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agthomson

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Everything posted by agthomson

  1. Last night was touch and go for me. The right hand side of my capture has lost about 5% due to cloud cover but I can crop and work with it. I took a break from AP for a while mostly due to time constraints, but also because i've "seen" the objects I want to with my current setup and would need decent investment to get a better view of the smaller DSOs. Believe it or not, but the Vaonis Vespera actually got me back into astrophotography. No, I didn't buy one, but I had one in my basket. I decided to run through my usual AP set-up process to actually see how long it took me to set up and get imaging compared to the 10 minute claim of the Vespera. I had it in my head it was around 1hr30mins to cart all of my kit outside, plug it all in, polar align and run some test exposures on my target. The Vespera interested me as it took nearly all of that time away, leaving me with my favourite part which is planning my acquisitions and working with the collected data. I used to bounce around from target to target every clear night, but i've "seen" most of the targets I can from my garden, so i've decided to actually put effort into each one from now on. While my 1hr30mins was slughtly over-estimated for the 1st setup time, night 2 and 3 on Orion I was collecting data within 30mins. Most of that time was getting the equipment set up in my garden and testing the exposure time. What I need to do now is just collect more data at my preferred exposure time, instead of having to work with 3 or 4 different exposures!
  2. Thanks all for the suggestions. Yes, I gave myself plenty of headroom in the stretch as I didn't want to bring out too much Ha. While the Optolong filter is great for most of the targets I like to photograph it ruins several others! I much prefer your colours Steve, so that's something for me to work towards. Once I replace the broken LP filter (I really need one when pointing South) i'll give M42 another go. Next step for me is to move into mono + LRGB and narrowband, as that side of AP interests me much more. I took 120 x 10s exposures (so 20mins) and 10 x 300s exposures (bringing the total to 4 hrs 30mins) so that I have a range of data to play with. From a quick stack I can definitely get the core to be less blown out with just the 10s exposures. Need to actually brush up on my processing skills beyond a quick stretch and levels balance and actually work with the RGB channels prior to combining into a colour image. That belnding technique looks interesting, so will give it a proper read later as well.
  3. Hi all! I managed to finally get a photo of M42 Orion. Based on where I live, and the surrounding buildings this is an incredibly difficult targte for me to get. I literally need the stars to align in terms of day job, the moon, the direction of the wind (chimney smoke) not to mention cloudy skies or poor sky quality. This is a combination of 43 x 120s exposures and 115 x 60s exposures for a total of around 3hrs 20mins, taken through an Optolong l-Enhance Duo (dropped my LP filter), stacked in DSS, and processed very lightly in PhotoShop (balanced levels, slight curve change, increase vibrance and saturation). I suppose my question is I have another opportunity this evening to add more data. What would be more useful - longer exposures for feint detail, or shorter exposures to tame the core? The 120s exposures completely blow out the centre of M42, but are useful for picking up the feinter nebulosity. I was thinking of adding in some 300s exposures to really bring out the feinter details, but offsetting that with a bunch of 30s exposures to try and bring down the core.
  4. So, after many frustrating nights, all caused by me inadvertedly chaning a setting or two in SharpCap, I finally have something that's actually usable from a session with my Dual Narrowband L-eNhance filter. This was 22 x 4 min exposures taken on a WO ZS61 with an L-eNhance dual narrowband filter using an ASI294MC Pro at 200 gain. Mount is an HEQ5, guided in PHD2. Images were stacked in DSS using recommended settings, apart from the 10 Dark frames that were shot and stacked in SharpCap, with the stacked Dark image added to DSS as a master Dark. This did a great job of removing the amp glow. Only processing was individual channel levels to balance/align them, a quick stretch and a minor adjustment to curves. Self-critique: I messed up the framing a bit, so lost IC 1795 from the bottom (or top?) of the heart. I'm also terrible at processing in Photoshop, so there are colour balance sisues. I'm still working out the best way to process images taken with this filter! Focus looks okay to me, but maybe a little soft? Next steps? I want to up the exposure time a bit to maybe 5 or 6 minutes while still leaving the gain at 200. I'll then reduce the gain from there if necessary, but this filter seems to need all the time and gain it can get. the 294MC Pro works quite well at high gains anyway. Any pointers? Better processing tips?
  5. Exactly. I need to work out what the cause is. On the plus side I now have a 64-bit version of Ubuntu Mate running everything I need that I can VNC into via its hotspot.
  6. I had a huge issue with StellarMate OS on the Pi4. It's fine during the initial setup after flashing, but after I close down the Pi the StellarMate will never fully reboot. I can connect to the hotspot, but not sign in or do anything. In the end I installed Ubuntu Mate on the Pi4, then INDILib, KSTARS, PHD2, then a VNC client. I then had the issue that the Pi4 wouldn't boot to a desktop without a monitor, so had to install a dummy display driver. Now all set up, but not tested yet. I'll take another look at StellarMate with a screen connected to see exactly what's happening. I have seen a few people post about just getting a blank screen after shutting down and rebooting, but others saying it all works fine, so not sure what the root cause is.
  7. Hi all, hoping for some words of wisdom! I recently purchased an Optolong L-enHance filter to go with my ASI294MC Pro and ZS61, partly to remove light pollution and partly to allow me to experiment with targets I just couldn't get data on before. My understanding of this filter, as shown here, is that it lets through Ha, Hb and OIII as Red Blue and Green respectively. The filter adds a green hue to images, as shown here (from Astrobackyard), which I should be able to sort out via flats etc. For my first test session with the filter I pointed the scope at the Heart nebula, didn't capture flats, and for whatever reason DSS won't stack my darks, possibly as I captured in 8-bit PNG by accident. Ignoring the issues with the data, i'd like to do something with it if I can. Below are my stacked red, green and blue channels. Unstretched. Blue is as I expected - quite empty. Red contains the most prominent parts of the Heart Nebula, but green contains more than I expected. How would you combine these layers back into a colour image, ignoring fine tuning for now? My thinking is: Red should be Red + Green, taking the brightest pixel from each to form a new red (or something close to that) Green should be a mix of Red and Blue so that stars have a more natural colour, and the brighter bits of nebula trend towards lighter red Blue should stay blue, but possibly take in some of Red (brightest 5% or something? Does this make any sense? Any help / suggestions would be much appreciated!
  8. Olly, thanks for that. Checked the polarscope in daylight and all is fine, so just working off the assumption that the scale is inaccurate and there's nothing to worry about. Regarding your second point, that was my feeling when capturing images - they seemed fine and would likely stack quite well (albeit a little green due to the filter). When stacked, the solid colour in the middle of the nebula and the bottom right of the heart are essentially a solid colour with no distinguishable detail. This might be a stacking issue, and something I need to play around with. I haven't been able to stack in the darks I collected at the same time as these have totally thrown off the image calibration (made it very noisy and neon green), but will take another look this evening. Maybe DSS is the area I need to focus on. There may also be an issue with the debayering that I need to look at which will be hard given I only have debayered PNG files. Serves me righ tfor trying to cut a few corners.
  9. Okay, this is a multi-part question, but instead of creating a few threads i'll bundle them all here as they are all related to AP. The scale on the side of my HEQ5 seems off. Is that common? I'm at ~56.5N, but to get polaris in the polarscope, or evn when using SharpCap, I need to crank it up to 59. Not a huge issue, but beginning to question things! I re-set my HEQ5 to what it should be for last night's session, which is the 1st of the season (and only my 5th with the HEQ5) and just assumed SharpCap was telling lies before. I'm polar aligning, then fine-tuning in SharpCap (also normally used for capture), using PHD for guiding and ASCOM/StellariumScope for GoTo and 3SA. I made the mistake of updating software a few weeks ago in preparation for darker skies and the connections were very unstable to say the least. Couldn;t 3SA properly, telescope wouldn't slew to a target and the telescope and Stellarium weren't sync'd. Having 3 or 4 pieces of software open didn't help - can I simplify this? I'm really considering ASIAIR as I only own ZWO cameras and a compatible mount. Looked at SGP and APT before but it seemed they also needed 3rd party software, or did I miss something? I made several mistakes last night in a rush as it took close to two hours to work all of the bugs out. I have lost a bit of faith in SharpCap for image gathering (plus it can't dither properly) so gave ASICAP a chance (mistake 1). I have an Optoplon L-enHance filter for some Ha targets and to deal with LP, so targeted the Heart Nebula. 30s check exposures in SharpCap with 500 gain looked very promising. I forgot to switch on the cooler when I swapped back from SharpCap to ASICAP (mistake 2) but temps seemed stable at 1.5deg in all images. I also imaged at RAW8 (is this a mistake?) and imaged directly to .PNG as opposed to my usual raw (mistake 4). For some unknown reason I settled on 3min subs at unity gain (mistake 5) and the resulting images are unusable pretty much. I have attached a single sub. My 3rd question is does the combination of all of those mistakes explain the image I have, or can I narrow it down? I expected the green hue due to the filter, and was aware of the very bright star to the right of the image. The moon was out but relatively far away. I seem to have blown out the detail of the nebula, lost all the faint detail, and looking at the histogram I have lost a lot of data to the left of the curve. The image is also beyond noisy. Any help would be much appreciated!
  10. https://www.365astronomy.com/Blitz-Hotshoe-dSLR-Camera-Adapter-and-Red-Dot-Finder-COMBO.html When I used my A6000 this is what I used. Works well. Need to get a bracket so I can attach it to my current setup.
  11. Evening all! I too tried guiding, and just got a bunch of errors after selecting a guide star and letting it go, so gave up and turned it off. Will work on it next clear night. Anyway, finally got a first light with the ASI294MC Pro. No flats, darks or bias (need to work out what is and isn't needed for that camera). Stacked in SharpCap (live stacked), and minimal processing in Photoshop (levels, black point, curves, exposure). M31 Andromeda - cooled to -5 degrees, Gain 120, exposure 60s x 45 M45 Pliades - Not cooled, taken at 3 degrees (forgot to switch on cooling), Gain 270, exposure 20s x 116 My spacing was off. I forgot to account for my LP filter properly, so i'm out by at least 5mm which has caused the elongated stars from all edges. The M31 has red artefacts, but I think that's a problem with my combining of the RGB layers in photoshop. In the M45, there's halos around the brighter of the 7 sisters, so need to work on that. I'm also missing a chunk of nebulosity. Not too bad given the moon was out and about. Not a bad 1st light by all accounts!
  12. This ^ When I had my A6000 (plus strap) any breeze and any exposure over 15s was a risk. Guess I was too lazy to remove the strap, as I used it for astro and terrestrial.
  13. Well, my portable SA setup is pretty much complete for now! As per my sig, Manfrotto 055 supporting a Star Adventurer, WO ZS61 + Flat61, ASI294MC-Pro, guided by a ZWO Mini + ASI120MM-Mini. The powered hub on the 294 powers the mount, so one less cable. Only have the USB3 and camera power running from the scope. Think I need to add a second finder bracket to add a small finder, but that's about it! Maybe a power bank for true portability. Sadly no imaging with it yet ?
  14. A bit late to the party, so you may already have everything in place, but you're right in that you'll need the M48 to T2 adapter plus the T2 to Sony E adapter. What I found through this setup was that my overall spacing from lens to sensor was too long by just over 12mm. Spacing sees very important on this setup. With my mirrorless A6000 I had to replace the end part of the Flat61 (essentially a 20mm extension tube) with a 7.5mm piece to get the right distance. I can swap this out for a LP filter if required. The ZS61 plus the Star Adventurer seems like a great combo that does allow for future guiding if you require slightly longer exposures, but given you're on Sony you may be limiting them anyways.
  15. I recently bough the William Optics Zenithstar 61 APO, and it's pretty good. As Ronin said, it's only a doublet, but from quick tests in a light-polluted area I am impressed enough with it. It's 360mm in FL, and the flatener is a 1:1. It is also F/5.9, so maybe doesn't tick your boxes, but the build quality is pretty good. Edit: At 1.45kg it is very light, which would be my primary concern on the SA.
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