blended exposures - transition regions

[Paul Alivisatos]

I am learning how to blend exposures. On this shot, the garden at right was much darker than the water, sky, and mountains on the left, so I have belnded two exposures that differ by two stops. I used a layer mask, and painted with a brush, but the transition regions are still hard to manage. For instance, you can still see a curved demarcation region between the two exposure zones in the water near the shoreline. Do you have a favored method for blending such photos and managing the transition regions?

Thank you for any advice.

Paul Alivisatos


http://palivis.smugmug.com/photos/72489280-M.jpg

The picture was taken last week at Villa Monastero, on Lake Como, in Italy. I used a Canon 5D with a 16-35 f/2.8 lens.

[Asher Kelman]

I am learning how to blend exposures. On this shot, the garden at right was much darker than the water, sky, and mountains on the left, so I have belnded two exposures that differ by two stops. I used a layer mask, and painted with a brush, but the transition regions are still hard to manage. For instance, you can still see a curved demarcation region between the two exposure zones in the water near the shoreline. Do you have a favored method for blending such photos and managing the transition regions?

Thank you for any advice.

Paul Alivisatos


http://palivis.smugmug.com/photos/72489280-M.jpg

The picture was taken last week at Villa Monastero, on Lake Como, in Italy. I used a Canon 5D with a 16-35 f/2.8 lens.

Paul,

This picture is so challenging because the scene is wonderful but the structures of interest are strong and complex.

To me, at least, the blending is adequate, although one could use a few more layers of different percentages of presence, using an erasor with a feathered edge to blend in more detail into the foreground waters.

The steps need to be pulled back as there are close to or already, blown out.

However, there is another issue in making the final print: whether or not you have an image to the left to add or whether you might consider cutting the picture horizontally and just using the upper half.

The reasons which follow, and I represent are merely from my sense of what might optimize this image, if I hapenned to find it in my camera. (By that, I mean "not knowing all about your artists vision")

The structures on the right are very strong and powerful. It seems to demand much more to the left of the picture, expecially since the light pattern on the left side of the picure reflected in the water, seems to have been cut off.

If the picture cannot be widened by adding this missing information, then I'd decrease the power of the forground. One way of doing this is to sacrifice the lower 50% of the picture in order to have a great print.

The blending issue is not the barrier to getting a fine print. The blending is pretty good. Could be better but doesn't bother me at all! What is needed to print, is not better blending. It's the print, only the print that matters!

I, BTW, believe that this could make a wonderful print that would sell.

Asher

[Paul Alivisatos]

Asher,

Thank you very much for this thoughtful and very detailed response. I have some other images form the same shoot that may more closely balance the two sides as you suggest, so I will go back to the drawing board. I will also try to deal with the blown out stairs, just to see if this composition can be better presented. Thank you for emphasizing the importance of the print, it is very useful to be reminded of this. As an amateur, I am glad that you think there is potential in the image....

Best wishes,

Paul

[Asher Kelman]

Paul,

The print? That's the whole point of OPF! It's your vision in as finest form as possible for us to enjoy, admire and perhaps even buy. Sharing this active process of arriving there is why we have recruited such great moderators!

Asher

P.S. Paul, please note the edits in my original post!

[Roger Lambert]

Hi Paul

I have been really excited about the artistic possibilities opened up by blended exposures, and long exposures.

However, it wasn't until I got a technique described in a forum at dpreview to actually work for me, that I feel that the true utility of digital blending has become a useful, as opposed to a truly frustrating, option.

The technique involves creating a luminosity mask, and the beauty of the technique is that the computer does the hard work. No brushwork is required, although you can certainly go back and add your own fine handwork to the process.

I was frustrated for months, trying to read recipes for this process and get them to actually work in CS1! The recipe involves hitting four keystrokes simultaneously at one point, with one of them being the tilde key. I have a sneaking suspicion that the tilde symbol (~) got lost in previous translations of poster's documents into HTML.

I can tell you that the first time I hit those four keystrokes, and was rewarded with a screen filled with "marching ants", I literally let out a war whoop, and danced around the room! :D

Here is the technique. It works best if you combine exposures that are each not too too different from each other. I have a favorite landscape that is a blend of 4 or 5 exposures - which translates to something like 8 or 10separate exposure settings across the range, with every other one being blended.

Here is the technique - I hope it can help you. :)



How to do Automated Luminosity Masking


1a) Open up the two images to blend. If you have a bunch of the same scene using a tripod, and want a blend using the whole dynamic range, it is better to make multiple blends, each of exposures *not too far apart from each other*

1b)Using move tool, SHIFT-left click to drag darker image onto lighter image
1c) Minimize the 1st dark image

2) Important - - verify alignment by Layer window ( where you see the layers, layer masks, etc) options list - difference mode. Zoom in is best, so that you can move image by pixil at a time using arrow keys. -> be sure to set Layers Mode back to normal when done!

3) ALT-left click on eye icon on background ( lower) layer. The picture should become lighter.

4) CONTROL-SHIFT-ALT- ~ ( tilde key) creates luminosity mask. Hit all four of these keys simultaneously. You should now see “marching ants” delineating the highlights.

5) ALT-click missing eye icon (hit the space where it used to be) on the upper layer. The picture should now turn very dark. i

6) Go to the main “LAYERS” menu at top of screen, , select “Add layer mask” and “reveal selection”. Boom!!

to improve:

7) ALT-click on layer mask icon ( on original layer, to the right. This will be the upper layer of the two, and all the way tot he right)

8) Gaussian blur of about 3 pixils - apply. This should sharpen the pic. To check, zoom in, click ( not alt-click) on the layer thumbnail, to the left of the layer mask thumbnail.

To improve BIGTIME:

9) again, click ( not alt-click), on the layer mask thumbnail to activate it. Open up the LEVELS box in the Adjustments section, and adjust blend using “Levels” adjustments. Basically slide the middle slider to the right to “blend” the relative contributions of the two pictures. That’s all, folks!

10) Flatten image

11) Continue processing

[JohanElzenga]

In step 4: If you find it difficult to press four keys at the same time, you can also ALT-click on the 'RGB' icon in the channels palette. That does the same thing (and works better if you try to automate this by recording all steps in an action).

In step 8, I would advise not to ALT-click on the layer mask, but just click. ALT-click will activate the layer mask so you only see the mask. You will see what you are blurring, but you won't see the effect. If you just click, you can blur the mask but look at the result at the same time (if you check the 'Preview' checkbox in the blur dialog), so you can see how much blur is needed.

[Roger Lambert]

Excellent Johan!

Anything to make life easier - thank you. :)

[Paul Alivisatos]

Hi Johan,

Thank you so much for showing me how to use the automated luminosity mask to blend exposures. Attached below is a shot of the same sence, blended by the method you have shown. I will ceratinly practice this more, as it is much easier than the simple layer mask method.

As for the composition, well, it is not balanced too well between left and right sides, but it is one of the better shots I got that day, so maybe next time...

Paul

http://PAlivis.smugmug.com/photos/74550604-M.jpg

[JohanElzenga]

Paul,

Could you perhaps also post the two images before blending? The reason I ask is that you have lost all detail in the sky. Something is not right in this blend, because this is probably not what you want.

[Paul Alivisatos]

Hi Johan,

Yes, thanks for noticing. The problem was not with your procedure. After blending, I increased the contrast, and blew out the sky. I repeated the process, and here are the three images:

Light Exposure:

http://PAlivis.smugmug.com/photos/74648864-M.jpg

Dark Exposure:

http://PAlivis.smugmug.com/photos/74648510-M.jpg

Blend:

http://PAlivis.smugmug.com/photos/74648202-M.jpg

The blending procedure works, but the image does appear flat.

Thanks again,

Paul

[JohanElzenga]

It does, but you can fix that in many ways. The best way is to select the mask and play with levels or curves to increase the contrast in the mask. Also blurring the mask a little with Gaussian Blur helps to get back some 'micro contrast'.