Iris and Ghost stitched together - Work in progress(?)

[Mike in Rancho]

Yep, nice graphic, Dietmar.

No big deal on the flip or mirror, Stefan. Some objects are just so often seen in a particular orientation that you get used to it.

The "seam," if it really is one, shows with a bit of distance. The opposite of pixel peeping! Again it could be true data and just an illusion due to the narrowness of the short side distance. But for nature photos, the eye tends to be drawn to anything that appears straight and thus perhaps artificial.

Could be a big space freeway out there.

So, it might not be a classic mosaic seam, which would take actual pixel peeping to check out, and those are usually just a thin line of mismatched pixels or narrow strip of them. But since it's up the center and thus perhaps close to where the two sides came together, and you stated the stitch was post-processing, is why I pondered if edge behavior might have weakened that edge, making it stand out once they were attached to each other.



Inspection of some reference photos, maybe after cropping similarly, might confirm reality and that it's only an illusion of a space freeway.

[Stefan B]

Thanks, Dietmar, for pinpointing

I really pixel peeped for single pixels in a straight line but now I get what you mean. This doesn't exactly correspond to the overlapping region but is rather next to it. Here you can see the individual, processed image used for stitching (although heavily compressed):

Ghost, 2023-09-10, 249x5min, EQMOD ASCOM HEQ56, (UV-IRcut), ATR3CMOS26000KPA_stacked_PS_small.jpg (426.57 KiB) Viewed 19230 times

I think it looks the same and thus wasn't introduced by stitching. So it might be real in the sense it's in my data. Though this has to be taken with a grain of salt since the images have been strongly wiped (>90% gradient aggressiveness) since the moon was 50% on average and not far away. Not ideal for faint broadband targets.

After looking at some reference images I also think that there actually might be less nebulosity. Maybe a freeway indeed

Hope you guys have some luck with imaging during new moon!

Regards
Stefan

[Mike in Rancho]

Aha, so the vertical path (freeway, Autobahn?) is certainly within the full panel, and far enough from the edge that Wipe behavior would be ruled out anyway - though query what the overlap was and how it all got stitched.

Just makes for an interesting illusion then, due to the way the FOV framing happened to turn out.

[decay]

Hope you guys have some luck with imaging during new moon!

Thanks, Stefan. Unfortunately the weather forecast doesn’t look nice for the next ten days. Last night was quite fine but I was much too tired to set up my rig. But I managed to get some few hours of light during the nights in which you too acquired your awesome images. I maybe will post tomorrow or the next days as I want to write some few words more …

Oh – and yes we too drink lots of beer here in Westphalia – I mean beer made of barley (had to lookup that word) and not made of wheat (hehe, just kidding a bit But unfortunately I made the experience that drinking beer and doing astro photography is not a good combination. At least it results in severe headache next morning.

No idea how you manage to gather this tons of integration time. Besides obviously having unlimited physical and mental strength – what do you do about dew, for example?! Whenever I set up my rig even on ‘dry’ (haha) summer nights it works for maybe one or two hours and then everything gets wet. Dew on the secondary mirror and on the guide scope results in unusable subs and later on guiding fails. Do you use some kind of mirror heating and/or dew cap?

On topic: It’s difficult to give any kind of constructive feedback simply because everything seems to be quite perfect. The Ghost looks awesome! And that Mike and I both noticed some kind of Autobahn, but not at the location where the images intersect, seems to be a strong sign, that you succeeded perfectly stitching the images, doesn’t it?! And to answer your initial question: Yeah, I would probably tone it down. A bit. Maybe. Not sure. And even if so, that’s just a matter of personal taste and most probably I am the one with the unusual taste .

Regarding the ‘interesting’ aspect ratio I have a question: What do you do with such images? Of course, it’s fun to explore them on the PC display but for all other cases that doesn’t seem to be very handy? I’m using an old 10” tablet as digital photo frame and this aspect ratio would result in large black bars at top and on bottom. And all the nice details would not be visible, because they are much to small … ?

Best regards, Dietmar.

[Stefan B]

Hi Dietmar,

looking forward to your image...

Oh – and yes we too drink lots of beer here in Westphalia – I mean beer made of barley (had to lookup that word) and not made of wheat (hehe, just kidding a bit

Oh, I don' t care if it's made of barley or wheat. I drink both of them

what do you do about dew, for example?! Whenever I set up my rig even on ‘dry’ (haha) summer nights it works for maybe one or two hours and then everything gets wet. Dew on the secondary mirror and on the guide scope results in unusable subs and later on guiding fails. Do you use some kind of mirror heating and/or dew cap?

That's no issue for me. For the guide scope I use a cheap USB lens heater. You can get them on ebay, amazon or the telescope shop of your choice. Dew on the secondary was a problem only once in a very humid night. Afterwards I installed a heating as described by Daniel Nimmervoll (https://www.youtube.com/watch?v=j_zRwwH5k7k). But actually I didn't use it during summer. Just the last two sessions after I saw all the fog in the morning.

And to answer your initial question: Yeah, I would probably tone it down. A bit. Maybe. Not sure. And even if so, that’s just a matter of personal taste and most probably I am the one with the unusual taste

I'm still unsure about it. It so much depends on the screen used. On my TV it's too bright. On most other screens it looks fine to me. I'll probably leave it as it is for now.

Regarding the ‘interesting’ aspect ratio I have a question: What do you do with such images? Of course, it’s fun to explore them on the PC display but for all other cases that doesn’t seem to be very handy? I’m using an old 10” tablet as digital photo frame and this aspect ratio would result in large black bars at top and on bottom. And all the nice details would not be visible, because they are much to small … ?

Basically true. Although I like this widescreen ratio you are right about the bars at top and bottom. But I might hang this one to the wall with a 30 x 90 cm poster

Regards
Stefan

[decay]

Oh, I don' t care if it's made of barley or wheat. I drink both of them

Afterwards I installed a heating as described by Daniel Nimmervoll (https://www.youtube.com/watch?v=j_zRwwH5k7k).

Thanks for pointing out, Stefan. Your location indeed seems to be a much drier place than mine. I think I will give that a try.

[Stefan B]

Forgot to mention that I initially used a DIY dew cap for the guide scope before I had the heat strap. Well, you barely can call it dew cap. It has just been a sheet of construction paper (Tonpapier in German), rolled together, taped so it doesn't unfold and slipped over the guide scope (you can also tape it to the guide scope so it doesn't slip of). That was always enough to prevent dew from forming. I still replaced it with the heater since the paper gets constantly wet and so you have to exchange it every 5th session or so.

But it's cheap and worked in my case (and dew on the guide scope has indeed been a constant problem before).

Regards
Stefan

[decay]

Thanks, Stefan! I read about this Tonpapier dew caps somewhere. And I think I will first try something similar and have a look, how it works. Buying a heat stap would be OK for me, but this means one cable more to build Gordian knots. No. I don't like knots. And cables At least not at my scope

Thanks again for the link to the video clip. There is one interesting hint in the comments: Dew also can form on the front side of the coma corrector. I'm not 100% sure at which of these places dew forms, because I cannot see these locations when the camera is in place. Will have to check that.

Best regards, Dietmar.

[Stefan B]

I read about this Tonpapier dew caps somewhere.

No way! I really thought I would have invented this...

No. I don't like knots. And cables At least not at my scope

Well, I'll have to show an image of my rig from 2021:

IMG_20210307_181804.jpg (81.98 KiB) Viewed 19107 times

In the meantime, it improved a bit but not much. And consider that the camera hasn't been even attached I know there are lots of Youtube videos exclusively on cable management. Can you believe I haven't seen a single one of them

There is one interesting hint in the comments: Dew also can form on the front side of the coma corrector.

That's right. I even had that once! I removed the dew with a handkerchief. That's an incredibly stupid idea since the effect lasts for 30 sec max and you risk damaging your filter. But out of desperation... But again, that happened only once.

Regards
Stefan

[decay]

Well, I'll have to show an image of my rig from 2021

Very impressive, Stefan! This looks a bit like the things in my head

With my new EQ6 I tried to tie some of the cables together. But that's still work in progress, I would say. But for now it's OK, just like your approach

Best regards, Dietmar.