processing raw

<p>I've been working with raw images for several months now, but find that some images are very difficult for me to process.</p>

<p>For the most part I use the auto setting and sometimes fiddle with recovery, brightness, contrast, etc..<br>

but really I'm flying blind here and need advice.</p>

<p>High color images such as the one posted here, really are difficult for me. I end up with glaring areas, noise, and just not true to life color... and in this case, the blue sky is all splotchy for some reason.</p>

<p>So how do I process this? Is there a how to guide out there somewhere??<img src="http://img.photobucket.com/albums/v143/whispering_rain/004small.jpg" alt="" /></p>

<p>Carol, This is the result after less than two minutes in Photoshop. (Auto Levels, 10% contrast boost, a bit of Selective Color adjustment to darken the cyan\blue) No RAW involved. I thought the blotchy skies were wisps of cloud. Best, LM.</p><div></div>

<p>IMO for this image it is not really a post production matter.<br />The main issue is that the image is underexposed.<br />The main repetitive difficulties you are encountering are likely due to incorrect metering techniques for various scenes.<br />The EXIF indicates that it was captured with an E510 set to an automatic exposure mode with no manual overrides using a pattern metering.<br />The automatic exposure and the pattern metering read way too much sky - hence the acute underexposure.<br />Following LM's Post Production technique, below is the effect of just “Auto Levels”: note the histogram and how the BLUE channel alters.</p>

<p>WW</p><div></div>

<p>. . . and this is the closest I can get to a <em>simulation</em> of what the correct exposure should have been. (i.e. only adjusting the EXPOSURE)<br />Your shot is about 1⅔ STOPS underexposed, reckoned by the result of this adjustment on the sample posted and extrapolated by the shooting specs.</p>

<p>NOTE: Noise is exacerbated with UNDEREXPOSURE</p><div></div>

<p>PS<br>

One of your pictures which pop up at the bottom of the thread is "The Dragon Hunter".<br>

There are similarities - the mass of water in the scene, although it appears overcast.<br>

I note for <em>The Dragon Hunter</em>: "Spot Meter" is indicated in the EXIF and I note there is reasonable detail in the shadows of the bird’s body.<br>

My assumption is the Spot Meter nailed most of the head of the bird and very little of the background.<br>

My other guess is that you <strong>did not</strong> spot meter the bird's <strong>greyish</strong> body; lock AE; Recompose . . . because, IMO, that image is also underexposed, by about ½ to ⅔ of a stop, indicted by the lack of mid tone guts.</p>

<p>WW </p>

 

<p>Hi Carol, I get that blotchy posterized look when I accidentally work with 8-bit color instead of 16. Regards.</p>

<p>One of the wonderful (and difficult) things about Photoshop is that there are often literally dozens of ways to approach a given image. Not only are there all the tabs and levers to push around in Adobe Camera Raw, but alternative (but related) choices are available under "Adjustment" and other menus.</p>

<p>That's not even beginning to address the already mentioned differences in color spaces and levels.</p>

<p>I love the program, but it can be like wandering into the middle of a Rio Carnival and losing track of where you are. Just keep plugging, try things, and then try something else. There are lots of good books on almost every aspect of Photoshop. (Oh, and always work on copies, although most things can be reversed one way or another.)</p>

<p>Although I didn't download your image and work with it myself, it's not at all clear to me that the original was underexposed. </p>

<p>Look at the "before" RGB histogram posted by William W. It shows a significant number of pixels with large red values between the large blue peak and the RH end of the histogram. If the photographer or the camera had increased the exposure of the frame as a whole to place the main blue peak near the RH side of the histogram, those pixels would have been clipped in the red channel and lost significant color information. To me, the "before" histogram looks to be about the best exposure that the camera/photographer could make without blowing out one channel in a significant number of pixels. </p>

<p>As long as all the info is present in the initial exposure, then, in post processing, one can pull tricks like separately adjusting the sky and the balloon to obtain an enjoyable overall appearance, albeit one which is not entirely faithful to the original scene.</p>

<p>Just my $0.02,</p>

<p>Tom M</p>

<p>Thanks everyone for your comments.<br>

There is a lot to absorb here and a lot of learning for me to do...</p>

<p>I really appreciate each and every response!</p>

 

<p>Below is the progression from: the original; simulated 1 stop exposure increase; simulated 1⅔ stop exposure increase; the last frame shows some whites blown out when the Exposure is simulated 1⅔ stops increase , there are a few other blown areas also.</p>

<p>There are definitely predominately red pixels in the area of the original image between the RH side of the blue peak and the RH edge of the histogram. Whether they are significant in number <strong>or significant at all is up for debate.</strong> I am firm in the belief that they are not significant in this shooting scenario, but I understand that other have differing opinions.</p>

<p>It is important to realize that Digital Sensors can take a little hammering with over exposure – in this shooting scenario I can get about ⅔ stop, maybe 1 stop and still maintain detail in the whites with recovery in RAW processing.</p>

<p>I agree with the sentiment and as a general premise - to get all the information present in the RAW file and then manipulate it.<br>

But the point is: that is impossible to do in a scene like this – that is the whole point of my original comment.</p>

<p>The EV range of this scene is far greater than the EV capacity (Dynamic Range) of the Digital Sensor used to capture it. In this regard I believe the original image is underexposed. I make this comment NOT from the histograms alone, but also from interrogation of the metering mode and capture mode selected also and from experience metering and shooting similar, to the scene itself.</p>

<p>WW</p><div></div>

<blockquote>

<p>"I get that blotchy posterized look when I accidentally work with 8-bit color instead of 16."</p>

</blockquote>

<p>Thanks for that information. I played with 8bit last night and I can simulate the effect similar to the sky in the sample too. I did not know this characteristic – but I don’t work in 8bit.</p>

<p>There is definitely something going on with the sky, irrespective of exposure or not. The posterized look must be a result of some post production processing, IMO. I am not versed to comment but I think the OP should treat this as a separate condition / problem to: Noise, lack of mid tone range; lack of detail in the shadows and exposure and metering techniques.</p>

<p>WW</p>

<p> </p>

 

<p>After Tom’s comment I have been thinking about this more. I looked at the issue a different way about and with the following assumptions:</p>

<p>The EXIF is correct.<br />The shot was taken between 0900hrs and 1500hrs and not at extreme degrees of latitude.<br />The sun was not behind cloud cover.</p>

<p>Shooting scenario: Open Sunlight, side lighting a ball of reasonably dense rainbow colours with very few whites – (i.e. not a Bride in a Wedding Dress in full sun, for example) </p>

<p>Computations on site:<br />Nominal Exposure at ISO200: Use F/16 @ 1/200s @ ISO200.<br />(Conservatively) Open only 1½ stops for side lit sun: = F/9.5 @ 1/200s @ ISO200. (I would allow 1? stops)<br />(Conservatively) Allow only ½ stop to increase DR and with recovery of the WHITES in RAW: = F/8 @ 1/200s @ ISO200. (I would allow 1 full stop)<br />(My exposure computation on site) Allow about 1 stop to nail <em>the density of the colours</em> and ignore the potential small areas of blown white which are in the scene = <strong>F/5.6 @ 1/200s @ ISO200</strong></p>

<p>N.B. Each shooting scenario is different, and part of that difference is the SUBJECT and the colours and tones of the subject and what is required in the final result: I would NOT take the same exposure compensation on site and apply it to a Bride in a Wedding Gown in Full Sunlight or a White Cat in Sunlight and Shade: <a href="../photodb/folder?folder_id=972502">http://www.photo.net/photodb/folder?folder_id=972502</a><br>

But the question here revolves around:<br /><em>“</em><em>but find that <strong>some images</strong> are very difficult for me to process . . . <strong>high color images</strong> such as the one posted here, really are difficult for me. I end up with <strong>glaring areas</strong>, <strong>noise,</strong> and just <strong>not true to life color</strong>”</em></p>

<p>EXIF shows the shot was pulled at: F/5.6 @ 1/640s @ ISO200 = <strong>F/10 @ 1/200 @ ISO200.</strong></p>

<p>Even <strong><em>without applying “my” final compensation</em></strong>, I would argue (above) that the TTL metering system was <strong>conservatively</strong> under by about (at least) ? stop.</p>

<p>Moreover, opening up another stop to drive those colours home and maintain beautiful BLACKS and SHADOW DETAIL at the expense of some possible small areas of unrecoverable whites would make the BEST exposure <strong>for that particular scene</strong>, to <strong>allow the optimum Post Processing</strong>, whatever avenue that post processing might take.</p>

<p>WW</p>

<p> </p>

<p>EXIF also shows camera is set for High Saturation which can also cause problems with certain exposure situations such as this. Carol, try settings for low contrast and low color saturation in the camera and do some test shots to see if that helps.</p>

<p>Ray - excellent suggestion.</p>

<p>William - Thanks for your thoughtful analysis and comments. Let me respond to some of the points you raised:<br /><br />1. <em>"...There is definitely something going on with the sky, irrespective of exposure or not. The posterized look must be a result of some post production processing, IMO. I am not versed to comment ..."</em><br /><br />We had a big discussion of this phenomena back in February of this year: http://www.photo.net/digital-darkroom-forum/00Vl7k<br />In that thread, the posterization is more banded than in this photo because of the gradient in the sky in the earlier thread. However, when the gradient is less pronounced, as it is in this thread, the posterization looks more random and less banded, but the reason for it is exactly the same. <br /><br />2. <em>"...The shot was taken between 0900hrs and 1500hrs ..."</em>. My reading of the EXIF data shows that the shot was taken at 18:32:53 PM on Sept. 18th, ie, only about an hour before sunset on that day for most places in the USA. That late in the day, one has lost about a stop or a bit more of light from the usual "sunny f/16" conditions. <br /><br />3. The "sunny f/16" rule is a incident light rule, and a conservative one, at that. I've never seen any knowledgeable photographer ever suggest modifying this rule or incident light meter measurements of the ambient light because of the presence of a dark or light subject. That's the whole point of incident light measurements: They work independently of the subject. <br /><br />4. Because of #2 and #3, I would say that the "sunny f/16" rule would estimate the exposure for her ISO=200 shot at 1/200 @ f11, or 1/800 @f5.6. Since her shot was taken at 1/640th sec @f5.6, by my calculation, her shot was taken at exactly the exposure that the (conservative, no-pixels-blown) sunny f/16 rule would suggest. <br /><br />5. That being said, while the sunny f/16 rule and her camera both produced a conservative, no-pixels-blown exposure, both you and the OP are absolutely correct that it produced a dull and not terribly attractive image. So, since one obviously has to brighten it up, the question then boils down to whether it is better to do the brightening completely in-camera, completely in post-processing, or split the difference and do a bit of brightening at each step.<br /><br />IMHO, the answer to this question depends on the scene, the photographer's intent, and the equipment they are using. For example, if the photographer is using a camera with good dark noise performance (eg, a D700), one can be conservative when taking the shot, expose so that no pixels are blown, and brighten the dark areas without having to worry about increasing the noise in these areas to unacceptable amounts. OTOH, if the camera is a small sensor P&S with poor shadow performance, one would have to use the opposite approach and accept having some blown areas. She used an E510, so it's in-between these two extremes. <br /><br />Another one of the factors entering into the decision of where to increase the exposure (ie, in-camera vs in post) is whether the photographer is saving only JPGs (8 bit per channel) or saving RAWs with much higher bit depth. If they are shooting 8 bpc JPGs, as soon as you try to brighten things up in post, you quickly run into posterization, especially in areas of nearly uniform color, such as the sky. I don't know which file format the OP saved when producing this image, but the only image we now have available is the 8 bpc JPG that she posted, so we were essentially guaranteed to produce a crummy looking sky by brightening it up in post. OTOH, if she had used exactly the same exposure, but saved a 12 or 14 bpc RAW file, and then brightened it up in ACR before posting, I can guarantee that the crud in the sky would be vastly reduced compared to the best we can do with the 8 bpc image she posted. Take a look at the previous thread on this subject (cited above) for more discussion of this.<br /><br />Another one of the factors entering into the decision of where to increase the exposure (ie, in-camera vs in post) is the photographer's intent, specifically, their decision about which areas of the image should be rendered best. For example, if the balloon had the sponsor's name in white lettering on the side, and the photographer was hired to record this, they better damn well not overexpose in-camera and try to rely on highlight recovery to save their hides. OTOH, if, as in this photo, the brightest pixels (in any channel) only occupy a small and relatively unimportant part of the scene, and you want bright, postcard-like colors and color accuracy isn't a big deal, than it's just fine to overexpose a bit in-camera.<br /><br />In conclusion, I would say that for this particular photo, the equipment used, and it's likely purpose (ie, a nice, vivid image), I would have to agree with you and overexpose in-camera, but in other situations, the opposite approach could be absolutely necessary. <br /><br />Anyway, just my $0.02 on the subject. <br /><br />Cheers,<br /><br />Tom M</p>

<p>You all are far more knowledable then I.. I'm trying to absorb all of this.</p>

<p>I have this image in raw and in jpg, but I didn't think I could upload a raw file.</p>

<p><strong>What is ACR?</strong></p>

<p><strong>How do I change it to 16 bit?<br /></strong></p>

<p>(I'll be reading this for days to actually comprehend it all.. )</p>

<p>I REALLY appreciate every one responding!</p>

<blockquote>

<p>"EXIF also shows camera is set for High Saturation which can also cause problems with certain exposure situations such as this."</p>

</blockquote>

<p>I assume (but don't know for sure - because I don't use this camera) that High Saturation would only affect the JPEG File?<br>

i.e. this is a question . . . please explain.<br>

<br />I understood that the image posted is a JPEG modified from the RAW file - hence not affected by the Saturation setting?</p>

<p>WW</p>

<p>Tom, Thank YOU for the considered response.<br />Carol - I too am reading and filing – this thread is most informative.</p>

<p>Tom:<br />A few responses from me - in your point form<br />0. Re Ray’s comment I am confused as to how it might be applicable, I have commented separately above requesting more info.</p>

<p>1. Thanks I have filed that thread: excellent reference and very much appreciated.</p>

<p>2. I was unsure of the Exposure TIME, that’s why I was purposeful to scribe “I assume”<br />I get your reading “2010-09-18 18:32:53” when I extract using <em>Opanda EXIF II</em> - but I also get “1216Hrs” via <em>EXIF data</em> – Perhaps Carol can confirm ? <br />If the shot was pulled at 18:32hrs, then the sample image would be <strong>more underexposed</strong> by my argument.<br />I assume that is what you are intimating?</p>

<p>3. Yes the F/16 rule is based upon incident light meter readings.<br />Yes incident light meter readings work independent of the subject.<br />This is now a difficult area of our correspondence – as you have stated that you know of “no knowledgeable photographers” who suggest modifying this rule and applying it or adapting it to various situations.<br />So my response is, “but I do”.<br />By way of explanation - the F/16 rule is a rule of thumb – i.e. “a guide”.<br />So please be clear that I am not arguing a point, for point’s scoring – I am however stating that there are limits beyond the F/16 rule which can be pushed – and I know in similar shooting scenarios to the sample image that photographers, other than I would and have push those limits based upon the rule of thumb.</p>

<p>4. Yes I agree in general to this point – but at 1 hour before sunset I would be “opening up” (for the f/16 rule), more than 1 stop – so I would argue the image is still around ⅔ stop underexposed.</p>

<p><strong><em>5. This is the most critical point</em></strong> and I would dearly love to sit with you over Coffee or Scotch or both, discussing these issues to which you point.</p>

<p>If anything in this thread is important it is these points: the equipment; the subject; the lighting scenario; the final intent.</p>

<p>I only know Canon DSLR. I come with experience from film.<br />When I received my first two Canon DSLR’s I spent about six months learning them before I shot one frame for any paying job.<br />During that learning process, I feed files to my studio, who at that time had employed an experienced digital photofinisher - from whom I learned and adjusted my exposures and techiques to suit each camera.<br />I can now state that I know a 20D, 30D, 5D and 400D. They are all different – just like each film I know, is different.<br />I do not know the E510 I have never used that camera.<br />I do however know very well, similar to the scene which was taken.<br />Thanks again for the time and effort you took to respond.</p>

<p>Cheers to you also,</p>

<p>Bill</p>

<p> </p>

<p><em>18:32:53 PM on Sept. 18th, ie, only about an hour before sunset on that day,</em> is correct.</p>

<p>So can I upload a raw file here? Or anywhere so that I can show you all the original before I screwed it up even more?</p>

<p><strong>This is a link to the raw converted to jpg with no adjustments made</strong></p>

<p>http://img.photobucket.com/albums/v143/whispering_rain/004-2.jpg</p>

<p>Thanks - I am looking.<br>

"before I screwed it up even more?" . . . None of what I wrote implied you scewed anything up - <em>I trust that comment was in jest</em>. I read every comment by every poster on this thread as being assistance only.<br>

WW</p>

<p> I do not think anyone implied that I screwed it up...<em><strong> I</strong></em> think I did though! lol ..I am laughing at myself truly... because I think the raw file looks MUCH better then what I ended up doing to the image. oi.. lol</p>

<p>I am very grateful for everyone responding here and value their input. I appreciate you and others sharing your knowledge :)<br>

Thanks! :)</p>

<p>Carol, exposure in scenes like this is tricky, and so is the post processing, but both are worthwhile. Good for you for trying to get help figuring out what was wrong and not just getting discouraged. There's definitely a learning curve.</p>

<p> <strong>..I am laughing at myself truly... because I think the raw file looks MUCH better then what I ended up doing to the image. . . </strong></p>

<p>OK, thanks I understand your comment now.</p>

<p>The first thing I noticed about the "RAW" file is the Blue Sky, is not posterized.</p>

<p>WW</p>

 

<p>One of the things I like about Photoshop CS5 over CS4 is the much expanded ability to make corrections of the RAW image before opening it in Photoshop. I now do the lion's share of tweaking in Photoshop RAW and do any last tweaking in CS5 itself.</p>

<p>There are numerous resources on the web that can get you started but one of the best teachers is to take an image and just start fiddling with it.</p>

<p>William I notice that too. I did manage to get one processed that didn't have that splotchy look, but then the sky had lots of noise.</p>

<p>Scott I have CS3 and HOPE within a few months I can upgrade... but I'm just a poor girl, so it's not looking likely... blah</p>

<p>Thanks Jay :) I think the learning curve is a bit steeper for ditzy blondes ( that would be me! lol)... but I'll keep trying. :D and with the advice given here I'm sure I'll get it. (eventually! lol)</p>

<p>Truly there is a wealth of information here and everyone is so gracious in sharing their knowledge! THANK YOU!</p>