AIC 2012

[skyshooter]

Ron's talk was quite good. Warren Keller was there as a vendor, offering his new tutorial series on PI processing and use, I purchased a subscription and look forward to viewing it this week, he already sent the link (it is streaming only for now). http://www.ip4ap.com/pixinsight.htm
Looks to be a good series so far - and the price is right.

At AIC I would estimate that many new users will be joining our ranks this year, a lot of interest in PI from my perspective, it is destined to be the next big break through for astro processing software. 



::edited to provide direct link to Warren's sample PI Tutorial page::

[pfile]

i was a little despondent about all the Photoshop. Dr. Rector essentially belongs to the 'documentary school' of astro-image processing, and he wrote a 100 page paper about using PS to process science images from 'real' telescopes. and of course his co-authors are the hubble heritage guys(gals). if anyone is a candidate for PI, it's them, and they're pretty heavily invested in PS.

still, to have warren doing a tutorial series on PI and ron wodaski giving a talk about PI are big deals.

[skyshooter]

In Ron's later class (the one I attended) he also said he is writting a book on PI, though no word when or if it would be ever finished, him being too OCD about it. Hopefully he completes it. I loved his first book and still refer to it from time to time, it was very readable as a reference on a tough subject.

[pfile]

sal grasso was interested in hearing about PI and sedat (the guy who won a door prize and then the photoshop license) also expressed interest in some tutorial-like work. but he was pretty busy running around. my 'problem' is that i live in the area and so i kind of have to get back to my family. this does not lend itself well to late-evening BS sessions.

There are a few of us that lives in the area, so maybe something could be arranged...?

Thorsten

have you ever been to an SJAA meeting (Houge park)? i've been once when rogelio spoke. don't know if that's central enough for everyone (it's kind of a haul for me)...

[marekc]

Man, I wanted to go to RBA's workshop at Hogue in late July of this year. I was in the mountains of British Columbia at the time. When I heard he was doing this, a part of me thought `hmmm... should I cancel my Canada trip, and eat all the costs I have invested in it?...'  In the end, mountaineering won out over learning more PI, but the desire to get a few secrets from the master was very strong!

[pfile]

yea - i missed that one because i was going to iceland on the day it was held. but sometime before then he gave a talk, not really a workshop, at the normal meeting. went to that one.

[Nocturnal]

I'm traveling to the Bay Area a few times a year still so it would be nice to get together at some point. A couple of years ago I joined Rogelio for an imaging session (well, the start of it) in the dark part of CA. I'm in LA at the moment and will probably travel back here on occasion as well.

I find it hard to take anyone serious who uses PS for a documentary approach. The simple fact that PS does not do 32b float images is a show stopper right there.

[RBA]

I find it hard to take anyone serious who uses PS for a documentary approach. The simple fact that PS does not do 32b float images is a show stopper right there.

I'm not here to defend Photoshop but I don't see the issue in using Photoshop with documentary goals in mind. Of course, one can use it to produce fabrications, but that also applies to any other image processing program. I do believe Photoshop handles 32 bit images, but due to the way Photoshop works internally, many processes do not support 32 bit modes.

[mschuster]

I find it hard to take anyone serious who uses PS for a documentary approach.

IMO Dr Travis Rector is hard not to take seriously. He gave a talk at AIC 2012 on his use of PS for documenting professional observations. I thought it was a great talk, one other attendee told me he thought this talk alone was worth the price of admission. I count 42 APOD's to Dr Rector's credit, the most recent here.

Mike

[Nocturnal]

Well I suppose I was a bit cynical of Dr Rector, sorry.

It is my understanding that recent versions of PS can load 32b float images but need to do a conversion (linear or not) to 16b which is what it uses internally for all processing. I'd be happy to be corrected on this of course. I don't have PS but the understanding comes from discussions on the DeepSkyStacker yahoo group where people try to shoehorn 32b float images into PS.

[RBA]

No, Photoshop does not use int16 for all internal processing.

When Photohsop reads a float32 image, it stores the data in float32 variables. Some "old" processes were written to handle only int8 or int16 data and have not been "updated", and so when you load a float32 image, they are disabled. Other processes have been rewritten to also handle float32 data, and that's what they do.

Now, the fact that Photoshop processes need different code/variables to handle different bit depth images is rather dumb, but that's a different story.

[Juan Conejero]

I usually never participate in these discussions, but I feel like I should make an exception to speak up a little here. Just a few remarks:

I don't see the issue in using Photoshop with documentary goals in mind. Of course, one can use it to produce fabrications, but that also applies to any other image processing program.

I agree completely. The main problem is not with this or that software application. It's with image retouching and painting practices, as opposed to image processing based on documentary criteria. It's with arbitrary manipulations, as opposed to knowledge and understanding of the data. We don't have powerful painting tools and this makes painting more difficult in PI than in PS, but you can destroy your data nicely in both applications. I'm sure you already know this, but a more complete summary of our (my) opinions about this topic, including what I think about PS, can be found in FAQ 1.11.

I do believe Photoshop handles 32 bit images, but due to the way Photoshop works internally, many processes do not support 32 bit modes.

I'll comment more on the 32-bit topic later, but much worse than that is the fact that it cannot work (correctly) with linear data. For this reason PS requires specific plugins to pre-stretch the linear data in order to import them, or pre-stretching the data in other applications.

I count 42 APOD's to ...

In my opinion, APODization does not certify per se the quality of an image in astrophotographic terms (indeed we can document this), and has more to do with how an image can be used to describe something relevant about science or nature, including concepts such as "opportunity", "spectacularity", and "WOW effect", among others. There are absolutely wonderful APOD images (many of them by members of this forum) and also (IMO) many mediocre and even terrible ones.

What APOD does have is a huge power to broadcast our images worldwide. We definitely need APOD to show our images to thousands of people, even if APOD's purpose is not related to astrophotography, and this causes strange effects many times.

... use of PS for documenting professional observations

For a long time PS (and PS-like applications) has been the only tool available for image manipulation on a graphical desktop. Well, this is not really true, because image processing and graphical desktops were there before PS, but I refer to relatively easy-to-use graphical interfaces suitable for people that cannot develop their own tools. In my opinion, the fact that most of the people dedicated to transforming science data into images still use PS reflects just this, and also the fact that changes (both technical changes and mind changes) are difficult and require a lot of time and effort. They simply don't know (and in some cases don't look for) other ways.

The team of DSA/CAHA observers led by Vicent Peris is currently using PixInsight to process images acquired with professional instruments, including the 1.23 meter and 3.5 meter telescopes at Calar Alto Observatory. You can see a small sample of their work on our gallery. Much more important than that, this team is doing a continued research and development work to create innovative image processing techniques. Most of these techniques are the basis of present and future PixInsight tools, and some of them have been documented on our processing examples and tutorials sections.

Now, the fact that Photoshop processes need different code/variables to handle different bit depth images is rather dumb, but that's a different story.

Our little team, with a few self-made workstations, a couple laptops, a 2008' Mac Pro, working at home and at the university, and lots of good wine, has been able to develop a much better engine for PixInsight on four platforms in about eight years. Our PCL (PixInsight class library) has always been able to handle any data type, including real and complex numeric data, to represent pixel samples. The latest version 2.0 of PCL, which we are about to release as an open-source library with PixInsight 1.8, allows you to handle pixel data in purely abstract terms with type-independent, type-safe and thread-safe pixel iterators. See for example the documentation (just uploaded this morning) for the GenericImage class. With PixInsight 1.8, I have rewritten more than a 30% of the PixInsight Core application and a 90% of PCL since March this year. I cannot understand why other teams don't have the same (or more) mutation capabilities.

[wnourse]

Our little team, with a few self-made workstations, a couple laptops, a 2008' Mac Pro, working at home and at the university, and lots of good wine, has been able to develop a much better engine for PixInsight on four platforms in about eight years. Our PCL (PixInsight class library) has always been able to handle any data type, including real and complex numeric data, to represent pixel samples. The latest version 2.0 of PCL, which we are about to release as an open-source library with PixInsight 1.8, allows you to handle pixel data in purely abstract terms with type-independent, type-safe and thread-safe pixel iterators. See for example the documentation (just uploaded this morning) for the GenericImage class. With PixInsight 1.8, I have rewritten more than a 30% of the PixInsight Core application and a 90% of PCL since March this year. I cannot understand why other teams don't have the same (or more) mutation capabilities.

I think the issue is more a matter of it being a large product combined with likely a large dev team and a product roadmap that hasn't prioritized it due to lack of demand from the primary customer base (which is not astrophotographers!).  You and your team work on PI as a passion and are small enough to be nimble - Adobe clearly is not

I've been using PI for about a year now and love the product, but I struggle at times and often will shift an image to PS in order to 'finish' it off.  I think both tools have their place and it's a matter of comfort that can drive usage.

Will Nourse
My Astrophotography work on Flicker:  http://www.flickr.com/photos/10388832@N03/sets/72157627000847596/with/8165682676/