powerlord

Any usb hub works fine. I use one with my asiair sometimes. However you might as well make sure you get a usb3 one. They are a few quid more and a bit more future proof as you will be able to plug usb3 stuff in. Stu

temp control is easy electronics wise - just 4 quid: https://www.ebay.co.uk/itm/184140691488 But.. you are going to have quite a bit of hysteresis. And gets invasive if you want to start fitting that probe inside the case. Yes, the fan is big, but that peltier is using 60w of power. without it, the heat sink gets too hot to touch. A smaller fan you just not do it imho. Well, not with that peltier - of course if you wanted to only use something like a 10w peltier and settle for a few degrees cooling, different ball game. That was the problem as I saw it with other people's attempts, they'd stick a tiny fan and heatsink on the case - that just won't work. With a Peltier cooling system the hot sink needs to be MUCH bigger than the cool sink - look at the kit - I'm using the hotsink. the cool sink if it was being use as a fridge is the tiny square heat sink. Here's its the already considerably larger asi case. To be honest, if you wanted to do this with custom parts, I'd be looking for a massive, ideally passive heatsink from a CPU or GPU. Possibly heat pipe based: https://www.scan.co.uk/products/nofan-copper-icepipe-cpu-cooler-80w-fanless-for-all-intel-and-amd-cpus But again, complexity, cost, and yer not gonna get that lucky screws match coincidence. The fan is cheap and unbalanced for sure - but again, the idea was cheap and easy. But if someone wants to try with a balanced ballbearing fan and some vibration isolation, I'd say it has a good chance of working. add the temp controller above and you may get somewhere, I'd probably just put the peltier on the controller, but keep fan all the time. If you wanted to get more complicated and vary the voltage to the peltier and fan, then yes - arduino (well esp32 better - cheaper at about 4 quid, tiny, arduino compatible, much faster and wifi out the box so could monitor remotely), but again - it is getting complicated when as you say, $200 bux isn't too bad premium for the work to do all that well. interestingly I noted that my asi2224 has the cmos on a seperate board like my asi1600 - it makes sense as there was a cooled version. Maybe this is just for cameras that have a cooled version ? So you can see basically that the proper cooling is just to move the bottom board to the side, fit small peltier and heatsink directly to bottom of cmos board. But of course, that isn't going to fit in the case anymore. But then you just need tiny peltier, small heatsink, etc. AND less troubles with condensation.

Well, I'm afraid it's all moot anyway. It fell at the final hurdle (and possibly many previous ones as Vlaiv points out). On the bench I was getting 30C reduction, no lens condensation, etc. Today I tried screwed onto telescope. With the extra conductivity to the scope, reduction is down to around 23 degrees, which isn't terrible. And there is no condensation on the lens. Maybe with a push fit it would be a bit less conduction to scope and get a bit more cooling. However, the fan is causing tiny vibrations that I cannot remove. I have tried all sorts of vibration isolation mounts and none are entirely successful. So I'm afraid with that, it is as much use as a chocolate fireguard. As I say, I'm doing nothing new here, it was just that I found a kit on ebay which had pretty much everything you need, and just happened to have screw holes in the heatsink that miraculously were perfect fit for ZWO cameras. Nothing here was trying for innovation - just ease of fitting and cost. The screw hole fitting making it a literal 5 min job was what made me think it was worth sharing. This one here (price went up for that seller now, I paid 12 quid): https://www.ebay.co.uk/itm/265111254730 Big heatsink, big slow fan and powerful peltier. It just bolts straight onto the back as if it was made for it. Yes yes yes it's a terrible way to cool.. I'm cooling a big block of aluminium, etc, etc. I ain't daft. But we were going for simplicity here. Not taking everything to bits and trying to rearrange in some sort of custom new case where I could cool only the CMOS. Idea is - don't worry about efficiency - cool that case down. The inside will then cool down. Yes, you will get condesation all over the case - don't care - case it mental. so what. The small amount of air inside case with condense some water out too, but it will condense onto the inside of the case - it's the coolest bits. So not on electronics or lens. All of the above proved to be true. In fact, when screwed onto the telescope, you make the lens even better protected from condensation, as the M42 mount or whatever cools, and condensation forms their preferentially. I proved all of that in tests. It drew about 4a @ 12v, and took around 20 mins to cool to 23 below ambient while attached to scope. On the bench when my study was cooler I had it sitting there covered in ice, lens still clear, temp -10. However.. the fan, even though I could feel no vibrations through my fingers, DID cause vibrations when I got to actually try it on a scope. With it on, the asi224 output was jelly. fan off, fine. I tried about 6 types of antivibration mount (I used to build my own quadcopters to have spares boxes full of options). I could cut it down to nearly nothing, but not nothing. It is worse case, it's a tiny asi224 sensor fitted on a mak102 with a FL of 1300. But frankly any vibration makes the whole thing a non starter imho. I then tried no fan - it is a big heat sink after all - but that limited the cooling to only 7 degrees below ambient. So with that, I'm calling it a day. Sure, you could stand a fan next to it and cool it down, or do some elaborate fan on an arm mounted to the tripod or something.. but any of that and the whole point of simplicity is thrown out the window. So.. it was an interesting experiment, and if anyone want to try you can find lots of sellers selling the same kit - just search for the keywords 'Peltier Cooling Kit' but for me, zee war is over. Here's some pictures:

OK, I didn't and don't want this to get into a theoretical argument about whats and whys Vlaiv. You clearly know what you are talking about - my take on this is much more simplistic: I thought: "camera can be cooled and uncooled. cooled better." can I cool it cheap. is it worthwhile ? that's it. I'm not building a new camera from scratch, or doing some fancy thing with 2nd order temperature feedback. It's a 12-20 quid project for a camera. that's it. Not an attempt at creating a world leading astrophotography camera... you say 'For me "considerably better than it was" is set point temperature and not coooler camera. " - that's fine - go build one of them. That wasn't the project though - it was off shelf zwo vs same zwo cheaply cooled. The result above seem pretty obvious to me - a faint star in that 29C one above could be lost in the crap* you see in the histogram. It would not be lost in the 2C historgram. Why make things more complicated than they need to be ? Looking at pictures is why I take photographs, I don't take them to analyse that they have the right amount of this and that - it just isn't where I get my jollys. You've still not answered why cooled cameras are a good thing? They're not 'set temperature cameras' - they are cooled cameras. Unless you really don't think they are good ? When I got my asi1600 I focused on a nearby tree and leaves. I saw the crap. I turned the cooling on. and I watched the crap disappear. end of. Could I have got the same result by taking bias, darks, subtacting and stacking them up the wazzo - I don't know. But more importantly I don't care. I just used my eyes. -20 was a hell of a lot less crap. But look, this topic has got side tracked. It really is just about trying to cool a camera down. Not analyse theory. It is not going to be for you, I get that. I must admit, I didn't expect this to be controvertial 😪 I'm not sure this is worth doing now whereas I thought it was before... *im using crap as I think you get fussy about what definitions are, where as to me, I don't care - its stuff thats not there.

sorry, I kinda screwed a few of the names up there, and my 300+ ones are pretty bad as just had lens cap on. So here's the best 2 - 100s, 135 gain. 2C vs 29C Now, looking at that histogram, to me that looks like quite an improvement - 29C lots of noise coming up to around 1500 or so. 2C - hardly any just amp glow. Now to

well here's some darks at various gains and temps. and one light. let me know if you think its really worthwhile or not. If not, not a lot of point in it. light is a bit rubbish, as I had to sort of make a dark place under my desk, and use the allsky lens - but as thats exposed it is of course, going to get condensation, etc - but anyway - that's the data captures.zip

Huh. So why is this different for cooled cameras then ? I mean the difference when I take a shot with my asi1600 at 20C vs -20C is night and day on that - vastly less noise ? I assumed it would be the same with most sensors ? I mean folk do this for DSLRs too for example ? Mine as an asi224. ZWO themselves used to sell a cooled version - so there I assume is a good reason ? If the point was just to keep it at the same temperature, casing it in an insulating material rather than a block of aluminium would surely have been a much cheaper solution to that problem ? They themselves seem to think there is a good reason to cooling it to 30C below ambient ? what am I missing ? As I've done it now, I might as well take the practical approach and shoot some shots at different temps and see I think.

while that's a fair point vlaiv, you ain't got a set temperature with an uncooled camera to start with - it's whatever ambient is and/or changes to through the night. so, it's no worse from a variable POV, just colder. If you're the sort of person that covers the camera in layers of insullation to keep it at within a narrow range, then that same insulation solution will work. I did consider this, but adding a temp controller into the mix adds to the complexity too much imho. the measure of success here is 'is it considerable better than it was', not 'is it as good as my actual zwo cooled camera'. If right now, my camera varies between 15-20 degrees during the night, and with the cooler varies between -15 and -10 during the night, bottom line is (I hope) noise will still be a lot less. Your flats/bias/darks will have the same issues you already have (which temp do you choose). But they will at least have a base level of noise that's a damn site lower. stu

Hi chaps, I did find a few articles/videos on adding a cooler to zwo camera, but they were all a bit.. janky. either focusing too much on theory, or very rough DIY attempts with no real analysis of results or performance benefit. So.. I thought I'd set myself a problem statement: 1. make a tutorial than even my granny could follow on how to add cooling to any ZWO camera, and must be cheap: no soldering, no fancy kit needed, not drilling and fashioning bits. 2. ideally must not cause irreverable changes to camera. 3. measure the amount of cooling achieved, and power needed 4. take darks and pictures at various pictures to actually clearly measure how temperature affects them. Bottom line - unless really good improvements in noise, whats the point ? I've did 1, 2 and 3 yesterday. And have 4 left to do today... I'm hoping I haven't wasted my time...but doubt it. Assuming I've not - do you think there would be much interest in an easy to follow tutorial with parts, suppliers and assembly for people ? To give you an idea of the results I've achieved I can cool the sensor by approximately 30 degress below ambient, for 12 quid. And the whole thing can be built by my granny in about 10 mins. stu

i don't think the mak 102 allows any collimation ? that wasn't my C8 - it was the mak 102. C8 I didn't even try as after 40 mins of collimation it was still rubbish. i've read that back focus on C8 should be 5" though, and I had it much closer - around 2". but it was focusing... but maybe not optimally ? so just tried to collimate it again pointing at a ball bearing on a bit of black flow at the end of the garden. I dunno.. seems better.. but I thought that last time until pointing at a star and finding it rubbish

A bit of a waste of money imho. It needs a couple of amps. It would pass it through bell wire. basic multicore speaker wise is fine. However, I realise that means you'd have to wire something yourself.

ah well maybe that was it. it's first time I tried a planet. I have used the mak102 before on stars and got decent results. Perhaps I did just choose a day that the seeing was rubbish ?

10,000 frames. asi224 and mak 102 with 2.2x barlow. tried pipp then autostakker, then wavelets on registax, and cuttinng out pipp. thats all i could get out it. when @paul mc c gets this: out of a mak127 and same camera I feel Im screwing up somehow

vastly better thab I managed last night with a mak 102. gods knows what I'm doing wrong,

Well.. tried my C8 last night.. and definately something wrong with it - i swear it seems it is collimated, but can't get stars to look like anything other than circular blob. bahtinov doesn't even show spikes. Anyway, since one star is so blurry it's the size jupiter would be, I gave up with it. so I swapped to my wee mak 102, and this is what I got. Is that about what I can expect ? It was with mak102 + 2.2 barlow. pretty disappointed in that tbh, and dunno what to do with C8.. don't suppose anyone knows anyone in Suffolk/North Essex area that could look at it ? stu

hi, there are linux partitions on there, you need to use a raspberry pi type imager to make a copy. saying that, I'm on a mac, and I found pibaker and etcher failed to make an image properly. Or failed to write it - i forget which. they seem to assume there is only oner partition and either only image one, or only restore one windoze will be different, but you want to be using something like that - a raspberry pi imager. make an img file. and to be sure it will work, write it to a new card and try it. oh and don't worry about the 29.52/32 thing. for the mac, i found diskutil images ok (creates img with all partitions), and then etcher can be used to write that.

i took it apart. well.. took the glass and secondary off. it was dusty inside anyway. I cleaned it and poked the edges of the primary a bit - seems secure. seconday secure also. so put it all back together. and none the wiser. tonight/tomorrow morning forecase is cloud free so I will be trying it then. First I'll try it on a few stars and see how the collimation is. adjust if required. Then the plan is to try to capture my first planets at 2.30am or so with my asi224 and 2" ED barlow. stu

Samyang 135mm - You can pick em up brand new cheaper though if you keep your eyes open. I bought one this week, new in box for £350.

That's why I bought a 2nd hand 300mm F4L from Japan without IS. If you look on ebay UK you'll find lots of japanese sellers - the prices are very low compared to the UK, in my personal experience I've bought 3 lenses and never had duty/customs and they have arrived as described in 3-4 days. My 300mm F4 cost be just over £300 delivered and is in excellent condition. I also for a 1.4x and a 2x canon extender. All as described in perfect condition - all for maybe 60% or so of 2nd hand price in UK. My 300 gives lovely sharp stars, and even with the 2x extender giving me 600mm at F8 Worth a look. stu

agreed - about first one being best, and clarkvision being mince. never listen to someone telling you it's wrong because it's 'not realistic' - if it was realistic you'd not see the milky way at all!! what does that even mean ?? I've only been doing this 6 months, but I don't think I've read a single comment from someone on here telling someone their image is 'not realistic'... To me, one of the great things about this AP business, is though you are taking the a picture of the same things 1000s of people have taken before - how you shoot it, and more importantly, how you process it is all down to you and how you want it to look - no one else. That's where the creativity lies. stu p.s. great pic - I've still never managed to get a good MW shot!

your right, i went backwards - as i'd read the aperture was 77mm, hence FL must be 154mm.. without realising that is clearly mince as it's a 135mm, so clearly the review meant the size of the lens hood. huh. thats an interesting article. I don't understand why a faster scope will get less H alpha.. but if the graph is right, it's not looking good. I'd read nothing but glowing reviews on the L-extreme, and yet that graph seems to say it's rubbish compared with the L-enchance, so not really following that tbh. Even if you have a slow scope its suggesting L-enhance gets you more H-alpha.. are they just meaning because the bandpass is much more than the L-extreme's 7nm ? stu

here it is fitted to the new Samyang 135mm i just got in the post. the rubber on the focuser has enough grip, so no need for rubber strip with that. as only tiny wee amounts needed to get that in focus it's gonna make it a hell of a lot easier to get it pin sharp.

Hi chaps, sp picked up a brand new Samyang 135mm F2 ED cheap. Gonna try it out next clear night with my 6D. I thought I'd try it with my 2" L-extreme as an aperture reduction. what do you reckon ? i.e. step down filter rings to 48mm, and screw in 2" L-extreme. This will still give an aperture of F3.2, no nastly spikes and fast enough to not make exposures mentally long. I'm sure others have tried this before, but couldn't find any examples of it. I've tried it before with my Canon 300mm F4 L, but as I screwed up and left the screen on all I got for my trouble was amp glow, so it's still an unproved idea at present. Figured if we actually even get to see the sky at night again (as rain batters off of conservatory roof...) I'll point it at around north america nebula, sadr ? stu

Hi chaps, so.. my C8 is behaving weird. I thought I collimated it. took some shots which were ok. A few weeks later was getting terrible pictures - checked collimation and it was terrible. fitted bobs knobs and roughly collimated it again. and seemed sharp. 2 days later, just tried and its blurry again.. this is during the day.. even weirder - the focus seems to change almost as I watch. something is up. I'm wondering if the secondary is actually loose inside ? I'm hoping its that end rather than the other... So my next step was going to be to try and get the glass/secondary off the front following this guide: https://astromart.com/reviews/telescopes/show/disassembly-of-an-sct-childs-play am I on the right track, or wasting my time ? I don't really want to shake it and rattle is around.. but a very small shoogle doesn't suggest something is lose, but it doesn't make sense otherwise. stu

bahtinov's are specific to the aperture and FL of the lens, so worth checking that you've got right one for your Z73 ? jacktheprinter on ebay does a great job of doing custom ones for a tenner if not. with bahtinov you are trying to get the straight line in the middle of the X. that's it - not trying to make the line or X sharp. If the line is in the middle, you are in focus. I know vlaiv isn't a fan, but for us mortals, I fond them invaluable unless I'm using autofocus on the asiairs. unless you have a fancy WO perspex job, the cross patten can be pretty tiny, but same principle.