HubertChen

HubertChen

Lives in China Guangzhou, China
Works as a CEO
Joined on Jun 29, 2011

Comments

Total: 596, showing: 61 – 80
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On Sony Alpha A7 / A7R preview (2381 comments in total)
In reply to:

HubertChen: @ dpreview. I just spend half hour to post one post. Your system insisted my post included a swear word. It did not. I had several people looking over it. My post was considered polite. Still could not post. I have rewritten it many times, still can not post.

--> Please notify me which word you did not liked. Do not keep me trying and failing. This is not a good experience!

I finally found the offending word:
http://www.pentax forums.com

As soon as you remove the space from the link to that website it does not allow you to post with the reason this is a swear word.

Not true!

Direct link | Posted on Oct 17, 2013 at 13:36 UTC
On Sony Alpha A7 / A7R preview (2381 comments in total)
In reply to:

HubertChen: Sony 7 Cameras: Small, powerful and reasonably priced
Sony FE Lenses: Big, slow, expensive

I always use both: Camera + Lens. What is the point of a small camera with big lens? Seems Olympus, Fuji and Pentax have bigger camera bodies. But once lenses mounted to them, they have smaller and lower cost systems with faster lenses.

I am really impressed with the alpha 7 cameras. I applaud Sony. I worry the big, expensive and slow FE lenses will hamper the success.

I found this one just minutes later. I hope it will make you smile:
http://www.pentax forums.com/news/sony-a7-first-affordable-pentax-full-frame.html
(to use the link you have to remove the space in the domain name)

There are some in the Pentax community waiting for a Full Frame camera for their Full Frame Pentax glass. This Sony with an Adapter fits the bill.

And maybe it works also the other way around. If you want this camera and want small full frame lenses then get an adapter and you can use: Leica M, Pentax K, Voigtlander, or any other Full Frame lens you like (or own). Thanks to Intelligent Auto ISO you will have even good functioning automatic exposure. With the 3 lens mounts listed you can have an mechanical Aperture Ring. I used Sony NEX 5 with Pentax K lenses and usability was fine in terms of lens coupling.

Michael Reichmann looks forward to use the alpha 7R with his Leica M Lenses:
http://www.luminous-landscape.com/reviews/cameras/sony_a7r_hands_on.shtml

Direct link | Posted on Oct 17, 2013 at 13:34 UTC
On Sony Alpha A7 / A7R preview (2381 comments in total)

@ dpreview. I just spend half hour to post one post. Your system insisted my post included a swear word. It did not. I had several people looking over it. My post was considered polite. Still could not post. I have rewritten it many times, still can not post.

--> Please notify me which word you did not liked. Do not keep me trying and failing. This is not a good experience!

Direct link | Posted on Oct 17, 2013 at 13:31 UTC as 368th comment | 4 replies
On Sony Alpha A7 / A7R preview (2381 comments in total)
In reply to:

HubertChen: Sony 7 Cameras: Small, powerful and reasonably priced
Sony FE Lenses: Big, slow, expensive

I always use both: Camera + Lens. What is the point of a small camera with big lens? Seems Olympus, Fuji and Pentax have bigger camera bodies. But once lenses mounted to them, they have smaller and lower cost systems with faster lenses.

I am really impressed with the alpha 7 cameras. I applaud Sony. I worry the big, expensive and slow FE lenses will hamper the success.

@ whtchocla7e

Thanks for your comment. You are correct if you want to compare existing systems. My post was meant not so much as shopping advice but more as inspiration to thinking what if you couple a tiny FF camera with a tiny FF lens?

Sony delivered a tiny camera and monster size lenses. This simply seemed not consistent! And I promise you tiny size full frame lenses are possible. Just have a look at Primes from: Pentax, Voigtlander and Leica M.

Maybe my next post illustrates the point?

Direct link | Posted on Oct 17, 2013 at 13:05 UTC
On Sony Alpha A7 / A7R preview (2381 comments in total)

Sony 7 Cameras: Small, powerful and reasonably priced
Sony FE Lenses: Big, slow, expensive

I always use both: Camera + Lens. What is the point of a small camera with big lens? Seems Olympus, Fuji and Pentax have bigger camera bodies. But once lenses mounted to them, they have smaller and lower cost systems with faster lenses.

I am really impressed with the alpha 7 cameras. I applaud Sony. I worry the big, expensive and slow FE lenses will hamper the success.

Direct link | Posted on Oct 17, 2013 at 12:38 UTC as 369th comment | 12 replies
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

HubertChen: There is a method to separate imagined quality differences from real quality differences: Double blind test: The test engineer does not know which sample he is showing / playing and the test person does not know. For each sample the judgment of the test person is recorded and later analyzed.

Have a large enough number of test persons, say 10, and you can clearly identify quality features that are recognizable. Say at least 8 out of 10 notice the higher quality.

As for harmonic distortions in audio, trained musicians can detect even minute distortions, regular people can't. So depending on who is the audience, low distortion is important or not.

Once a group of people start discussing relevance on a level where everybody seems to have a different opinion, it actually is becoming time to do double blind tests and see how in real life this quality difference can or cannot be recognized. Who continues talking at this point, loves to talk and actually does not care to find the truth.

My apologies for this post to show. I started writing my above posts based on this one which I posted elsewhere. By the time I was finished the post system had posted the original text. It did not allowed me to delete it, nor did it allowed me to post my final result with the error message something like this: "Your post can not be edit due to time out". If any dpreview admin is reading this, I suggest to change this behavior. I am not OK that a version of my text is published before I press the post button and then what I did not wanted to publish can not be deleted or edited. Such kind of behavior of your system makes me less motivated to use it.

Posted on Oct 13, 2013 at 03:54 UTC
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

HubertChen: dpreview clearly formulated a question to which they wanted to find the answer: How does performance compare of the new AF system (Dual Pixel) versus the old AF system (View Finder PDAF).

I see dpreview to clearly express the test question, then design a series of tests to find the answer to the question. These tests are created in order of relevance and less important tests are left out to leave more time for the important tests. Then perform the tests with precision and analyze the results. Finally to back the findings of the lab with real world shooting.

dpreview earned my respect for doing an important job with integrity and accuracy.

I see many people in the forum to take the test results and formulate new questions, such as was the test procedure tuned to optimized precision of OVF PDAF? This simply is not meaningful.

The tests were not designed to answer these questions and as such the test results can not be used to be interpreted to find answer to these questions.

Yet a lot of discussions do just that. Such discussions are very harmful. They reduce motivation of dpreview to spend a lot of resources on thoroughly testing new technologies about fitness in real photography life.

Such discussions in this intensity also reduce motivation of the serious reader. In order to find meaningful posts, we have to wade through a huge amount of noise.

Make this Win-Win: It is obvious many posters here are interested in optimizing OVF PDAF precision with micro adjustments. Then why not create a forum thread and discuss it there. Keep information focused on topics to increase the Signal to Noise level for everybody.

Posted on Oct 13, 2013 at 03:49 UTC
On Preview:canon-eos-70d (1333 comments in total)

dpreview clearly formulated a question to which they wanted to find the answer: How does performance compare of the new AF system (Dual Pixel) versus the old AF system (View Finder PDAF).

I see dpreview to clearly express the test question, then design a series of tests to find the answer to the question. These tests are created in order of relevance and less important tests are left out to leave more time for the important tests. Then perform the tests with precision and analyze the results. Finally to back the findings of the lab with real world shooting.

dpreview earned my respect for doing an important job with integrity and accuracy.

Posted on Oct 13, 2013 at 03:46 UTC as 60th comment | 1 reply
On Preview:canon-eos-70d (1333 comments in total)

There is a method to separate imagined quality differences from real quality differences: Double blind test: The test engineer does not know which sample he is showing / playing and the test person does not know. For each sample the judgment of the test person is recorded and later analyzed.

Have a large enough number of test persons, say 10, and you can clearly identify quality features that are recognizable. Say at least 8 out of 10 notice the higher quality.

As for harmonic distortions in audio, trained musicians can detect even minute distortions, regular people can't. So depending on who is the audience, low distortion is important or not.

Once a group of people start discussing relevance on a level where everybody seems to have a different opinion, it actually is becoming time to do double blind tests and see how in real life this quality difference can or cannot be recognized. Who continues talking at this point, loves to talk and actually does not care to find the truth.

Posted on Oct 13, 2013 at 03:20 UTC as 61st comment | 1 reply
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

jkokich: This reminds me of stereo systems in the 70's. There was all this hype about distortion levels you needed an oscilloscope to measure; the human ear couldn't detect the difference.

There is a method to separate imagined quality differences from real quality differences: Double blind test: The test engineer does not know which sample he is showing / playing and the test person does not know. For each sample the judgment of the test person is recorded and later analyzed.

Have a large enough number of test persons, say 10, and you can clearly identify quality features that are recognizable. Say at least 8 out of 10 notice the higher quality.

As for harmonic distortions in audio, trained musicians can detect even minute distortions, regular people can't. So depending on who is the audience, low distortion is important or not.

Once a group of people start discussing relevance on a level where everybody seems to have a different opinion, it actually is becoming time to do double blind tests and see how in real life this quality difference can or cannot be recognized. Who continues talking at this point, loves to talk and actually does not care to find the truth.

Posted on Oct 13, 2013 at 03:19 UTC
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

crackshooter: As soon as I learned that the camera rememberes the micro-adjustment of AF from lense to lense, (thanks Erik Magnuson and Bob Meyer), then I really see no problem whatsoever. I am used to, and expect to tweak equipment when it is brand new, be it bicycles or a kayak...
-Regards from first time DSLR buyer.

@ R Butler: I fully agree! May I suggest a third question?

3) After you tune the Micro adjustment, how long will it remain accurate?

The Mirror mechanism is mainly made of plastics. Pretty much all plastics have a thermal expansion coefficient, and worse, they expand with increased humidity and shrink with low humidity. Plus the reflex mirror is a moving part, which never can be so accurate. At the precision you have been testing, changes of the mirror position in sub micrometer will show as change in focus position. So if calibrating focus will only last for a few days or maybe even hours, and calibrating it takes you 20 minutes, then it would not be an efficient solution for most photographers.

For this reason I even never bothered to adjust my PDAF. I live in a place where humidity can change by 70% in only one day, which I am sure will ruin all micro adjustments. If I need this accurate, I shoot CDAF on sensor, which with my camera is super accurate.

Posted on Oct 12, 2013 at 07:51 UTC
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

HubertChen: Canon made a dramatic technological breakthrough: Sensor based AF has now the speed of OVF AF and at the same time is much more accurate. If you put this sensor into an LCD Viewfinder camera, the advantages become more obvious:

1) Camera is about 100 USD lower cost, because the complete OVF, plus mirror mechanism, plus additional PDAF sensor is removed, plus great simplification in firmware.
2) New LCD viewfinder are becoming more appealing than OVF: Larger image, more display information, depth of field preview
3) More accurate AF. Important to anyone with fast lenses who like to shoot shallow depth of field

This will be the winning camera and Canon just delivered the last missing piece to the puzzle: Sensor AF with no compromise. Big news!

About the PDAF inaccuracies shown in the Article. Anyone shooting very fast lenses in close distance knows these problems. Any PDAF camera has it. It is an inherent System Problem, not a dpreview staff problem!

@ Ralf B
Exactly! The Sony SLT is an improvement over the conventional DSLR in that it makes the mirror mounted in a fixed position instead making it move. This is an important simplification and this will make for less discrepancy of PDAF with real focus on the sensor. But still you have two AF systems than need to be developed and manufactured, one of which still need to be calibrated, with calibration being an expensive process in production.

Instead once you go for electronic viewfinder and the new Canon Sensor, you remove the redundant development and production of 2 AF systems and remove calibration.

Considering that production cost of mechanical parts is getting more expensive and production cost of electronic parts is getting lower cost, it is clear where this industry is going.

Posted on Oct 12, 2013 at 07:42 UTC
On Preview:canon-eos-70d (1333 comments in total)

@ Andy Westlake, Shawn Barnett and Richard Butler

Great Article, great research, great testing. Thanks so much for identifying the dramatic breakthrough Canon delivered and for explaining it in great writing. I truly enjoyed it. Keep up your excellent work! You made me read a Camera review cover to cover of a system I do not have :-)

Posted on Oct 11, 2013 at 16:34 UTC as 80th comment
On Preview:canon-eos-70d (1333 comments in total)

Canon made a dramatic technological breakthrough: Sensor based AF has now the speed of OVF AF and at the same time is much more accurate. If you put this sensor into an LCD Viewfinder camera, the advantages become more obvious:

1) Camera is about 100 USD lower cost, because the complete OVF, plus mirror mechanism, plus additional PDAF sensor is removed, plus great simplification in firmware.
2) New LCD viewfinder are becoming more appealing than OVF: Larger image, more display information, depth of field preview
3) More accurate AF. Important to anyone with fast lenses who like to shoot shallow depth of field

This will be the winning camera and Canon just delivered the last missing piece to the puzzle: Sensor AF with no compromise. Big news!

About the PDAF inaccuracies shown in the Article. Anyone shooting very fast lenses in close distance knows these problems. Any PDAF camera has it. It is an inherent System Problem, not a dpreview staff problem!

Posted on Oct 11, 2013 at 16:29 UTC as 81st comment | 2 replies
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

ijustloveshooting: what a lame that Conventional, OVF autofocus screws all the time...then what's the point of a dslr?

I have shot with a variety of cameras and if you use an extreme narrow depth of field lens at close focal distance every PDAF I have shot with was off, about the same as shown in the Article. So this Article is very much in line with reality. If you shoot with lenses of smaller apertures you will never see these problems.

Posted on Oct 11, 2013 at 16:16 UTC
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

ManuelVilardeMacedo: It is ridiculous that some blame the test for the poor OVF AF results!
As for me, Canon can include their 'dual pixel' autofocus system among its least of Most Relevant Innovations. People should congratulate the ones who developed this technology, as it's definitely an advance for photography.
...Still it puzzles me to see manual focus works even better than 'dual pixel'. One would be forgiven to ask why they bothered inventing autofocus at all.

They bothered because of speed. Try to manual focus reaching the accuracy level as described in here on any moving subject and you will get dramatically better results with AF!

Posted on Oct 11, 2013 at 16:12 UTC
On Preview:canon-eos-70d (1333 comments in total)
In reply to:

57even: So to get this camera to focus properly you have to hold it in front of you like a compact and focus using the rear screen? I am the only one who thinks this doesn't really move the game forward in any meaningful way?

You can use an LCD viewfinder and use the camera same way as an optical viewfinder, except you have a much larger, more immersive viewfinder.

If not to your liking, you can at least recognize the progress in live view and look forward to the time when they combine this sensor with a great LCD viewfinder.

The time is near where LCD viewfinder will be preferable over optical viewfinder. Better user experience paired with lower cost.

Posted on Oct 11, 2013 at 07:23 UTC
On Curiosity in the WiFi Remote Capture challenge (3 comments in total)

This picture made me smile from ear to ear! Nice shot and congrats to deserved win

Direct link | Posted on Oct 11, 2013 at 06:56 UTC as 1st comment
In reply to:

mister_roboto: Accounting for inflation in USD it'd be about $600 today.

Thanks for these calculations. It puts the whole thing into a different perspective.

Direct link | Posted on Oct 7, 2013 at 07:56 UTC
In reply to:

SRT3lkt: people are happier back then

This always has been the excuse of the unhappy ones. Happiness is is the result of a person's hard work to become happy. It is not about a time or place.

Direct link | Posted on Oct 7, 2013 at 07:56 UTC
Total: 596, showing: 61 – 80
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