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"digital" flash mode (no actual flash fired) HP945
I was just reading what Bob Atkins had to say about the "digital" flash mode
on the HP945. He demonstrates with a mountain scene. It doesn't actually fire the flash at all, but it lightens up darker parts of the scene. For some purposes, it looks like a good idea to me. I wonder, could this technique effectively replace the split neutral density filters that are commonly used in mountain scenics where the valleys are so much darker than the white capped mountains? (Of course, only in digital cameras...) Can you achieve this with basically all digital cameras by just reducing the contrast settings? Are there any other cameras besides the HP945 that has a similar flash, or program setting? I wonder how well this would work for flashless portraits near full telephoto (~300mm equiv.) to bring out shadow detail in the eyes on a sunny day. Thanks for any help or info you can provide. David |
#2
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"digital" flash mode (no actual flash fired) HP945
I was just reading what Bob Atkins had to say about the "digital" flash mode on the HP945. He demonstrates with a mountain scene. It doesn't actually fire the flash at all, but it lightens up darker parts of the scene. For some purposes, it looks like a good idea to me. I wonder, could this technique effectively replace the split neutral density filters that are commonly used in mountain scenics where the valleys are so much darker than the white capped mountains? (Of course, only in digital cameras...) Can you achieve this with basically all digital cameras by just reducing the contrast settings? Are there any other cameras besides the HP945 that has a similar flash, or program setting? I wonder how well this would work for flashless portraits near full telephoto (~300mm equiv.) to bring out shadow detail in the eyes on a sunny day. Thanks for any help or info you can provide. David Hi... I had the HP 945 for a week now and it's an easily likeable camera, though i have not used the digital flash function and don't really have intention to anytime soon. From what i read, and I assume you probably read it itoo, the advantage of the one done on the HP is that the camera does it directly on the fresh CCD data, which means it'll probably do it better than JPEG editing on the computer. I think it's different from contrast settings in cameras, because this one seems a little "intelligent", if that's the right word. Basically, reviewers seemed impressed with it, which gave me the impression they probably didn't expect it to work, but it did. I have no idea how it'd perform on a sunny day portrait, but i have the vague impression that i read somewhere that it can be used for such situations of harsh shadows on sunny days and that it does actually work. That said though, the camera has up to +/-3 in exposure compensation which is the usual trick, plus a spot metering mode. Those two are what is usually used for such situations, at least in 35mm photography. I also vaguely remember reading one user review that said indoors it could turn a black hair gray, but that was the only negative comment i read regarding it. Maybe i ought to try it for you. The only other camera that has it is the newer HP camera, HP Photosmart R707, just out lately. |
#3
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"digital" flash mode (no actual flash fired) HP945
"David Bindle" writes:
I was just reading what Bob Atkins had to say about the "digital" flash mode on the HP945. He demonstrates with a mountain scene. It doesn't actually fire the flash at all, but it lightens up darker parts of the scene. For some purposes, it looks like a good idea to me. I wonder, could this technique effectively replace the split neutral density filters that are commonly used in mountain scenics where the valleys are so much darker than the white capped mountains? (Of course, only in digital cameras...) The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. With some cameras by going to the RAW formats, you get a bit more range. I suspect that in general you will get better results under a photo editor like photoshop or gimp than with the camera doing the processing. -- Michael Meissner email: http://www.the-meissners.org |
#4
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"digital" flash mode (no actual flash fired) HP945
"David Bindle" writes:
I was just reading what Bob Atkins had to say about the "digital" flash mode on the HP945. He demonstrates with a mountain scene. It doesn't actually fire the flash at all, but it lightens up darker parts of the scene. For some purposes, it looks like a good idea to me. I wonder, could this technique effectively replace the split neutral density filters that are commonly used in mountain scenics where the valleys are so much darker than the white capped mountains? (Of course, only in digital cameras...) The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. With some cameras by going to the RAW formats, you get a bit more range. I suspect that in general you will get better results under a photo editor like photoshop or gimp than with the camera doing the processing. -- Michael Meissner email: http://www.the-meissners.org |
#5
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"digital" flash mode (no actual flash fired) HP945
"David Bindle" wrote in message ... I was just reading what Bob Atkins had to say about the "digital" flash mode on the HP945. He demonstrates with a mountain scene. It doesn't actually fire the flash at all, but it lightens up darker parts of the scene. For some purposes, it looks like a good idea to me. I wonder, could this technique effectively replace the split neutral density filters that are commonly used in mountain scenics where the valleys are so much darker than the white capped mountains? (Of course, only in digital cameras...) Can you achieve this with basically all digital cameras by just reducing the contrast settings? Are there any other cameras besides the HP945 that has a similar flash, or program setting? I wonder how well this would work for flashless portraits near full telephoto (~300mm equiv.) to bring out shadow detail in the eyes on a sunny day. Thanks for any help or info you can provide. David David, while it's neat that the HP-945 provides this function in-camera, the same sort of "digital flash" can be applied out of the camera using any fairly sophisticated photo editor such as Photoshop or Photoshop Elements. The technique is called "constrast masking" and is used to selectively brighten darker portions of an image while leaving the brighter parts relatively untouched. Actually, "contrast masking" is a bit of a misnomer; "luminance enhancement" would probably be a better term. Here's how it's done in Photoshop Elements. With an image loaded into the program, 1) Duplicate the image layer and make the duplicate layer the active layer 2) De-saturate the layer (ctrl-shift-U) 3) Invert the layer (ctrl-I) 4) Set the blending mode of the layer to "Overlay" or "Soft Light". Overlay provides greater contrast. 5) Set the layer transparency to around 80%. 6) Apply a Gaussian blur to the layer. Start with something around 50 and work up/down from there. The purpose of this blurring step is to reduce the severity of the transitions between light and dark areas in the photo to avoid that awful cut-and-paste look. 7) Optional--Play around with steps 4, 5 and 6 to get the most pleasing result. 8) Flatten the image (ctrl-E) 9) Optional--Adjust Levels or Brightness/Contrast, if desired 10) Save the picture under a different name. If you've never done this before, it might sound complicated, but it really isn't in practice. Just a few keystrokes/button-presses and you've got an amazingly enhanced picture in many cases and you can often even turn throw-away shots into real keepers using this technique. ("Yes--now you can turn TRASH into CASH!" as an infomercial might put it.) Also, if you're using full Photoshop, not Elements, you can turn this process into an action. Finally, to answer your other question, enhancing brightness/contrast on a digital camera simply can't duplicate the digital-flash/contrast-masking effect. I'd rather do my "digital flashing" outside the camera anyway since I have far more control over the finished result, though as I said above, it *is* an interesting feature to include in a digital camera. BTW, www.steves-digicams.com has an HP-945 review with a couple of digital-flash examples along with their normally-shot counterparts so you can try out contrast masking on your own to see how it compares to HP's implementation. Hope this helps. |
#7
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"digital" flash mode (no actual flash fired) HP945
In article ,
m says... Actually, "contrast masking" is a bit of a misnomer; "luminance enhancement" would probably be a better term. Here's how it's done in Photoshop Elements. With an image loaded into the program, [snip excellent step-by-step] Hope this helps. Indeed! Thanks for posting this; it's a great tool to add to my quiver. -- Charles Jones -- Loveland, Colorado ICQ: 29610755 AIM: LovelandCharles Y!M: charlesjonesathpcom MSN: |
#8
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"digital" flash mode (no actual flash fired) HP945
Michael Meissner wrote:
The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. With some cameras by going to the RAW formats, you get a bit more range. I suspect that in general you will get better results under a photo editor like photoshop or gimp than with the camera doing the processing. Yup. Andrew. |
#9
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"digital" flash mode (no actual flash fired) HP945
Michael Meissner wrote:
The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. With some cameras by going to the RAW formats, you get a bit more range. I suspect that in general you will get better results under a photo editor like photoshop or gimp than with the camera doing the processing. Yup. Andrew. |
#10
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"digital" flash mode (no actual flash fired) HP945
lid writes:
Michael Meissner wrote: The problem is most digital cameras have a lot less range than print films do, between dark and light. Slide films have the same sort of problems, and the solution is typically the same (expose to avoid burning out the highlights and bring out shadow detail in post processing). In the most common case of JPEG, there are only 8 bits (values 0-255) for each color per pixel. Yeah, but usually those 8 bits represent a value that you raise to the power 2.2 to get luminance. When you work that out, 8 bits is a heck of a dynamic range. The classic counterexample is shooting weddings, and trying to get detail in both the bride's white dress and the groom's black tux. From what I've read, most digital cameras give you the range of slide film, but print film still gives more latitude. From what I can see, digital sensors (or at least those in DSLRs) have more dynamic range than transparencies but less than print film. It may be that with a drum scanner you can squeeze a bit more out of a transparency. I believe in general you only get that extended range in DSLRs when you use raw mode, which for many cameras can give you 10-12 bits of precision. I believe some of the newer Fujis are trying to address the dynamic range problem by having two sensors for the high and low values. And even the Sigmas are trying to attack the problem, its a pity that the implementation leaves a lot to be desired compared to the theory. I suspect within 5 years or so, there will be a shift to using 16-bit formats in cameras. As bragging rights, I would hope the megapixel race is nearly over, and manufacturers start concentrating on higher ISO values (with less noise) and more tonality. -- Michael Meissner email: http://www.the-meissners.org |
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