Digital Light & Color

For anyone interested in 'free form' HDR, a time limited free beta download is available here: http://www.oloneo.com/

As I understand it, PWP HDR is specifically designed to process images taken in predetermind +EV and -EV steps.

My inclination is to adjust the exposure to suit the circumstance and I presume that is why I just cannot get decent results from PWP HDR. (General incompetence may play a part, I have to admit).

Below are two images that I shot recently when visiting my Mother in England. Tried hard with PWP HDR, but no good. Am I the only one so unstructured? Is there a way to use PWP HDR for such images?

Mike.

Just like Mike, I'm having trouble in adjusting curves to get a realistic transitions between areas borrowed from each base image. Perhaps it's because with 2 images there are 4 independent curves (two masks, two tones) + two overall blending amounts to be adjusted - and they need to match. Could someone offer an automation recipe?

I forgot one important qualification in my original post.
I should have written (words to the effect of) "I can't get a decent result without using one or more masks."
A number of times I've abandoned Stack HDR, made one or more masks and used the composite transform - plus futher tone adjustments.
Mike.

MikeG,

Your original example looks pretty extreme indeed. But here's what I get when I use the HDR/Stack images transform:
and this came from a workspace that looked like this:
What effect are you trying to get (i.e., if you use masks, what result do you like best)?

Bob Walker

PS -- attachment posting limitations are too restrictive (50KB and 400x400 pixels).

What I find difficult is handling the transitions between parts of the image that originally belonged to two different takes. Black spots on the curtain and washed out window frame in Bob's composite are the examples. I suspect that one reason is that all the curves determining what's going to be blended are totally independant, thus difficult to adjust in concert for the smooth result. The other is the blending method: for simple blending of properly exposed parts of two images, the masking curves need to be such so that the areas of each image that are not to be used in the final composite need to be perfectly blacked out, otherwise thay will wash out the 'good' areas from the other component image. I find it hard to manipulate to get decent results.

Bob,
The result show in your post is very similar to that I achieved with full size files. Problems with the curtains and the wooden tray/trolley just below the bottom mid point of the window.
As Maciej has written, it does seem to be the transitions that are the problem.
Below is the output of Enfuse (as built into cPicture's HDR function). No post processing after 'fusing'.
I've also tried EnfuseGUI which (unsurprsingly) gives a very similar result.
EnfuseGUI allow adjustment of some (all?) of Enfuse's parameters. I found it very easy to adjust to give a worse result than the default settings - and impossible to adjust for a better result.
Knowing what I know now I would have taken an intermdiate shot. My two shots covered the extremes fine but didn't provide enough information in the transition areas, I now realise.
We live to learn!
Mike.

BobW... thank you for the screen shot with the SI Brightness/Density curves. I have had difficulty understanding the concept of the Density Masks and your post has helped!!!

MikeG... I know that you were interested in blending your two images with StackImages with minimal Amount mask use but it is my normal practice to use the SI transform with both symmetrical and asymmetrical tone range Amount masks and even 'mask of masks' for transition zone refinements.

Certainly as you recognized, it would have been helpful to have taken one or two more exposures to capture more of the detail surrounding the window frame which for your two images is the transition zone.

To create artifical exposures, one could take the first image [indoor exposure] and apply a RGB BrightnessCurve BrokenLine curve=[0,0], [20,0], [100,80], [100,100]... then take the 2nd image [outdoor exposure] and apply a RGB BrightnessCurve BrokenLine curve= [0,0], [0,20], [80,100], [100,100]. Remember here... all that is of interest is the image area near the window frame outline.

Your two images can then be reasonablely blended with the artificially created intermediate exposure images using StackImages and Amount masks... followed by manual tone mapping [or one could use the 3-Zone Adjustment transform] and a bit of 1:1 cloning, painting, and misc tools... with the result:

There is probably lots of HDR-like programmes around, but here is the simplest freeware I came across: single .exe, few adjustments, only two images to blend, automated (it doesn't do that well on Mike's images, but it's not that horrible...)

http://www.idimager.com/downloads/freeware/DRI.exe

Den, Very impressed in what you've been able to wrestle out of inadequate starting material. It's totally clear that I must take more care at the start of the process, or face the alternative of quick mediocre results, or quite a lot of work to get a good result.
I've taken another set of images. Not of the same scene - that's more than 20 hours of flying away - this time with a mid point image. Now I can get similar results the Enfuse way, or via my previously generated Stack HDR curves.
I think I've learned three things:
1. Always take a 'mid' exposure image. May not be needed, but could enable a quicker and/or better result.
2. If the images are marginal in exposure cover (as my original post) then Enfuse will quickly give a mediocre result which would take much longer (for me) to achieve with PWP.
3. Provide Stack HDR with decent input and all is well.

Maciej,
For what it's worth EnfuseGUI offers a bit more that DRI. Can handle more than 2 images and has a useful multi preview feature.

Mike.

Here's a link to yet another HDR program:
http://www.hdri-handbook.com/picturenaut/index.html
Freeware/donation ware. Can work from RAW, fairly sophisticated.
My little experimentation with it reinforced for me the great importance of masks.

Mike.