Sky Panels


This image of wires and clouds is tone-mapped from a single image. I was intrigued by how the processing resulted in slightly different contrast and density on two sides of the wire, creating panels a bit different from each other. It is an interesting reversal of the colour original where the wires are like lines drawn on the sky. In the tone-mapped version, I see the lines as edges of the panels rather than lines over a uniform background.

The rest of these images play with that idea by using masks, one for each ‘panel’, and then adjusting levels of contrast, blacks, whites, highlights and/or clarity differently in each panel. In one I added very subtle colour tinting and in another, more obvious tinting. The very last image transfers the stronger tinted masks to a different picture of clouds in an attempt to create panels on that image, without their edges. It does not really work, (especially with the image darkened during the WordPress upload), but I think it is an idea worth further exploration. I expect it would work better on a simpler background. My own preference of these different versions are the two un-tinted ones I have used in the main body of this post.

Mask tinting removed and other levels more heavily adjusted, different for each panel.


I can honestly say I have maxed out the Lightroom 4 capacity of my computer. Processing these masks, editing and exporting all ended up using 96-99% of physical memory (3 gigs RAM), and 100% of the CPU (on all four processors). I have never seen the computer work this hard before, even when editing movies. Obviously there are better ways to achieve these same effects – layers in Photoshop and so on, so I guess if I want to go down this road I am going to have to consider different software. There may be some tricks about doing edits in a particular order, or not editing the photograph as a whole if the masks cover the whole image too, or something. I could experiment, but considering at the end of this I was waiting 4 or 5 minutes for some operations to finish, I would need a few days.

It is frustrating that once again WordPress has darkened the images considerably as in so doing it has obscured some of the more subtle differences between the panels, and between the different versions. I think if you right-click (in Windows anyway) on any image and open in a new tab or window you get a larger version that is a bit less dark. Maybe I am going to have to save my images in exactly the same size format that WP uses for their largest files in the hopes WP won’t then resample or whatever it is doing that messes with the image.

Canon EOS 5Dii, Canon 100mm/f2.8 lens, ISO 640, f13, 1/800th (last image 1/500th).


18 thoughts on “Sky Panels

    • Hi David, something tells me you worry about a lot more than the developer for your lovely shots. You must put a lot of time in at the enlarger getting things just right. Or are your negatives so good that is not necessary?


      • I wish !
        I have my fair share of problems but manage to find a way around most. Not with digital I am afraid: even electronic test equipment these days seems far less intuitive. I am told this is progress…..!
        Still, when I eventually leave Oman and can get the chemicals, I can feel ‘Wet-Plate’ 5×4 calling.
        Now that will be a challenge.



      • The siren song of 4×5. Wet plate no less! I have 90 year 4×5 field camera that I had always intended to use, but it required me replacing the roller blind shutter in it, or buying a lens with inbuilt shutter. Somehow that was enough obstacle, except my enlarger would not handle 4×5 negs either. So I never used it. Have been thinking of selling it. The lens set could be something quite special though it is next to impossible to find out about them. Another obstacle, this time to selling. I kind of like having it around, singing gentle in my subconscious that I should get it out and put it to use.


  1. What a neat study here, Ehpem! Your comments regarding processing, image size and computer processing power are echoed in my experiences, too. I tend to stay in the TIFF space myself until the last step when I create the production image that gets uploaded, in an effort to preserve and maintain all the detail I can. TIFF is a lossless format and JPG is definitely LOSSY. Of course, this procedure results in massive files sizes on output. Eeep. In the day and age of CPUs that are capable of processing billions of instructions a second, I find it absolutely mind-altering that we find ourselves waiting, sometimes for minutes on end. for a process to complete.


    • It is mind boggling sometimes. I just can’t afford the disk space, nor really the waiting time, but I think if I really like the way something is working on a jpeg i can generate a tiff and apply my edits directly to it. Hopefully they will be close enough that I don’t need to make too many adjustments.


    • Thanks Karen – I like those ones the best too, but once I noticed what was going on, it was interesting to see what it was like if I took it a bit further. I might revisit this sometime. Adjusting just one control, like clarity, differently in each panel. It could make some subtle shifts of interest.


  2. An inventive series. Actually I like the first shot the best. Assessing brightness of an image and wondering what it will look like on other folks screens is something I ruminate over. However as I know that I have a full range of tones in my images from max highlight to deepest shadow usually with minimal clipping, then they should be ok on all screens providing the recipient has their screens bright enough to view them. I am aware that some people have concerns that WordPress re-sizing of images downgrades the quality a bit. All images I submit are usually 1200pixels on the longest edge, in sRGB colourspace and at 72ppi. WordPress will resize those to (i think) about 690 across to fit the width of my blog’s template and I always suggest to viewers that they click on the image to get the full size image which is big enough size as many viewers will be viewing on a laptop. Certainly enlarging to the file’s original uploaded size will guarantee the best quality. I’ve never used TIffs partly because I knew they were always big files. I shoot in RAW, convert them to DNG files and the largest file size I see is about 45Mb. Most once flattened come down to about 20Mb. My upload size to WordPress is usually 600-700Kb in the format I use. Don’t know whether that’s of any use to you or not, but it does help to share knowledge sometimes.


    • Thanks for all the information Andy. That is very useful. I always output so that the longest dimension is 1600pixels, but my WP Theme trims them to 1024 width (they can be taller than that if a portrait orientation). Actually, I am not completely sure what it does because it tells me that the image is 1600x nnn pixels, but gives me an option to insert a ‘large’ or a ‘full sized’ version, both of which are no wider than 1024, and usually (or perhaps always) no different in size.

      Since it is trimming them down anyway, I should probably just produce what WP wants, maybe that way it won’t be altered as much, or at all. My files run in the 700-900kb range. Since I am now at about 1/3 of the WP limit before I have to start buying space, I should get my file size down a bit to delay that day (and post fewer pictures too).

      As to using Tiffs, that was a rookie mistake on my part, though Photomatix does not give a lot of options. I should have been paying closer attention.

      I too wonder about the quality of viewing that others get and agree that getting the best quality image out there is going to be the best for all viewers. Sometimes though, the image is too subtle for some of the cheaper laptop monitors that I have access to, and the image quality is very poor. But, perhaps they just need to be set with greater brightness. I will have to check into that.

      Thanks again for all the info – sharing often does help.


      • I don’t find WordPress too helpful when it comes to advice on image sizing. When I come to the point of inserting one of your images into a Post I get offered a range of sizes: thumbnail 150x***, medium 300x***, large 1024x*** and the ‘fullsize’ version (which is the size your Blog template can accommodate, in my case 640x***). I’m not sure therefore how the ‘large’ version comes into the overall scheme of things or whether that is the size of the ‘enlargement’ that is shown if you click on an image in a post. Maybe someone out there reading these comments will have a clear idea. It occurs to me that if the max size WordPress will present to viewers is the ‘large’ version (1024x***) then there is no point uploading an image larger than that because it will be re-sized down and we will be wasting our time and space on submitting larger ones. If I find the answer I’ll let you know!


  3. This is an outstanding series. Very imaginative and well produced.
    Image editing is very memory intensive and I’m not sure if new software is the answer here. My first choice would be to at least double the DRAM since this is relatively cheap and easy to do. I have 6 gigs of DRAM and occasionally things slow down a bit but overall I’m satisfied. However, my D80 RAW files converted to DND still end up being 10-12 NB each. I’m not sure what file sizes you are dealing with but if they are full frame RAW they are probably twice the size of my files with your 5D. Basically, no matter what road you take, you can’t have too much DRAM.


    • Hi Ken, thanks for your comments, and I am glad you like the series, it is something a bit different for me, and a lot more post processing than usual, for me.

      Your comments prompted me to look at my file sizes, and there lies (most of) the answer. The dng files are ~20meg. However, the tone-mapped tiffs are well over 100meg each!. Yikes. And that is what I am editing, so no wonder the computer is choking. I nearly choked on my tea when I saw that since this one folder from a few minutes of shooting the sky now has 13 of these tiffs in it, at 1.49gb. I have been using a 16bit tiff output format. I just tried outputting to 8 bit tiff (60meg) and jpg (11meg) formats. I guess I will be using jpg output format. The detail looks pretty good for the final editing process. And I guess if it needs something a bit more that the jpeg does not offer, I can edit the jpeg which should go quickly and then apply those edits to a tiff afterwards, and go make a cup of tea while it is processing.


      • 16 bit TIFF is only good for extreme printed enlargements. You can always go back and reprocess to 16 bit from the original if you need anything like this. Otherwise, the only difference you’ll notice is faster processing. Also, you might find the PSD format to be a bit smaller, though not as universal as TIFF.


      • Hi Ken- the tiffs are generated by Photomatix during the tone-mapping. I only have the three options. But, as you say, if I generate a jpg and edit that, I can transfer the edits to a tiff later if I want (though getting the same result in tone-mapping could be tricky).


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