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HAlfie

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Everything posted by HAlfie

  1. wow that's splendid, nice colors and nice work!!
  2. Hello Ken, I've been there. Last year I used Baader LRGB-SHO filterset and since a few months, I've decided to jump into Astrodon LRGBSHO 3nm filterset (in second hand). Chroma are clones of Astrodon so don't worry about it. The baader filters are the best bang for the buck in narrowband but once you want to step up a little, Astrodons/Chromas are the best out there (narrowband). Indeed, the 5nm Chroma costs the same as 3nm, it's no mistake, it's the same ridiculous price difference in the US. That's why 3nm are a better choice for Chromas, especially compared to Astrodons 3nm prices! The Chroma & Astrodons have a real transmission of at least 90% guarantee, when the Baader can vary from 75% to something like 90% in the reality. Having used the Astrodons for a few months, the difference is significant over the Baader (I mean thank God for a 3 x narrower filters!). With narrower filters, you'll increase the time available to take deep sky picture as even with presence of the moon, the 3nm Ha is almost bulletproof! You just have to avoid to have a full moon really close to the object you're aiming at. Now let's talk about the 3nm OIII, the difference is important as I had almost no halo with the Astrodon when the Baader had some halo on bright stars. Adding to that, the 3nm is almost 3 times narrower than Baader OIII 8,5nm. Stars are tighter, and you the 3nm is more resistant to the presence of the moon. Though, using OIII during moon phase isn't always the best idea as it is the one the most affecter by it. I think you can reasonably use the OII until 50% moon phase and with an object, at least 50Ā° away from the moon. I've compared the 5nm & 3nm astrodon filter on a same night/same object. The 5nm gives the same signal/noise ratio (as the 5nm has NII line in it) but, the stars are slightly smaller than with the 3nm. A good combination would be 5nm Ha, 3nm OII & SII but as chroma narrowband filters have the same price betwee, 5nm & 3nm version, don't hesitate to go for 3nm šŸ˜.
  3. Hello ;), a photo during confinement in France, but fortunately weather is excellent for about 4 weeks šŸ™‚! TSA102, AZEQ6 PRO & Berlebach Planet with double clamp from FLO! I'm using 3 antivibration pads to prevent rubber feets to sink into the ground šŸ˜…! Clear skies
  4. Hello šŸ˜‰, very nice pictures on this topic! This is my contribution with Vixen VMC260L and ASI178MM : Best regards
  5. @ollypenrice : thanks for your answer! How is your experience with both FSQ? What are their weaknesses? I may presume the spherochromatism should be better in the red (HA & SII) light? Yes the TEC 140 is a very nice piece of optic :).I would love to get my handson the TEC 110 lenses in the WO optical tubes. Yes the issue is a little bit troubling but can be compensated with a slight offset applied with autofocus some nothing dramatic indeed! @Alexbb: thanks for your answer! Yes you're right, I'm curious to see your next images with your new refractor :). Have a nice day and clear skies
  6. Hello Alex! Thanks for your answer! Aah, you're picture of NGC6992 remind me of the one I took 1 month ago that I don't totally yet finished in post processing but I'll show you anyway !! What camera and time integration per filter did you use? In my case ASI183MM PRO, 57x600s Baader Ha 7nm and 48x600S with Baader OIII 8.5nm filter. And you? This is impressive how the 2 pictures are similar. Your stars seem smaller though! Regarding dark gap in the stars halo, yes some Esprit can be "affected" by that. That's why Tommy from Teleskop Austria guarantee a smooth star halo. In my case, the lens buffer ring has been exchanged (to avoid the dark gap in stars halo), and lenses has been collimated one by one. It's a step above "just" check the collimation but it's more expensive. But if Es Reid has chdk the collimation, no need to worry šŸ˜€! Regarding the picture with AstroProfessional 102/714 ED with FPL51 + 0.8x reducer, yes corners aren't perfect as I presumed, especially at the top left corner. It's not catastrophic but not as "flat as with the Esprit. Gosh, why is it so hard to find the perfect refractor šŸ˜œ! Except the FSQ lines which cost an arm and a leg, the ideal fast focal ratio < 5, with excellent color correction in red & green channel, with perfect corners and a stiff rotating focuser is hard to find. Maybe an "old" TMB 80/500 or 80/480 with Feathertouch and Riccardi reducer could be a solution? On another hand, there is the Takahashi TSA 102 (still expensive) but it's only F6 with the reducer. As the ASI183MM is very demanding with its the tiny pixels, it pushes you to increase your time exposure to smooth noise. I would not dare to use it with a focal ratio > 5.5. The esprit 120 with Riccardi Reducer F5.25 could be a good match but it's heavy... Near 12kg/26lbs šŸ˜–! Clears skies to you and best regards!
  7. Hello Alex, and congrats for your very nice images! I'm following you on Astrobin šŸ˜‰! Yes a triplet at F6 or more combined with a very good quality reducer/flattener (such as Riccardi 0.75x which is a beast or the TS 0.79x which is good) may give better stars in the red Channel. However, everything has a price to pay. How are corners exactly with your 102/714 and the reducer/flattener? This solution is often more critical regarding TILT and right distance with sensor than with only flattener that doesn't change the focal ratio. In my case I want perfect stars on the whole image, including corners because I want to be able to perform mosaics. I'm wondering, if your stars with the Esprit 80 are that big and soft, are you sure the lenses are properly collimated? I know that Ed Reis check them if bought on FLO and Tomy as well if bought on Teleskop Austria. I think it's a nice "insurance" just in case. Have a nice day and clear skies to you!
  8. Hello, I check with Tommy and his explanations were crystal clear : Everything was explained here and it is the same for ESPRIT 80 and ESPRIT 100 (in German but we can translate): http://interferometrie.blogspot.com/2013/09/skywatcher-esprit-80400-und-100550.html?view=magazine The solution is either and/or use deconvolution process when processing the image, or apply a little offset when focusing in SequenceGeneratorPro (I apply +12 for instance but I may try +20 or +25) to find the "sweet spot" and deal with that. For those who would be worrying about the results in RED or HA light, and the level of sharpness we can achieve with Esprit Triplet, using both of the solutions (optimized sharpness in Photoshop & offset to the Ha focusing), here is a first attempt on the Pelican nebula, 62x600S Baader Ha 7nm, some part under full moon, Esprit 80 PRO 80/400 with flattener, ASI183MM PRO, please click on the image to see the full version : I think the level of detail/sharpness/tiny stars is pretty good especially considering it's taken with "only" 80mm of aperture. I'm still confident that the Esprit line are a bargain in the price/quality range. Hope this topic helps some future owner of Esprit refractor šŸ˜‰
  9. Hello and congrats for the very nice picture! Even the full version has very reasonable noise (especially with CMOS sensor) and stars are very tight :)!! Colors are perfect in my opinion šŸ™‚!
  10. Hello and thanks a lot for your answer! you're totally right, a Roddier on 3 channels would give me the answer :)! I'll look into it!! That's very interesting especially to see which channel is the strongest suit and which isn't. Yes the Strehl of 0,95 was on 550nm...! The fact that I'm Ć  F/5 (which is quite fast) could be a part of the explanation. The difference of focus quality between colors channel isn't really catastrophic but I may be flirting with my optics's limits :). Cannot trying to be a Takahashi when you're not ;). Have a nice day and clear skies!!
  11. Hello everyone and thanks for your answer šŸ˜‰! Laurin Dave & Adam J : I'm afraid I'm not sure the reason would be the seeing (I wish I would) as the effect is the same on several nights on differents objects šŸ˜ž . vlaiv : 2. With SGP, the HFR (which is a bit different from FWHM) values follow my empirical observation. I mean, when I can reach HFR around 2.5 in OIII, I usually not get below 2.9/3.0 with Halpha and SII. The HFE is very stable during the night (range of 0,3 because I refocus every 0,6Ā°C temperature drop and every 30min). 3. Regarding your point NĀ°3, my ESPRIT 80ED comes from Teleskop austria and was "perfectly" collimated by Tommy : Ususally I was expecting to have a cleaner Halpha channel than OIII, but it's the opposite. I also know that asiderom the optical color correction, in green, you get a better resolution and even better in blue than in red. 4. Yes I agree, if one filter was faulty, I would have some issue with both Halpha AND SII (which share the red light) but they both look quite similar regarding this effect. Maybe the NĀ°3 explanation is the right one as I looked into autofocus routine and analyzed more precisely pictures. Here is an example of my autofocus routine with RED filter. I have exactly the same results with Green filter, my triplet seems to have the exact same focus position with R & G (and almost same with blue). If you look at the circle with the 2 small stars. You'll probably find that the best focuser position seems to be 32434 or 32407. Now if you look at the "big stars" with HFR value, the best focuser position seems to be 32353 which was chosen by SGP but the small stars seems slightly out of focus. It's like I can"t get a perfect focus with both big and small stars. How is that even possible šŸ™„? Do you see the same pattern as me? Here is another example taken the same night on another object, the effect remains the same. Autofocus seems perfect with tight pinpoint stars but it's kind of slightly blurry/out focused with Halpha & SII . On pixinsight, I applied exactly the same process. Autohistogram, Joint RGB/K channel : 0.18 / histogramtranformation with exactly same values for the 3 images. OIII Channel : Halpha channel : SII : channel Thanks for your answer ansd best regards!!
  12. Hello there šŸ˜€, I'm still trying to improve my imaging Workflow and did some tests on NGC 6992. My SETUP is : Skywatcher ESPRIT 80ED 80/400mm + Flattener + ASI 183MM PRO + Baader LRGB-SHO filters. I use SGP (Sequence Generator Pro) for many things and among them autofocus routine. But, it's like my OIII channel is always sharper with tighter stars than with my Halpha/SII channels which seem more blurry and with stars less "pinpoint". See for yourself. Do I have a slight out of focus issue in Halpha/SII or is it normal that the OIII seems sharper and more detailed? Maybe it's my truiplet lense which is better corrected in green light than red light? OIII channel : Halpha channel: SII Channel : (don't bother the change of angle of the ampglow, it's just after a meridian flip with of course another autofocus just after the flip). Thanks in advance for your answer and clear skies !!
  13. HAlfie

    New member :-)

    Thanks and talk to you soon :)!
  14. Hello Carole, and thanks for your answer! Yes indeed in the "worst" case I'll do like you said, stack the stacks afterwards šŸ˜€. After stacking the same total duration in 450s exposures and 300s exposure at same unity gain: -->Noise seems to be the same (I thought that stacking more exposures would reduce it) -->SNR seemed improved Conclusion: I'll stick with 450s exposure and maybe try 600s . The limit is the ampglow which is more important when we increase gain and/or exposure time. I failed to totally remove the ampglow with my darks in both case. Maybe my "old dark" from 1 year ago has changed since. 17x450s (127min) stacked in Halpha gain 111 : 25x300s (127min) stacked in Halpha gain 111: Have a nice day and clears skies
  15. Hello Gav, and thanks for your answer :)! And yeah you're totazlly right, sometimes we use different exposure times in order to catch slight details such as the heart of M42 for instance :). In my case I'm more tying to find the sweet spot between exposure time & number of exposures to stack to limit noise. Here are 3 exposures without pre processing from last several nights : 300S exposure in Halpha with stretched levels, 800ADU (I live in a city) : 450s exposure in Halpha with stretched levels, 900 ADU : 450s exposure in OIII with stretched levels, 900 ADU (after meridian flip) : Have a nice day and best regards
  16. Hello Gav and thank you for your detailed answer šŸ¤—! Ok phew, my "bold" move should not be a problem in the pre processing process, that's a relief. To answer your question, I plan to use Pixinsight in order to akeep using as little as possible different softwares. Yes I agree totally with you : we have to find the "sweet spot" between a lot of variables! My system can track with almost 100% success sub of 10min šŸ˜€! I worked a lot to improve my AZ EQ6 and have tried all combinations possible and the DEC worm with the DEC tooth Gear gave me the best resultats in PE, along with the aeroshell 33 grease used in aviation. I have been going through the long topic on the ASI183MM on the Cloudynight forum, with a special attention to Jon Rista's posts. The conclusion was that the latest CMOS sony sensors (used in ASI183MM or 1600MM) don't behave like CCD sensor. They tend to need a bigger amount of image to stack while CCD are more into "the longest your exposure is the better" despite less number of subs stacked. It's a change of paradigm. In case of the CMOS sensor used in the ASI183MM, the sweet spot seemed to be Gain 54 for LRGB and gain 111 (unity) for narrowband. Below 54 you may face banding issues, and above 160 gain, you may face big ampglow which will not be totally corrected with darks. I remember that in order to squeeze the better from this CMOS sensor, you need to stack at least 60-80 subs per filter and make a lot of dithering like every 3-5 subs. It questions me though : what if I stack less subs with longer exposures? When doing HDR processing, is the noise would appears the same way? I think I may find out when I will do the pre-processing and processing exactly the same way between : 17 x 450s (7,5min ) in Halpha = total of 127,5min 25 x 300s (5min) in Halpha = total of 125min on the same target. Have a nice day and best regards
  17. Hello there, I'm getting used to the ASI183MM in narrowband! I would like to know : is there anything, in the image preprocessing step, that prevents from using 2 series of different exposures lengths with the same filter on a same target? I have of course, darks for both exposures lengths. For instance the last 3 days, I took 60 x 300s exposures of NGC6960 with Halpha & OIII filters. Then I wanted to be bold šŸ˜… and took the liberty to push up a little bit til 450s exposure's length. I ended up this morning with 17 x 450s exposures both in Halpha & OIII. The SNR improved over 300s exposures and I think from now on, I may use 450s exposure length for all my next targets. I just wanted to be sure, from your experience, what are the consequences of doing that? Could I stack exposures of 300S and 450s in the same preprocessing step (with respective darks of course) or would I need to preprocess them separatly and merge them in Photoshop? Though I would like to stack all the exposures in the same processing to have the best improved SNR. Thanks in advance for your answer and clear skies!
  18. Hello and welcome, I'm not far from your location (Colmar 68) :-)!
  19. HAlfie

    New member :-)

    Hello Everybody and thanks a lot for your warm welcome šŸ˜Š! Talk to you soon!
  20. HAlfie

    New member :-)

    Hello everybody šŸ˜, I'm member since last year but this is the first time that I plan to be more active on this forum. I'm an astronomer enthusiast for about 15 year from now! I enjoy high resolution astrophotography of the moon/planets as well as deep sky imaging where I'm planning to be back again very soon with my new setup :-). Here is my latest mosaic of 100MP of the moon with Vixen VMC260L & ASI178MM (you may click on the image to see the full version) : Hope to talk to you soon! Best regards & clear skies
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