khunpapa

khunpapa

Lives in Thailand Bangkok, Thailand
Works as a Human Repair
Joined on Sep 23, 2011

Comments

Total: 9, showing: 1 – 9
In reply to:

davev8: why is this lens so big and heavy....at 70mm by 70mm with a 62mm filter thread and 330g the canon FF equiv is the 24 F2.8 is ,at just over 68mm x 55mm and a 58mm filter thread and 280g ..the Nikon FF 24mm F2.8 AF D is 46mm x 55.5mm a 52mm filter thread and 267g

Today is June 2016, not 2006. WHY does some twisted knowledge still èxist?
Equivalent is equivalent. NO MORE THAN THAT.

Light gathering ability at f/1.4 is f/1.4, NOT f/2.8.

Only the DoF at the "equal image size" is equivalent comparable.

Link | Posted on Jun 26, 2016 at 00:16 UTC
On article Beta: try out our new 'light' color scheme (722 comments in total)

Finally, someone wake up, know that the paper is white, and realize that life should not mean to be absoluely staying in the dark.

Link | Posted on Apr 28, 2016 at 04:21 UTC as 153rd comment
On article Panasonic confirms Lumix G 25mm F1.7 (206 comments in total)
In reply to:

happypoppeye: Would probably still buy the 25 f/1.4.

Already have the 1.4. But still itching of getting this one after tried the 42.5/1.7 for 5,000+ shots.

25/1.4 is large and heavy <grin>.

Link | Posted on Sep 7, 2015 at 06:34 UTC
On article Panasonic confirms Lumix G 25mm F1.7 (206 comments in total)
In reply to:

Abu Mahendra: A 50mm f/3.4 eq. lens. Joy. How exciting...

Oh crap! this is 2015 year. Why some T.rex still exists and shows carboniferous math skill.

Link | Posted on Sep 7, 2015 at 06:31 UTC
On article Panasonic confirms Lumix G 25mm F1.7 (206 comments in total)
In reply to:

Abu Mahendra: I agree this whole thing is quite silly. A Canon 50/1.8 will set you back $125. You've made your bed. Now lie in it.

Hmm, seem like toddler who just knows toys wanna express its knowledge as adult does too.

Link | Posted on Sep 7, 2015 at 06:29 UTC
On article #1 in France: Hands-on with DxO ONE (278 comments in total)

Hope the phone has enough juice left when I badly want to use it as the MOBILE PHONE.

Oh, you talk about spare batteries? OMG .. now the combination is as large and heavy as the old dSLR.

Link | Posted on Jun 28, 2015 at 17:24 UTC as 61st comment | 1 reply
In reply to:

Lensjoy: The human eye is most sensitive to green. When calculating luminance (Y) from the respective RGB values for gamma 2.2, the formula is:
Y = 0.2126*R^2.2 + 0.7152*G^2.2 + 0.0724*B^2.2
Blue is only 7 percent of perceived luminance! So if I were to design a sensor doing what Sigma is purporting to do, I would put the high resolution four pixels in the center green layer, not the top blue layer.

Perhaps Sigma is doing something more complex than the schematic in the article above implies, but from the above description I expect this sensor design to have faults that we'll see remedied in a future version. I wouldn't buy the camera yet.

We have to go back to Physic 101 classroom <grin>

Photon can be both wave and particle _at the same time_.

The three layers sensor is doped with different elements. The final result is the uppermost P-N junction requires high energy photon to kick the electron (or hole) out of the orbit, generates electrical current.

After photons travel pass through, the high energy photon will be absorbed completely by this high-exitation P-N.

This 'absorption' is occured at the middle GREEN and lower RED layers, too.

Because of the wave/particle property, you may think that the "YELLOW" photon is really composed of RED and GREEN photon pairs.

Green will be absorbed in green. Red will be absorbed in red, and the same vertical axis.

After that - you just calculate what is the true color of that pixel, given signal strength from GREEN and RED layer.

Link | Posted on Feb 22, 2014 at 06:12 UTC
On photo DSC_0006 in dpreview review samples's photo gallery (16 comments in total)

Agree. It's not UW. You've to multiply focal length AND Depth of Field by 2.7.

Best for macrophotography. Shot with 105mm macro @ f/11 will give you 2.7 : 1 photo with DOF of 11 x 2.7 or about f/29-equivalent DOF !

Or low cost super-telephoto? The AF-S 300 mm f/4.0D-ED will give your bird size bigger than that price-of-leg&arm AF-S 600 mm f/4.0G-ED.

Link | Posted on Sep 23, 2011 at 02:27 UTC as 5th comment
On a photo in the Nikon J1 Preview Samples sample gallery (16 comments in total)

Agree. It's not UW. You've to multiply focal length AND Depth of Field by 2.7.

Best for macrophotography. Shot with 105mm macro @ f/11 will give you 2.7 : 1 photo with DOF of 11 x 2.7 or about f/29-equivalent DOF !

Or low cost super-telephoto? The AF-S 300 mm f/4.0D-ED will give your bird size bigger than that price-of-leg&arm AF-S 600 mm f/4.0G-ED.

Link | Posted on Sep 23, 2011 at 02:27 UTC as 5th comment
Total: 9, showing: 1 – 9