OK Apricot

Hi guys, Been becoming more conscious of eyesore stars in one half of my images. As I look at the sub frames, the left side corners have lovely round points for stars, but the right are elongated, and along the same plane at that. They don't really show a "fanning out" pattern from centre like you'd expect if your sensor was too close to the reducer, but the elongation is the same plane, size, direction etc in both corners. My reducer has a rotator so I've nipped up the tensioning bolts so that it's tight to eliminate that, I've tightened the OAG thumb screws one at a time half a turn at a time to get the most uniform "grip" so that the bracket is square in the optical train. The focuser rotator looks and feels well built and I can't see or feel anything from there. Tested tonight and it's an improvement over my last outing, but I'm still not satisfied. Packing away earlier I put the scope in its usual position in the lounge and with both lights on I could see and feel "slop" in the focuser draw tube. There is a little silver grub screw on the part of the focuser that the tube slides in and out of, but it's on its own and opposite to the focuser rotator lock knob. What might be the best way to take up the slack in this scope's focuser with this arrangement of screws? Many thanks in advance 👍

My rig weighs in just under 4kg fully assembled and it's definitely pushing what the SA GTI is capable of. Every so often I have to chuck a frame or two out due to wild guiding/tracking, and that's at 274mm. The counterweight is right at the end of the bar, and they say not to run additional weights. You might be able to push it a bit further but to be honest I think you might end up disappointed trying to use the C6 on this mount.

I gathered just over 5hrs data last night putting the mini rig through its paces to make sure it's ready for international travel. The scope is the Sharpstar 61EDPH II and I'm using it with the 0.8x reducer. Just looking through last night's subframes it appears I'm getting a shift in FOV at random moments, the period between each seems to suggest after autofocusing. I checked over the rig just now and it seems loose at the reducer rotator? I've done a little searching but I haven't managed to find any discussion about this reducer, how to adjust for tilt, tightness of the rotator etc. I wondered if any brains on here might have had to deal with a similar issue? On a side note, how do I view my guiding logs as a typical PHD2 looking graph?

Thanks chaps, much appreciated 🙂

What scope do you have? I wouldn't say you've missed out at all - there's a whole hemisphere up there to explore, and the planets will be on parade again, you just need to be patient 🙂. Take this with s pinch of salt as I only had a few months observing experience before moving to astrophotography... DSOs won't be beyond you at all. There is plenty to see as soon as it clears up. Spring is dubbed Galaxy Season as this time of year the milky way, and all the nebulae, clusters etc aren't really readily observable (unless you stay up late). There are a number of easy(er) galaxies to see though, like M51, M81 and M82, the Virgo cluster and Markarian's Chain. If you don't fancy that at this stage, double stars can be very rewarding. Albireo is a classic, Izar another good one top of my head. These can require high magnification and a steady mount though. I spent my first few months observing at this time of year and I was out every clear night. There's plenty up there, and an app like Stellarium on your phone can help you navigate around to start with. More experienced observers will be along shortly to give you some decent advice 😂

That's me signed. To add an emotionally charged comment, it's like society has become scared of the dark. Looking at it from a "green" point of view, can you imagine the energy and carbon savings from switching off street lights and office building lights? There's a an absolute filth of a street light right outside my garden, standing 20ft over it casting bright halogen light all over, and for what? There is nothing down my "street" - It's a dead end with a few garages in a line. Just turn it off. It's beyond frustrating and it's no wonder this thread is being moderated to the level that it is - people are going to do what they're going to do to deal with nuisance lighting, as there's absolutely no thought or recognition the other way, our way etc. All the while Mr. Einstein appears on telly asking us to turn down the heating, turn down the boiler.... What an absolute joke of a country.

I have a couple of trips planned this year, the dates of which will be around New Moon so I can do some imaging from quality skies. I posted over on the American astro forum about one of these trips and many suggested I take binoculars. I'm very much warming to this idea... With a very hard earned and honest 200 British pounds to spend, I'm probably looking somewhere around the Celestron "Pro" line or Opticron for a 70mm aperture jobby. I'm also not going to be using a tripod because of limited luggage side. I'm not a particularly experienced observer, so I'm just wondering really - I am most open to suggestions: Just what might I be able to see under very dark skies? According to lightpollutionmap I'm going to be under B2 skies, and we're going in June and October, so will have the milky way core area, Cygnus, cass etc.. The question is if any of these targets might be visible with such a small aperture. Are filters recommended with binos? What are your experiences?

@Carbon Brush thanks for following up with the certificates and such. Should be useful in the event of an x-ray interrogation. The SA GTI can run on AAs similar to the AZ but as @Elp said its unreliable at best so not an option I'm considering. Perhaps it may be best to have a backup, one of these Talentcells taken with me so I can get something while I'm out there should I not be able to source anything locally.

There may be better locations as @Louis D points out, but for my personal goals of the trip Dallas seems to be the best compromise. I actually think I'm leaning towards a couple of locally sourced leisure batteries at this point with a method of charging from both mains and a car, particularly for Fuerteventura. It looks like professional photography batteries can be found for rental in Vegas so I think that covers that base too. Still have to look further into it. The inverter idea has been ditched. @malftobe Texas looks very good from a light pollution perspective, there's certainly going to be some driving involved to get to the darkness! The hobbyking jobby looks like a good unit, red to red and black to black and you've got some power. I used to buy loads from there back in my days of RC racing 😂 Very reputable company.

Indeed true - I use a vape so carrying spare batteries is a must when I travel and I've always been sure to take the allowance in my carry on. Please keep us posted, it would be most helpful! I'm currently brainstorming ideas for the eclipse in '24. I'm swaying towards a fly-drive type holiday as I'd like to be mobile 1)for the eclipse to be able to drive in case of weather/cloud and 2)April is getting to prime tornado season in the Midwest and I've always loved me some good severe weather! Needless to say I'd like to bring the mini rig on this one as well as, again, dark skies are to be had nearby. My gut says you'd probably be alright, after all, just how many astrophotographers are going to be on the same plane? Really? I wonder if there is a way of checking with the airline nearer check-in what expected capacities might be. The only way I could be remotely comfortable using a rental car battery alone would be if I could monitor the voltage, be it a multimeter or onboard monitoring. I don't like the thought of being stranded in the Nevada nowheres 😬 It brings me back to my thought about the inverter, and having to start the engine to keep the battery topped up.

Cheers @Elp, useful to know. Two of those to all intents and purposes could do the trick. I could even charge one on an inverter while the other is being used 🤔. Do you mind providing a link for your talentcell? I see one on amazon but I'm not sure - the one I'm looking at has 12V output but only at a piddly 1A. I also did a little googling and found a couple of businesses in Vegas that hire out batteries for the professional photography industry so I wonder if astrophotography applies enough to get a rental. A 130Wh 14.8V unit with inverter would give some good run time for a respectable $40 for three days.

This sounds like a flowchart, like a biological process that astronomers develop 😂. I'll add one - You've already been waiting months for a particular piece of kit to come up second hand, so you talk yourself into paying that bit more for new stuff, and as if by magic the item you were looking for for months turns up for sale the next day.

That's a great idea. It'd be great to have a 500Wh Jackery or similar 💡 I'll look into it, thanks! Very good considerations, thank you. Looks like I've got a little more reading to do. Of course there will be some spoils to show on my return, their quality being questionable! Really need to work on my processing 🙈

I could but I wouldn't want to be getting a flat battery out in the middle of nowhere! The hassle and recovery fees wouldn't be worth it 😂 Ideally I'd like to be able to run for up to 10hrs uninterrupted seeing as that's about the length of astronomical darkness in Vegas when we go. I wondered if a simple connector would allow me to maximise imaging time. Thinking about it, I suppose I could use one battery per target - 2-3hrs on each out there would be like 10hrs at home anyway 🤔

Hi ladies and gents, I have a couple of holidays booked and plan on taking the recently finished mini-rig for some imaging under quality skies - Fuerteventura in June and Vegas in October, both around New Moon. OK I won't be imaging from Vegas per se, but have a few potential sites a couple hours' drive away. Both holidays I'll be using a rental car to get out to the darkness,so won't have any mains. Anyway, the completed mini-rig is: Sharpstar 61EDPH II + 0.8x R/F, Star Adventurer GTI, ASI533MC-Pro, OAG, ASI120MM-Mini, filter drawer, ASIAIR Plus, EAF, dew strap. I'm happy enough with the logistics of the trips and sorting appropriate insurance but I'm umming and arring over how best to power it. According to my Anker 521 the power draw, with the camera at -10°C, dew strap at 80% and the mount slewing is in the region of 20W. I need to consider airline battery restrictions and for both carriers the maximum capacity of a single lithium battery is 100Wh. It's two per passenger so I can bring four single batteries at this capacity, and that gives me potentially 400Wh of juice. I'm not great at maths or electrics but I believe at a nominal 12V this should realistically provide around 12-14hrs run time considering inefficiencies, slewing, temperature etc (400/20=20)? To me it sounds great, but I'd need to be able to wire these batteries in parallel to avoid having to power off, disconnect, power up again and so on. Would it be as simple as making a parallel connector? Sorry if this is a silly question - it seems very straight forward so I feel like I must be missing something. Another option would be an inverter to run from the rental car, but I think having to stop and start the engine would cause issues. Sure, an inverter will put out mains voltage which I can then plug an adaptor into to power the rig, but there would be a voltage drop to consider when starting the engine, which might knock my kit out, blow fuses etc? A top-of-my-head solution would be a capacitor but not sure how robust this would be, not to mention having to wire it into an adaptor appropriately. A stream of thought here but I would appreciate your thoughts and insights, your experiences doing the same? Many thanks 🙂

Fuerteventura national park is excellent, the only real light pollution being a bit of glow from Morro Jable. Tight windy rocky/Gravel Road to get there but so worth it when you get down towards the lighthouse where it levels and smooths off somewhat. It's where I had my first real taste of dark skies - a truly unforgettable experience!

Pretty sure it's the same focuser as on the 80ED, in which case I had no trouble fitting it with everything included in the box and no modifications. It's very straight forward 🙂

Swapped from guide scope to OAG. First night was difficult to find common focus, getting backspacing right and the like and guiding was all over the shop, albeit with round stars. On my other thread changes were suggested like Bin2, lowering aggression and changing where I Calibrated. This time numbers were between 0.4" and 0.6" and helped get these sweet galaxies 🙂

A decent astro night Monday! Tried to push and convince myself I didn't need sleep before work but came to my senses and packed up after 4ish hours of trouble-free imaging 😊 Galaxy season looms, so here is M33 the Triangulum Galaxy and M101 The Pinwheel Galaxy. Quite pleased with how it turned out with such little data - 1hr 54mins for M33 and 1hr 45mins for M101 of 3 minute sub frames.

Just checking in here to report from Monday night. I tried a couple of your suggestions and got some very acceptable guiding. I double checked over my mount but couldn't really feel any backlash, certainly not amounts that my grease monkey hands could deal with, so just decided the first things I would try would be non invasive things such as settings. Cam was binned x2, calibration was done more or less 20deg above the celestial equator, and I reduced the aggression on both by about 25%. Happy to say that for the most part it was reporting a total error between 0.5" and 0.6". Thanks a lot for your help guys, that will do me nicely!

Great stuff, that's given me plenty for next time. I'll get to work as far as I can with the mount and report back. Thank you very much chaps 😊

@alacant the screenshot you've posted is when I was using the Evoguide 50ED - The log I posted for that was from Nov 2022 and I'm doubtful it's representative of last night. Please could you evaluate the log from last night with OAG? It's the first attachment if it helps?

@alacant The subframes themselves were fine from what I could tell with the preview. The image through the guide camera were, I thought, acceptable - There was some astigmatism/aberrations present but nothing like oblong or crescent shaped like I've read they can be. I've attached a guide log from both OAG and guide scope. I will try calibrating further north next time. I've been getting excellent results with a separate guide scope but the idea of the OAG is to save space and weight, and in theory more accurate guiding. I'll be taking a small rig to Vegas later this year so space and weight saving are important. @newbie alert As said above the idea of the OAG is to save space and weight on the mini rig I take abroad. I'm testing it on the 80ED because it's mostly galaxies I'd like to image for the next few months and this scope is the highest FL at my disposal! I didn't confirm in my original post, but the guide focal length was the first thing I'd changed before entering the ASIAIR. It has it down at 520mm with reducer after plate solving so I just copied that as my guide focal length. I didn't measure anything but to summarise, the process was this - Find focus with imaging camera and lock focuser, fiddle with OAG until focus achieved, double check focus of both cameras is close. The stars are perfectly acceptable with a little astigmatism present. If there is a guide assistant with the ASIAIR please could you point me in the right direction? According to Astro Tools CCD calculator the image scale of my 80ED/533 is 1.52"/px. Most of the time the guiding was slightly below that, but there were some excursions... @ONIKKINEN The sub frames, from what I could tell from the preview, were pretty decent - no obvious trailing - No readily visible difference in subs from guide scope to OAG. I don't think I have the software to measure FWHM, but from eyes it all looks pretty close. I've attached guide logs from separate scope to OAG. Thanks for the support so far chaps, much appreciated! So far the next things I'm going to try are to Bin2 and calibrate further north. I've attached guide logs - 07/02/23 is from last night with OAG, 23/11/22 with Evoguide 50ED. Same guide camera, same imaging scope, balance as close as I could get it. I don't know what to make of these logs so any education would be great! I've attached some snap shots for what it's worth. Thanks again guys PHD2_GuideLog_2023-02-07_194639.txt PHD2_GuideLog_2022-11-22_203308.txt

So this is at 520mm. I'm not sure how to provide a log from ASIAIR? As far as polar alignment I got it to 4" accuracy according to that. For starters I'll try bin2 next time.

I toyed with the idea of getting an OAG for a couple weeks and decided to just do it, thinking if it fails I can sell it and go back to a smaller guide scope. So it was delivered yesterday and last night I managed to get out to try to set it all up. After a couple of hours trial and error I managed to find mutual focus between both cameras, shout out to the moon 🙌. The setup: Skywatcher 80ED>0.85xFR>ZWO OAG(ASI120MM-Mini)>ZWO filter drawer>ASI533MC-PRO, controlled by ASIAIR Plus on an EQ6-R Pro. After finding rough focus I slewed to my target, fine tuned focus and set it off for calibration and to take some test shots. Backspacing of camera looks pretty close, no obvious aberrations on the sub frames (but will find out later tonight when I process the data). I was a little disheartened to see figures up near 2"RMS. I calibrated close to celestial equator and meridian (Thor's Helmet). Mount was balanced, tried 1,2,3s exposures, tried gain between 75-100, changed aggression, duration of RA/DEC but the best I could get was 1.3"ish average. A couple things I noted was when a plane flew through the guider Fov it was not to be seen on my sub frame, I'm assuming this is normal seeing as the prism is not in the line of sight of the sensor, so doesn't see the same thing. Also that DEC was reporting the highest error up around 1", RA around 0.8". I'm just wondering really whether this could've just been seeing, guiding showing higher error due to smaller image scale? Or could it be something else? I wasnt hoping for miracles to start with but was expecting a bit better than this seeing as the guiding software will show a good 0.4" on good nights with a guide scope.