trungthu

Lives in Viet Nam Viet Nam
Joined on Jan 28, 2007

Comments

Total: 41, showing: 21 – 40
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In reply to:

trungthu: "... This means it has only one photosite per output pixel, so won't offer the same color resolution as Canon's EOS C300 professional video camera, which has four capture pixels (a Red, Green, Blue, Green quartet) per output pixel... "

I don't know how it can record color information in only one photosite. While almost all others use three color filter in four pixels (RGBG).
Please help me. Thanks.

Yes, I see.
Bayer filter use four capture pixels to record color informations.
""" .. This means it has only one photosite per output pixel, so won't offer the same color resolution as Canon's EOS C300...""" what does i mean?
Only one photosite per output pixel""" ???
Thanks Brian Lund for your respond.

Link | Posted on Mar 6, 2013 at 16:02 UTC

"... This means it has only one photosite per output pixel, so won't offer the same color resolution as Canon's EOS C300 professional video camera, which has four capture pixels (a Red, Green, Blue, Green quartet) per output pixel... "

I don't know how it can record color information in only one photosite. While almost all others use three color filter in four pixels (RGBG).
Please help me. Thanks.

Link | Posted on Mar 5, 2013 at 16:53 UTC as 25th comment | 4 replies
On article First Impressions: Metabones Speed Booster (355 comments in total)
In reply to:

trungthu: Because the F-number is the entrance pupil divided by focal length, reducing the focal length without changing the entrance pupil increases the F-number.
I think, it's wrong here.
When reduce the focal length without changing the entrance pupil will DECREASE the F-number. So it's from 50mm f/1.4 will be 35mm f/1.0.

I understood. Thank Revenant very much

Link | Posted on Feb 3, 2013 at 16:31 UTC
On article First Impressions: Metabones Speed Booster (355 comments in total)

Because the F-number is the entrance pupil divided by focal length, reducing the focal length without changing the entrance pupil increases the F-number.
I think, it's wrong here.
When reduce the focal length without changing the entrance pupil will DECREASE the F-number. So it's from 50mm f/1.4 will be 35mm f/1.0.

Link | Posted on Feb 1, 2013 at 16:49 UTC as 57th comment | 2 replies

It's an interesting news.

Link | Posted on Sep 18, 2012 at 15:23 UTC as 98th comment
On article Pentax launches smc DA 50mm F1.8 for APS-C cameras (108 comments in total)

Why all the lenses at 50mm f/1.8 for full frame from other branches have the prices around 100USD, while Pentax has 50mm f/1.8 for APS-C, with a smaller covering power, and a higher price?
Why?

Link | Posted on May 23, 2012 at 03:59 UTC as 9th comment | 4 replies
On article Just Posted: Sigma SD1 / SD1 Merrill review (374 comments in total)
In reply to:

trungthu: It's only 15 M positions to receive light to record image, not 15X3=45Mp as Sigma said. But when they don't use AA filter, the detail is better (than other 15Mp camera).
When other camera use two green pizels for one blog to equal to human eyes, Sigma can't do that, so the color is not good.
If Sigma says SD1 with 15Mp, and add one more position to detect green, I hope, it is better. The price stagery is so bad, it's unreal!

Thanks.
I have known Sigma Foveon X3 from SD9, and I knew about it with the more "sharpness of the details" than other 6Mp camera, but, with the less of green in it.
By unused AA filter, SD1 can deliver more detaisl than other camera at 15Mp, that noone have any critique.
Foveon has really "three colors in one position", and other has to interpolate "three color in one position", and Foveon has to "interpolate" to have the size of 15x3Mp, other has really 45Mp in size. The only better one from Foveon is the unused AA filter.
And please wait to see some comparisons between SD1 and D800e (Nikon) in sometime later.
Thanks for your reply.

Link | Posted on Apr 11, 2012 at 02:27 UTC
On article Just Posted: Sigma SD1 / SD1 Merrill review (374 comments in total)

It's only 15 M positions to receive light to record image, not 15X3=45Mp as Sigma said. But when they don't use AA filter, the detail is better (than other 15Mp camera).
When other camera use two green pizels for one blog to equal to human eyes, Sigma can't do that, so the color is not good.
If Sigma says SD1 with 15Mp, and add one more position to detect green, I hope, it is better. The price stagery is so bad, it's unreal!

Link | Posted on Apr 11, 2012 at 00:55 UTC as 88th comment | 3 replies

I think, the differences is very little in quality between the "normal lenses" and these Zeiss lenses.
Because, the resolution of motion picture is only 2K (about 2Mp), and all the lenses of the camera's maker can adapte this clearity, even the kit lens.
But, the problem maybe only is in the conviniences, and the posibility of making money of the film maker, so the price is "no problem".

Link | Posted on Apr 6, 2012 at 02:53 UTC as 14th comment | 5 replies
On photo Egg in the 1 color (size rule) Please read all... challenge (12 comments in total)

Excelent composition. I love it.
Thanks for sharing.

Link | Posted on Mar 24, 2012 at 09:14 UTC as 6th comment
On article Facebook adds higher resolution photo viewing (70 comments in total)

Very good.
Thanks.

Link | Posted on Mar 22, 2012 at 16:20 UTC as 22nd comment
On article Just Posted: Lytro Light Field Camera review and video (309 comments in total)
In reply to:

trungthu: As I see in the second photo in
http://www.dpreview.com/reviews/lytro/3
When I click to the glass, the leg behind it also be in-focus, and when I click to the guitarist, the leg behind the glass turn out-of focus.
I think, this is only a software game, by separating each plan by software to put it to in or out of focus with some faults. It's only a game, not technology, as they say.
I think so. I hope I'm wrong.

Thanks HowaboutRAW.
I think I know less than you, but please explain the phenomenon that I have seen in the photo in the link I have talk to?
""" http://www.dpreview.com/reviews/lytro/3
When I click to the glass, the leg behind it also be in-focus, and when I click to the guitarist, the leg behind the glass turn out-of focus.
I think, this is only a software game, by separating each plan by software to put it to in or out of focus with some faults. It's only a game, not technology, as they say."""

Link | Posted on Mar 2, 2012 at 13:03 UTC
On article Canon announces EOS 5D Mark III 22MP full-frame DSLR (488 comments in total)

I think, maybe this is a wrong strategy of Canon as Nikon.
- The resolution has "no change", while "double" in D800.
- Full HD is like the older version (Mark II), like in D800.
Why don't they choose Nikon D800?
Not "new version" from 5DII.

Link | Posted on Mar 2, 2012 at 11:14 UTC as 92nd comment
On article Just Posted: Lytro Light Field Camera review and video (309 comments in total)
In reply to:

tkbslc: right now this is mainly a toy, but who knows where it will be in 10-15 years. I remember back in 1999, the $1000 1.3MP digital cameras really weren't useful for anything but happy snaps, but now look at them. If you could do this on a large sensor and shoot f2.8 from infinity to mfd and adjust the best DOF and focus like we do any of the standard RAW settings now.

In October, 2002, I have used Fuji FinePix S2Pro (6,1Mp - $2450), it's not a toy.

Link | Posted on Mar 1, 2012 at 06:05 UTC
On article Just Posted: Lytro Light Field Camera review and video (309 comments in total)
In reply to:

trungthu: As I see in the second photo in
http://www.dpreview.com/reviews/lytro/3
When I click to the glass, the leg behind it also be in-focus, and when I click to the guitarist, the leg behind the glass turn out-of focus.
I think, this is only a software game, by separating each plan by software to put it to in or out of focus with some faults. It's only a game, not technology, as they say.
I think so. I hope I'm wrong.

Thank. But if you see in the photo?
Because they use a very small sensor, so all of the field be in focus, after that, they use a software to separate each plan (by use the interpolation), but with something with "opacity", the software can not distinguish it.
I hope they can do more than that.
Thanks.

Link | Posted on Mar 1, 2012 at 05:49 UTC
On article Just Posted: Lytro Light Field Camera review and video (309 comments in total)

As I see in the second photo in
http://www.dpreview.com/reviews/lytro/3
When I click to the glass, the leg behind it also be in-focus, and when I click to the guitarist, the leg behind the glass turn out-of focus.
I think, this is only a software game, by separating each plan by software to put it to in or out of focus with some faults. It's only a game, not technology, as they say.
I think so. I hope I'm wrong.

Link | Posted on Mar 1, 2012 at 01:15 UTC as 73rd comment | 4 replies
On article Just Posted: Lytro Light Field Camera review and video (309 comments in total)

Very impressive.
If we can do it in larger format camera.
Thanks.

Link | Posted on Mar 1, 2012 at 00:59 UTC as 74th comment
On article Book Review: Vivian Maier, Street Photographer (150 comments in total)

I like the word "street portraitists".
Thanks.

Link | Posted on Feb 27, 2012 at 11:18 UTC as 2nd comment
On article Depth of Field in Macro Photography (159 comments in total)

""" Depth of field is dependent upon three factors: aperture value, focal length and subject distance. """
I think, there's one more factor relates to the DOF, that's the sensor's dimension. The more of the sensor's dimension, the less of the depth of field.
Because the "normal lens" is equal to the diagonal of the image sensor, and the smaller of the sonsor, the shorter of the focal, and so the wider of the DOF.

Link | Posted on Feb 16, 2012 at 04:48 UTC as 54th comment | 1 reply
On article 'No Future in Photojournalism' Interview: Dan Chung (267 comments in total)
In reply to:

DaveMarx: First, it's all "electronic photography." One imaging sensor, one CPU. Motion, stills, audio, text, time and position data in a small, hand-held device. One investment in lenses, a common memory storage device. Stills darkroom plus audio/video post in another compact and portable device. We can document the world with one little bag of gear.

Ignore this convergence if you will, but if you do, you're restricting your creativity, and the ability to use the right tool for the job - motion when it's called for, stills when that's called for, and often both, because there are several ways to tell the same story.

I started shooting stills over 40 years ago. Within a few years I was working in radio, television, and film, eventually online and web, print publishing... It's not hard, it's all about communicating. Each medium has its strengths and weaknesses. If you can be eloquent in one, you can be eloquent in several. It's not one vs. the other, it's all for one and one for all.

"" because there are several ways to tell the same story. ""
I like it.
""" Each medium has its strengths and weaknesses. """
I agree with you.

Link | Posted on Feb 10, 2012 at 09:34 UTC
Total: 41, showing: 21 – 40
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