bomberbaz

Hello all. I have recently acquired a 650 FL reflector and I already have a camera which was actually purchased to be used with another scope which didn't work out. So problem being is it is the ASI 183MM, px size is 2.4 which potentially leads to oversampling at 0.75"/px I have been offered a loan camera, the ASI 174MM, px 5.86 which gives under sampling at 1.86. So clearly neither are ideal but rather than rush out and buy a new camera, I want to test out the rest of the setup for balancing, tracking etc, you get the drift before doing so. Given the above, I am swinging towards the 174 given most of what I do is from a heavily light polluted garden but anyone else have any pointers as to which may be best suited to test out until I am ready to make a decision on a more permanent solution.

That is only a little more than my AZ-GTi setup but with a significant gain in bearing capacity plus from all accounts, an improvement in tracking accuracy. It would be quite a layout but I am thinking of selling a bit of kit that would cover the cost and free up a space in the conservatory to hold it, win, win. Anyway, holiday first, decisions later. Thanks Michael, much appreciated.

Looks a really nice setup Michael. I have been reading about this mount some more and it versatility / weight bearing capacity is setting me thinking I may have a use for it. As we look at it there in this picture, roughly what is the height and weight of what we see? (Minus the OTA)

Had a look at the clamp and see what you mean. I guess it depends what you looking at putting on it. If it was EG a 72ED, I would have no concerns. If it was say a 150P-DS I would be inclined to sway it for something more substantial. The rest of it looks a sublime piece of engineering.

Looks like a good bit of kit that does, I would be happy with that myself.

Weight as always the biggest issue pal, that is why the heritage. The open tube design and simple fittings knock about 800gram off, a lot when we are talking the AZ Gti.

nice setup Lee, good idea not to convert to eq. I found mine had issues at times when trying to run in Altaz. My latest purchase, a heritage 130p will arrive tomorrow. Intended use is as a galaxy imaging OTA and for spectroscopy. After that is I do at least 4 mods to it.

UPDATE: After thinking this through I have initiated a return, main reason the focusing issue. The focuser unit provided is triangular in shape at its base & sits into a plastic housing with a recess that is also triangular in shape. Any new focuser which are usually square in shape at the base would have to deal with this somehow. Removing the recessed housing didn't seem to be an option as it appeared the entire upper plastic part also held the secondary spider. So it seems that Celestron have done their best to ensure modifications of any type are very difficult. I decided not to dig any deeper as I didn't want to lose my return warranty and so I gave the idea up as a bad job. Steve

cheers @Nik271 & @ONIKKINEN, I do have this ota on sale or return basis, so (weather permitting|) I have time to have a little play with it to ascertain if I can get anything worthwhile from it. For now just going to see if the spectroscopy results are any good, then take the rest from there. cheers steve

OK not quite ready to give up on this & as you responded, I hoped you could give me a further opinion. Had a play with a FOV app and here's what I find. The camera, a 183 will magnify at about the same as a 15mm plossl, or about x40. Would the lesser quality mirror (assuming it is spherical) underperform the parabolic cousin at this magnification?

Hello fellow members. I have in my possession the above mentioned OTA. I am aware this is not a top end bit of kit but I am hoping to use it for imaging galaxy & basic spectroscopy. I have looked at other options but aperture/weight wise, (this is 3.6kg) this hits the spot. I have tried my 72ED (doesn't focus well enough even though it is ED), a 127 mak seemed to throw up problem after problem with focal length, weight and balance until I gave up. Then quite by accident I came across this OTA very cheaply (Amazon return with a damaged box). If it does work out ok then a simple focuser upgrade could give me a very lightweight, low priced & useable OTA. Thus far I have only done a terrestrial test visually (which seemed ok) and quick image with the 183mm and the result below seems very promising. Ignoring the dust mote and bottom right tree blur (and my awful focusing with the awful focuser), the image looks pretty tidy from lower left to upper right. Tonight the skies are iffy so might not get chance to do anything from the night sky sadly. I have found a few posts on here and CN that are contradictory with some adamant it is spherical and similar calling it a parabolic, but at F5 I am leaning towards the parabolic camp based upon information I believe to be correct, mainly that a spherical will be a mushy mess at this focal length. Trouble is, Celestron appear to be pretty rubbish at disclosing product information they either don't want or think it necessary to know. So anyway, looking for any additional info that is available, preferably not anecdotal type. Cheers steve

nOT wishing to sound negative And I am far from an expert. But don't you thinnk Another 10 hours to a near perfect image is just overkill. I reckon less data and toned down processing will get you there. It is already a beautiful image.

That is what I did. I don't actually use my dob that often but it is kept in a steady, temperature room in a bag to help keep the dust out.

Managed a half hour on M101 to get the SN2023ixf nova. Yes it's grainy as it is no where near enough data and I only had darks to stack with but it is very clear and in the bag. More importantly, my tracking issue seems sorted as you can see. The stars look pretty decent to me too, this is magnified x4 (ish)

Just as an heads up. I don't think it was the bearing where the issue was. I tried as above a re-grease/loosening but the error was still there. Then after that resetting the mount firmware which didn't work either, so then i tried re-instaling the app on my tablet, the latter appears to have worked. Steve

thank you and nice image, I think I will try a gathering data both with and without to see if there anything to be gained by combining. I think median filter may need to be turned off for stacking though.

Hello everyone. I want to have another go at SN2023ixf tonight but in addition, I planned to grab some dual band filtered data. Can anyone tell me if SN of this category respond to dual band filters in anyway or am I wasting good imaging time trying? Cheers Steve

Cheers Lee, I picked up a link from the thread and followed it, simple enough. For anyone reading, I did a light regrease with lithium grease between washer and bearing then slacked off the locking nut by a half turn and the whole thing seemed a lot easier. In addition I removed an earlier mod I did where I had slipped two pieces of plastic inbetween the drive motor and drive to lock it. I was concerned this might be putting too much pressure on the motor/drive connection. Instead I have re-inserted the spring mod between motor and housing to apply more pressure whilst still leaving some flexibility. So far I have just spun it round on the mount fully loaded but the sounds seem nicely unstrained and even. I will let you know how I get on with full on imaging. Steve

hello all. Well tonight I tried grabbing some data but it was a disaster. The tracking worked only for a minute or so then went totally haywire, both going off in different directions although I have not changed any settings. I am totally baffled. Tried restarting the system, re-callibrating and changing target objects but no luck. Noticed a ticking sound coming from the mount, this needs investigating further which I shall tomorrow. Seem to remember reading something about this before, any clues anyone? Anybody got any other tips/ideas about this up front? Steve

Finally bought myself a longer marine grade M12 bar for the counter balance. I half considered a 16" bar but instead opted for a 12" one. I think that 16" was a little risky by adding a possibility of wobble caused by wind, even light. I have watched a lot of building/engineering related documentaries where such issues have been highlighted. Not sure if these issues will translate on this level but I felt more comfortable with the 12" version.

What a very sensible man you are and refreshing to see such a pragmatic approach.

Should get this well with the 14" dob and I am also going to have a go at getting its spectra with the portable imaging rig. These are exciting times.

I use the sw az gti in eq mode with a sw 72ED. It isn't a triplet granted, but it does give a well corrected, flat field when in use with the stellamira FF and is only 2kg. However I have 2kg of counterweight to contend with too. The william optics range al;ways seem highly recomended and the 81mm triplet weighs in at 3.3kg. Ttoal weight is 4.5kg. William Optics GT81 WIFD Apochromatic Refractor | First Light Optics

Mike makes a very good point. It's all well and good us lot on this thread pointing out that we use this and prefer that, but you are who you are and what suits you may be totally different to us. Find a local club, ask to go around and you will be welcomed with open arms. Take a list of questions with you and you will find the answers, as well as a demonstration where practical of these answers EG collimation.

Blooming heck, those were a flipping bargain then, good buy!