Warren Keller's PI book...

[ollypenrice]

I had my first fireside afternoon with Warren Keller's Inside Pixinsight yesterday. It was highly instructive, as I expected it to be from such a good imager and communicator. In no time at all I'd made two useful discoveries. Furstly, when my DBE models are hghly posterized, as they often are, I can smooth them easily. Secondly he answered a question which has bugged me for a whie. If a DBE model is essentially like a flat, why subtract it rather than divide by it? The answer is that vignetting is multiplicative (a word better written down than pronounced aloud!) whereas light pollution is additive. Well, thanks for that, Warren! Now, back to work on the next chapter...

Olly

[Davey-T]

Haven't got PI but thinking of buying the book just to see what it's all about 

Dave

[RayD]

I've got it on Kindle and well worth having.

[wxsatuser]

Working my way thorough it as well, also have the dvds, well worth it if your a PI newbie or even a master that needs a bit more info.

[harry page]

Hi

Lots off usefull information in there

The only thing I do not like ( IMO ) is the way Warren recomends DBE on individual channels of a colour image

The STD way and better IMO is too use it on a combined image this will give you better visulization of complex gradients

and normally good colour correction.

regarding division or subtraction , If you only have vignetting problems you can divide the model , but most people have as you say

multi problems which is combination of vignetting and things like light pollution therefore subtract

Regards

Harry

 

 

[Marky1973]

It explains things well even for a novice like me - I haven't made it past about the first third of the book yet, but that is more down to my ability and the learning curve of AP/PI than the book.

[gnomus]

21 minutes ago, ollypenrice said:

I had my first fireside afternoon with Warren Keller's Inside Pixinsight yesterday. It was highly instructive, as I expected it to be from such a good imager and communicator. In no time at all I'd made two useful discoveries. Furstly, when my DBE models are hghly posterized, as they often are, I can smooth them easily. Secondly he answered a question which has bugged me for a whie. If a DBE model is essentially like a flat, why subtract it rather than divide by it? The answer is that vignetting is multiplicative (a word better written down than pronounced aloud!) whereas light pollution is additive. Well, thanks for that, Warren! Now, back to work on the next chapter...

Olly

Oh no - if Penrice turns to the dark side then we are all doomed.......  

[ollypenrice]

1 minute ago, gnomus said:

Oh no - if Penrice turns to the dark side then we are all doomed.......  

Just call it reconnaissance behind enemy lines...

Olly

[gnomus]

Just now, ollypenrice said:

Just call it reconnaissance behind enemy lines...

Olly

Or perhaps you could be the Great Unifier ....  

[ollypenrice]

9 minutes ago, harry page said:

Hi

Lots off usefull information in there

The only thing I do not like ( IMO ) is the way Warren recomends DBE on individual channels of a colour image

The STD way and better IMO is too use it on a combined image this will give you better visulization of complex gradients

and normally good colour correction.

regarding division or subtraction , If you only have vignetting problems you can divide the model , but most people have as you say

multi problems which is combination of vignetting and things like light pollution therefore subtract

Regards

Harry

 

 

Yes, the single channel idea seems odd to me but I haven't tried it. I get fantastic results from applying it to RGB.

Olly

[harry page]

4 minutes ago, ollypenrice said:

Yes, the single channel idea seems odd to me but I haven't tried it. I get fantastic results from applying it to RGB.

Olly

Hi

It can work in removing simple gradients from each plane , but gives no colour balance to the combined image

I can never get it to work as I have to much going on in my images

Harry

[ollypenrice]

Yes, I use DBE not just to lose colour gradients but to fine tune the colour balance, which it does to perfection from shadows to stellar cores. How about doing it to the individual channels and then to the combined?

Olly

[MARS1960]

It sure is a good read.

What surprised me was the use of DSS (Digitized Sky Surveys) for the background.

[RichLD]

Just bought this for my Kindle, looking forward to going in deep 

[harry page]

6 minutes ago, ollypenrice said:

Yes, I use DBE not just to lose colour gradients but to fine tune the colour balance, which it does to perfection from shadows to stellar cores. How about doing it to the individual channels and then to the combined?

Olly

Hi

If you have no gradients left after combination ( not in my world )  and you find a channel bias left ( most cases ) you can just use

the background neutralization tool which will balance the histogram

 

Harry

[ollypenrice]

39 minutes ago, harry page said:

Hi

If you have no gradients left after combination ( not in my world )  and you find a channel bias left ( most cases ) you can just use

the background neutralization tool which will balance the histogram

 

Harry

I have never had much joy with BN so I tend to do it in Ps but I dare say Warren will enlightnen me.

Olly

[RichLD]

Slightly off topic, but seeing as Harry is taking part in this thread I'd like to extend my gratitude to the man himself for his excellent online tutorials which have been hugely useful in getting me started and way beyond with PI. I think it's fair to say that PI is not exactly intuitive and can be quite daunting at first, especially for a PS guy like me (or for anyone for that matter ). I'm enjoying the Warren Keller book very much but I'm not sure that I would have been quite as receptive to it if it weren't for Harry's excellent (and freely available) video tutorials.

Cheers Harry!

Rich 

[harry page]

8 minutes ago, RichLD said:

Slightly off topic, but seeing as Harry is taking part in this thread I'd like to extend my gratitude to the man himself for his excellent online tutorials which have been hugely useful in getting me started and way beyond with PI. I think it's fair to say that PI is not exactly intuitive and can be quite daunting at first, especially for a PS guy like me (or for anyone for that matter ). I'm enjoying the Warren Keller book very much but I'm not sure that I would have been quite as receptive to it if it weren't for Harry's excellent (and freely available) video tutorials.

Cheers Harry!

Rich 

Hi

I am all in favor of warrens book , more info the better :}

But I do agree it does require so pre Pixinsight knowledge , so mine or warrens video's are a good place to start

Harry

[ollypenrice]

Quite rightly, Harry is given honorable mention in Warren's introduction.

Olly

[Gina]

Have to say I find the book rather hard going (probably just me ) and the tutorials on-line by Harry Page and Vortex to be crystal clear in comparison

[Gina]

2 hours ago, RichLD said:

Slightly off topic, but seeing as Harry is taking part in this thread I'd like to extend my gratitude to the man himself for his excellent online tutorials which have been hugely useful in getting me started and way beyond with PI. I think it's fair to say that PI is not exactly intuitive and can be quite daunting at first, especially for a PS guy like me (or for anyone for that matter ). I'm enjoying the Warren Keller book very much but I'm not sure that I would have been quite as receptive to it if it weren't for Harry's excellent (and freely available) video tutorials.

Cheers Harry!

Rich 

Amen to that - great stuff - many thanks Harry

[ollypenrice]

8 minutes ago, Gina said:

Have to say I find the book rather hard going (probably just me ) and the tutorials on-line by Harry Page and Vortex to be crystal clear in comparison

I think it is hard going in that it's a manual a lot of the time. You pick up the book, read six lines, put it down and pick up the spanners - in the grand tradition of how to replace the big ends in a Bonneville* with the help of Mr Heynes...

Olly

* a real one, not the retro fake!!!!

[Gina]

Yes, I think you have it there Olly.

[RayD]

3 hours ago, Gina said:

Have to say I find the book rather hard going (probably just me ) and the tutorials on-line by Harry Page and Vortex to be crystal clear in comparison

Definitely.  The most intuitive way to learn about using the programme is Harry's videos, and I can see the book becoming a great reference guide as a quick go to for something you need a quick answer to or refresher on.

[Singlin]

I photocopied page 247 and use this as a reference for my workflows and on that basis look up each part of the workflow in the index as I get to it.

I watch harry's videos on my tablet at the same time that I am processing on my PC.

I am just waiting for the Penrice video tutorials to come out this year.