Dan Tong

Dan Tong

Lives in United States Chicago, United States
Works as a Computer Consultant, Photographer
Joined on Jan 3, 2003
About me:

Olympus 2100UZ
Minolta Dimage 7i
Canon S400
Canon EOS 300D

Comments

Total: 143, showing: 81 – 100
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On Sony NEX-6 Hands-on Preview preview (229 comments in total)

The NEX-6 would be great but for video purposes, my main interest for the NEX series, except for the lack of touch screen controls. It looks like the NEX-5R would better suit my purposes.

Direct link | Posted on Sep 13, 2012 at 04:28 UTC as 67th comment
On Just Posted: Sony Alpha NEX-5R hands-on preview news story (127 comments in total)
In reply to:

xoio: More crappy 'wave the camera around - Iphone Style' rubbish.

King Penguin is absolutely correct. I have used the the "tight strap" method for video using a Canon 5D Mark II with 70-200mm /F4 lens plus 2x telephoto adapter, and the video is very steady, with slow panning (from the torso). It would have been simpler with a tripod (and even better) but shooting conditions (shooting road construction out of window) made tripod use impractical. The problem with the "tight strap" method is that, on the5D Mark II, pressing the start and stop button was nearly impossible without jiggling the camera.
Of course a viewfinder that attaches to the LCD would have been better, but I did not have one.

In case no one has noticed, the strap attachment geometry of the NEX-5R has been greatly improved!

In summary, I highly recommend the "tight strap" method for shooting using LCD with any camera.

Direct link | Posted on Aug 30, 2012 at 22:57 UTC
On Sony Alpha NEX-5R preview (145 comments in total)

This is a nice follow up to the 5N. Can the flash accessory port be used with external flash, or any wireless flash controllers (other than Sony) ? For video purposes it's too bad there is no 720p video resolution, and of course we're all hoping that the hybrid focus system lives up to our expectations.

Direct link | Posted on Aug 30, 2012 at 22:03 UTC as 18th comment
On Mars rover camera project manager explains 2MP camera choice news story (187 comments in total)

More proof that a large percentage of DPreview commentators cannot even read. This excellent article answers just about all of the questions, dumb or otherwise, raised in a prior article about Curiosity's cameras, yet lots of fools still keep asking the same tiresome questions. In fact, many of the questions were already correctly guessed, and it is a testament to the fact that there is a small intelligent, well informed segment in the Dpreview community.

Thanks for the excellent interview and CONGRATULATIONS to all of the people at NASA, JPL, and other places all over the world whose intelligence and hard work has made this possible.

Direct link | Posted on Aug 9, 2012 at 21:50 UTC as 33rd comment
In reply to:

cpkuntz: Why do they use 2 mp sensors? Robust build? The Apollo mission used Hasselblads. Why not get some medium format goodness on board one of these rovers?

Correction to my post:

At the time of the landing I heard or read 13 minutes (one way), so that is probably for the distance during the landing.. Just now I learned it varies between 4.3 and 21 minutes depending on the min or max Earth to Mars distance.

http://www.physlink.com/education/askexperts/ae381.cfm

Direct link | Posted on Aug 8, 2012 at 06:57 UTC
In reply to:

CameraLabTester: The whole Mars landing is quite an amazing triumph considering it takes at least 6 minutes for any command on Earth to be confirmed. (3 minutes send, 3 minutes echo).

Just like in the Apollo missions, future landers will carry much better equipment.

NASA will eventually be infected with camera upgrade fever.

.

Radio waves travel at lightspeed, so the 45 minutes does not make sense. Most likely the reporter got it screwed up (as usual).

http://www.haydenplanetarium.org/universe/duguide/app_light_travel_time_dista.php

Look at Table A-2 which says:

Mars is 12.7 light minutes away. This is where the 13 minute delay I got from the NASA boadcast during the landing. But that's probably right now, which may be a sort of average distance (in between the shortest and longest perhaps).

This link shows that you are correct:

http://www.physlink.com/education/askexperts/ae381.cfm

The time varies between 4.3 and 21 minutes, and the 45 minutes then is pretty close to the round trip of 21 minutes each way. Voila mystery solved!

Thanks, CameraLab Tester!

Direct link | Posted on Aug 8, 2012 at 06:50 UTC
In reply to:

Nightwings: TWO...... megapixels? .......... ok.

Only reason why I think this is.... would be the bandwidth required to transmit higher (Larger files) resolution images??

Can anyone else speculate why they mounted a 1999 era sensor on a multi-billion dollar probe?

Another possibility is to render images with the least amount of noise possible so as not to contaminate the images when specific filters are used.......

Ok.... That's my two guesses.

Attomole,

Good to hear some intelligent commentary!

Direct link | Posted on Aug 8, 2012 at 06:29 UTC
In reply to:

LuisGui: I don't dare to underestimate the intelligence and resources of the NASA scientists and engineers.

The less some people actually bother to learn or look up even, the more they foam at the mouth :)

Direct link | Posted on Aug 8, 2012 at 06:26 UTC
In reply to:

cpkuntz: Why do they use 2 mp sensors? Robust build? The Apollo mission used Hasselblads. Why not get some medium format goodness on board one of these rovers?

First of all:

The correct value for the transmission time (time from when it is sent to when it is received is) 11-13 minutes depending on the (min or max distance between Mars & Earth), according to the NASA webpage:

http://www.nasa.gov/vision/universe/solarsystem/world_mars.html

Some of your reasoning, or perhaps your explanation is a bit off I'm afraid. No matter whether transmission is continuous or not (it isn't!), the greater the amount of information, the longer it takes to transmit. Period.
However you are almost certainly correct about priority of non photo image data over photo image data.

Direct link | Posted on Aug 8, 2012 at 02:02 UTC
In reply to:

CameraLabTester: The whole Mars landing is quite an amazing triumph considering it takes at least 6 minutes for any command on Earth to be confirmed. (3 minutes send, 3 minutes echo).

Just like in the Apollo missions, future landers will carry much better equipment.

NASA will eventually be infected with camera upgrade fever.

.

The correct value for the transmission time (time from when it is sent to when it is received is) 11-13 minutes depending on the (min or max distance between Mars & Earth), according to the NASA webpage:

http://www.nasa.gov/vision/universe/solarsystem/world_mars.html

Direct link | Posted on Aug 8, 2012 at 01:57 UTC

R Butler's very helpful link disappeared. So I'm re-posting it.

http://www.truesenseimaging.com/news-and-events/34-msl-landing

Direct link | Posted on Aug 8, 2012 at 01:51 UTC as 73rd comment | 1 reply
In reply to:

thisisjh: http://www.physicsforums.com/showthread.php?p=4025122

It says...

The camera need to withstand solar radiation- the cameras we flew (and are still onboard) the space station crapped out after about 2 years- ionizing radiation causes 'latching', resulting in the steady accumulation of hot pixels.

I couldn't find clear evidence of who made the CCDs, possibly Kodak. In any case, it's most likely a rad-hardened CCD chip, which is also why it's not a (high end) consumer grade chip.

thisisjh,

Thanks for the link.

Direct link | Posted on Aug 8, 2012 at 01:47 UTC
On Roger Cicala investigates Canon's AF marketing claims news story (89 comments in total)

Ever wonder how our own visual system (eye and brain) focuses so accurately and fast?

Here is an abstract of research with defocus and how that can be used for focusing on natural images, and suggests that this method will soon be developed and used in cameras.

http://www.pnas.org/content/early/2011/09/16/1108491108.abstract

Direct link | Posted on Aug 3, 2012 at 06:59 UTC as 19th comment
On Roger Cicala investigates Canon's AF marketing claims news story (89 comments in total)

Another superb Roger Cicala article. It's such a pleasure to read worthwhile article which based on intelligent testing and thinking. I find Cicala's articles by far the most interesting and worthwhile, I always learn something new that explains a lot about photographic equipment, therefore I am awarding Roger Cicala an honorary Ph.D. (that is a Photography Degree :)

All kidding aside, Cicala not only has a great sense of humor but he thinks like a scientist which is praiseworthy, indeed.

Direct link | Posted on Aug 2, 2012 at 03:48 UTC as 39th comment
On Photoshop CS6: Top 5 Features for Photographers article (98 comments in total)
In reply to:

Dan Tong: As far back as I remember you always had the ability to name/rename a layer. This was possible in CS5, but some idiots, managed to take away this option, or hid it so it is hard to find. Why is it so common lately for programs to take away perfectly useful and important features (or change where they are) in subsequent newer "improved" versions ?

Put it BACK!

Hey Graybalanced,

Thanks for the information. I was looking for it to work the same way as it used to in CS5 etc, where it was a menu option after right clicking. So I never tried a left mouse click. With Windows Explorer you right click and choose Rename.

I guess I would claim that it was there but hidden from anyone who expected it to work the way it used to.

In any case I'm delighted that you rescued me from ignorance.

Dan

Direct link | Posted on Jul 10, 2012 at 00:21 UTC
On Photoshop CS6: Top 5 Features for Photographers article (98 comments in total)

As far back as I remember you always had the ability to name/rename a layer. This was possible in CS5, but some idiots, managed to take away this option, or hid it so it is hard to find. Why is it so common lately for programs to take away perfectly useful and important features (or change where they are) in subsequent newer "improved" versions ?

Put it BACK!

Direct link | Posted on Jul 9, 2012 at 00:55 UTC as 15th comment | 2 replies
On Quick Guide to Video Lighting article (33 comments in total)
In reply to:

marike6: Since in general you're not using a meter when lighting for video (or are you?) I assume things like ratios, where you have the key and fill light at different stops, are not an issue. I'm wondering lighting if simple video lighting is done more by eye than with still photography.

On a side note, I sure wish Nikon or someone made a small, short barreled shotgun mike similar to the Nikon ME-1 shown above but with XLRs instead of a 3.5mm mini-plug. I'm looking for a shotgun mike for my D800 but I don't want one that is so long as to appear in the shot with my wide angle zoom. Unfortunately the ME-1 is not a shotgun mike.

Anyway, thanks for the useful article. The setup looks much, much better with the back-light.

I think I see where you are coming from. Those of us photographers who often deal with strobes, may forget that with continuous lighting it is much easier to eyeball the lighting effect without a test shot. I find that my rather dim strobe modeling lights don't help nearly as much as I would like in predicting resulting lighting of the shot. Hence the need for a test shot. With a meter, the outcome is pretty predictable. With continuous lighting it is pretty much "what you see is what you get".

Direct link | Posted on Jun 12, 2012 at 05:07 UTC
On Quick Guide to Video Lighting article (33 comments in total)
In reply to:

marike6: Since in general you're not using a meter when lighting for video (or are you?) I assume things like ratios, where you have the key and fill light at different stops, are not an issue. I'm wondering lighting if simple video lighting is done more by eye than with still photography.

On a side note, I sure wish Nikon or someone made a small, short barreled shotgun mike similar to the Nikon ME-1 shown above but with XLRs instead of a 3.5mm mini-plug. I'm looking for a shotgun mike for my D800 but I don't want one that is so long as to appear in the shot with my wide angle zoom. Unfortunately the ME-1 is not a shotgun mike.

Anyway, thanks for the useful article. The setup looks much, much better with the back-light.

Metering is just as important for video.
Keep in mind that one big difference between video lighting and still photo lighting, aside from requiring continuous light for video, is that if the light is very close to the subject, subject movement may not only change the lighting of the subject a lot, but the lighting equipment may show up in the frame. To the extent that your video is about motion and the subject may often not be stationary, the lighting may need to be placed at more of a distance than for still photos.

Direct link | Posted on Jun 12, 2012 at 04:54 UTC
On Quick Guide to Video Lighting article (33 comments in total)

Nice easy intro to lighting any photo or video. Well done.

Direct link | Posted on Jun 12, 2012 at 04:44 UTC as 6th comment
On Photoshop CS6 Beta: New Features for Photographers article (176 comments in total)

Thanks for this very informative summary of CS6.

Direct link | Posted on Mar 24, 2012 at 21:32 UTC as 32nd comment
Total: 143, showing: 81 – 100
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