Tuesday, 07 September 2021
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Hi,
i am quite unhappy with the stars on this Pier and from what i can gather it is due to the 0.73x reducer. Earlier i was all for keeping the wider FOV but have since changed my opinion. Would love to hear what the other members think and if agreed upon by most propose roboscopes to change to native focal length at a suitable time....
2 years ago
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#3624
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Vikas,

I support removing the reducer at the next opportunity.

The last time this was discussed we were still learning how to use the rig, and had a number of our first mosaic projects on the go. It was agreed that we would keep the reducer and see what sort of images we could get.

With more experience, I can see that the mismatch between the reducer and the camera causes a lot of problems. For single frames, the coma and lack of field flatness are less of a problem, as we can always crop the images. However, for mosaics, it becomes a real pain. I am struggling with the 2 x 2 Sadr region mosaic at the moment, as we have distortions flowing in different directions in the overlap regions.

Mosaics will be much easier without the reducer.
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Every forum probably has one!  I give 3/4 of a vote for the change. :) 

Ray
Roboscopes Guinea Pig


2 years ago
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#3626
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hi, i just processed the Sadr mosaic .... see attached ....and notice a huge flare on gamma cygni ....is that normal or is that another artifact of the 0.73x reducer ....shud i leave it or get rid of it ...looks very odd to me ....vikas Sadr-Sh2-108-4-panel-mosaic-RS-FSQ-106-copy.jpg
2 years ago
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#3627
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Vikas,

I don't think it is the reducer, I think it is the narrowband filters. We have seen this in a number of images from this rig.

If you use Starnet to create a starless version of the image, you can use a variety of approaches to reduce or 'paint out' the halo, but when I do it I introduce more errors, so I tend to leave things alone.
2 years ago
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#3628
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That's an awesome image Vikas :)

Phil McCauley
Roboscopes Website Admin


2 years ago
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#3629
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yes - will change that star out .....
2 years ago
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#3630
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here is the final image with the star cloned and the mandatory sign!!

Sadr-Sh2-108-4-panel-mosaic-RS-FSQ-106-copy.jpg
2 years ago
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#3631
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thanks Phil!!- glad u liked it
2 years ago
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#3632
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Yes the Baader narrowband filters are prone to halos on bright stars. have a look at Ray's test image in HA on Pier-3 from the other day as it's now using the Antlia 3nm filter set I was going to fit on Pier-14 on the last visit ;)

Its something we can re visit in the future if you all want ?

Steve

Please ignore my dylexia wherever possible, just be thankful I can control my Tourettes ;)

Things to do, so little time!

Steve
Roboscopes Tea Boy


2 years ago
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#3633
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here is the final image with the star cloned and the mandatory sign!!

[attachment]Sadr-Sh2-108-4-panel-mosaic-RS-FSQ-106-copy.jpg[/attachment]


Nice clean image Vikas :)

Fingers crossed it makes it to the Gallery also.....

Please ignore my dylexia wherever possible, just be thankful I can control my Tourettes ;)

Things to do, so little time!

Steve
Roboscopes Tea Boy


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Hi Vikas,

I agree. That's been processed excellently and I really like the colours you have managed to achieve. When, and you should, put it into the gallery there's apparently an approximate 30mb size limit, you may have already read the thread on it. Anyway that's going to need a massive size reduction I imagine. :) 

Regards,

Ray 

Ray
Roboscopes Guinea Pig


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Hi Vikas, 

Congratulations on the award in Astrobin and fully deserved. Having to reply here since I'm not a pier 5 syndicate member, but can fortunately still get to read the posts and see that great picture. You have extremely good processing skills, that's very plain to see. I hope you don't mind me asking if you carry it out just in Pixinsight or an  equivalent app, or use additional tools like Photoshop. I do make some use of Photoshop for any finishing touches, but still have a lot to learn. 

Excellent publicity for this site and I'm sure Steve will be very grateful. 

Cheers, 

Ray 

Ray
Roboscopes Guinea Pig


2 years ago
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#3636
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Thanks Ray!1 I am glad you liked it. I do most of my processing in PixInsight and sometimes i will go to Photoshop just to add spikes or do some cloning work as i did in the Sadr star.  Still learning the ropes of PixInsight though and a long way to go!!!....i think from one of my mails with Steve he did mention he doesn't care much for Apods, Aapods2, iOTD or TopPicks !!! I think they are fun but as long as u keep them at arms length.... looking at them though does improve ones perception and possibly processing and acquisition skills ....cheers!!
2 years ago
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#3637
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It is a nice image to be fair and worthy of praise.

you have a good memory Vikas, APOD for me is not what it used to be, Either that or with age, I ramble and reminisce more through rose tinted spectacles :)


still for advertising Roboscopes to the masses, then I am all for it :) :)

Steve

Please ignore my dylexia wherever possible, just be thankful I can control my Tourettes ;)

Things to do, so little time!

Steve
Roboscopes Tea Boy


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Hi Vikas, 

That's very interesting to know. I know that Steve says he's bored seeing the same objects repeatedly being shown on astrophotography web sites and magazines, but not about his attitude towards Top Picks, APOD and the like.

I won't say what I was going to on that and regarding his reply, but instead relate a story of someone where I worked. 

Around mid morning would be the time for some of us to browse the daily newspapers while partaking of a beverage. Occasionally when a picture  taken at an event appeared this person might then comment on any member of the public who was close to the action and got  included in the picture. They'd be accused of "trying to get their picture in the papers".  They had a word for them but I cannot remember what it was right now. Anyway, one day that person came into the office and immediately proceeded to open up a newspaper they had with them, open it up to the page where they'd inadvertently been snapped while at a concert. Everyone there had to see it of course, much to the amusement of everyone. :) 

I'd be very proud (chuffed) if I ever produced anything that I felt could be submitted somewhere, let alone then be picked out. I too like to look at and enjoy them, it certainly helps and inspires. 

Cheers,

Ray 

Ray
Roboscopes Guinea Pig


2 years ago
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#3639
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Hi Vikas, 

That's very interesting to know. I know that Steve says he's bored seeing the same objects repeatedly being shown on astrophotography web sites and magazines, but not about his attitude towards Top Picks, APOD and the like.

I won't say what I was going to on that and regarding his reply, but instead relate a story of someone where I worked. 

Around mid morning would be the time for some of us to browse the daily newspapers while partaking of a beverage. Occasionally when a picture  taken at an event appeared this person might then comment on any member of the public who was close to the action and got  included in the picture. They'd be accused of "trying to get their picture in the papers".  They had a word for them but I cannot remember what it was right now. Anyway, one day that person came into the office and immediately proceeded to open up a newspaper they had with them, open it up to the page where they'd inadvertently been snapped while at a concert. Everyone there had to see it of course, much to the amusement of everyone. :) 

I'd be very proud (chuffed) if I ever produced anything that I felt could be submitted somewhere, let alone then be picked out. I too like to look at and enjoy them, it certainly helps and inspires. 

Cheers,

Ray 


Ray, My issue with APOD is it seems to have diluted in its nature in so much of how broad a spectrum they use for "astronomy" picture of the day. It also seems become very political with the winners hat being used in a very Masonic fashion across an ever decreasing gene pool.

I love seeing well processed images ,different takes on things not to mention some of the stunning wide-field and Aurora shot, a lot of other sites still seem to be carrying the mantle forward I am happy to say. A lot of skill goes into this hobby and its great to see recognition for that skill.

I hope that expands a little on my thinking

Steve

Please ignore my dylexia wherever possible, just be thankful I can control my Tourettes ;)

Things to do, so little time!

Steve
Roboscopes Tea Boy


2 years ago
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#3640
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Vikas

I am sure I should know this, but how do you add the signature?

Regards

Mark
2 years ago
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#3641
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hi mark. I use photoshop actually to add the signature though i think there is a way to do it in Pixinsight too. a quick google search revealed this though i have not tried it...PI sign


u can get a custom made signature from here....sign

i find it easier to manipulate in PS

vikas
2 years ago
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#3642
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Beautiful image Vikas and I agree to remove the reducer.
Takahashi is well known for the outstanding performance but the reducer is degrading the image quality.
If you want a bigger field of view than you have to get a bigger sensor or another high end astrograph with a shorter native focal length.
A reducer is only second best.
Imaging in prime focus is always preferable above using a reducer.

Mike van den Berg
2 years ago
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#3643
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Beautiful image Vikas and I agree to remove the reducer.
Takahashi is well known for the outstanding performance but the reducer is degrading the image quality.
If you want a bigger field of view than you have to get a bigger sensor or another high end astrograph with a shorter native focal length.
A reducer is only second best.
Imaging in prime focus is always preferable above using a reducer.

Mike van den Berg
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