the mono comment in the other place Rusted 😀 . Although looking at the ASI120MM mini or ASI290MM mini placement of the sensor does suggest that those could be straight swapped with the EP? (Nigella you take your amazing photos with an ASI120MM right?) I haven't tried a 20mm spacer yet (interestingly that's the same thing as Nigella is recommending with keeping the blocking filter out about 20mm). I thought that the light path needed to be shortened rather than lengthened if a CMOS sensor replaces an EP b/c the chip sits back from the focal plane of an EP (based on what folks in the other place were saying)? I did try fiddling with the filter placement (although I couldn't do it systematically as the clouds kept getting in the way). Given ZWO's Black Friday sale till 31 Dec, I may just take a punt on this anyway: https://astronomy-imaging-camera.com/product/m42-m42-extender-21-mm-length Remembering that the turtle got there in the end, I shan't get disheartened just yet! Cheers, Vin

Hello, That is beautiful. At first I thought maybe the blue was Ca-K! May I ask what size Lunt you were using? (I struggle to get my Lunt 50 to find focus with my ASI178 - not enough inward travel). Lovely photos, Vin

Hi Rusted, I tried again this morning, and have come to the conclusion that the problem is insufficient inward travel on the stock helical focuser on the Lunt (the focuser only has 1cm of travel). So I started trying to put a Barlow in to extend the light path to see if that might allow the ASI to find focus - and then the clouds came in :) The Sun is being coy. Will have to wait for a sunnier day (next spring at this rate?). Alternatively, I noticed that there's a spacer between the focuser and the diagonal - so if I can replace that with a shorter spacer maybe that will create the extra inward travel synthetically. (But will the light path then be too short to find focus w the EP?). What a palaver! Still it was nice seeing the orange peel skin on the Sun this morning. Cheers, Vin

Managed to get some views in for the first 45 mins or so - intermittent, and then progressively more, clouds. Managed to see second contact Seeing the relative scale of the Sun & Mercury - wow, I cannot imagine how much the Sun must dominate the sky on the little messenger! Couldn't get my ASI to focus (still learning how to use it) so instead just plonked my iPhone over the EP. White light wedge, with and without a green filter. The yellow photos below are obviously ones I've played with. The other three are untouched on the colour, but just cleaned up a bit re contrast etc. Kit was a TV102iis, Lunt wedge, and Lunt zoom EP. (I even managed to see it through a Lunt 50THa but no shots of that). Given how bad the forecast was, very pleased to have seen even a bit. Cheers

Cheers Ed, that is helpful. I've been checking other forums as well and yep it seems 102 apertures have been used to split the Sirius pair. That was a v unexpected & v welcome gift from the heavens last night (it was fair dazzling above the roofs, twinkling away). Gutting result on the football - I was watching the Wall and the couple on that too ended up wiping out, not a lucky evening tonight I guess. Cheers, Vin

Hello, Noticing how clear the skies were at about 0045 last night, I did a quick visual setup. It was really nice seeing stars (I put a Baader neodymium in to help) - it really just takes you away. Sirius was just dazzling so I took a quick look at it. Well actually, I'm returning to stargazing after so many decades that I didn't even know it was Sirius at the time - just something dazzling SW of Orion 😂. So I pointed my 4" refractor at it and worked down from 15mm to 4mm. And as I was doing that, I was thinking to myself, "this looks like a double, is it a double or am I just not focusing properly" with the double-y bit seeming to be at about 5 o'clock from the the brighter one. I just left it at that and went to bed. Looking at KStars this morning, I realised "oh that was Sirius" and then looking a bit more into Sirius (after being embarrassed that I couldn't even recognise the Dog Star I'm so rusty...) I saw various threads on the double and the Pup and even down to the position (ie, it's at 7 o'clock but obv that gets mirrored to 5 o'clock). And so now I'm wondering did I actually see that last night, was it a dream 😂. Did anyone else see the Pup last night or do I need to get my eyes tested? Cheers, Vin

Cheers Highburymark - yes I intend to keep a close eye on it. Bresser Germany are kindly also sending out a replacement o-ring just in case. Rusted, I'm not sure whether its inwards or outwards but in either direction it doesn't reach focus. The closest it comes is when the graduated dial is at 0 - I lock that in and then try the fine-tuning dial but no joy. Wrt workarounds, I've tried the followsing: 1) leave the nose piece off on the ASI and thread it into the diagonal directly (ie, with the black cylinder that an EP would normally sit in taken out) 2) leave the nose piece off on the ASI and thread it into the black cylinder directly (from memory this is when it got the closest) 3) lock a generic Barlow into the black cylinder that comes off the diagonal, and then lock the ASI (w nosepiece) into the Barlow I was running out of time before having to go to work so I couldn't be more systematic than that. Given (2) I think I will try a couple of additional variations next time A) pull the telescope side of the diagonal out a bit (instead of having it sit all the way in) and then tighten w the screws B ) take the optic out of the Barlow, and just thread the black extension of the Barlow to the black cylinder on the EP side of the Lunt diagonal, and then sit the ASI in with a nosepiece I'll also re-try the options I tried yesterday more methodically. I suspect I need to extend the light path a bit (but not too much)? I've also read somewhere that Powermates may be better than Barlows for Ha optical trains? Btw it seems PhotoFiltre is not for Mac, so I will look at a few other alternatives that can hopefully avoid having to pay for Photoshop! Still on the learning curve for K-Stars & EKOS right now Cheers all, Vin

Thanks Davey-T & johninderby. I eventually contacted Lunt directly, and Bresser Europe in Germany are sending some o-rings (FLO also recommended speaking to Bresser). Btw, while talking to Faye at Lunt she explained that the 50THa ships with 1 o-ring only deliberately. They found that if there were two o-rings, re-threading the tuner on required too much force. So it is now deliberate that the first (lower) groove is empty, and the o-ring is in the second (higher) groove. Anyway, happily after re-greasing, taking the tuner off completely to equalise and then slowly threading back (and, ahem, putting a black t-shirt over my head) I managed to see some Ha features this morning Cheers, Vin

Hi Rusted, wow that is really kind of you, thank you - I had to do a double take to check it was the same image! And thank you for the other tips too (will check out PhotoFiltre7 too). I was playing around some more this morning while the Sun was out. I think the pressure-tuning is sorted (managed to see some Ha features). The workarounds I was trying to get the ASI178 to focus still didn't work sadly, although I'll maybe try a few more things next time. So I ended up just grabbing this shot with my phone through the eyepiece. There was a prominence (or is it called a flare?) at about the 2 o'clock position on the disc which may just be discernible on this [EDIT: not really b/c of the image reduction!]. There was one surreal moment when the silhouette of an aeroplane went in front of the bottom right hand quarter of the sun but sadly I couldn't click fast enough! Anyway, thank you again - that is v kind & helpful. Cheers, Vin

Thanks Alexandra - you're being v kind. It's a pretty poor photo but everyone starts somewhere Thanks re the over-exposure tip, ok I'm going to dial that down a LOT next time. I'm also fairly certain that the sun is out of focus. The ASI instructions say that once focus is achieved in the eyepiece, it just needs to be replaced with the camera - but I reckon that the focal plane for the ASI is not the same as the EP b/c the image was sharper in the EP. I've subsequently read elsewhere that others have had this problem with this ASI and the Lunt, and there are a couple of work-arounds suggested that I will try. (And I think I've discovered a problem with the pressure-tuning on the scope: only 1 o-ring in there...?!). Let's see what the next session brings! Thank you again for the tip. Cheers, Vin

Wow, how did they let that happen; doesn't bode well for product control? Anyway, thanks Dave - I'd tried looking on their website and it's not listed, but will try calling directly! (I'll also look in my local hardware store - no doubt it'll be a bespoke thickness just because...) Cheers, Vin

Hello, I recently bought a 2nd hand Lunt 50PT Ha (on a different platform). The vendor said he had only used it a handful of times since buying it and it shipped in the original box. It seems fine, focuses well (although I find the helical focuser a bit of a pain compared to crayfords). But it doesn't show any Ha features on the surface of the Sun! Long story short, I completely opened up the pressure tuner and found a bizarre thing. Its well greased, there's no detritus (and it doesn't lose pressure). But there was only one O-ring in it?! The tuner itself has grooves for two o-rings and the video on Lunt's website (on how to replace o-rings) shows a tuner with two o-rings when it comes out. And they ship replacements in batches of two. So I'm guessing that somehow the original scope shipped with only one o-ring fitted? (It wouldn't make sense for the vendor to have removed one?). I'm hoping that's what it is, b/c then the inability to resolve Ha features may just be insufficient pressure building up? In which case, does anyone know where I can get these replacement o-rings please (Lunt's US website has them but that's only for shipping to the US)? If it's not that, and the scope is only meant to have one o-ring, any ideas on the problem? The ring & tuner seem well greased. Thank you! Vin (EDIT: in the meantime, the next time the sun comes out, I'm going to try moving the current o-ring from the higher groove to the lower groove in case that longer distance from the base is why the pressure isn't building up sufficiently?)

Hello, newbie member here (also new to AP & solar!). Thought I'd amuse everyone by sharing my first ever exceedingly amateurish photo of the sun today. Lunt 50PT Ha, ASI178MC (I know, its colour not mono!), 20 shots stacked in SiriL. The camera, the software and even the scope (judging by the focus ) are all new to me. Steep learning curves ahead! Cheers Sun 31 oct take 2_00001.tif