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Old Dec 30, 2007, 6:01 PM   #1
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I've just read on an online manual about the Extended Optical Zoom. I fully understand and appreciate this is NOT Digital Zoom. I can't however understand how 18x optical can become 28x optical - it seems to me though it is just reducing the pixels.

Am I missing something, can someone explain it better to me - or even better can someone post a picture under same conditions, distance etc. showing how this looks? I'm sure this is a trick of some kind, otherwise it would be used for marketing as more effective than a converter?

Food for thought.....

PS I have ordered the camera, just waiting for it to arrive and following the reviews/forums.

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Old Dec 30, 2007, 8:58 PM   #2
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By reducing the effective size of the sensor, focal length is increased. I was sceptical too, but I now keep my FZ30 on the 5MP setting much of the time. I'm getting some great results, much better than digital zoom or cropping.

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Old Dec 30, 2007, 9:01 PM   #3
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Ok, extended optical zoom is the same as you cropping in post production.

Take a photo.

Print it 4x6

Take the same shot, crop down to the centre, you will be throwing away all the pixels on the outside, but never mind.

Print the resulting crop at 4x6

It looks like you got a lot closer...

Congratulations, you have zoomed into the picture by cropping it.

Normal digital zoom, crops the centre as above, but then blows it back up the the full number of pixels, by "inventing" false pixels, ie it guesses what pixels it needs to fill in the blanks.

Safety or extended zoom, crops the pixels but does not uprez the result ie no false pixels are added, so while the photo may only be 640x480 (or whatever) it is at least real.




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Old Dec 30, 2007, 9:28 PM   #4
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There are other factors at play, AF seems to be more precise at long distances using the EZ. I seldom shoot anything but small subjects at a distance, I'm pleased with the results.
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Old Dec 31, 2007, 2:31 AM   #5
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I shot a few "closeups" yesterday for the first time at the 3:2 aspect ratio and 2.5MP, which gave an effective magnification of up to 28.7X. It was possible to still hold steady, because the lenswas still at 504 equivalent (13X); only the image was cropped in camera. You could do the same thing by cropping from the whole image in post processing, but I noticed the lens (or chip) "sees" the "enlarged" image and adjusts exposure accordingly (a light flower blown out against the darker background in the"wider" image became properly exposed when "zoomed in" and filling the frame);I couldalso better judge DOF and touch up focus if necessarily. I wish my DSLRs could do this - it looks like it is a great feature, and a necessary one with the small EVF on this camera.
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Old Dec 31, 2007, 3:55 AM   #6
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I've had problems locking focus on very small birds, the camera couldn't pull them out of the BG. EZ is a big help with this. As I said, I was sceptical but I'm getting over it!:-)
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Old Dec 31, 2007, 9:12 AM   #7
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I use the extended zoom option with myFZ8 and it works great. The FZ8 extends to 648mm at the 3 MP setting, which can easily be printed to a first-classletter size print if prints are the primary goal....for me, prints typicallyare not. That's the main limitation of going to the maximumextended optical zoom setting...resolution, unless you're in to up-sizing images, which I am not.

Here are a couple extended opticalzoom shots I've done, this first oneat the 3 MP,648mm setting of the FZ8. You can click oneither to get to the image on my website and download the full-sizedfile if you want to give it a look..



This was shot at the 5MP size, which is a 35mm equivalent of 518mm..



A convertercan still be a good thing to get, especially if you want to print big and/or retain the full resolution your camera gives, but I'm more of a wide converter lens user. For the sometimes need of a longer focal length, extended opticalzoom is an excellent alternative....and it really does work well today with these higher pixel count cameras. Back in the day of the maximum4 megapixel camera, this wouldn't have been as exciting...a 1 MP extended zoom setting wouldn'tbe a good option!



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Old Dec 31, 2007, 5:34 PM   #8
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:?This is where I lose the plot somewhat.

Is it then correct to say it is not an extended zoom at all but some mathematical jiggery pokery? It is similar to the digital zoom in that it magnifies a (central) portion of the shot?

Or as suggested, it is a "ready made" crop to save doing it post production with the added bonus of being an optical crop as opposed to digital one?

It is something I hadn't heard of until very recently. Certainly a new term to me. Does anyone have any side-by-side shots for comparison? - to someone who will use the camera primarily for capturing small birds at distance. Ideal for using the technology/facility.

One further question - is the "in-camera" crop better, or of better quality than a post-production one. I accept both are better than digital zoom.

Thanks

Steve


PS Tsiya - loved the shots of the Florida Blue Jay - a bird I believe is the state bird of Florida but which sadly remained hidden from me during my June visit this year.
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Old Dec 31, 2007, 6:01 PM   #9
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Quacker wrote:
Quote:
:?This is where I lose the plot somewhat.

Is it then correct to say it is not an extended zoom at all but some mathematical jiggery pokery? It is similar to the digital zoom in that it magnifies a (central) portion of the shot?

Or as suggested, it is a "ready made" crop to save doing it post production with the added bonus of being an optical crop as opposed to digital one?

It is something I hadn't heard of until very recently. Certainly a new term to me. Does anyone have any side-by-side shots for comparison? - to someone who will use the camera primarily for capturing small birds at distance. Ideal for using the technology/facility.

Thanks

Steve
Quote:
How about, "I'm not smart enough to know how it works, but it works".
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I take a lot of pics, don't even walk to the mail box without a camera, I'm not a scientist, I just want to take pictures. I've messed with digital zoom, cheap TC lenses, and all that crap,but the FZ30 is something else. Better yet, my old OLY A-200 lens acts like it was made for the FZ30.
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No, I don't get DSLR results, if you want to get scientific, but, I can take pics of little tiny birds a long way off, without a $4000.00 lens!
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Old Dec 31, 2007, 6:35 PM   #10
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Quacker wrote:
Quote:
:?This is where I lose the plot somewhat.

Is it then correct to say it is not an extended zoom at all but some mathematical jiggery pokery? It is similar to the digital zoom in that it magnifies a (central) portion of the shot?
Quote:
Extended optical zoom is real. Digital zoom is mathematical jiggery pokery.Extended optical zoomsimply uses a smaller and smaller central area of the sensor...it does notmagnify anything, and there are real advantagesto capturingan image usingit vs. just cropping later on the computer. See below.

Or as suggested, it is a "ready made" crop to save doing it post production with the added bonus of being an optical crop as opposed to digital one?
Quote:
You can look at it that way, but again, see below...

It is something I hadn't heard of until very recently. Certainly a new term to me. Does anyone have any side-by-side shots for comparison? - to someone who will use the camera primarily for capturing small birds at distance. Ideal for using the technology/facility.
Quote:
Go read some posts and ask this question on the Panasonic forum over at DPReview. There are several serious bird shooters who use the extended optical zoom of the FZ50 all the time. I'm no bird shooter. I've actually only used this feature a handful of times and never withmy FZ50... only my FZ8, but I definitely see the advantages of it for those who do use it a lot in their bird shooting, such as these guys as just three examples...
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I think you'll catch the sarcasm in the subject line of this nextpostwhen you see the images...
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Take a look at this next post and read down to where the author talks about how he used both a tele converter AND theextended optical zoom atthe SAME TIME to get these shots...
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One further question - is the "in-camera" crop better, or of better quality than a post-production one. I accept both are better than digital zoom.
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When you use optical zoom, you not only are using a smaller section of sensorto capturethe image, but you are also limiting the part of the sensorusedto meter the scene, which can result in a much more accurate meterreading for the actual image being recorded than just going back later and cropping on the computer. Why extend metering to an unused area that won't be included in the finalfile if you can use extended optical zoom and just meter the actual scene?
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