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Ellie
9th October 2009, 01:32 PM
Okay, I've managed to get myself nicely bemused, and slightly confused, by Nick's thread about editing to fix perspective (http://e-group.uk.net/forum/showthread.php?t=6780). I have a feeling I'm not the only one. :rolleyes:

My problem isn't about vanishing points and how they work, I fully understand that from A-level Art. This problem is about using software.

I use free stuff and have never been on a training course to use expensive software, so can't transfer any knowledge or skills.

One of the problems I have with understanding this is the "why" and "how", I suppose it's a bit of a mental block.

I don't really understand what layers do and why/how they should be used instead of simply editing the picture itself (- and yes, I know about taking care of original images etc.). As far as I can see, especially when changing perspective and fixing distortions, any layer goes on top of the original and covers it up. So what's the point of "layers", and why/how should they be used?

Is there a 'complete idiots guide' somewhere or other? Either that or could somebody please gently guide this idiot through the confusion.

Thanks.

Nick Temple-Fry
9th October 2009, 02:44 PM
As I've already demonstrated the ability to spread confusion.

Layers are the key to doing all sorts of clever things.

This morning I had an image out of Photomatix with some small black marks where the software had not coped with the movement of leaves. Not visible at web resolution but potentially a problem for a good quality printed image.

To get rid of these I created a duplicate layer (one that contained all the info of the original) and then upped the resolution to 200% and cloned the spots out with a small diameter brush. Then I blurred the whole area of leaves with a small diameter gaussian blur to get rid of the brush circles. Finally I recombined the layers with 'lighten only', which gave back practically all the sharpness but meant the spots (which had been black) were gone.

I can't see how I could have rescued that area of the image without layers.

OK a very specific example but

1) Layers let you try out an edit and then back-out to the image as was - useful if you are midway through a complex series of actions.

2) Layers let you merge together (in a variety of ways) 2 versions of the same image, very useful to emphasise shadows (duplicate layer, up the contrast, merge back to taste with soft light (or darken only)).

3) Layers (and or channels) are how you can automatically make masks (effectively very complex selections you don't have to draw by hand) which means you can work on parts/tonal ranges/colours etc seperately.

4) Layers are also the way that GIMP supports cut and paste, so the bit you want to paste into an image becomes a floating layer/selection that you can move/position.

5) Plus throwaway things like lines you later want to remove.

It's a wonderful world with layers - really unlocks the potential of the tool.

Nick

OlyPaul
9th October 2009, 03:14 PM
Ellie, think of layers as pieces of clear perspex that you can add to or remove from and anything underneath that has not been covered shows through.

Typicaly layers are used for compositing images, but the most usefull are "adjustment layers" for making tonal or colour adjustments none destructivley which can be altered or removed at will without pushing any pixals around and degrading the image.

There is a simple adjustment layer tutorial on my pbase website for selective colouring, but the premis is the same for curves/colour/levels adjustment layers...you will need Elements or software that supports adjutment layers to follow it.

You can find it here, just start at the first image and press next
http://www.pbase.com/paulsilkphotography/selective_colour_tutorial

photo_owl
9th October 2009, 03:32 PM
Ellie

I don't think the original thread is a great one to consider layers against - the instincts you express in you post are spot on there.

However as Nick has further outlined there are a huge number of tasks that can only really be done effectively by merging two, or more, versions of the image and with the additional controls of the layer opacity and the merge mode itself.

I probably use 1/1000th of the capability in my processing (and even that badly) but, even at that, I get 1000 x the results I could achieve before I used layers at all.

Give me another 20 years and I might even achieve some of it without the trial and error that remains core to my approach today.........

Graham_of_Rainham
9th October 2009, 03:49 PM
I believe the only way to learn how to use layers (or anything) is by playing with them. There are some good "tutorials" about that will help

http://www.photoshopessentials.com/basics/

http://www.photoanswers.co.uk/Video-Tutorials/

The real big advantage with layers is that you don't have to "undo" and do it differently, just add another layer, try something else on that swap from one to the other to see what you like best.

Get a bold colourfull image and try different things

There's no mistakes only lessons learned...:)

Kiwi Paul
9th October 2009, 03:50 PM
It is confusing understanding layers and why and where you need to use them. I can't remember how I learnt to use them but once I did it all fell into place and then you can have lots of fun. The pic below was created using about 7 or 8 layers, this is a classic example of layering.

Paul


http://lh6.ggpht.com/_0TYZ-W4CVzA/SrEgAVtjhyI/AAAAAAAAA3c/xV75NqMkOvw/Woofmix%20party.jpg

Zuiko
9th October 2009, 03:56 PM
I'm with Ellie on this. Hopefully, Layers is one of the topics Ian will cover in his proposed workshops. :)

Ellie
9th October 2009, 10:44 PM
Lots of interesting reading to keep me busy

I'm with Ellie on this.
Phew, I'm glad somebody is!

No chance of me getting to one of Ian's workshops, so I'll have to rely on the internet - and Gimp!

@Woofmix/Paul - How about explaining how you did that! :rolleyes:

Kiwi Paul
10th October 2009, 09:59 AM
Sure Ellie,

I just figured it out myself, trial and error it's really not hard just requires patience, this one only took me about an hour to proccess and about the same to setup and photograph.

In a nutshell set the camera on a tripod and either use a remote release or self timer and take as many shots as you need. For your first one just use 2 images to keep it relitively simple.

Open them all in Photoshop (I use CS3), pick one shot as the background (I use the one of me furtherest away from the camera) and drag all the other shots in as layers using the "move" tool while pressing shift, I then use the magnetic lasso tool to select my image from each shot (you don't have to be accurate in fact including stuff just around your image is beneficial), then select "copy merged" then "paste into" the background image, each one of these cutouts then appears as a new layer which can be edited on it's own to make it fit in with the background.
Just play about, once you understand how things work it becomes quite easy.

Good luck, ask if you need a hand :-)

Paul

Ellie
10th October 2009, 11:46 AM
Thanks Paul, it's as clear as mud at the moment. :eek: I ought to spend some time playing and see what happens, but I keep bottling out in case I break something.

I haven't got Photoshop but I'd guess it's the same sort of process in Gimp.

Nick Temple-Fry
10th October 2009, 12:25 PM
Thanks Paul, it's as clear as mud at the moment. :eek: I ought to spend some time playing and see what happens, but I keep bottling out in case I break something.

I haven't got Photoshop but I'd guess it's the same sort of process in Gimp.

Well nothing will break if you start with a copy of an imge - at least not irrevocably.

Ellie - if it's any help it took me ages to get over the hump you are now balancing on, from the 'down hill slope' it's hard to imagine not working with layers.

And whilst The GIMP lacks a good book there are lots of on-line tutorials that google will find.

Nick

OlyPaul
10th October 2009, 12:28 PM
Ellie, Paul is correct that layers in that context are just cut and paste and then just a matter over moving them to the position you want and in the layer order you want them to overlap. You can also fade them using the opacity slider or blend them using a layer mask on the cutout layer.

Sounds complicated but once it clicks into place you wonder why you never understood in the first place.:)

Well worth learning as you can do some artistic montages or just replace objects in a image.

You will not have seen this here as they were shot in my film days but this is a montage of a American Civil War reeenactment I attended.

I call it North Meets South

Which was made up from these images
http://www.pbase.com/paulsilkphotography/image/118123941.jpg

http://www.pbase.com/paulsilkphotography/image/30414499.jpg

Or for a portait with a little difference something like this is possible using layers.

http://www.pbase.com/paulsilkphotography/image/28685937.jpg

mas
10th October 2009, 04:58 PM
One thing worth mentioning is that *the* big failing of gimp compared to CS3/4 etc is that Gimp does not support adjustment layers. ie layers which are modifiers rather than images.

I understand that Krita is an opensource/free package which does handle adjustment layers (it is in the timeline for gimp but not for some time), but I'm not sure about Krita availability outside linux. (it is packaged as part of the Koffice so KDE based distributions.) there is an online guide to installing it on the mac but it didnt work for me and I've not had time/inclination to fiddle about.

shenstone
10th October 2009, 09:00 PM
Layers are wonderful

Even in a simple exercise like some dodging & burning, if you create a duplidate layer from time to time you can switch beween them for comparison and have "fall back" positions if you decide you've overdone it

At the end of the process simply delete the ones you don't want and hey presto ..

There have been threads on replacing skies ... I use layers for that as you can slide the background layer around until you're happy

Or of course you can do the adjustments etc as suggested

Do learn them .. .you'll love them

Regards
Andy

Ellie
10th October 2009, 10:29 PM
Layers are wonderful

Do learn them ... you'll love them

Gulp!

You all make it look so incredibly easy.

Can I just eat some Maltesers instead? :rolleyes:

ndl0071
11th October 2009, 07:10 AM
Don't dispair Ellie, it's only in the last year or so that I have got to grips with the layers concept, one day the penny just dropped.
Prior to that I was editing much the same as you appear to be, don't forget it's the end product that counts and if you're happy with what you are producing carry on as you are, just try to learn a little more as you go along and I'm sure you will be fine.

Adagio
11th October 2009, 10:24 AM
Perhaps some kind soul could give an explanation of Layer Masks that an old man can understand :confused:

Ellie
13th October 2009, 11:59 AM
Perhaps some kind soul could give an explanation of Layer Masks that an old man can understand :confused:

Whew David, I'm glad I'm not the only one still more than a little bemused by the whole thing. :)

I don't know how many people use Gimp, how many use other software, but I'm sure the process is about the same whichever you use.

I've looked at tutorials online, but if I don't fully understand what they've written I can't ask questions. One of the things is the language used, it's so alien!

I know it's asking a lot, and asking somebody to spend a huge amount of time, but could somebody please put something together, step by step, so I could try and copy it - and if it doesn't work I can ask what I might be doing wrong.

Would the easiest thing be to combine pictures, like both Pauls have done?

photo_owl
13th October 2009, 06:48 PM
Whew David, I'm glad I'm not the only one still more than a little bemused by the whole thing. :)

I don't know how many people use Gimp, how many use other software, but I'm sure the process is about the same whichever you use.

I've looked at tutorials online, but if I don't fully understand what they've written I can't ask questions. One of the things is the language used, it's so alien!

I know it's asking a lot, and asking somebody to spend a huge amount of time, but could somebody please put something together, step by step, so I could try and copy it - and if it doesn't work I can ask what I might be doing wrong.

Would the easiest thing be to combine pictures, like both Pauls have done?

Ellie - here's a little exercise that illustrates quite a few of the principles in just 2 steps.

I'm so confident that I am not going to show you examples but just run through the steps - to a very great degree the examples have already been given above in the selective colouration exercise; I'm just going to take it further.....

take any image which has a subject and a background and open in your program (I will use photoshop notations but GIMP should be the same).

Fit to screen.

create duplicate layer

this new layer will normally be selected following this step but if not then click on it in the layers window (this needs to be on in Window -> layers)

you now have a new layer ontop of the old layer (and it's shown ontop in the window)

now do image-> adjustment-> desaturate (because it's easy to see what's happening later this is a good exercise)

the image will apear black and white because the top image is desaturated and therefore what shows.

now click the button to 'add vector mask' and a second blank frame will appear in the layers window to the right of the image on the copy layer.

select a brush (quite big!) and load black - now paint over the area you wish to bring the colour back to. what you are doing is creating a mask that hides the effect of this layer. if you overlap too far just switch to white to 'repair'.

this gets you to the end of the lesson shown in a post to this thread above - so far so good.

now create a duplicate of this layer complete with it's vector mask

select this new layer

now 'add layer mask' to this layer - right click on the layer and select this function in photoshop... you should see what is left of the previous layer appear as a selection on the screen. now you can do something to either the background or the subject by switching between selection and inverse in the normal way - and anything you do is within this layer (you can do both if you wish in the one layer. try simply filter -> blur -> lens blur on the background and filter -> smartsharpen on the inverse (subject)

then layer -> flatten to finish

this illustrates a number of the basic functions that make life so so easy for a number of tasks.........

honest!

ringneck
13th October 2009, 10:56 PM
Ellie - here's a little exercise that illustrates quite a few of the principles in just 2 steps.

I'm so confident that I am not going to show you examples but just run through the steps - to a very great degree the examples have already been given above in the selective colouration exercise; I'm just going to take it further.....

take any image which has a subject and a background and open in your program (I will use photoshop notations but GIMP should be the same).

Fit to screen.

create duplicate layer

this new layer will normally be selected following this step but if not then click on it in the layers window (this needs to be on in Window -> layers)

you now have a new layer ontop of the old layer (and it's shown ontop in the window)

now do image-> adjustment-> desaturate (because it's easy to see what's happening later this is a good exercise)

the image will apear black and white because the top image is desaturated and therefore what shows.

now click the button to 'add vector mask' and a second blank frame will appear in the layers window to the right of the image on the copy layer.

select a brush (quite big!) and load black - now paint over the area you wish to bring the colour back to. what you are doing is creating a mask that hides the effect of this layer. if you overlap too far just switch to white to 'repair'.

this gets you to the end of the lesson shown in a post to this thread above - so far so good.

now create a duplicate of this layer complete with it's vector mask

select this new layer

now 'add layer mask' to this layer - right click on the layer and select this function in photoshop... you should see what is left of the previous layer appear as a selection on the screen. now you can do something to either the background or the subject by switching between selection and inverse in the normal way - and anything you do is within this layer (you can do both if you wish in the one layer. try simply filter -> blur -> lens blur on the background and filter -> smartsharpen on the inverse (subject)

then layer -> flatten to finish

this illustrates a number of the basic functions that make life so so easy for a number of tasks.........

honest!

........I am having an ELLIE moment now...not able to follow you as you asume I can see what you are doing.......
I can do colour popping so had a go at your way...which has the added thing of doing things to the b/g or subject AFTER popping.
Started O.K.....clicked DUP LAYER but what is the window...I had a thing appear that says background copy 1 ......clicked O.K.

Quote..."you now have a new layer ontop of the old layer (and it's shown ontop in the window)".... again what window..nothing on my screen.

Anyway carried on and de-saturated....got that right.

Quote "now click the button to 'add vector mask' and a second blank frame will appear in the layers window to the right of the image on the copy layer."....

DOUBLE DUTCH time has arrived....all I got was a drop down option of REVEAL ALL or HIDE ALL.....not the foggiest idea what you have on your screen but mine does not have any a layers window(??) to the right of the image on the copy layer.

ABANDON EXERSIZE.

I think I may have illustrated what ELLIE was hinting at...namely that all these descriptions are fine but if EVERY step is not described to the minutest detail it is as good as useless.
The only way is a video tutorial where you all have the same system (p/shop 7 in my case) and you can pause ...catch up ....go over certain steps making sure you have got it right...start again and actually SEE the curser/arrow moving around clicking and backed up by a narrative.
When I read through this thread I thought I would have a look at some tutorials I have copied and got lost on there as well ...you would think 4-5 steps were foolproof...NOT SO.It wanted me to click on the LAYERS STYLE ICON.....but where is it ...on their sgreen there was a layers window with drop downs with BIG arrows pointing to the icon but I could not get anything.
AS ADAGIO says can we have something that AN OLD MAN can understand ....if so everyone will get it...after all babies are born with all the new technologies already downloaded to there brand new otherwise empty memories...it's OLD MEN that are at the other end of the spectrum...I know I am there waiting for all of you.
Sorry to have gone on a bit (LOT) but it was only way I could say what I thought.

Thanks
Keith *chr
p.s.I looked at the origianal thread about perspective......NO WAY....he he.

Nick Temple-Fry
13th October 2009, 11:15 PM
Ellie - here's a little exercise that illustrates quite a few of the principles in just 2 steps.

I'm so confident that I am not going to show you examples but just run through the steps - to a very great degree the examples have already been given above in the selective colouration exercise; I'm just going to take it further.....

take any image which has a subject and a background and open in your program (I will use photoshop notations but GIMP should be the same).

Fit to screen.

create duplicate layer

this new layer will normally be selected following this step but if not then click on it in the layers window (this needs to be on in Window -> layers)

you now have a new layer ontop of the old layer (and it's shown ontop in the window)

now do image-> adjustment-> desaturate (because it's easy to see what's happening later this is a good exercise)

the image will apear black and white because the top image is desaturated and therefore what shows.

now click the button to 'add vector mask' and a second blank frame will appear in the layers window to the right of the image on the copy layer.

select a brush (quite big!) and load black - now paint over the area you wish to bring the colour back to. what you are doing is creating a mask that hides the effect of this layer. if you overlap too far just switch to white to 'repair'.

this gets you to the end of the lesson shown in a post to this thread above - so far so good.

now create a duplicate of this layer complete with it's vector mask

select this new layer

now 'add layer mask' to this layer - right click on the layer and select this function in photoshop... you should see what is left of the previous layer appear as a selection on the screen. now you can do something to either the background or the subject by switching between selection and inverse in the normal way - and anything you do is within this layer (you can do both if you wish in the one layer. try simply filter -> blur -> lens blur on the background and filter -> smartsharpen on the inverse (subject)

then layer -> flatten to finish

this illustrates a number of the basic functions that make life so so easy for a number of tasks.........

honest!

Well - you lost me and I use layers quite a lot. Some of what you are doing in GIMP would require a channel mask.

Well the underlying concepts are the same the exact terminology differs somewhat.

Nick

photo_owl
14th October 2009, 01:49 PM
Keith

the video tutorial already referenced covers the initial steps -

[URL="http://www.pbase.com/paulsilkphotography/selective_colour_tutorial"[/URL]

the thirf image shows the 'layers window' which is similar to Photoshop in most ways (but appears to lack a quick mask/add vector mask button?)

Nick Temple-Fry
14th October 2009, 02:30 PM
Keith

the video tutorial already referenced covers the initial steps -



the thirf image shows the 'layers window' which is similar to Photoshop in most ways (but appears to lack a quick mask/add vector mask button?)

This may help

[url]http://helpsetmaker.sourceforge.net/tutorial/doc6.html ("http://www.pbase.com/paulsilkphotography/selective_colour_tutorial"[/URL)

Nick

Ellie
14th October 2009, 07:24 PM
Ellie - here's a little exercise that illustrates quite a few of the principles in just 2 steps.
.
.
.
this illustrates a number of the basic functions that make life so so easy for a number of tasks.........

honest!
Thank you. Really. Thank you so much for taking all that time to try to explain how to do this. You deserve a medal. *chr

I remember doing this, and ended up with a very sore mouse-hand and sore eyes too from trying to follow outlines, and got very frustrated too and didn't end up with what I'd hoped for.

I hadn't realised that doing that is "layers", and to be honest I followed instructions I'd found and then promptly forgot what I'd done and had no real idea what I was doing. I still don't understand what/how/why anything happens. Anyhow, I'll see if I can find it again.

(added info) Here http://www.gimp.org/tutorials/Selective_Color/

.....I am having an ELLIE moment now...
Somehow that sounds nicer than the other sort of moment people have when they forget what they're doing! Can it go in a dictionary? ;)

photo_owl
14th October 2009, 10:27 PM
that's really why I was trying to match words with the actions Ellie - for me I need to be able to visulise what's happening in a way that my kids don't (pure maths v applied all over again!)

the somewhat scary part is that this really only scratches the surface....

jonesy
15th October 2009, 06:47 AM
Ellie, I had no idea about layers in photoediting software until I started my Open University course, and this course has introduced me to this concept in a very gentle way. I'm still taking baby steps in this method, and sometimes forget to use layers outside of the adjustment layers, but I'm getting there. I would recommend the OU course for the photo editing side (let alone the software that becomes yours) Though you would probably not need the "how to take a good photo" and "how to use the camera off auto" side that I do