Cheng Bao

Cheng Bao

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

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Total: 156, showing: 1 – 20
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On Olympus OM-D E-M5 II Review preview (686 comments in total)
In reply to:

mosc: I'm skeptical of DPR's comments on the high resolution mode with various lenses. Each pixel doesn't change size when it's moved. I think DPR is incorrect when it says a lens is perfectly fine for 16mp but not for 40mp. None of the 8 shots taken are more than 16mp. They're all 16mp, they're all the same resolution as all the other samples. The lens only needs 16mp of resolution to give a 40mp image... provided you take 8 of them with precise shifts and do a lot of math.

It's possible the issue is lens related but if it is I'd say it probably has to do more with the algorythm's inability to deal with "digitally corrected lenses" more than the lens's lack of resolution.

It is relevant. I can give you an extreme example. Think a trash lense that can only resolve four pixels on a 2x2 cm area. the picture that a 2x2 sensor would see
1 0
0 1
now, give you a single pixel that resolve 1/1000,000 of the area of 2x2 cm, can you move that pixel to capture a 1MP picture without moving lense and subject?
If your logic is right, it could by moving and capture one pixel for 1 million times. But in fact, when the one-pixel sensor moves on top left 250,000-pixels zone, it can only capture digit 1 because the lense can only resolve 1 on that area, your final picture is still
1 0
0 1

Direct link | Posted on Mar 19, 2015 at 15:57 UTC
On Olympus OM-D E-M5 II Review preview (686 comments in total)
In reply to:

mosc: I'm skeptical of DPR's comments on the high resolution mode with various lenses. Each pixel doesn't change size when it's moved. I think DPR is incorrect when it says a lens is perfectly fine for 16mp but not for 40mp. None of the 8 shots taken are more than 16mp. They're all 16mp, they're all the same resolution as all the other samples. The lens only needs 16mp of resolution to give a 40mp image... provided you take 8 of them with precise shifts and do a lot of math.

It's possible the issue is lens related but if it is I'd say it probably has to do more with the algorythm's inability to deal with "digitally corrected lenses" more than the lens's lack of resolution.

You comments would stand correct if sensor only moved a whole single pixels, thus create a 16MP full-color image. so, in this case, you don't need more lense resolving ability.
However, olympus moved sensor by 0.5 pixel, you will need higher resolving power to distinct details between 0.5pixel

Direct link | Posted on Mar 19, 2015 at 00:05 UTC
In reply to:

samhain: Good job Sony, nice to see a f1.4. I didn't think they had it in em.
That's the kind of lens that grabs other brand shooters attention.
Hopefully more fast 1.4's to come.

But- putting out a 90mm macro before an 85mm or 90mm portrait lens?
Seriously?
That just doesn't make sense to me.
Just like when Fuji's intial lens launch included a 60mm macro and no portrait lens. Widely considered a 'wtf' move. Even Fuji later admitted that was a mistake.

If 45/2.8 m43 can be portraits lens, every one has a portrait lens at beginning, and for sony FE, sony evengot 3 portrait lenses at launch, 28-70/5.6, 24-70/4, 70-200/4, all save 28-70 are more suitable for portrait than 45/2.8 m43. Since ppl always complain that sony don't provide portrait lenses, so, no, 45/2.8 is not portrait lense.

Direct link | Posted on Mar 5, 2015 at 06:32 UTC
In reply to:

samhain: Good job Sony, nice to see a f1.4. I didn't think they had it in em.
That's the kind of lens that grabs other brand shooters attention.
Hopefully more fast 1.4's to come.

But- putting out a 90mm macro before an 85mm or 90mm portrait lens?
Seriously?
That just doesn't make sense to me.
Just like when Fuji's intial lens launch included a 60mm macro and no portrait lens. Widely considered a 'wtf' move. Even Fuji later admitted that was a mistake.

45mm F2.8 on m43, it has same DOF as 90mm F5.6 on FF, or 60mm F3.6 on aps-c.
Since fuji user don't think 60mm F2.4 is a portrait lens, there is no way to treat 45/2.8 as portrait lens

Direct link | Posted on Mar 4, 2015 at 21:24 UTC
In reply to:

samhain: Good job Sony, nice to see a f1.4. I didn't think they had it in em.
That's the kind of lens that grabs other brand shooters attention.
Hopefully more fast 1.4's to come.

But- putting out a 90mm macro before an 85mm or 90mm portrait lens?
Seriously?
That just doesn't make sense to me.
Just like when Fuji's intial lens launch included a 60mm macro and no portrait lens. Widely considered a 'wtf' move. Even Fuji later admitted that was a mistake.

Yes, you can predicate bokeh from MTF. If the solid line and dotted line of same color/width stay closely, it would have a smooth bokeh.

Direct link | Posted on Mar 4, 2015 at 20:49 UTC
In reply to:

samhain: Good job Sony, nice to see a f1.4. I didn't think they had it in em.
That's the kind of lens that grabs other brand shooters attention.
Hopefully more fast 1.4's to come.

But- putting out a 90mm macro before an 85mm or 90mm portrait lens?
Seriously?
That just doesn't make sense to me.
Just like when Fuji's intial lens launch included a 60mm macro and no portrait lens. Widely considered a 'wtf' move. Even Fuji later admitted that was a mistake.

according to initial sample and MTF, 90mm macro has a very nice bokeh that could also be a portrait lense.

Also, it seems m43 doesn't have any portrait lenses either until the 3rd year after launch.

Direct link | Posted on Mar 4, 2015 at 20:35 UTC

A new comer to a dying market in already-dead niche

Direct link | Posted on Feb 24, 2015 at 19:54 UTC as 146th comment | 3 replies

actually, according to ft quoting sony ceo, sony is considering spin-off sensor business too

via http://image-sensors-world.blogspot.com/2015/02/sony-to-spin-off-image-sensor-business.html

Direct link | Posted on Feb 20, 2015 at 21:10 UTC as 20th comment
On CP+ 2015: Canon shows off prototype 120MP CMOS sensor article (255 comments in total)
In reply to:

Renzokuken: 2.2 µm pixel pitch.... That's almost the same as certain smartphones in the market. Hurray ???

@lacikuss RX100III uses a 2.4 µm sensor
http://www.sony.net/Products/SC-HP/new_pro/may_2014/imx183_e.html

Direct link | Posted on Feb 14, 2015 at 01:18 UTC

This is a steal, $850 for 24/1.4 ART?

look at how much canon/nikon/sony charged for their 24mm lenses

Direct link | Posted on Feb 11, 2015 at 18:45 UTC as 28th comment | 2 replies
On Sigma dp0 Quattro announced with 14mm F4 lens article (138 comments in total)

The lens must be stellar, for this 14/4 lenses looks bigger than already stellar 14/2.8mm XF lense

Direct link | Posted on Feb 10, 2015 at 21:22 UTC as 9th comment | 1 reply
On Canon EOS 5DS / SR First Impressions Review preview (2340 comments in total)
In reply to:

Cheng Bao: The sensor, seems comes from old fab
http://cweb.canon.jp/eos/lineup/5ds/img/feature-highquality/cmos.jpg
while x8i sensor is from a new fab
http://cweb.canon.jp/eos/lineup/kissx8i/img/feature-highquality/2420.jpg

This is about S/N, not DR

Direct link | Posted on Feb 6, 2015 at 04:50 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2340 comments in total)
In reply to:

Cheng Bao: The sensor, seems comes from old fab
http://cweb.canon.jp/eos/lineup/5ds/img/feature-highquality/cmos.jpg
while x8i sensor is from a new fab
http://cweb.canon.jp/eos/lineup/kissx8i/img/feature-highquality/2420.jpg

and no mention about dynamic range in press release and product brief, make me think it is only marginal improvement over 5D3

Direct link | Posted on Feb 6, 2015 at 04:36 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2340 comments in total)

The sensor, seems comes from old fab
http://cweb.canon.jp/eos/lineup/5ds/img/feature-highquality/cmos.jpg
while x8i sensor is from a new fab
http://cweb.canon.jp/eos/lineup/kissx8i/img/feature-highquality/2420.jpg

Direct link | Posted on Feb 6, 2015 at 04:25 UTC as 622nd comment | 5 replies
On Hands-on with Canon's 'not-coming-to-USA' EOS M3 article (532 comments in total)

This is canon's "We are serious about mirrorless"?

Direct link | Posted on Feb 6, 2015 at 04:03 UTC as 164th comment | 3 replies
On Hands-on with Samsung's new NX500 article (343 comments in total)
In reply to:

Havanai: I am spoiled by the fully-articulated LCD screen on my Panasonic G-series. Why don't all manufacturers provide full articulation? A merely tilting LCD is no sufficient. And, simultaneously, I value a good EVF. You use different modes of viewing and framing in different situations. Otherwise this handsome camera looks intriguing.

fully-articulated LCD has many advantages you already know, however, it has disadvantages too compares to tilt-only LCD

1. It is more bulky and cost may be higher, and limit the LCD size on smaller body
2. It is not as easy to turn from normal mode to waist-level mode as tilt-only
3. in waist-level mode, it interferes your left hands for holding camera
4. in waist-level mode, LCD is off from the lens light axis, which someone may prefer tilt-only when shooting long zoom or macros
5. it is harder to hold and use in selfie mode than tilt-only LCD (if it is 180 degree tilting)

So some one who mainly use LCD for normal shooting or waist level shoot might prefer tilt-only LCD more

Direct link | Posted on Feb 5, 2015 at 17:26 UTC
In reply to:

miles green: Yessss, finally!!!!!!!!!!

As a bonus, it looks compact, with a huge pentaprism and will obviously have SR in body. This is great.

It does look like the 67 with AE prism!

The newly released 70-200 and 150-450 don't have any build-in in lens IS. If there is no in body is, the premium tele zoom solution is out of any IS option, which is unthinkable as today's standard.

and there a little square on the bottom-left side of mount of the mockup, on where would SR logo have been.

Direct link | Posted on Feb 5, 2015 at 00:20 UTC
In reply to:

Pentax_Prime: Where is the confirmation of a FF K-mount? Nothing in the news release, your article, your links, anywhere.

http://us.ricoh-imaging.com/about/press/347/Ricoh_Imaging_Broadens_Lens_Line-up-Providing_Photographers_with_Two_New_Options_to_Capture_Outstanding_Sports,_Action_and_Landscape_Photography.
" As the result, it not only assures brilliant, high-resolution images without compromising the sharpness at edges even when mounted on an existing PENTAX digital SLR camera body, but it is also capable of accepting future models with larger image sensors without modifications."

Direct link | Posted on Feb 4, 2015 at 23:10 UTC
On Budget X: Hands-on with Fujifilm's new X-A2 article (159 comments in total)

From slide 7, we can see sensor with gold fingers.
This is a different sensor than x-pro1 sensor without x-trans CFA as shown in this video
https://www.youtube.com/watch?v=6koZ-3KqahA

Direct link | Posted on Jan 15, 2015 at 21:07 UTC as 32nd comment
On Fujifilm releases XQ2 premium compact article (60 comments in total)
In reply to:

RedFox88: DPR: 2/3" is really 1/1.5". Use common nomenclature to make it not sound like a much bigger image sensor.

Camera industry use 2/3" at least as early as year 2000, why they didn't use 1/1.5" at first place is another puzzle.

Direct link | Posted on Jan 15, 2015 at 17:33 UTC
Total: 156, showing: 1 – 20
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