geeklee

HI @nephilim I don't believe this will give you the correct backfocus. As stated on the site for the M48 adapter (and is normal for camera lenses) - 44mm is required. As discussed throughout this topic, usually a little more is needed to land the focus in the current marker (depending on filter). From your image above I think you're using the 11mm female-female M42 adapter and the 16.5mm M42 to M48 adapter. Including the 6.5mm from camera edge to sensor, this gives you a total of 34mm. Apologies if I've missed something in the image though. If you have a look back at an earlier discussion we had, it gives some options. Hope this helps clarify. I currently have a ZWO filter drawer, additional spacer + the 11mm female-female adapter plus thin Baader shim. Around 45ish mm

Fantastic @Spongey The rescaling probably helps with the stars. I only noticed when I went looking and even then it wasn't obvious.

That's excellent Sean. A fantastic outcome without lucky imaging and stacking.

All excellent Richard. Picking images from your collection must be very hard indeed! I personally voted for the Coathanger. I remember seeing this one when you posted it and loved it. As mentioned above, you've always got to keep an eye on what the judges subjective view might be (common targets perhaps) rather than the better photograph I imagine there will a lot of M42/M43 images entered - yours is exceptional though.

A substantial improvement @mackiedlm It's hard to believe the second image is from the same data set (except the framing). Unfortunately, I think it is definitely possible that good data is perhaps not being used to its potential. Highlights a good reason to hold on to your data and revisit it later with fresh knowledge and fresh eyes! Let your ASI2600 loose on the same area

Both fantastic images. M82 looks stunning with the detail in the Ha "bursts" so defined.

That has come out very nicely Adam. Lovely images, I really like the first one - shows how worthwhile the total integration was (as is always the case!)

Just fantastic Richard. As always, a visual treat viewing at full resolution, with even more to admire.

quite 😅 I believe - from my own testing - you would need to add a little spacing. If you're the opposite and at the end stop "past" infinity then you'd need to take away. Sure someone will chime in if this is incorrect ( @Adreneline ) When I say a little spacing, it will likely be less than 1mm. Me too! Lovely image above, what a vast FOV that camera gives with the Samyang.

I'm intrigued, go for it!

I grabbed this area back in December and got about the same but 180 X 60s and F2. There seemed to be some there when the data was worked hard. Unless I'm mistaken and it's dust. https://astrob.in/wudss6/B/

Great image @Rattler really nice wispy, over lapping detail showing when viewing at 1:1.

Nice write up of the new setup Adrian. Do you still have the Hoya in front of everything with the 294 setup or is the window of the 294 UVIR cut alongside AR?

For the images above, apologies, I should have been clearer - it's just "zoomed out" one level so you're looking at 50%. If I am actually resampling, I use the IntegerResample Process (rightly or wrongly... probably wrongly!). You've just described my typical approach (although I do try) 😅 It will be interesting how you get on with this. My current rig doesn't really have a place for an EAF but I'm thinking about alternative options. @Adreneline has some great images of his setup with an EAF in the "Imaging with Samyang 135" thread. Can you run autofocus routines when you're so close to the end stop in one direction? I guess it's tiny steps at F2 so maybe so. For completeness, the images above were with an ASI533, smaller FOV but same pixel size (3.76 um) so 5.74"PP image scale at 1:1

Hi Des, I certainly get the same behaviour as you describe (I've been using F2 as well) with the red channel looking a little bloated/out of focus. The critical focus zone at F2 is so small and I've found that minute changes can show certain aberrations (like tilt) much worse. If I get a chance to use the lens again this season, I plan to try getting focus with the Bahtinov mask like normal but then vary this slightly either way and check the subs then, see if I can make the red more acceptable. I find it more noticeable on certain images, especially some strong Ha targets where the red channel looks poor ... and that's where the Ha is! Example RGB sub below at 1:1 (just UVIR cut filter) It's the stacks which generally end up looking poor in the red channel - likely highlighting how critical it is to keep a close eye on focus and each sub before stacking. Here's an example from a stack using the L-eNhance filter. That red channel looks so soft. At 1:2, it's more difficult to spot: All of these are unprocessed, just Auto STF in PI. My backfocus is around 45 and a bit with the focus mark in the "L".

Much same as the non observatory imagers above, I try to keep everything in the smallest number of parts. I'm causing raised eye brows this winter by keeping the tripod and mount together (without counter weights) and carrying this out in one - it's an AZEQ6, so a bit of a lump. Then counter weights + optical train including camera, dew heaters and cables where possible. Put the two together and finish off the cabling. In the past and something I may have to return to is tripod and mount out separately and then put together with the rest.

That makes more sense! Not sure I've seen a horse with ears that big...

I finally see it! ☺️

That's rediculous...ly good Tristan! Only 114 minutes? Brilliant. Great processing too - you seem to have extracted all the detail and the faint stuff too.

Some serious FL there Sean, that's come out great. I've recently found this one pops out to me as a galloping... horse?

Fantastic Dave and just as stunning viewing at 1:1 where all that additional hi res blending makes all the difference.

Just echoing my comments on Astrobin, but sensational as usual Richard. Apart from the obvious depth and detail with such a relatively short integration the stars are what makes my jaw drop.

Thanks for the comments and feedback @Allinthehead @Adreneline @simmo39 @CraigT82 @tooth_dr The RedCat is forgiving of many things at just 250mm FL so usually allows an automated imaging session with minimal stress (I've certainly jinxed that now!)

I started to capture some Ha on the Rosette nebula during the full moon spell at the end of February. The altitude and position is still favourable from my garden for 2-3 hours each evening. I'll likely aim for some OIII and maybe SII next season (given the forecast). As always, the Ha from the RedCat and Baader 7nm has some decent detail and structure in there. Both images taken with the WO RedCat, Atik 460EX and Baader filters. This is 45 x 600s (7.5 hours) across three nights. This next one isn't a typical target for such a modest focal length but I didn't want to waste the mainly clear skies so grabbed some time on this. A couple of channels had some cloud, but overall there was some good signal. ~1 hour each on R, G and B + 2 hours of L (all 300s) 1:1 crop of the triplet: Both captured with Voyager, calibrated & stacked in APP then processed in PixInsight. Thanks for looking and clear skies.

A few OSC images taken on and off during February 2021. All with Samyang 135 (@ F2), ASI533 and UVIR filter. Most can click through for slightly bigger versions. M44 (42 minutes) Virgo Galaxy Cluster - 2 panel mosaic (85 minutes per panel) A very small M101 (70 minutes) M42 and M43 (102 minutes) A very cloudy (wrong sort of cloud though) Orion - 4 panel mosaic (15 minutes per panel) Clear skies