R1k

Jellyfish Nebula in HOO - 4h 45 min integration over 2 nights - Bortle 6 NW England - Feedback welcomed Equipment - Skywatcher HEQ5-pro (Rowan Belt Mod) - Canon 800d (modded) - TS Optics Photoline 80mm Triplet - TS Optics 0.79x focal reducer/field flattener - ZWO ASI-120MM-mini guide camera - Skywatcher Evoguide 50ED guidescope - 2 inch mounted Optolong L-eNhance Acquisition - Sharpcap polar alignment, ASCOM guiding/dithering with PHD2 - APT image acquisition - Lights - 36 x 300s, ISO1600 and 15 x 420s, ISO800 (4h 45 min) - Darks - 8 + 20 - Bias - 40 + 40 - Flats – 40 + 40 Processing - Raw images stacked and calibrated in APP using the algorithms Ha-OIII extract Ha and Ha-OIII extract OIII. - Mono images combined in APP using the HOO1 algorithm, OIII signal boosted by 2x - Autostretched file saved as 16bit TIFF and run through Starnet++ - Selective contrast, saturation and stretching to nebula in starless image in Photoshop, denoise of background in this image using camera RAW filter - Star mask on original combined/stretched image using select colour range – highlights tool - Stars blended onto starless image - Original combined and stretched image layered on at opacity 25% so that there was some signal in the dimmer stars - Crop to preference

Just to update - thanks to all who helped. Scope has been sent to ES Reid in Cambridge today.

Thanks Terry - yes with the field flattener I tried 55mm and 62mm (7mm spacer) backfocus - same issue both ways. issue also persisted without any flattener at all. edit - using a modded Canon 800d (sensor set back 55mm)

And single frame from 3rd jan where things weren’t looking so bad. I’m really at a loss as to what’s gone wrong since 😔

And here is an image just from 3rd January where it was looking quite a bit better. I hadn’t done anything since then (to my knowledge at least) to cause the optics to become mis-collimated.

Thanks for the response. I loosened the retaining ring on the lens cell (which was EXTREMELY tight, jiggled it around a little and then finger tightened it. I’ve not adjusted anything else at all. Below is an image of the whilst the optics were pinched a few weeks back

Could it be due to sudden temperature change? I took the scope outside in the freezing temperatures directly from a warm room?..

Hi guys, having persistent issues with my TS optics 80mm triplet. Started when I received this (used) scope a few months back - pinched optics which have now been Un-pinched. Had a few nights where stars were looking reasonably good again. went out last night and had very odd looking stars. Optics not pinched, no play in imaging train, no focuser tilt, persisted when field flattener taken out of the train and no dew whatsoever. Rotated the OTA and the shapes persisted in the current direction they’re in below. Anyone seen this before (easier to see when zoomed)

Shot this target last night predominantly as a star test for the scope, fairly happy with the result although still some tilt somewhere in the imaging train to isolate. 20 x 180s ISO200, 20 x darks, bias, flats TS optics 80mm Triplet 0.79 x TS optics focal reducer Rowan Belt modded HEQ5 Modded Canon 800d

Thanks! Belt modded HEQ5

M81/82 and NGCs 3077, 2976, 2959, 2961 24/12/20 I like this image but I’m still struggling with odd stars, I think it’s collimation but could also be focuser tilt with my heavy DSLR hanging off it so scope will be heading back to TSO in the new year for a look. Equipment: - Skywatcher HEQ5-pro (Rowan Belt Mod) - Canon 800d (modded) - TS Optics Photoline 80mm Triplet - TS Optics 0.79x focal reducer/field flattener - ZWO ASI-120MM-mini guide camera - Skywatcher Evoguide 50ED guidescope - 2 inch mounted Optolong L-Pro Acquisition: - Sharpcap polar alignment, ASCOM guiding/dithering with PHD2 - APT image acquisition - Lights - 40 x 180s and 40 x 90s, ISO800 (180 minutes) - Darks - 40 - Bias - 30 - Flats - 30 Processing: - Raw files stacked in APP using algorithm adaptive airy disc - light pollution, background calibration and star colour calibration in APP - stretch of data with star mask in PS - saturation and vibrance - Topaz denoise

Hi all, loosening the retaining ring on the lens cell completely sorted this. I am still sending back to TS optics as I think it requires a little collimation (colour correction not as great as I expected!) Thanks for all the help Rik

Cheers Ken - read the whole thread and was sad to hear you returned the scope! Will post the R G and B channels tomorrow - using an OSC DSLR. Thanks Rik

Massive thanks for the detailed reply I have uploaded: - a single raw image of the doulbe cluster in perseus (right up at the zenith) with the FF/FR installed - a single JPG image of Vega (sorry no Raw for this) of Vega in the centre of the screen showing the same colour separation) without the FF/FR attached. TS optics seem to think this is a collimation issue. Thanks again Light_0009_ISO200_150s__18C.CR2

Hi guys, recently picked up a used TS optics 80mm FPL53 triplet. I have come from a SW evostar 80ED doublet. I am slightly disappointed with the colour correction with the scope, I am using the dedicated 0.79x FF/FR and a canon 800d at 61mm back spacing (as per manufacturer recommendation). I expected stars totally free of CA but instead find that bright white stars are surrounded by a small rim of blue CA (see autostretched single 150s frame of M45 attached as an example.) Would you guys say that this is acceptable CA for this scope or should I be right in being disappointed? I am considering sending the scope to TS optics who have agreed to look at it. Thanks Rik Light_0028_ISO200_150s_19C-St.tiff

Hi guys, I have recently taken delivery of a used TS optics Photoline 80mm triplet which got its first light last night. It was shipped carefully packaged from Cyprus to the UK. It quickly became apparent that my stars were misshapen, but in a consistent manner. I excluded the following problems - tilt, focuser misalignment, back spacing. A quick read revealed this was likely to be pinched optics, and indeed when I took the lens cell out, the retaining ring was incredibly tight. I have since loosened the ring and finger tightened it as per recommendations on other threads. Unfortunately I was unable to re-test as the clouds (and rain!) rolled in. Would any of you experienced folk have a look at these images (one is just a tight crop of the other) to determine whether the misshapen stars appear to be consistent with the problem of pinched optics? Thanks, Rik

Thanks for the suggestions all, very helpful!

Hi guys, after some constructive feedback if possible on this one. This is data from September which I have re-processed in PS now that I am more familiar with the use of star/layer masks (still very much a beginner). I have used the Ha and Oiii extract algorithms in APP and recombined as HOO in APP before moving across to PS for further processing. Acquisition details below. I have also recently sold my SW ED80 and have replaced this with a TS optics photoline 80mm Triplet (f6) + 0.79x TS optics reducer, if anyone else is also using this scope I'd be keen to hear about your experiences! Equipment: - Skywatcher HEQ5-pro (Rowan Belt Mod) - Canon 800d (modded) - Skywatcher Evostar 80ED - Altair Lightwave 0.8x focal reducer/field flattener - ZWO ASI-120MM-mini guide camera - SW 9x50 finderscope - 2 inch mounted Optolong L-eNhance Acquisition: - Sharpcap polar alignment, ST4 autoguiding with PHD2 - Manual acquisition using intervalometer - Lights - 20 x 360s (2 hours) - Darks – 20 - Bias – 30 - Flats - 30 Thanks Rik

Unusual target but in a nice position from Northern skies at present. Shot in the early hours of the morning on 22/11/20 Constructive feedback appreciated. Equipment: - Skywatcher HEQ5-pro (Rowan Belt Mod) - Skywatcher Evostar 80ED - Canon 800d (modded) - Altair Lightwave 0.8x focal reducer/field flattener - ZWO ASI-120MM-mini guide camera - SW 9x50 finderscope - 2 inch mounted Optolong L-Pro Acquisition: - Sharpcap polar alignment, APT acquisition, autoguiding/dithering with PHD2 - Lights - 10 x 150s and 38 x 90s at ISO200 (1 hour 22 minutes) - Darks – 5 x 150s and 10 x 90s - Bias - 20 - Flats – 20

Thanks Olly, this is very very helpful. Appreciate the help (as always!)

Sorry to bump an old thread. olly - could you kindly explain what you mean by adding Ha to red in step 2? Do you mean splitting the RGB channels and adding the monochrome Ha data to the red channel?

Thanks for this Olly, totally makes sense. I will try this entire technique (RGB with various sub lengths, blended and the NB layer on top) in the coming months when I get to have a bit more time on the nebula. Very much appreciate you making the effort to explain this in great detail, have certainly learned a few things that I’ll be able to move to other projects/targets too. By the way, your M42 on Astrobin has totally blown my socks off, wow! 🤯

thanks both for the very helpful comments, I agree it is overstretched and probably a bit oversaturated. Olly - Many thanks again, this type of feedback is exactly what I am after. how short should the subs be for the core? We talking 30s and less? As for the filter, I’m fairly new to the hobby, so assumed that any object with emission nebulosity would benefit from a NB filter. I will have a bash without a filter and see how it compares. thanks again both!

Very much enjoyed shooting this for the first time ever last night, keen to receive feedback as always -- Technical details: Equipment: - Skywatcher HEQ5-pro (Rowan Belt Mod) - Canon 800d (modded) - Skywatcher Evostar 80ED - Altair Lightwave 0.8x focal reducer/field flattener - ZWO ASI-120MM-mini guide camera - SW 9x50 finderscope - 2 inch mounted Optolong L-eNhance Acquisition: - Sharpcap polar alignment, ST4 autoguiding with PHD2 - Manual acquisition using intervalometer - Lights – 15 x 180s (45 minutes) - Darks – 25 - Bias – 30 - Flats - 30 Processing: - Stacked and calibrated in APP using HA and OIII extract algorithms - Monochrome images combined in PS CS6 (HOO Palette) - Crop to area of interest - Levels/curve stretch - Unstretched core blended carefully onto stretched image so that it was less blown-out - Contrast enhancement and denoise - Slight desaturation of brightest stars (they appear too blue with the L-eNhance filter)

Thanks so much for your very detailed and excellent explanation. Appreciate the help