How to blend different exposures


Dr. Mhuni

Link Posted 19/01/2010 - 13:19
I'm revisiting an old image of mine in order to try and get a better end result. The image (or rather the old processed image which I uploaded on to Flickr that I'm aiming to improve on) is the following:




As you can see there are both under and overexposed elements to this image. What I wanted to do was to try to combine 2 or more exposures from the RAW file in Photoshop to address this.

I began trying to do this by doing the following:
a. Loading the images into one PS file with the lighter image below:
b. Manually selecting the brighter area in the centre of the image (quite time consuming this), with the Refine Edge settings at 0, 2.0, & +2;
c. Creating a new levels layer, moving it below the darker image I've extracted it from and clipping the two together.

At this point the lighter image shows through in those areas I haven't selected. It is a big improvement. However, the transition between selected and non-selected areas is rough, with haloing and other defects.

Now I'm pretty sure that there is a much simpler way of doing this, which probably involves painting through parts of the image I want visible. But my PP skills are horribly rudimentary (if improving slowly) and I have no idea how to. Any suggestions much appreciated.
Mhuni

500px
Last Edited by Dr. Mhuni on 19/01/2010 - 13:21

johnriley

Link Posted 19/01/2010 - 13:27
Trying to think of something simple leads me to taking the two images and dragging one into the other. Reduce the opacity of the top layer so you can be sure that the two images are excatly aligned. You can put the opacity back to 100% to work on.

Then use the eraser tool to remove the unwanted parts of the top image. You can selct a hard or soft edged brush as appropriate. Don't forget to zoom in on detail - you can go right down to pixel level if you want and then no-one will tell what you have done. If you have the patience....

Finally flatten the image and save.
Best regards, John

womble

Link Posted 19/01/2010 - 13:47
Extract two/three tiffs from the RAW file at different exposures then blend them in Photomatix pro. You'll then need to re-edit in is PS to improve contrast etc. Trial download of Photomatix is free.

Best wishes, Kris.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

My website

Anvh

Link Posted 19/01/2010 - 14:39
First of all extraxting two images from one file and combining them would not increase your dynamic range, so you will not be able to pull out more details that way by working with two copies instead of just one.

It does make your life a bit easier if you know how the HDR software works or are good with a masking layer, but all can be done with the help of curves and other tools you've to progress RAW for exposure.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

womble

Link Posted 19/01/2010 - 14:53
Technically you are right Anvh but sometimes it can add something that just tweaking levels and curves does not. I have found photomatix a little hit and miss at times: images I think should work look horrible no matter what I do and others come out surprisingly well. It is worth a play once in a while!

K.
Kris Lockyear
It is an illusion that photos are made with the camera… they are made with the eye, heart and head. Henri Cartier-Bresson
Lots of film bodies, a couple of digital ones, too many lenses (mainly older glass) and a Horseman LE 5x4.

My website

Anvh

Link Posted 19/01/2010 - 15:02
I know what you mean Kris, it's all a bit trial and error but you can do a lot with a RAW converter and a good RAW photo. Most photos I see here that have been through an HDR was not needed in my eyes. But everyone has there own way of working.

I've done this with one photo in lightroom.



And this a HDR with 3 photos but with the tonemapping most HDR programs use, well it isn't HDR any more but I still have the HDR file though it's 130mb I believe.



This the middle exposure that I used for the first (lightroom) image.


Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 19/01/2010 - 15:14

Dr. Mhuni

Link Posted 19/01/2010 - 15:23
Thanks guys.

John - Embarassingly, I didn't know it was that simple to adjust between layers. Have had a play with the eraser. While the area I have to erase is probably too large (and/or the edges are too complex) for it to work here, I'm sure this will come in handy!

Kris/Stefan - I had wondered about HDR (I haven't downloaded software for this yet), but wasn't sure if this would be appropriate here. But I should try it and see if it's hit or miss in this case.

Regarding what can be extracted using curves etc. - looking again at the image above, I'm amazed how much I extracted here. This is an old conversion done in PSP (which no longer works on my computer - no matter what I've tried). I tried to do the same thing in PSE earlier but to no avail (yet) - the end result was considerably worse. I'm sure I can achieve the same effect - it's just working out how. Also, having seen the imperfect results of my earlier experiment with two exposures there is clearly room for further improvement.
Mhuni

500px

Anvh

Link Posted 19/01/2010 - 15:32
Mhuni, you can't truly make an HDR since the DR stays the same as your RAW file and it's the tonemapping that makes the WOW effect of HDR photos.
If you look at my HDR photo (the middle one) it looks very bland to what HDR normally looks like, it's just the way you process the photo.

And yes I'm also amaze with what you can do with curves and exposures, with my photo for example you've hardly any details in the windmill since it's too dark but you can pull out a lot of it.
With the normal one you've no idea that there is a door there but you can see it clearly with the first photo with even details in it.
But the halos you get from this pulling and squeezing isn't so great
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

Mannesty

Link Posted 19/01/2010 - 15:49
This topic might help.

Constructing an HDR image from one raw file does work. Stefan is technically correct in that the Dynamic range doesn't change, but the range of the image that you can 'see' is greatly improved if executed sensibly.

For example, if you were to increase the exposure by 1 or 2 stops, you might reveal some detail within the shadow of the doorway.

This could be saved and used as a psuedo-HDR composite to good effect.

You can download a freeware HDR prog from www.picturenaut.com. It works very well.
Peter E Smith

My flickr Photostream
Last Edited by Mannesty on 19/01/2010 - 15:55

Malo1961

Link Posted 19/01/2010 - 16:04
Hi Andrew,
The most efficient way is using a layer mask. There are free plug-ins available for PSE 6. I use grant tools myself.
Using HDR programs is a lot of overkill for the result you are after and takes also a lot of time to master.
Working with a layer mask and painting back the areas you want to modify gives you the best means of control.
The way to install grant tools was described here.. (screen shots are off-line, but easy to follow.)

See following example.
duplicate background layer.
Click; enhance----> adjust lighting----->highlight/shadows.
Change lighten shadows to 15% Leave other settings untouched.
Now add a layer mask and using black as the foreground colour use a soft edged brush to pain back everything but except the walls you want more detail in. Quick, clean and no halos due to feathering of painful selections or tone mapping. Oh....and about 3 minutes work.
Hope this helps.




Obviously the enhanced noise levels are due to working on the low res Jpeg, instead of the original.
Best regards,

Martin.


Curious about my photography?? Just Follow the Light.
Last Edited by Malo1961 on 19/01/2010 - 16:06

Dr. Mhuni

Link Posted 19/01/2010 - 16:36
Thanks Peter. Actually I had already begun to try this but gave up when I realised a. I didn't have Corel Photopaint (or even PSP X2 anymore); and more embarasingly, b. I don't know what a Layer Mask is (or how to create one).

Is this what you get when you create a(n unadjusted) Levels Layer and then clip it underneath the one you've obtained it from?!

Martin, good to have you back! I have had the Grants Tools add ons folder on my desktop since I last tried to install it (you may recall me writing to you about this!). I tried to install it then but failed and in the end gave up. Have just tried again now and I can't even locate Documents & Settings on my C drive - it's not listed. I actually think I got past this stage last time I tried, but can't work out how now?!

Anyway, what you outline does look sensible. Will have to try this tomorrow. My eyes are getting computer weary now.
Mhuni

500px

iceblinker

Link Posted 19/01/2010 - 17:04
I don't suppose you want to buy another software package, but the auto dodge function in Silkypix Pro would do a good job with this image.
~Pete

Anvh

Link Posted 19/01/2010 - 18:21
Mhuni what software do you've at the moment, just PSE?

Mannesty wrote:
Constructing an HDR image from one raw file does work. Stefan is technically correct in that the Dynamic range doesn't change, but the range of the image that you can 'see' is greatly improved if executed sensibly.

See isn't the word for this it's the monitor that can not display all of the dynamic range... so yes see might still be right
There are true HDR monitors but they cost you a rib.
link
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 19/01/2010 - 18:24

Malo1961

Link Posted 19/01/2010 - 18:56
Andrew,

To install you must first change computer settings to show hidden files.
Than.....follow procedure as mentioned in the link I gave.
If everything fails... , pm me and I coach you through it.
BTW...to achieve the effect you can add a adjustment layer in PSE 6 by clicking on the small round b/w icon left of the bin icon.
Click levels to lighten the dark parts and this will show a mask. Proceed as described in my earlier post. So Grant tools are not needed, in this case.
Best regards,

Martin.


Curious about my photography?? Just Follow the Light.
Last Edited by Malo1961 on 19/01/2010 - 18:57
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