Tech blog

This blog is for my future and past info and reviews on various tech stuff….


Phones / Phablets
Cameras
Compact cameras
Various tech
Various tech stuff
Reviews
Reviews
Resolution...
Resolution and Noise
 
Battery
Batteries and usage
PC
PC
Code
Code examples
TwoPlusTwo
Math
Other stuff
Other stuff

Newer reviews can be expected to be ongoing projects, with minor additions or corrections.

Note: When I rate stuff, a 10/10 does not indicate perfect in an absolute academic sense, but as in (at least) as good as could be expected at the time, minor flaws allowed. For portable devices typically limited by the size and weight. Value for money also counts. An electronic device that got a high score in 2005, most likely would seem like pure trash ten years later….


 

  • Superzoom and DOF plus TZ70 iZoom

    It should be remembered that there are no miracles in superzoom!

    And you should be careful on where your focus plane is, even if all in the frame to the human looks as ‘far away’.

    Crop of 30x zoom:
    P1020262_Crop

    (As usual, click to enlarge)

     

    Continue reading...

     

  • Panasonic TZ70 vs FujiFilm F900EXR in lo light

    A compare of the low light abilities of these two cameras in extreme lo light conditions.
    1426237696653[1] versus                   F900EXR_Black_Front_Left_76975fa68b[1]

    Reviews available here: TZ70 and F900EXR

    Continue reading...

     

  • Megapixel-craze and tiny sensors & lenses. Myths & Facts

    This is an attempt to replace some of the common myths, urban legends and misunderstandings with some facts.
    (last updated 20181103)

    There are at least three physical issues and one biological that are interesting:

    1) Rayleigh’s criterion and sensor width.

    F * √N < W , (N number of sensors in Mpixels, W in mm, red light F numerical aperture)

    AR-principles[1] Airy_disk_spacing_near_Rayleigh_criterion[1]

    2) The eye’s real life resolution

    Resolution beyond 1/12000 of viewing distance is pointless for most

    3) Thermal noise.

    Relative noise increases by 1/d, (+)almost √n and √T, (N number of sensors in Mpixels, d sensor diameter, T in kelvin, i.e. °C+273.15)

    4) Effective pixel count

    The effective pixel count falls with the amount of light, the less the pixel size the worse.

    5) Stacking images

    Stacking can compensate, but can not perform miracles.

     

    6) Thickness of device versus sensor size

    The angle of light to the sensor edges binds max sensor size to thickness.

    Continue reading...

     

  • Panasonic TZ70, Review

    Panasonic Lumix TZ70 (ZS50 in the US)

    Upgrade of TZ60 with larger/fewer pixels, RAW and better viewfinder, but removed GPS.

    This post is likely to be enhanced/edited over the next days and weeks

    Eske Rahn 2015-04-25

    Overall: Really satisfied. 10/10

    1426237696653[1] 1420186774799
    The only real competition today is the upcoming HX90V from Sony, that haven’t got RAW, and have pixels as small as the TZ60

    Overview

    The TZ60 took much beating due to the small pixels, And Panasonic answered that by increasing the pixelsize by a factor 150%, and thus reducing the pixelcount by the same to 12MP.
    This is an obvious upgrade from Fujifilm F900EXR, that are beaten or on par in all areas, less triffles.
    See my review of the F900EXR here. On which this review to some extend will be based.
    Practically the whole plus-list could be repeated, and most of the cons are not there!!

    Continue reading...

     

  • Automower 230ACX, Husqvarna, Review

    I can HIGHLY recommend this Automower 230ACX, as it have exceeded my expectations.

    Overall: Really satisfied. 9+/10

     

    7f4781b0[1]

    It has handled my highly sloped 1000m² lawn for seven full seasons, with some minor repairs outside the warranty along the way.

    Continue reading...

     

 

Newer postings are in English (well sort of, bare with me, non-native…), some earlier than 2010 just blunt copies of the texts in Danish.

Collecting of old stuff started May 2015. Entries are generally attempted dated with original stamps, even if they are somewhat updated since, several reviews have been ongoing ‘projects’.