Cheng Bao

Cheng Bao

Lives in United States United States
Joined on Oct 3, 2003

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Total: 59, showing: 1 – 20
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On Nikon 1 V3 First Impressions Review preview (586 comments in total)
In reply to:

Lucas_: It's yet an interesting camera, but I guess it'll need further development to cope with the competition later generation technology, mainly in IQ ( Nikon should just buy the Sony 1" sensor ). Price is definitely another big issue.

@Sonyshine, but aptina sensors itself don't have OSPDAF
https://www.aptina.com/products/image_sensors/ar1411hs/
https://www.aptina.com/products/dslr/ar1011hs/
That means PDAF pixel could be customized.

Another example, EM-1 use a sensor based on panasonic MN34230, which has OSPDAF as revealed by chipworks,
however, MN34230 itself don't have any PDAF pixels
http://www.semicon.panasonic.co.jp/ds4/MN34230PL_E.pdf

Direct link | Posted on Jul 16, 2014 at 15:44 UTC
On Nikon 1 V3 First Impressions Review preview (586 comments in total)
In reply to:

Lucas_: It's yet an interesting camera, but I guess it'll need further development to cope with the competition later generation technology, mainly in IQ ( Nikon should just buy the Sony 1" sensor ). Price is definitely another big issue.

Nor does aptina version has pdaf as shown on its website.
I believe ospdaf can be customized on sensors.

The big different of sony sensor aptina sensor is readout speed, although Sony sensor is capable to out put whole sensor area at 20fps, however, high speed af may need higher fps for certain area. Previous aptina sensor has 700M bps output ability for single lane, while Sony one has only 576M. That could make difference on af speed.

Let's see how fast fz1000 can focus.

Direct link | Posted on Jul 16, 2014 at 15:01 UTC
On Nikon 1 V3 First Impressions Review preview (586 comments in total)
In reply to:

thomasw333: Nice looking camera, but the V series should have the EVF built in. And that chart that they show in the beginning of the review just makes the Sony A6000 seem like the best to me. But if you like Nikon, I thought the J3 had good IQ so this V3 should be better and a decent camera.

Native nex lense is so so, however, if the critics is coming from nikon 1 camp, hmm...

standard zoom, check
3x 70-200 range zoom check
7x 28-300 range zoom check
wide angle zoom, nex has 15-27mm, 1 got only 18-35
nex has standard zoom start at 24mm, 1 got only 27mm

for fixed focal lense
sony has 24, 35, 40, 45, 50, 75, 85
while 1 only have 28, 50, 85
further more, nex has much larger equivalent aperture, with only exception is 32/1.2, which has F3.2 EA, the counter part 55/1.8, which is F2.7 EA.

The only lense that sony lack of native support is 70-300mm, but consider the size/weight/price, sony 70-300G for full frame has same size/weight/price, although it is not E native.

Direct link | Posted on Jul 15, 2014 at 23:52 UTC
On Nikon 1 V3 First Impressions Review preview (586 comments in total)

page 11, no primary camera is selected in studio comparison tools.
And the reason is v3 is not in drop down list

Direct link | Posted on Jul 15, 2014 at 22:39 UTC as 151st comment | 1 reply
On Ricoh announces Pentax XG-1 superzoom article (194 comments in total)

The interesting part is this camera's brand name.

Ricoh has dropped pentax brand on its fixed-lense digicam line, updates of old pentax wg line all bear ricoh name now.

Now this one use pentax brand again.

Direct link | Posted on Jul 15, 2014 at 16:12 UTC as 18th comment | 3 replies
On What is equivalence and why should I care? article (1715 comments in total)
In reply to:

Erick L: Total light on sensor affecting noise doesn't make sense to me. Don't smaller sensors appear more noisy simply because the image needs to be enlarged more, noise included?

Seems to me that saying a FF sensor has less noise because it gathers more light is akin to saying a telephoto lens "compresses perspective".

Well, you need to "enlarge" value of a single pixel on small DC is "equivalent" with you can "concentrate" value of a single pixel of a full frame sensor, because you get more light on a single pixel on FF than small DC. Same theory, different approach to tell it. However, by "total light" way, you can unify all means of equivalent by a single formula - equivalent focus length to determine field of view, equivalent aperture for depth of view and noise performance (with sqrt())

Direct link | Posted on Jul 14, 2014 at 17:15 UTC
On What is equivalence and why should I care? article (1715 comments in total)
In reply to:

Louschro: What is the advantage of using a camera with a larger sensor? You can take any (!) equivalent picture, that a camera with a smaller sensor can take. But additionally there is the potential to take (non equivalent) pictures with less DOF and less noise, which cameras with smaller sensor can't take. You have decide: Is this potential so important for you, that you would accept the burden to always carry the larger and heavier system?

Very often larger sensors have more resolution. How does it affect equivalence? In this case the equivalence of noise is not given. Instead the pictures will have more noise due to the smaller pixels.

You can use canon 5D and 50/1.2 lense for extreme low light or very shallow DOF. To achieve similar effect on m43, you need 100/0.6 lense, last time I check, m43 doesn't offer that option and certainly won't be cheap either if they do. That's the advantage of larger format.

Direct link | Posted on Jul 11, 2014 at 23:58 UTC
On What is equivalence and why should I care? article (1715 comments in total)
In reply to:

DrummerCT: What are the theoretical limits as to how "good" digital cameras can become? For the sake of discussion, assume sensor sizes as referred to in the article, nothing larger than FF. What I'm getting at is, in the next 20-25 years, will we have sensors/lenses/ISO/electronics etc. that can produce images beyond our ability to see noise and other aberrations in non-cropped forms. Same question, I suppose, would apply to display and print technologies.

In the world of audio recording, we're pretty close to having reached such prowess in the recording process, i.e., noise is hard to perceive in non-compressed, high sampling rate recordings (not there yet with playback).

@Mike FL

Yes, you can see noise from your naked eyes if you are really want to find them.

I did this experiment before, in a very dark room, with very little available light, and when your eyes are accustomed to the darkness, try to look at darker area in the darkness, you will see the noise from your naked eyes. Normally if there is something interesting in the scene, our brain will focus on the interesting part, you won't notice the noise. You can see the noise only when you are looking for it.

Interestingly, the noise I saw is more like electronic noise from a CCD or CMOS, they are colored as red,blue, green. I believe that's because our eyes has 3 types of cells to detect each type of light

Direct link | Posted on Jul 11, 2014 at 19:08 UTC
In reply to:

Reality Check: As interesting as this sounds (especially to those of the recent digital age, and some Sony engineers apparently) this is just OLD technology/concept revisited...
We tried this back in the film days (in concept) for the very same reasons - smaller/simpler/cheaper lenses with better performance across the image frame, etc..
What was determined back then (as is being 'discovered' today) is the very limited beneficial uses provided. Wide angle lenses, due the intrinsic field curvature of the elements used in their design, are almost the only area of benefit. Just about anything longer than ~50mm would itself have to be -redesigned- in order to project effectively, which would of course exponentially consume any cost savings of simpler/cheaper wide angle lenses.
Sony has provided theoretical information to suggest greater sensor performance, noting signal noise reduction etc, but nothing that could not be accomplished by putting R&D towards 'fewer' 'larger' and 'better' photosites..

You can trace the idea of airplane way back to Greek Mythology, that's doesn't mean Wright Bro or modern jet flights are just OLD concept revisited.

Some innovation are easily to formulate from mind, but it is very hard to turn it to reality given technology limits.

Unlike film, solid cmos/ccd sensors are very hard to bend, so it takes great courage and money to invest that direction.

Direct link | Posted on Jul 10, 2014 at 22:35 UTC
On What is equivalence and why should I care? article (1715 comments in total)
In reply to:

nerd2: One observation is that designing the truly equivalent lenses for smaller format (for example, AF 35mm 1.0 for APS that's equivalent to 50/1.4 for FF) won't be THAT hard, at least for mirrorless cameras, contrary to claims.

See, nikkor 50mm 1.4G weighs 278gr, has 8 optical elements, costs around $400. We now have $100 generic focal reducers which adds ~100gr of glasses at the back of the lens to convert it into 36mm f1.0 lens - then WHY don't manufacturers just put them together and sell a well calibrated, AF-capable 36mm f1.0 lens with 400gr weight at $600?

Or, Sigma and Tamron already have enough information to make AF lens with IS/VR for all mounts. Why don't they release a 'quality' focal reducer that has full AF and IS/VR capability?

"Or, Sigma and Tamron already have enough information to make AF lens with IS/VR for all mounts. Why don't they release a 'quality' focal reducer that has full AF and IS/VR capability?"

Because they want to sell lenses. If they make a quality focal reducer, the obvious consequence for them is they would sell less lenses, because the owner of focal reducer will more likely to continue to use old lenses instead of buying new native designed ones for smaller format.

Direct link | Posted on Jul 10, 2014 at 17:14 UTC
On What is equivalence and why should I care? article (1715 comments in total)
In reply to:

forpetessake: There has been more than 1000 comments so far. What can be learned from them?

1) Many people don't read, at least don't engage their minds while reading, but nevertheless they are quick to reply. They don't read the replies to their replies either, or unable to comprehend them, because they keep repeating the same fallacies again and again.
2) Many people have difficulty understanding simple laws of physics and elementary school arithmetic. It's really shameful state of affairs. Blame expensive government schools for that.
3) the previous 2 problems are exacerbated by a "choice-supportive bias" (http://en.wikipedia.org/wiki/Choice-supportive_bias). Notice that most (if not all) of the objections are coming from the people with small sensors (m4/3, 1").

Now, the really ugly thing is that most of those people are your average voters. I shudder thinking people with such cognitive faculties go to the voting booths.

@forpetessake for point 3)
Ironically, if you present them the comparison between m43, 1" with 1/1.7", they can master the fact more quickly that between m43 and FF

Direct link | Posted on Jul 9, 2014 at 23:42 UTC
On Olympus takes Pen E-PL6 beyond Asia article (75 comments in total)

So, why delay pl6 for more than one year outside Asia?
because rest of the world don't care about latest models, it is safe to dump left over pl5 to them?

Direct link | Posted on Jul 9, 2014 at 19:54 UTC as 15th comment | 1 reply
On Panasonic Lumix DMC-FZ1000 First Impressions Review preview (1282 comments in total)
In reply to:

iAPX: I don't understand why this one has not been rebranded Leica, I will die for it with a high-res viewfinder, a better creen on the back, and a better construction (says $2000 for all of that).

Ah and Audi design, and nice finish as the leica C!

Hold your breath, keep your finger crossed,
Leica is about to release new V-LUX. Base on its name (v = fz), it is FZ1000 with red dot brand.

http://www.mirrorlessrumors.com/new-leica-v-lux-typ-114-coming-soon

Direct link | Posted on Jul 2, 2014 at 23:13 UTC
On Panasonic Lumix DMC-FZ1000 First Impressions Review preview (1282 comments in total)
In reply to:

Jogger: Either way, Sony wins since they both use the Sony 1-inch sensor.

FZ1000 sensor spec is perfect match with sony IMX183 sensor. (and samsung nx mini too).

3+ manufactures use same specced sensor hints that sensors are same commercially available sensor, not some exclusively homebrew sensor.

For EM1 example, EM1's sensor size and total pixels is not same as E-M5, which indicates different sensor.

Direct link | Posted on Jul 2, 2014 at 18:53 UTC
On Panasonic Lumix DMC-FZ1000 First Impressions Review preview (1282 comments in total)
In reply to:

Serickmetz: Wow the Panasonic isn't even out yet and already looks bad next to that Sony.

Maybe Panasonic should have come out with something innovative instead of just copying Sony and stealing a piece of their pie.

As sony fans, I still welcome more competition. At least it drives price of rx10 down ($999 now everywhere, from $1300).

Even at same price, FZ1000 still offers a different package to choose from, some are better than RX10, like double the long zoom power, 4k capability ,etc.

I'd very like to see more manufactures to jump on 1" wagon, to drive the price of RX series down.

Direct link | Posted on Jul 1, 2014 at 19:04 UTC
On Sony Alpha 7S added to test scene comparison tool article (269 comments in total)

Did you messed with exif? @dpreview

for A7s shot, day light simulation, ISO 12800, 25600, 51200,
All displayed as F5.6, 1/5000s

Direct link | Posted on Jun 22, 2014 at 03:57 UTC as 4th comment

If any manufacture want to risk for develop whole new lens system from ground zero, yes, it can be done with interchangeable lens camera system.

Just like mirrorless system, manufacture need to invest a lot to build new lenses. Old lenses can work on mirrorless system or curved sensor system, but with comprise - for mirrorless system, you have to sacrifice AF performance greatly or use bulky and expensive adapter like sony LA-EA2 and LA-EA4.
For curved sensor, the compromise is same: you have to sacrifice corner qualiity or use bulky expensive adapter which makes flat focus field curved again.

or we need to wait for more technology advancement. Like on sensor PDAF to work with legacy SLR lenses for fast-AF (like E-M1) or in curved sensor case, a flexible curvature sensor, which I don't expect to see in near future.

Without performance/cost figure of some lens-sensor combination, we cannot judge if it is worth to make new cameras base on that, let alone new interchangeable lens one

Direct link | Posted on Jun 18, 2014 at 17:16 UTC as 53rd comment | 1 reply
On Sony Cyber-shot DSC-RX100 III First Impressions Review preview (2979 comments in total)
In reply to:

aleste37: Is there any timelapse options in any of the RX100 models?

https://www.playmemoriescameraapps.com/portal/usbdetail.php?eid=IS9104-NPIA09014_00-000003

only works on m3 model

Direct link | Posted on Jun 11, 2014 at 18:04 UTC
On Sony a6000 Review preview (711 comments in total)
In reply to:

G1Houston: Is the lack of an external charger really a negative?

I have come to appreciate the fact that when I carry these cameras on a trip, I do not have to pack all the bulky chargers with them. I just have to bring a single USB cable that I already use to charge my phone and tablet. Is that really so difficult to charge a separate battery at night time in the camera? It is also possible to use those external batteries we have for the smartphone to quick charge the "camera" in the filed. I thus suggest Dpreview to reconsider calling the lack of external charger a "pro," to encourage companies to simply the accessary. It drives me mad that each one of my camera has a different battery with a different charger.

You can take any cellphone usb charger. i.e. I am using Iphone's usb charger with a standard usb micro cable, which is rated 2.1a, 4 times as faster as included a6000 charger.
On my a7, it took 40 minutes to charge to 80% from 0%. 1 hours and 20 minutes to 100%

Direct link | Posted on Jun 3, 2014 at 17:32 UTC
On Sony a6000 Review preview (711 comments in total)
In reply to:

steelhead3: I guess the reviewer was not familiar with the Sony lens line up "(there's no real portrait prime"; what is the 50 1.8? The ZA Emont 55 1.8 is also available.

55/1.8 is 82.5mm equiv.
I don't think that 2.5mm will make it less than 85mm for portraits

Direct link | Posted on Jun 3, 2014 at 16:23 UTC
Total: 59, showing: 1 – 20
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