CraigT82

My own grinder is a bit wobbly but it is usable, just about. First thing I did was use chalk on the slowly rotating wheel to mark the 'high' points of the outside of each wheel, and then rotated the wheels on the arbor so that the high points were opposite each other. Then I checked the outer securing flanges holding each wheel on. The hole in the flange was quite a bit bigger than the shaft and so they tended to sit off centre after tightening up and creating some inbalance. A few wraps of electrical tape on the shaft helped to centre the flanges. Finally I dressed the wheels using a draper tool which took a good while but again made a bit of a difference. It's not great buts it's fine for my needs and is much better then it was out of the box.

Yes 12.5mm including the flange. You can buy any T2 extension tubes, you don't need to stick to ZWO (unless you really want to) https://www.firstlightoptics.com/adapters/astro-essentials-t2-m42-extension-tube-set-4mm-5mm-6mm-7mm-8mm-9mm.html

Have made a new secondary holder from 50mm diameter Acetal rod. Acetal has a lower coefficient of thermal expansion than the aluminum of the original. The 50mm size is also much larger than the original, allowing me to use glue the secondary on using the 'three blobs of RTV' technique, as opposed to the OE method of a square of double sided sticky foam tape.

You want the ADC in the barlow as they are meant to work better with shallower light cones (higher F ratios). The barlow will also kick out the focal point which should allow you to come to focus easily. The ADC will eat up about 37mm of focus travel (I.e. the length of the ADC body) so it may be impossible to use without the barlow in front of it. To prevent the barlow strength from increasing too much you can put the barlow lens cell straight onto the nose of the ADC, if your barlow has a removable cell that is.

Just a thought, you might want to check if you've got a righty or a lefty.... that is, if the levers should go on the right or the left when it's in the focuser. To check, simply hold up the ADC with the levers on the right and look through it. Whilst looking through, move the levers apart, if the image you see through the prisms moves upwards downwards then you've got a righty. If it moves downwards upwards then it's a lefty and you need to use it with the levers on the left when it's in the focuser. The ZWO unit I had in 2016 was a lefty and the one I have now is a righty.

Very nice capture Neil. Nicely done 👍

Here is how I do it...

Very nice Martyn the turbulent region in front of the GRS is a real feast for the eyes. Lovely work 👍

Awesome!

Very nice Peter, especially for just 2 mins collection.

Does the drawtube still rack in and out smoothly? The alignment of the focuser with the optical axis can be checked with a laser collimator if you have one? You can clamp it in the focuser and check the dot exits the front lens bang in the centre (assuming the laser is straight). If not in the centre then the focuser should be adjusted until it does... I'm not sure how it's done with your focuser but I had a TAL100rs which needed adjustment and I did it by loosening focuser mounting screws a tad, moving the whole focuser assembly until it was straight as I could get it (as per the laser dot), then tightening up the screws again (this was a bit of a faff tbh) You can also check for decentred front lenses using a cheshire sight tube if you have one.

That is really very nice Mike, perfectly controlled tonal range (as usual from youl!). I'd love to have a look through that frac.

Sorry to hear about this Rustang, I'm sure it is fixable, if there's no broken glass then there's not much else that can go wrong with a scope that can't be fixed. Poor cat must have been manic. You could also try Steve Collingwood over in Tonbridge. Very nice chap. http://sctelescopes.com/contact/

Nice work Simon, still plenty of detail to pour over... worth getting out for sure 👍

Forgot all about the imaging comps! Here is my entry (probably one of many no doubt). Captured morning of the 16th July. Blue tube Sky-watcher 300p on EQ6 with QHY462c and about 2.8x barlow power. ZWO ADC. 6 x 90 second captures, best 10% stacked of each and then run through winjupos.

Excellent Neil, Jupiter is very nice but your Saturn is gorgeous with the subtle colour variations on the globe, greens, turquoise, oranges, yellows... could maybe stand a bit of a saturation boost?

Yeah I guess it depends on if your doing video derotation or image derotation? For video you want to derotate each frame to the mid point of the capture, which may be pretty long and so have a lot of rotation between first and last frames. For image derotation each capture should be short enough not to show any rotation at all between first and last frames, so the timestamp for that capture could be start middle or end and that theoretically shouldn't matter as there's no rotation between them. Then when you do the actually derotation of all the captures you need to match them all to the middle one.

Nice one, bet it feels good to be back at it after 3 years. Its such dynamic target, never the same year on year

Thanks Peter, there was a few attempts made at getting up early in the last few weeks, all ending up with me not being able to leave to comfort of my bed after the 3am alarm goes off! This time I was determined though and went to bed especially early. Looking forward to opposition and imaging at reasonably sensible times.

I have firecapture set to name the captures with winjupos compatible filenames so that WJ reads the time when you load it into the image measurement. I'm pretty sure it is the capture midpoint which is written to the file name. I'll have to double check but I think that is what it does.

Excellent work! I think the bright spot visible on Ganymede is Osiris crater. Tons of detail on Jupiter... looks like it was taken with a much bigger scope to be honest.

Yes I think it does although to be honest I haven't done a back to back test. When I first get lined up on Jupiter the blue and red fringing is very obvious on the live view, and once the ADC is adjusted there is no fringing visible, which to me indicates that it works. Whether the final image contains more detail with the ADC just without the fringing I don't know as I've never tested, perhaps I should. There are plenty of before/after ADC pics online showing how well they work to have convinced me, particularly Martin Lewis' website (skyinspector). Good info there. I've got the ADC adjustment down to a tee now so using it is no real hindrance, takes about a minute.

Fab images Neil, well done. I admire your efforts using the big newt on the little eq5

Yes I did the the video derotation once and it took ages to complete, might be my old laptop though. Never bothered with it since as the image derotation seems to work so well.

Just noticed you went better than top pick and got IOTD with this one! Congratulations, it is s stupendously good image.