Friday, January 15, 2010
Olympus Stylus Tough-8000 12 MP Digital Camera with 3.6x Wide Angle Optical Dual Image Stabilized Zoom and 2.7-Inch LCD (Silver)
Posted by s7013297 at 8:45 AM
Wednesday, December 23, 2009
Polk Audio RM6750 5.1 Channel Home Theater Speaker System (Set of Six, Black)
- Six piece surround sound package that includes 2 front and 2 surround speakers, 1 center-channel speaker, and 1 subwoofer
- Satellite and center-channel speakers utilize 3.25-inch polymer-composite cone drivers for distortion-free midrange
- Features 0.5-inch dome tweeter in each satellite speakers and 0.75-inch dome tweeter in center-channel speaker
- Subwoofer utilizes an eight-inch long-throw dynamic-balance poly-composite driver for longer driver excursion and better linearity
- Satellite and center-channel speakers can accommodate 6.1 or 7.1 channel systems
Tuesday, December 22, 2009
Panasonic Lumix DMC-ZS3 10MP Digital Camera with 12x Wide Angle MEGA Optical Image Stabilized Zoom and 3 inch LCD (Blue
|Panasonic Lumix DMC-ZS3 10MP Digital Camera with 12x Wide Angle MEGA Optical Image Stabilized Zoom and 3 inch LCD (Blue)|
- 10.1-megapixel resolution captures enough detail for poster-size prints
- 12x MEGA optical image-stablilized zoom; 25mm ultra-wide-angle lens
- Capture HD video in "AVCHD Lite" format
- Intelligent Auto (iA) mode; Face Recognition feature
- Capture images to SD/SDHC memory cards (not included)
Product DescriptionThe ZS3 records HD motion images at a smooth 60 frames per second with 1280x720-pixel resolution. It uses the AVCHD (MPEG-4/H.264) format via AVCHD Lite, which stores less data than other formats and thus lets you shoot more minutes of HD motion images before running out of memory.The ZS3 is equipped with an HDMI output terminal for direct transmission of digital picture and sound signals. Just connect the camera to an HDTV using a single HDMI mini cable (purchased separately), and it's easy to view beautiful HD photos and motion images. If you have a VIERA HDTV, you can control the camera's playback functions with VIERA's remote control unit.The ZS3 packs a LEICA DC VARIO-ELMAR lens with 12x optical zoom into a compact body. This versatile photographic tool lets you shoot everything from sweeping vistas at the 25mm wide-angle setting to dynamic 300mm telephoto shots. And the lens system's exquisite rendering ability lets you capture even the subtle nuances of the sights and scenes in your travels.
By Jeff Huang (Jersey City, NJ)
I previously owned a Canon SX200i and I was not fully satisfied with it, and after I read all these great reviews about the Panasonic ZS3 I decided to give it a shot. First of all the ZS3 has advantages on portability, and its ability to zoom while recording video. But that's about it! Images are blurry when you zoom in to take shots; the video is more like SD quality, other than HD 720P; pictures are very grainy and noisy in night shootings. In my view the Canon SX200i delivers better image and video quality; it doesn't get as much noise as the ZS3. Manual setting can sometimes help to minimize the noise or lighting issues but the ZS3 just can't do it. It is your call to decide which is a better camera but I am going back to my Canon.
By faffie (aptos, ca USA)
I purchased a previous model of this camera, the DMC-TZ5K and returned it because the audio was so poor in movie mode and the low light performance was sub-par. (Amazon handled the return no problem.) The audio on the ZS3 is awesome and the low-light performance is improved. I have been researching compact point and shoot cameras for a while now and eagerly awaited the arrival of this model. Purists insist that video cameras are the only way to shoot decent video, but I find that hybrid P&S cameras are less intimidating to subjects so people tend to behave more naturally than when I whip out a dedicated videocam. Plus, it is easy to carry. I compile a lot of movies on my Mac for east coast friends and family to commemorate their visits to our California home and the ZS3 is easy to work with. I can shoot (and archive) in AVCHD lite mode and Imovie 09 (Mac) can import the video directly from the memory card, although it has to convert the footage to a different format it can edit. The camera also shoots in JPEG mode for those whose editing software can't process AVCHD lite. I was very happy with the quality of video I shot with my Sony subcompact, but the proprietary Sony memory card and incompatibility with Mac software without converting the footage on my PC (to retain the audio) were deal killers when it came to upgrading the Sony with an HD video model. The camera has a lot more features than I even care to understand, but I like the fact that you can switch to video mode with the touch of an easily accessible button. MY MAIN COMPLAINT about the ZS3 is that it takes a few seconds for the movie mode to engage after pressing the record button, and I have had to learn to wait for the indicator on the LCD screen to tell me I am in record mode before shooting. When I reviewed my footage the first few times I realized I hadn't been recording sometimes when I thought I was and was sometimes recording when I thought I wasn't. Very frustrating. The camera should be quicker to respond when switching modes. The Lumix also has proprietary batteries, which is expensive. I gave up trying to order an AC adaptor, since I couldn't find a vendor, including Panasonic's own website, where I could buy the expensive 2 piece (sold separately) adaptor. Fortunately, since my Mac was able to read the memory card directly through IMovie 09 (NOT IMovie HD) I didn't have to worry about burning up battery power uploading the video from the camera itself. The battery life is decent BUT BE VERY CAREFUL WHEN ORDERING EXTRA BATTERIES. I ordered the wrong ones from Amazon the first time, because the description of what Panasonic cameras these NON-COMPATIBLE Panasonic batteries (DMW-BCF10) fit was misleading in the description. I returned these two I ordered directly from Amazon with no problem, but had to get the correct ones from another vendor (but through Amazon) and pay a little shipping (I am a Prime member). Unlike many of the reviewers I did get the correct battery the second time , but that company, inspiretech, does not seem to be selling these batteries through Amazon now. The CORRECT BATTERY, the DMW-BCG10PP, is now listed as available through Amazon by Vortex Cable. Presumably Amazon switched vendors for better reliability. Way to be responsive, Amazon!
Pros: Picture/video quality, audio quality, uses standard SD/SDHC memory cards, compatibility/ease of use with Mac, size, 12X zoom, size, decent battery life, two modes to shoot HD video, wide-angle Leica lens, facial recognition, image stabilization
Cons: Slow to switch from picture to movie mode, some accessories hard to find, proprietary battery
By Luca P.C.P. (Mountain View, CA)
I ordered this camera due to its ability to zoom while making movies, and due to the very positive reviews I read on the web. However, I was rather disappointed by the poor picture quality, and I decided to return it.
We have older Canon cameras, such as an A620 and an A720, as well as a Panasonix LX3. Compared to those cameras, the picture quality of the ZS3 leaves much to be desired. Even at ISO 80, the strong noise reduction smears the fine detail, while leaving behind visible artifacts. This was very noticeable, for instance, on the shaded portions of people faces. There is little texture left in the skin, and yet, the noise reduction leaves behind artifacts that look like a mix of sparse grain, and pockmarks.
The results were very much a negative suprise. The sensor of the ZS3 is the same size as the sensor of the Canon A720, and the A720 being two years or so older, we expected the ZS3 to be at least as good, if not better. The converse is true: the A720 gives very good quality photos at base ISO, and up to ISO 200, while the ZS3 even at base ISO produces poor results.
It was very surprising to us that this camera, which received such good reviews, would be so disappointing.
We are somewhat experienced photographers, and we own several cameras, from the afore-mentioned Canon A620, A720 and Panasonic LX3, to various DSLRs.
By Brian Gottschalk
I purchased this camera as an upgrade to my aging Canon A520 camera. 2 things that were prompting me to upgrade - pictures taken of my daughter's basketball games in the dimly lit gym were not very good (either too dark and grainy or a streak of blur instead of a clear action shot). Second was video capabilities - the Canon just took 30 sec. max of small grainy video.
I got this camera a week ago and have to say I am very impressed with it! For issue #1, I took it to my daughter's ball game on Saturday and tried it out. The pictures were definately an improvement. I will say that this scenario is very difficult for any point and shoot (low light - fast action - needing to zoom to get a close enough shot - not a good combo for a small lens). So, I wasn't expecting miracles, just an improvement over the Canon and that is exactly what I got. The pictures were brighter and sharper - very usable. There was still some blur in extreme situations - shooting the basketball. There just isn't enough light to completely stop the action. And if you look closely at the brighter shots, they are a little grainy due to higher ISO settings. But, unless you blow the picture way up, you don't see it at all and it is still a huge improvement over the aging Canon.
The part that I didn't expect was issue number 2. I expected longer recording times and better video quality. But what I got was nothing short of absolutely stunning video. I took video of my daughter's choir concert. The stage is well lit with spotlights and I expected good video. What I got was razer sharp wide screen video that looks so good on my 50" 1080p Plasma (Panasonic - so I can play the AVCHD video right from the card) it was hard to believe. Next I tried the basketball game - much less light. Again the video was nothing short of amazing. The picture looked just as good as it did with the well lit stage. Absolutely no noise or grain - just bright, colorful, beautiful video. I even compared it to my older Canon true camcorder (digital, but not HD) and the picture is better by far in bright light. In dim light, it is even more pronounced - the camcorder has a washed out grainy look - the ZS3 looks stunning. I always hated finding a tape with room, getting it to the right spot, charging the battery and lugging the camcorder along with a normal camera. Now, I don't have to and I can still get stunning video. Condition 2 met wonderfully.
I haven't tried all the features and modes yet, but with the auto mode working so well, I probably won't use them much. A few thoughts:
- The mode wheel isn't super stiff like on the Canon, but it's tight enough that it doesn't move on its own.
- The battery lasted for about 45 min. of video, about 30 flash pictures and a whole lot of playing around with menus, settings, etc. It charged in just under 2 hours.
- If you look around you can find a couple batteries that do work with firmware 1.2. I ordered on from Amazon for $25 that should arrive soon. The two hour charge time compared to my old 15 min. AA charger has me wanting the second battery for backup.
- The AVCHD plays wonderfully (no additional software) on my Windows 7 Core2 Quad machine. I had to install the included software and it still plays a little jerky on my Core2 Duo laptop. So I'm thinking you may need a decent machine to play the native video. However, I believe the included software can convert it to a less demanding format (with probably some quality loss) - I haven't tried it.
- The zooming works well in video mode - it is plenty fast and while I did notice an occassional tiny amount of refocusing during the ball game while zooming, it was very slight and nothing more than my old camcorder did - especially in the low light.
- It appears to be very solidly built. I haven't dropped it - yet, but even the controls and doors are hinged and solidly built - unlike the rubber covers on my Canon.
- The record button for video is a little awkwardly placed - I have to hunt to find it to stop recording and I think I will probably end up hitting it accidentally a few times when I don't mean to.
For now, I am very happy with the still picture quality (understanding the limits of a compact point and shoot) and am totally amazed by the AVCHD video quality. I can see I'll be purchasing a 1 TB drive soon to house all the video I'll be taking now that it is much more convenient than my dedicated camcorder.
Edit - Since my last review I have used the camera a little more and have a couple minor complaints:
- The video I just took using the AI mode was a little overexposed - a band concert on a spotlit stage. Same stage as the Choir concert so I'm a little surprised by the different results. There is probably a better setting to have used, but I didn't try. That leads to one of my minor gripes. Because you can't see what the video mode will look like until you press the button and start recording, it's kind of hard to tell if you need a different mode. It would be nice to be able to preview (and see how much time is left) before starting the video recording. If there is a way to do that I haven't found it yet.
- I still don't find the zoom too slow in video recording (like some other reviewers), but I did find it a little touchy. It was a little difficult to get just the zoom I wanted. I found myself zooming in and out too much trying to get just right framing. Might just be a getting used to it thing.
These are minor quibbles and don't do anything to reduce my love of the camera. Just something to be aware of...
By Photo-Am (Brooklyn, NY USA)
I purchased my Panasonic ZS3 about a month ago. It is a really great camera. Everything good what I've read about it before is true. And even better - it seems I've got an updated version because on my instance the mode dial is not as loose as it was complained by many earlier reviewers but is accuratly fixed in each distinct position.
The real wonder is the AVCHD-codec. It's a miracle - there is almost no noise on the video clips taken in the low light conditions. If you switch to MPEG mode you will see as the same decent level on noise as on other good P&S cameras with HD movie feature, but Panasonic's AVCHD-codec does something really incredible - almost no noise at all. On the other hand I did not see any noticable compression artifacts which could appear as a result of a stronger compression (if any). Just a nice clear picture with no sacrifice.
When I compare the quality of the video-clips taken by ZS3 on a sunny day with the ones taken by my other Panasonic camera ZR1 they look pretty similar. But shooting in the low light reveals the difference - while ZR1 shows pretty much noise with it's MPEG coding in HD mode, ZS3 shines with its almost noiseless quality provided by AVCHD codec. I'm only wondering if that great noise reduction is an idependent algorithm added to AVCHD-codec or it's an inner quality of the AVCHD compression algorithm itself. Anyway the result is very good.
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Friday, December 4, 2009
กฎของโอห์ม (Ohm's law) เป็นสมการที่อธิบายความสัมพันธ์ระหว่างความต่างศักย์, กระแสไฟฟ้า และความต้านทานของวัตถุต่างๆ มีอยู่ว่า
เมื่อ V คือความต่างศักย์ในวัตถุ ในหน่วยโวลต์, I คือกระแสไฟฟ้าที่ไหลผ่านวัตถุ ในหน่วยแอมแปร์ และ R คือความต้านทานในหน่วยโอห์ม
ดังนั้นความต่างศักย์ทั้งหมดจึงเ ท่ากับผลรวมของความต่างศักย์ เราจึงหาความต้านทานได้เท่ากับ
ตัวต้านทานที่ต่อแบบขนาน จะมีความต่างศักย์เท่ากันทุกตัว เราจึงหาความต้านทานที่สมมูล (Req) เสมือนว่ามีตัวต้านทานเพียงตัวเดียว ได้ดังนี้
Posted by s7013297 at 4:16 AM