khunpapa

khunpapa

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

Comments

Total: 14, showing: 1 – 14
In reply to:

Storen: What is the deal with the 2 cameras? Are they with different lenses or for combining images and reducing noise?

Great conjuncture. Seem like thousands of people who already bought the 2-cam P9 did not notice your say and used it to shoot tgousands of Great Pictures.

Link | Posted on Jul 13, 2016 at 22:52 UTC
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

Seem like you don't understand the real meaning of f/stop and [b]light intensity per area[/b].

You also don't know what really is the Focal Length of the lens. Such _imagination _ meaningless number finally leads to another equaled meaningless number.

So, for my answer, if you really want, we've to be on the same plane of fundamental physics theory.

Link | Posted on Jul 6, 2016 at 14:24 UTC
On article 2016 Roundups: Fixed Prime Lens Cameras (115 comments in total)

http://www.dpreview.com/reviews/image-comparison/fullscreen?attr18=daylight&attr13_0=sigma_dp2q&attr13_1=leica_q116&attr13_2=pentax_645z&attr13_3=sony_dscrx1r_ii&attr15_0=jpeg&attr15_1=jpeg&attr15_2=jpeg&attr15_3=jpeg&attr16_0=200&attr16_1=100&attr16_2=200&attr16_3=200&normalization=full&widget=1&x=0.6066653023809774&y=-0.36319036600198795

I compare DP 2 Q with
- Pentax 645 (medium format)
- Leica Q (full frame, editor's choice)
- RX1R ii (full frame, editor's choice)

Both resolution and color fidelity.
SIGH. S I G H.

Seem like DPR staff do NOT care about the IQ anymore.

Link | Posted on Jul 2, 2016 at 15:02 UTC as 5th comment
On article 2016 Roundups: Fixed Prime Lens Cameras (115 comments in total)
In reply to:

TheWhiteDog: Shocking! The 2 most expensive cameras are the ones to buy!

Graphene is not the omnipotent panacea. Max DR it can increase should be less than 2 stops.

The sweetness of graphene is for camera company! The metal electrical conductor on the sensor require complex & ultrahigh precision, high temperature, manufacturing processes that are very, very expensive.

Graphene is chemical process. Easy (relatively) and very cheap.

Link | Posted on Jul 2, 2016 at 14:44 UTC
On article 2016 Roundups: Fixed Prime Lens Cameras (115 comments in total)
In reply to:

coldcut: In the studio scene, the sharpness of the Sigma is just.. unreal! Makes even the Leica look a bit unsharp.
But if looking at processing a couple of hundred Raw files with the sigma software, I would probably be very, very frustrated.
I wonder if its just generally bad programming practices, the wrong mathematical approach when converting the sensor data, ignorance how to code efficient software or something else that is the problem?

Foveon sensor camera were not, is not, will be not, as fast as Bayer sensor camera.

For the equivalent pixels *picture*, the amount of data and the complexity of mathematic calculation are order of magnitude higher.

For Bayer sensor - the "missing" pixel is calculated from plus/minus data of the adjacent pixels. But for Foveon, every picture pixel is calculated from matrix and recursive loop.

There's a genius who decoded sigma's processing algo. Google to find the source code and take a look at the calculation section to see what this complexity, compared to those from bayer calculation. (Can be found in many open source raw converter).

Foveon development goal is toward 'perfection', not just 'acceptable approximation' as in Bayer.

Link | Posted on Jul 2, 2016 at 14:33 UTC
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 (277 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 62nd 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: 14, showing: 1 – 14