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12-16-2011, 05:35 PM   #16
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QuoteOriginally posted by Just1MoreDave Quote
The Bayer filter on the sensor means half as many red or blue pixels as green ones. Your example is similar to a typical shot, red flower with a background of green foliage. The red pixels are the first to go. If you look at the RGB histogram for these shots, reds are often way to the right of the other colors. The K-7 and K-5 do better because the 77-segment meter is better.
Excellent - thank you for explaining And for that, Just1MoreDave, you get a cookie! Cookie here equaling the "like" button

12-16-2011, 09:14 PM   #17
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QuoteOriginally posted by Just1MoreDave Quote
The Bayer filter on the sensor means half as many red or blue pixels as green ones. Your example is similar to a typical shot, red flower with a background of green foliage. The red pixels are the first to go. If you look at the RGB histogram for these shots, reds are often way to the right of the other colors. The K-7 and K-5 do better because the 77-segment meter is better.
... you really got me puzzeled.
Because there are less red pixels then green ones red gets burned out faster, did i got that right?
12-17-2011, 04:12 AM   #18
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QuoteOriginally posted by Just1MoreDave Quote
The Bayer filter on the sensor means half as many red or blue pixels as green ones. Your example is similar to a typical shot, red flower with a background of green foliage. The red pixels are the first to go. If you look at the RGB histogram for these shots, reds are often way to the right of the other colors. The K-7 and K-5 do better because the 77-segment meter is better.
Very astute Dave! I have to remind myself to bracket on the low side with really reddish sunrises and flowers. I got this sunrise the other day with my nx10 (k20d sensor) and had a real hard time trying to get the red right. I never did get it how it looked to me, just close. I should have under exposed, of course then the shadow detail would be gone.

12-17-2011, 07:15 AM   #19
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I just took a phone in my home of a painted red wall. Color is dead on . I do not understand why red cannot be done correctly

12-17-2011, 09:34 AM   #20
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QuoteOriginally posted by JohnBee Quote
I'm not sure I fully understand the advice you're offering, but I use these caps exclusively in the field(including sunsets) and they work very well.


Sure, its quite simple actually...

As mentioned earlier, I use these on my camera's out in the field as I can't use a color cards most of the time as I do in the studio. And so the procedure is quite simple. All you do is meter your scene and pop on over to the WB section and choose one of the custom modes( there are 3 to choose from). Select ok and the camera will stake a snapshot and ask you to press OK to confirm. The only thing I'd point-out with this is to watch your exposure when taking a reading because the camera has a very low threshold for underexposure(SEE: OPERATION COULD NOT BE COMPLETED). And so it might be necessary to temporarely push your eV setting to compensate

Other than that, its a real snap to use. And extremely valuable for tougher lighting situations such as sunsets as you can point the camera to a specific location to set your basic grey point value.

PS. I might make a visual walkthrough later on but I've been so busy these past few months that I really haven't had any time to do anything other than the bare minimum to survive
Thank you, John!

I will try this today, even if I don't presently have such a "cap" -- I will use a blank "sheet" of white cardboard to "test" the procedure. That should get me going until I get the WB gadget!

JP
12-17-2011, 10:14 AM   #21
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When shooting a sunset, you should underexpose the sky a tad to bring out the color. A cloudy white balance setting can also help.

A "WB gadget" or gray card will also help out in the field.


12-17-2011, 04:32 PM   #22
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QuoteOriginally posted by Anvh Quote
... you really got me puzzeled.
Because there are less red pixels then green ones red gets burned out faster, did i got that right?
Yes. The red has to be bright in the scene anyway, which happens in sunsets and flower shots. If the greens are darker, then the meter will see the whole scene as not too bright, and raise exposure enough to overexpose the reds. The camera's warning, blinking highlights, is only triggered when all the colors are overexposed. It ignores just one color.

I like using Adobe Camera RAW (Elements, Lightroom or Photoshop) because it shows this happening very well. But one thing to check with ACR or any software is its camera profile. I don't like the Adobe profile for my K-7 at all. I switched early on to the Pentax profile.
12-17-2011, 04:56 PM   #23
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QuoteOriginally posted by Just1MoreDave Quote
Yes. The red has to be bright in the scene anyway, which happens in sunsets and flower shots. If the greens are darker, then the meter will see the whole scene as not too bright, and raise exposure enough to overexpose the reds. The camera's warning, blinking highlights, is only triggered when all the colors are overexposed. It ignores just one color.
So it has nothing to do with the pixels... that's what got me confused.

12-18-2011, 07:55 AM   #24
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Thank you very very much to all you guys for the help! the last days were so busy that I didnīt have time to enter the forum, thatīs why I took so much time to reply. I will quote some of your answers on posts below so it will be easier for me to solve my doubts (that arenīt few...).
Thanks again!
12-18-2011, 09:03 AM   #25
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QuoteOriginally posted by NaClH2O Quote
Hi Roger and welcome to the forums. I don't know what you did wrong, but something obviously isn't right. What you need to do is post some of the worst offending photos with the exif files intact. Then we can see what you did and all of the settings on the camera (that's what the exif file is) one of the benes of shooting digital is that the camera saves all it's settings so it's easy to spot if you did something wrong.

NaCl(it probably is something simple but we need to see the shots)H2O
People, I may have some knowledge about composition, focal distance/aperture interactions on depth of field, lighting, color temperature, the old films, filters, etc, etc, but I must say Iīm a completely IGNORANT about digital! As I said, I stopped taking photos about ten years ago because i refused to jump into those little cameras, and couldīt afford a decent DSLR at that time. Although I can consider myself a reasonable skilled and experienced guy w/ PCs, I have almost NO contact w/ digital photos, so dealing w/ uploads, file sizes, extensions, photologs, etc, is dificult to me. That said, please excuse me for the stupid questions Iīll ask you, OK? Starting w/ the first one: NaCl, what do you mean by the exif file? I think it a file attached to the photo, w/ all the data, isnīt it? How can I upload a photo here, making sure this file is sent along? As I said, Iīm pretty ignorant... Rsrs!

QuoteOriginally posted by elho_cid Quote
From what you describe there could be red channel overexposed. Look at the RGB histogram, that may tell you. K-5 has the best DR of all digital cameras, so use it. If you don't blow any color channel, you can recover extreme amount of detail from the shadows. But if you do it, even RAW can't help.
Excuse me Cid, but wouldnīt be the opposite? If this red channel was overexposed, I shouldnīt expect the photos to be more red than normal? I got the opposite: the beautiful red skies I tried to register, simply disapeared. BTW what is "DR"?

QuoteOriginally posted by Nuff Quote
Since you shot raw, pull out lightroom and adjust the sky so it looks the way you saw them. Easy...
A camera doesn't really know what the scene is and how it should look like, it's not a human eye. Interpret the captured data so it looks the way it's supposed to look.

Also you might want to show us few examples and even a raw file to play with. Since you are new to digital world, you should start learning about it instead of doubt it.
Nuff, are you sure I can upload a raw file here, isnīt it to big? In fact I tried a couple of minutes ago but there was an error message from PF saying the time was expired.
About the lightroom, as I can see, this is an excelent program to manage photos, probably one of the bests, but unfortunately I cannot afford for it now, (Itīs extremely expensive here in Brazil!), can I use one, or a combination of 2 or 3 free programs like Picasa, GIMP and the Pentax Utilities to get at least a reasonable result? Note: I installed Picasa and P.U.4 (that came w/ the K5), but I donīt know how to use any of them... BTW, Picasa deal and edit the raw (PEF) files? I thought I could only open this kind of files w/ the PU4, but the Picasa I installed open the raw photos w/o problems. Finishing, I couldnīt agree more w/you: I know I most learn about digital photography, and this is something I want a lot, but guys, If you think my doubts are too "basic" to be discussed here, please let me know, so you donīt waist your time w/ my silly questions... Any tip for an "online basic guide to digital photography for completely ignorants on the subject" will be helpfull! rsrs!
Thanks again
12-18-2011, 09:25 AM   #26
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QuoteOriginally posted by jatrax Quote
Roger it sounds like you have a lot of experience and that is a good start but if it is all film you have some learning to do. Digital is different in many ways, (and exactly the same in others) but there is a learning curve.

As others have said post a RAW file and let someone play with it, I suspect a lot can be recovered. Or at least they can tell you what happened.

But more important than this particular issue, I think you should think about the digital workflow. With film I am sure you had a process for taking, developing and archiving your photos. Maybe you had a favorite processing lab, maybe your slides are in little metal boxes with labels, whatever. With digital there is also a workflow, and you have control over more of the process than most of us did with film. It starts with taking the photo, then it needs developed, then it needs labeled (keyworded) and then it needs archived.

1) Taking the picture I think you have experience at although you need to learn digital. And this is only the first step.
2) Developing is part of the process. You can shoot in jpeg and not do any PP (post processing) but in my opinion that is leaving the job half done. Lightroom was mentioned above and I also recommend you take a look at it. Some might balk at spending money on software, well if you were shooting film you would be spending money on developing. In Lightroom, or the Pentax software if you want to use that, you need to take responsibility for making that image the best it can be. There is a large learning curve but the results are worth it.
3) With digital it is harder to find a particular photo, and conversely much easier since we can keyword them. Again Lightroom is your friend but many other programs can be used. Add keywords to your images so you can find them when you want.
4) Archiving images is important whether film or digital. But with digital a single hard drive failure can cost you everything. Backup and multiple copies are a must. Again Lightroom is your friend but a complete and through backup of your digital assets is required. This is sometimes called DAM for digital asset management.
Jatrax, I have nothing to add on what you said! Perfect analisys of my situation! On my previous post, I asked about a combination of free programs that could be at least a fair substitute for Lightroom, but I think in my case it will be a nightmare, since I would have to learn how to use 2 or 3 programs and combine them instead of using just one (Lightroom) for everithing. I will start thinking on this investment.
Again, how do I upoload a RAW file here?
Thank you very much!
12-18-2011, 09:52 AM   #27
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EXIF is information embedded within your image file that identifies the camera used, lens used, aperture, focal length, ISO, and other parameters used for a particular photo. DR is dynamic Range.

In regard to Lightroom, you can download a 30 day free trial from the Adobe Website. Gimp would be great as well for editing. It is a free tool and is essentially a one stop shop for your photo edits except you do not have a storage library.

You need to convert the Raw file to a more standard JPEG or PNG for upload and viewing on the web.
12-18-2011, 10:04 AM   #28
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To upload the RAW file use dropbox or something like that.
There is a lot you can do with a RAW file, certainly if the exposure is close and it's only the colours.
12-18-2011, 10:38 AM   #29
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QuoteOriginally posted by Ecaterin Quote
Count your lucky stars that you're joining the digital era *now* Even 2 digital-camera-generations ago, white balance was just a nightmare. I never even bothered with auto-WB on my K-10-d unless I was in bright sun, the K10 was all manual-WB alla time :P

As much as they've improved, one area where digital cameras still have a heck of a time, is transitional light. If you've got competing colored light sources, or the light quality is complex enough that the auto WB might not be able to figure it out, you have to go to manual. Sunset light is a bear that way If you take a set of photos under iffy WB conditions on auto-WB, the camera will turn out a series of hilariously different photos - picking tungsten WB for one shot, and daylight WB for the next, even when they're exactly the same.

On a similar note, the hardest color for digital to handle is red (anyone got good sensor-physics to explain this? I'm sure the reason is known ). Red toned highlights more than any other color can really get burned (meaning lots of digital data wasn't captured, resulting in a mono-colored hotspot) in a non-adjusted shot - one reason I went from the K-x to the K-5, was this issue. Any time I'm going to shoot something that's a pure red, and illuminated, I take care with a tad of under-exposure to be sure I have enough data in the red channel available to edit! If the red gets burned or really color-cast shifted, it's much harder to get red (more than any other color) back in post processing, because the actual digital data for red was never completely captured.

K-x's burned reds:


So if you've got iffy lighting for WB *and* you're shooting a very red subject, you'll be doing a lot of post processing, because while the K-5 has great adjustability no camera can beat a fully enabled copy of Photoshop or whatever software you're using

You can do a lot of fine tuning of WB in-camera, and then tune even more in the color settings, but frankly I find it really fussy and prefer to shoot in RAW and tune the WB in Photoshop where the controls are much more refined and the screen is huge. For any given sunset, I'll shoot a frame, try out several different WB presets and choose one that gets the closest - and then just ignore WB and concentrate on exposure. Knowing I'll tweak the WB the rest of the way in Photoshop, means I can relax and work on getting a good shot

This pano I was able to quickly grab an auto-WB setting that got very close to the color & pushed it the rest of the way in post. I don't know why the K-5 handled the deep orange so well that day, it's a mystery:


This shot, on the other hand, was an absolute work out - I was only able to get a WB color palette in the same zip code as the actual scene and had to post-process to tweak white balance, remove color cast and do a couple of other things to get there. It was completely eerie light, even wilder than it looks in the finished pic.


This is an area where you'll need to embrace your inner Zen blank-slate of ignorance. You're building an entirely new skill set, accumulating enough data to start being able to intuitively set the camera. Shoot every sunset you can, every illuminated red you can, while adjusting your camera settings and observing. Let the camera show you what settings get you close to what you saw. Pick up a copy of Photoshop Elements (much less overwhelming than the full program, but still powerful & lets you edit in RAW), because you're crippled without good post processing software. Learn all of the tricks of RAW editing - that's going to give you the most dramatic reclaiming of the photo you saw, in the photo you took.

Just as with film, taking the perfect exposure is only half of the process - you need the perfect 'development' in post-processing as well. And here's where we drag out the Ansel Adam's attributed quote "Great photos aren't taken, they're made."
Thank you very much for the tips Ecaterin,
The more I read, the more I see I know nothing about digital photography and it will be a long way to learn it...
About manual WB, I donīt know if I was doing wrong, but I couldnīt get to any decent result the times I tried to set WB manually on my K5, and I think the operating manual is poor in this regard. After taking the adjust picture of any white paper, or surface on one of the 3 custom modes, I tried to move the cursor between the B,G,A,M sides of that square grid in order to get to the whiter image possible, but i found it too dificult. Most of the times I simply couldnīt get to any "white" image. The more I moved the cursor the less white the image got. I found it difficult to trust my own eyes to tell which setting was the "whiter". Besides, I was wondering now: how about the calibration of the cameraīs LCD? How do you do it? I mean, I know there are adjustments for it, but how can one say one given color and brightness adjustment is proper for that cameraīs LCD? I guess if oneīs LCDs is adusted wrong, is worthless to take into account the images shown on it to make WB adjustments, donīt you agree? Anyway, I must learn a lot... Digital is really a whole new world for me.
Thanks for the tips!
12-18-2011, 10:50 AM   #30
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QuoteOriginally posted by IIGQ4U Quote
When shooting a sunset, you should underexpose the sky a tad to bring out the color.
Nice shot!

The "underexposing the sky" thing can easily be solved by metering properly, as your FL gets wider, the need to properly meter gets more critical.

Always remember this -> All Automatic Metering With Digital Cameras Suck!!!

Remembering that will help in improving your photog 10-fold...





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