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Old Aug 21, 2007, 8:12 AM   #11
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I don't do a lot of low light photography (unless you want to call flowers in shadows "low light" - I don't). I haven't noticed much difference in my house or outside when it comes to focus speed. Remember that any focus system requires contrast to focus - if you point your camera at a featureless sky it will have trouble focusing no matter how much light there is (certain sunsets are a problem because of this - not quite enough contrast).

I'm also not the best person to answer this question sinceall of my fast prime lenses are manual lenses (50mm 1.4, 50mm 1.7, 24mm 2.8 and a 135mm 2.5) purchased in the early 1980's. They all work very nicely with the K100, they are all "old friends" and I haven't felt a particular need to upgrade them.
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Old Aug 21, 2007, 8:16 AM   #12
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mtngal - it isn't a matter of focus speed (although that matters to) - it's shutter speed and DOF. anti-shake doesn't prevent motion blur. So taking shots of kids with 1/30 shutter speeds indoors is a bad idea. Also, there is the problem of DOF - sometimes you actually want TWO kids or more in focus while they're playing. That can mean using apertures of 5.6 or even 8.0. No way you'll get fast enough shutter speeds w/o flash at those apertures in many household situations.



edit - sorry - found what you were referencing a couple posts back :?

still wanted to leave the above point with regards to why flash is a good idea.
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Old Aug 21, 2007, 8:41 AM   #13
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Delius wrote:
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... Also I read somewhere that the K10D is slow to focus in low-light.
That is a fairly universal problem, thought some are better than others. And having a fast lens helps.

Delius wrote:
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... Usually I can get sharp shots at ISO 400/800 f3.3 on the FZ8 (with of course much noise) so I guess I could do much better than that with a DSLR and a good fast lens.
Actually, f/3.3 isn't a lot different from f/2.8, so probably not. But another factor that affects noise is pixel pitch. That is, the more pixels squeezed into a small area, the more likely that a pixel might react to adjacent pixels.

The Panasonic FZ8 has a 1/2.5 inch 16:9 aspect ratio, 7 megapixelimage sensor, which packs a lot of pixelsinto a small space. The Pentax and Sony have image sensors that areabout an inch by 5/8 inch, 10 megapixel image sensor. So the FZ8 has a much higher pixel pitch than the two dSLRs, and thus would be more prone to noise.

Delius wrote:
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... How ISO1600 on the Sony would compare to ISO200 on the FZ8?
ISO is ISO. ISO is a measure of light sensitivity, originally in film which is not adjustable, now in digicams where the light sensitivity of the image sensorcanbecontrolled.

You may be familiar with 'film speed' expressed in ASA and/or DIN.These values have been superceeded by ISO values and are (or are supposed to be) exactly the same from camera to camera, from manufacturer to manufacturer, from country to country.

Each time an ISO setting doubles, the sensitivity to light of the film or image sensor doubles, so ISO 1600 on the Sonyis four time more light sensitive than ISO 200 on the Panasonic (if both companies are using the ISO scale properly.)

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I see that the Pentax has the largest selection of lens but I worry a bit about the future of this company, only 2 DSLR and a lof of not-so-great compacts. Of course there is always Samsung to continue the line, but what if I get stuck with no upgrade path for the body? The K100D is very cheap and good but it's only 6mp (OK I know mp isn't everything).
Samsung buysits camera's from Pentax, soin the unlikely event that Pentax closes its doors, Samsung cameras will go away too. But I think there's little reason for concern. Pentax has always been a low profile manufacturer of cameras. And Pentax just signed an agreement to merge with Hoya. Hoya provides glass to almost the entire industry, and Hoya owns Tokina which, as I understand it, makes most Pentax lenses. The merger seems to make a good deal of sense, and speaks well for the future of Pentax.

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... And last, I would like to limit my budget to 1000$ if possible.
Soyou might pick up the K100D and one or two good lenses. Anything else, and you might be confined to thekit lens, which won't do you much good at all.
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Old Aug 21, 2007, 8:58 AM   #14
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TCav wrote:
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Soyou might pick up the K100D and one or two good lenses.
... or the K100D, a good lens and a good flash.

The lenses I mentioned in a earlier post are all superior to the kit lenses in more ways than just the larger maximum aperture. But if your budget confines you to a kit lens, a good flash will make up for some of its shortcomings.
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Old Aug 21, 2007, 9:31 AM   #15
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TCav wrote:
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[user=95008]
*Delius wrote:
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... How ISO1600 on the Sony would compare to ISO200 on the FZ8?
ISO is ISO.
I'm sorry my question was actually how do they compare regarding to noise? I mean, on the FZ8 at ISO200 you can already see a lot of degradation. Would a picture taken at ISO 1600 on the Sony be better than ISO200 on the FZ8?

The lens on the FZ8 has about 1.5 stop advantage on a DSLR kit lens, so I try to have a realistic expectation of what a DSLR will bring to me.

JohnG I undertand that anti-shake doesn't stop motion but not all my indoor picture will require motion-stop even with kids. During the day I see that I could use ISO800/1600 without having to use a flash to take good pictures.

I also tested some shots in public places like a metro and I could get "motion-stopped" shots at ISO 1250 with the FZ8. Of course with that camera at this setting, the quality of the picture degrade quickly but if I can get good pictures with a DSLR at ISO 1600 that would compare with what a compact could take at ISO 200, I would be happy. But maybe a bounced flash is a better answer?

Now coming back to my DSLR options... obviously I'm still confused. Oly, Pentax or Sony?
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Old Aug 21, 2007, 9:43 AM   #16
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Delius wrote:
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Now coming back to my DSLR options... obviously I'm still confused. Oly, Pentax or Sony?
You should be able to get any of them with a good flash OR a good lens, and stay within your budget. If you want to get a good flash AND a good lens, and stay within your budget, I think your selection is narrowed down to the Pentax. The K100D is an especially good value right now, so, for TCO, it's the clear winner.
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Old Aug 21, 2007, 10:52 AM   #17
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Delius,

The flash solution only refers to indoor types of shots with the kids. Just snaps of them playing in the living room or at a birthday party. High ISO isn't going to cut it there. It isn't enough.

Here's a thread where I discussed some of the features that are useful/important for taking shots of family. Scroll down till you start seeing the pictures I posted. The birthday party shots - just like shots of kids playing are not going to be possible AT ALL without a good amount of light. So, if they're in the evening - no house I've been in has that much light. If it's daytime the only time you'd have enough light is if you've got a large amount of windows facing the sun. To further illustrate the point, i included photos of my son's first steps. Those were taken at ISO 6400 (not 1600, but 6400) and 2.8. The 2.8 meant I had very shallow DOF (look at the blur in the background). You don't always want that shallow depth of field - and you certainly don't want to be using ISO 3200 / 6400 unless you have to. So for indoor pics of the family - a good flash is much more useful for non-portrait style shots. And what I'm saying is for many types of shots (think more than one person in the frame), flash is the ONLY solution that will work. And the on-board flash on any camera (DSLR or otherwise) really sucks compared to what an external flash gives you.

http://forums.steves-digicams.com/fo...mp;forum_id=87
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Old Aug 22, 2007, 12:17 AM   #18
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A couple of things - a flash is important to stop action in low light.

Your question about AF speed and accuracy got me curious, so I spent my lunch hour wandering around my favorite library, taking no-flash pictures at ISO 1600, and one at ISO 3200. Since I now have an AF 2.8 lens, I put the DA*50-135 on the K100 to see how fast and accurate it is. I chose to use the center focus point only, so I couldn't blame the camera for not choosing the right subject.

I hope you don't mind - I'm certainly no pro! But I thought they might be of interest to give you an idea of what an ordinary person taking snaps might get using ISO 1600, so you can compare it with what you could get. For some additional background, my computer is in the shop getting fixed, so I'm using an old laptop that won't run Lightroom or Photoshop CS2, and I took these pictures in raw format. I converted them using the Pentax PhotoLab software that comes with the camera (not even the latest version of it, either!) and resized the pictures in Photoshop 6, the latest version I have that will run (slowly)on this computer.

First picture - to give you an idea about the lighting conditions in the room. Taken with the K10, 1600 ISO, a manual 24mm 2.8 lens at 2.8 and 1/800 sec shutter speed. Composition is terrible but I didn't want to crop out the overstuffed chairs so you could see it full frame, just resized (well, slightly rotated - I couldn't get the lines straight without doing more Photoshop work than this picture is worth). The noise isn't very noticeable when you reduce the size downward.



This next one is the full frame picture of the ceiling, taken with the K100, ISO 1600,50mm, f3.5, 1/90. I thinkI had the camera in "P" mode and that's what it chose for aperture/shutter speed.



This is the same picture, just croppedwithout resizing.The noise isn't all that much to me, andthe picture quite useable.



This next picture is the onescene where the camera had difficulty locking focus. As soonas I moved the focus point to the edge of thebannister support, it locked on right away. I also had to play a bit with the white balance on this one, and I'm not sure it's totally right. This one isfull frame, taken with theK100ISO 1600, 50mm, 2.8, 1/20 sec.:



This second one is the samestaircase, taken with the K10 and the 24mm lens, 1600 ISO, 2.8, 1/25 sec. The white balance is more accurate on this one. The full frame version:



Andcropped so there is no resizing at all - you'll notice that the noise is more noticeablewith this camera (K10) than the K100, and you can see that the extra megapixels do come in handy when you crop:



Final set of 3 photos. I hope I haven't totally bored you withthis bunch ofordinary snaps.This tile picture is in a very dark spot, and I've always tried to take it at slower ISOs without success (shutter speedtoo slow). This first picture wastaken with the K100 at ISO 3200- it's not so bad when resized down to this size. Full frame version, 50mm 2.8, 1/45 sec.



Crop of the above picture - it does look pretty rough to me.



This is another crop with no resizing, taken by the same camera/lens combination at 1600 ISO.



These aren't trying to show how great the K100 is compared to any of the other dSLR cameras (by the way, I think I read where the K100 and the Nikon D40/D50 use the same sensor). The various manufacturers all tweek their software in different ways so there's differences, but I don't think they are all that huge. What I AM trying to show is what a dSLR (really any dSLR)is capable of at higher ISOs, so you can compare them toyour particularPanny FZ8 ). It also gives you an idea of the differences between the 10 mp sensor in the K10(and Sony?)vs. the 6 mp one in the K100 (and D40?).

Finally, I want to thank you for giving me an excuse to go to an oldbuilding I find fascinating, and use my new lens, which is a joy to use.
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Old Aug 22, 2007, 9:22 AM   #19
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It was late last night when I posted the above examples, and I forgot to make my second point. Look at the shutter speeds I used - they are all slow shutter speeds even though I was using f2.8 and ISO 1600, which shows that the need for a good flash, properly used, with fast moving children indoorsis really a huge factor toward getting good pictures. Mine were all ambient light, and hand-held (yes, SR does make a difference with longer shutter speeds).
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Old Aug 22, 2007, 10:54 AM   #20
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Many thanks, mtngal-

You lunchtime field trip was very well done. Thanks for your excellent photo samples.

Sarah Joyce
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