Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Northernlight

Members
  • Posts

    523
  • Joined

  • Last visited

Posts posted by Northernlight

  1. Is there a way to work out the suitability for the best camera ?  My main imaging rig will comes in at 0.78" resolution :-

    I am using an OAG and the 2 cameras i'm considering are the ASI174MM mini or the ASI200MM mini

    ASI174MM = 1.21" resolution with OAG

    ASI220MM = 0.83" resolution with OAG

    So the ASI220 will be the closest match to my main imaging rig, but the ASI174 will have a much wider FOV and more stars for the MultiStar guiding, which is likely better for the harmonic mount i've ordered.

  2. Hi all,

    I use an OAG with my 2 scopes which are 400mm & 1000mm Fl. I'm looking for a new guide cam recommendation and my old lodestar is getting a bit old now and struggles finding stars.  Traditionally, i  believe IMX174 based guiders were considered the best due to their larger sensor size. I just wondered if this was still the case as these are also quite old sensors now.

    Are there any newer modern guiders with a similar size sensor or are the older IMX174's still considered the best choice for acquiring more guide stars ?

     

    Cheers,

    Rich. 

  3. Hi All,

    I just ordered a Ioptron HAE69C mount but i'm starting to second guess myself.  I'm going to be using it pier mounted in an obs, but the thing that keeps bothering me is the 0.5-1.0s guiding. In the uk the seeing isn't the best, so I wondered if there are any harmonic mount owners in the UK that could give feedback.

    I'm just worried that the poor seeing will result in terrible guiding or if it will be fine using multistar guiding.

    So if there are Harmonic mount users from the UK, would really appreciate your feedback, especially on harmonics without encoders.

     

    Many Thanks,

    Rich.

  4. Hi all, I have a osc camera and I’m looking for recommendations for the best broadband filter for osc cameras in 2023. Im only interested in broadband targets such as galaxies & comets and maybe some reflection nebula.

    only interested in broadband filter recommendations, not interested in narrowband filters recommendations as I already have the optolong ultimate.

     Many thanks in advance,

    Rich.

     

  5. Hi Lee, this is very spooky, I had literally to finished reading your review when I noticed the notification pop up on my iPad. At first I had my doubts about Askar, but apparently a lot of the negative reviews are from early samples which have now been fixed.

    I emailed FLO, and they said they were very good and shared the same opinion that it was the early samples that had a few issues and have now been resolved.

     

    • Like 1
  6. Many thanks ELP I’ll take a look. The WO GT71 will be a good companion for my little SW star adventurer GTI mount for now then next month when I buy a new obs mount, it will compliment either my 8” RC or my 10” Quattro.

    heck if it guides ok on the little SA GTI mount, I might use that for wide field whilst working on galaxies / Dso’s on the main mount.

  7. Hi All,

    I think i'm now onto plan version 3 of my Astro Imaging comeback / revival and the latest plan includes the purchase of a small light refractor that can also be used on my portable rig.  I've been looking at a few options, but wanted to get peoples opinions on the best 70-76mm refractor that can be bought under £1200.  I cant really go any larger than 76mm and i need to keep the weight down to around 3kg for the scope and rings etc or 3.5kg including a FF/reducer.

    So far I've looked at the scopes listed below but welcome any other recommendations.  So far I've ruled out the sharpstar as I've seen several reports of chromatic aberration resulting in horrible blue halo's around bright stars, so that has put me off quite a bit.  So between the Askar and the WO, the WO GT71 seems like a better bang for buck as it's a bit cheaper and with the FF/Reducer it's quite a but faster and Winder than the Askar, so seems like a no brainer.

    Any feedback or recommendations would be greatly welcomed.

     

    Williams Optics GT 71 II Triplet

    • Scope £895 + FF £209   - total = £1104
    • 420mm @ F5.9   ( 336mm @ F4.4 with 0.8x FF)

    Askar FRA400 Quintuplet

    • Scope = £1259
    • 400mm @ F5.6

    SharpStar 76EDPH f/5.5 Triplet

    • Scope £865 + FF £265 + Adapter £19   - total = £1149
    • 418mm @ F5.5 (342mm @ F4.5 with 0.8x FF)

     

    Many thanks in advance,

    Rich.

  8. SamAndew I think you are being a little unfair to iOptron

    just keep in mind, iOptron drives competition and innovation in the market and with more options competing in the market you usually see prices of the technology driven down. So if iOptron didn’t exist, I bet your bottom dollar the AM5 would have been a lot more expensive.

    a good example of this was the rainbow Astro mounts, when they first came out, they were ridiculously expensive and then as soon as the completion turned up in the market they had to reduce their prices massively.

    also flip the argument the other, some might say that zwo’s offerings are too limited with their 2 mounts available.

    so it doesn’t matter if you like 1 manufacturers gear or not or if you find their product line up confusing , competitions is good for the end consumer.

    Lots of other manufacturers have extended and somewhat confusing product lineup’s especially when it comes to scopes,  but as other have have said, Google is your friend, do your homework and above all else understand what it is that you actually want.

    Rich.

     

  9. Unfortunately not. I suspect the issue is the type of lens im using, as when I look at YouTube to see what everyone else is using, they are all using prime lenses. In the test shots I took with my zoom lens, it also had significant coma.

    I just don’t want to spend £400 on the samyang 135mm prime lens, as i thing I’d rather put it towards a 80mm triplet.

  10. no lens hood, and no stray street lights as taken in my back garden.   The only way i can really test is to try my 13mm Prime lens to see how that differs from the zoom lenses.

    Will be interesting to test the same lens but without it being zoomed to see if i get the same effect. e.g. at the 16mm focal length vs the zoomed 80mm focal length.

  11. I also have a Fuji 70-300mm zoom, i'm also going to test that as well.  will be interesting to see if the results will be as we suspect e..g. my prime doesn't show similar circular artefacts, but i expect my 70-300mm fuji to show similar artefacts as the 16-80mm lens.  The annoying thing is that both of my Fuji lenses were not cheap, they were around £750 each, so it would be a shame if they can't be used for Astro, as i was hoping to use the long 300mm focal length of my longer lens which is is equivalent to 450mm on full frame.

    I'm also going to try stopping down my 16-80mm lens to F5.6, just to see what happens - whilst not ideal at F5.6 it will give me a good idea of what's going on with the lens.

    Unfortunately it looks like i'm clouded out for the next week, so will be a while before i can test again. - No i remember why i got out of imaging nearly 2 years ago 🤔 - Imaging is a constant battle, that i dont seem to win very often lol.

     

  12. 27 minutes ago, Elp said:

    I'm also guessing you're using native Fuji lenses and not a lens adaptor which can introduce internal reflections (from what I've read there aren't really any out there which don't internal reflect).

    It could be the lens construction, I specifically only use manual primes as they tend to focus to infinity better. 

    The reason I ask about camera model is because I recently got a Sony A7s, and upon trial I had a similar issue where from midpoint to outer edge I got a red/green ring pattern which didn't calibrate out. There's an option in camera for lens compensation and I've turned it off but haven't trialled it since. But with Sony cameras there's an apparent issue with these rings as well as the sensor being a half half design, as a lot of cameras out there use Sony sensors I wouldn't be surprised if the issues translate to different manufacturer bodies. Daytime photography is fine, but I can see the issue immediately at night when imaging 15-30s per image.

    Elp, have you got any examples of the similar issues you faced.

  13. I'm using a Fuji X-s10 and the native fuji lenses (16-80mm) Prime zoom, e.g. constant F4 throughout the range. I can test the theory about the lens design, as i can test one of my other lenses which is a 13mm F1.4 Prime

    I hope were wrong, otherwise it's screws my whole portable rig setup as i cant afford to buy any more lenses at the moment, but might have to consider saving for a small 80mm triplet instead of using lenses.

  14. It’s a Fuji x-s10, but the line issue is sorted as I just forgot to click cfa option for calibration settings in PixInsight as I was just used to mono processing.

    I still however haven’t figured out the issue of the ring appearing in my image, as I don’t see any such artefact appearing in my flats, so no way I can correct it in my image. I can only assume it might be something to do with using a zoom lens rather than a prime lens, but at the same time i don’t see similar artefacts when doing long exposure daytime photography.

  15. 5 hours ago, michael8554 said:

    Hi Rich

    I couldn't see what you described so I stretched your image:

     

    16JuneB.jpg.bfefe31c09254e1c7ed641f96f1f3fdc.jpg

    I can see vignetting, which as an experienced imager I'm sure you're aware of.

    More concerning are the vertical lines all over the image.

    Michael

    All I can only assume that the vertical lines are some issue with calibration. I’ll check the unprocessed images to see if they appear. It could also be an issue with the bias files I created.

    I’ll check tonight

  16. I did wonder about the vignetting, but the odd thing is that it didn’t show up in the flats as they only had a tiny bit of vignetting on the extreme corners.  I took the images at the max 80mm focal length, but I’m wondering if I took the flats at the shortest focal length 18mm which might account for the issues.

     

  17. Hi All,  I have a few years experience imaging with a traditional scope setup (Frac, newt etc) using a dedicated astro cameras, but recently i wanted to try a portable rig using my mirrorless camera.   So i shot 150 images using my camera with a 16-80 F4 lens which has a constant F4 aperture though the zoom range. My images were shot at 80mm Focal length,  but after stacking i noticed a central ring artefact, so went backed and check my individual images, and sure enough there was a ring artefact in the uncalibrated images.

    I can't make any sense of it, as i wasn't using any filters, and the lens had no obstruction, so i didn't expect to see such an artefact appearing.  So i'm struggling to figure out the cause of the ring.  Would be grateful for any suggestions to the cause of the ring from other mirrorless camera users.

    Many thanks in advance,

    Rich.

    ring artefact.jpg

  18. Well I got some clear sky for an hour last night, and now that the sync is properly enabled in Nina it’s working perfectly with cartes du ceil, so I’m a happy man as I’ve got a single app for my polar alignment and plate solving.

    I can now easily get under 30 arc seconds on my polar alignment without the need for a separate polar alignment camera and then get perfect pointing accuracy with the plate solving, happy days all round 😁

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.