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Samsung Galaxy K Zoom review for S4 Zoom users

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One Twelve
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(Last edited by One Twelve; 13th September 2014 at 06:18 PM.)
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Originally Posted by genus View Post
Very detailed analyzing
Hopefully it gives an idea when you can get away without tripod.

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Originally Posted by genus View Post
My part is testing on portrait photography.. at which focal length is the best for taking portrait with Kzoom.
yes am interested in portraits too. the general range is 96 - 132mm this is 4.0 - 5.5x magnfication.

Best part of the zoom lens is in the middle of the focal length so 4.7 or 5.1x (20.7 - 22.4mm) or in 35mm speak (112 - 122mm)

Now, that is the theory and don't know whether k zoom gives more range here or not. Did not test this out yet.

If you noticed, Olaf on the k zoom flickr group put up some nice portraits of his kids.

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Originally Posted by genus View Post
At wide open, equivalent 24mm, it is good for landscape shot, but not for portrait, due to len distortion, it only good if you want to take full body photo + scene background, or..special wide angle effect, eg: long leg.
Heh, yeah this is why you can't do portraits with fixed focal length smartphones, they are all around the 23-35mm range. Digital zoom cannot really fix this.

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Originally Posted by genus View Post
I tested at 2.1x zoom, ~50mm, it is very good, without any distortion, and the subject vs background distance are almost as what we see naked eye.
At 2.8x zoom / 4.0x zoom, ~70mm / 85mm, good too, no distortion, but the background perspektive was change from 50mm, which is good if you want to eliminate background subject.
at 10x zoom, 240mm, not so recommend, the portrait become flat, but if you like, it is good too.
I have not figured out optimal distance of the subject to focal length yet.

half body head shot at 4x you are 2 meteres away.

Thing with portraits is you have to pick your background carefully otherwise it will interfere with the subject.

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Originally Posted by genus View Post
The only thing left for Kzoom is small sensor & limited aperture size (not large enough), small sensor give large crop factor effect (compare to APS-C / full frame sensor), small aperture give not enough DOF effect for portrait.
Yes there is too much DOF.

K-zoom's lens characteristics are different to what the usual calculators give for lens of a given focal length. Need to find one that takes crop factor into account.

eg. at 10x a lens of focal length of 44mm with aperture F6,3 should give DOF of 4cm if subject is 1 meter away. But when i did a little test DOF was like 3 metres behind subject.

and then you can close the f-stop all the way down to F18.4 at 10x and increase DOF further by 3x (!)

The aperture i wish could go larger than 3.1 as it would make isolation easier. Would crop factor (5.6x for k zoom) negate this if they make a 2.8 lens ?

But it increases as focal length like any cheap zoom. And that maybe is the thing here, to keep apertures large i don't know if its possible to do in such a small form factor or it will increase the cost a lot due to optics.
 
Xdenwarrior
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Quote:
Originally Posted by One Twelve View Post
Hopefully it gives an idea when you can get away without tripod.


yes am interested in portraits too. the general range is 96 - 132mm this is 4.0 - 5.5x magnfication.

Best part of the zoom lens is in the middle of the focal length so 4.7 or 5.1x (20.7 - 22.4mm) or in 35mm speak (112 - 122mm)

Now, that is the theory and don't know whether k zoom gives more range here or not. Did not test this out yet.

If you noticed, Olaf on the k zoom flickr group put up some nice portraits of his kids.


Heh, yeah this is why you can't do portraits with fixed focal length smartphones, they are all around the 23-35mm range. Digital zoom cannot really fix this.


I have not figured out optimal distance of the subject to focal length yet.

half body head shot at 4x you are 2 meteres away.

Thing with portraits is you have to pick your background carefully otherwise it will interfere with the subject.


Yes there is too much DOF.

K-zoom's lens characteristics are different to what the usual calculators give for lens of a given focal length. Need to find one that takes crop factor into account.

eg. at 10x a lens of focal length of 44mm with aperture F6,3 should give DOF of 4cm if subject is 1 meter away. But when i did a little test DOF was like 3 metres behind subject.

and then you can close the f-stop all the way down to F18.4 at 10x and increase DOF further by 3x (!)

The aperture i wish could go larger than 3.1 as it would make isolation easier. Would crop factor (5.6x for k zoom) negate this if they make a 2.8 lens ?

But it increases as focal length like any cheap zoom. And that maybe is the thing here, to keep apertures large i don't know if its possible to do in such a small form factor or it will increase the cost a lot due to optics.
Well there is a panasonic phone with a larger sensor http://www.panasonic.com/de/corporat...a-DMC-CM1.html but it got no optical zoom or xenon flash, fixed 28mm and kinda bulkier since it doesnt have the curvature shape of the k zoom. Its also double the price and not out yet. So not really a competitor to k zoom series. (would be nice to have 1 inch sensor with 10x optical zoom in 2cm thickness but k zoom 2 will never have that).
But maybe it will encourage microsoft to launch a 1020 successor.
 
genus
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Originally Posted by Xdenwarrior View Post
Well there is a panasonic phone with a larger sensor http://www.panasonic.com/de/corporat...a-DMC-CM1.html but it got no optical zoom or xenon flash, fixed 28mm and kinda bulkier since it doesnt have the curvature shape of the k zoom. Its also double the price and not out yet. So not really a competitor to k zoom series. (would be nice to have 1 inch sensor with 10x optical zoom in 2cm thickness but k zoom 2 will never have that).
But maybe it will encourage microsoft to launch a 1020 successor.
Panasonic Lumix Smart Camera - wihtout OIS, Xenon flash, fixed focal length at 28mm
But it have large sensor 1", variable aperture setting, M/P/A mode are very nice step if Lumix have 5x optical zoom + OIS, this will be best.

From my point of view, I still prefer Kzoom, as optical zoom help me take a lot of great photo using the advantage of the focal length from 24 -240mm, and the help of OIS


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