CraigT82

An observatory! Failing that a really nice frac that could be with you for years. There's a used TMB LZOS 115mm triplet for sale on line for about £3200, snap it up!

Good choice, my last two astro lappies have been Lenovo think pads. No frills but haven't let me down.

Thanks NV. I'm going to try to get a couple more images before inferior conjunction to make a nice sequence. Hoping the current run of nice weather continues!

Very nice images! Autostakkert is great.

The FoV will be smaller when using the Barlow lens to reach focus

You can work out your focal length... all you need to know is the angular size of the object in the image (moon), how many pixels across it occupies in the image (use photoshop or gimp) and what you pixel size is.

Using the Barlow lens on it's own should give you less of a magnification increase than using the whole Barlow. The further away from a Barlow lens you get the greater the magnification increase.

Small selection of the best venus UV images I've managed this month. Shows nicely the increasing angular size and shrinking crescent. I've captured quite a few more than these three but mostly without any kind of details due to poor seeing or duff capture! Cheers

Yeah a little mak is probably going to be best for what you want to do. Either the 102mm or a 127mm if you think the ball head can handle it. Great little scopes in a small package and perfect for lunar snapping. Just a point to note. Lunar photography is best done with the moon high in the sky, to minimise atmospheric effects, so you may end up spending lots of time with the scope pointing up high which will be a pain with a ball head especially with a dslr hanging off the back of the scope. You may want to consider something like a used skywatcher AZ4 mount, or even a used eq3-2 in your budget. Will make things a lot easier and the eq3-2 will track (with some motors added). As mentioned above the really close in stuff is done by 'lucky imaging', where you used a snall format video camera to shoot fast frames (50 to 150fps) which the enables to you catch the brief moments of good seeing. Software then isolates these sharpest frames and stacks them to improve the SNR and allow sharpening. Not sure what the sony A7 does video wise but worth investigating.

USGS have just released a downloadable geological map of the moon, and it is AWESOME!!! https://astrogeology.usgs.gov/search/map/Moon/Geology/Unified_Geologic_Map_of_the_Moon_GIS?utm_source=twitter&utm_medium=social&utm_term=a0782f18-dace-4067-ba02-d2e232c35e2a&utm_content=&utm_campaign=usgs

It isn't. The 'mono' avi files are just un-debayered. You cant shoot mono with a colour camera. Actually, you can in infrared on certain cameras because the R,G and B bayer filters will leak infrared through... But that's about it.

You could try shooting a phone video instead of stills. Should be able to convert the video file to an AVI or something that can be stacked in autostakkert?

This would be my vote! Though I'm not sure what you mean by target? Do you mean the 45 degree shiny face? The purpose of that is to catch the light so you can see its reflection in the secondary as you look through peep hole.

Focuser slop. Slightly different diameters on the cheshire and laser shafts probably. Causes the laser to be gripped slightly different to the cheshire and hence a disagreement. I had same issue with my 200p. A Howie glatter parallizer fixed it.

You dont need to look at the angled face of the Cheshire directly. Just at it's reflection in the secondary as you're peeping through the hole. To be honest ditch the laser. If you can reach the collimation screws whilst looking through the Cheshire then just stick with the cheshire. The only reason id use a laser is if I cant reach the screws whilst looking through the Cheshire.

Thanks both. I'm really glad I spent the time just playing around with imppg, regsitax and PS. Didnt know what I was doing most of the time, just pulling sliders this way and that, but it's paid off. Now to go back and write down what I did!

Excellent, did not know that about the radiation, thanks Wouter!

Excellent image Avani. Interesting write up too. Is it true that it's the space environment that erodes the rays? Or is it rather that subsequent younger and younger impacts that covers the rays and renders them invisible?

Have spent a good few hours processing some L(IR)RGB Saturn data captured in September last year and have made some real gains in the final image, just from taking a different approach to the processing. For the new image I sharpened and tweaked two versions of the same image. One where I concentrated on the rings, and one where I concentrated on the globe, and merged them together to form the final image. I also spent much more time aligning each channel of each LRGB sequence at the pixel scale in PS (I collected 3no. LrGB sequences) before stacking them together whereas previously I relied on winjupos to derotate the images together, without really checking the alignment in any detail myself. Finally I took a more iterative approve to sharpening and noise reduction. Doing both in small steps at different stages and on individual channels, rather than just doing at all in one go on the final image. I'm really pleased with this and an glad I took the time to experiment. I guess that if you feel dissatisfied with your images and have the urge to invest in better kit chasing the better image, it might be worth investing some time at the computer first as you could be very pleasantly surprised!

Hi Damian, I think you'll be happy with the 174m as it will be a nice match for the TEC with 4x Barlow, though I think a 3x might be the sweet spot. Big sensor too so you'll be able to get a lot of the surface without resorting to mosaics. Will take longer to get x number of frames at full sensor though. I cant comment on solar as I've never done it. Filters wise you will get a lot use out of red or IR but I'd stay on the nearer side of IR for a 140mm scope (685nm or 742nm). I prefer a red filter myself and if the seeing doesnt support that I generally don't bother. In good seeing orange and green can work well and I've seen some superb hi-res images of a high moon taken in excellent seeing through a blue filter (the airy disk being smaller the shorter the wavelength of incoming light). HTH

To create a synth blue, what blending mode do you use to subtract sum of R and G from L? I've tried the obvious (subtract) but it looks very wrong!

I dont know much about DSO imaging, but I assume the RC would be easier to thermally manage? Big SCT with closed tube will need serious thought about how to homogenise the air inside for best quality images. Prob easier with an open ended RC? Though the edge version has vents and aftermarket fans can be fitted. I guess if you want to do any kind of science with it, as opposed to 'aesthetic' imaging, you'd be better off with the RC?

RVO have some great deals on ex display and used stuff. Got my APM barlow from them used at a smidge over half price and it was pristine.

Very nice. Makes me feel like I'm on holiday in Tasmania again, just what I need in lockdown thanks!

Nice work phase clearly showing, maybe a little overexposed?