mpgxsvcd

mpgxsvcd

Lives in United States USA, NC, United States
Works as a Jack of all Trades
Joined on May 17, 2004

Comments

Total: 1819, showing: 61 – 80
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That is a shame. I really was looking forward to seeing what the new HDR video mode was like. I am sure Canon will correct the issue. However, this is probably going to delay the release of the camera even further.

I followed the first reports of the issue in the forums and it did appear to be a significant issue. Hopefully it doesn't cause to big of an issue for the camera's release.

Direct link | Posted on May 1, 2015 at 15:35 UTC as 56th comment | 2 replies
In reply to:

mpgxsvcd: If my scene doesn’t have any highlights that are blown at the normal/auto exposure value then is it possible that I would actually have to increase the exposure compensation in order to ETTR? In other words are there ever times when ETTR doesn’t involve decreasing the exposure compensation and is it still recommended to ETTR in those scenarios?

Then Auto ETTR will become the next Megapixel war in the future. Except for this time it will actually bring real benefit to the photographs and videos.

Direct link | Posted on Apr 29, 2015 at 20:44 UTC
On GoPro announces Kolor acquisition article (46 comments in total)
In reply to:

mpgxsvcd: GoPros 4K footage almost looks like 1080p. Not quite though.

Youtube actually does an excellent job with 4K now. You just have to encode it properly. Too many people apply too much compression when they edit their videos. It really needs to be compressed efficiently and then it will look great even on youtube.

Direct link | Posted on Apr 29, 2015 at 20:41 UTC
On Massive $33,500 2450mm f/8 NASA lens surfaces on eBay article (235 comments in total)
In reply to:

mpgxsvcd: Just for reference a High End 800mm Aperture telescope with a 3040mm Focal length and F3.8 focal ratio runs about $220,000. However, you can get a nice 2800mm F10.0 11” SCT with a very nice mount and a warranty for $6999. You would have to be a fool to buy this telescope as anything but a collectible.

http://www.optcorp.com/officina-stellare-rifast-800-f3pt8-telescope-rifa800.html

http://www.optcorp.com/celestron-cge-pro-1100-telescope-11087.html

@mick232

Yes all of these telescopes and even much less expensive ones will cover a full frame sensor. If you need bigger coverage then there are some specialty scopes that you can get that wouldn't cost as much.

Direct link | Posted on Apr 29, 2015 at 18:13 UTC
On GoPro announces Kolor acquisition article (46 comments in total)

GoPros 4K footage almost looks like 1080p. Not quite though.

Direct link | Posted on Apr 29, 2015 at 18:04 UTC as 16th comment | 4 replies

If my scene doesn’t have any highlights that are blown at the normal/auto exposure value then is it possible that I would actually have to increase the exposure compensation in order to ETTR? In other words are there ever times when ETTR doesn’t involve decreasing the exposure compensation and is it still recommended to ETTR in those scenarios?

Direct link | Posted on Apr 29, 2015 at 15:58 UTC as 58th comment | 3 replies
On Massive $33,500 2450mm f/8 NASA lens surfaces on eBay article (235 comments in total)
In reply to:

Erick L: Keeping my money for the Hubble auction.

Shipping is going to be very costly on that one.

Direct link | Posted on Apr 29, 2015 at 15:27 UTC
On Massive $33,500 2450mm f/8 NASA lens surfaces on eBay article (235 comments in total)

Just for reference a High End 800mm Aperture telescope with a 3040mm Focal length and F3.8 focal ratio runs about $220,000. However, you can get a nice 2800mm F10.0 11” SCT with a very nice mount and a warranty for $6999. You would have to be a fool to buy this telescope as anything but a collectible.

http://www.optcorp.com/officina-stellare-rifast-800-f3pt8-telescope-rifa800.html

http://www.optcorp.com/celestron-cge-pro-1100-telescope-11087.html

Direct link | Posted on Apr 29, 2015 at 12:54 UTC as 37th comment | 3 replies
In reply to:

cpt kent: Seems to be a lot of folks exclaiming brilliance without questioning. Sources? References? Research? Further reading?

You shouldn’t take any of this on faith. You should read everything they wrote(Several times). Then reason through their conclusions. Then refer to other sources to confirm those results. Once you have done that you will come to the conclusion that they are in fact correct.

Direct link | Posted on Apr 28, 2015 at 19:18 UTC
In reply to:

Mssimo: In a few cameras with "ISO Irreverence". Would you recommend not to use anything but base ISO up to the point where the camera starts to use hardware amplification?

Stop chatting and keep writing. :)

Direct link | Posted on Apr 28, 2015 at 19:14 UTC
In reply to:

Karroly: "As a result, when you shoot two different sized sensors with the same shutter speed, f-number and ISO, the camera with the smaller sensor has to produce the same final image brightness.. from less total light."

I am sorry, I do not agree at all.

Please, let me put this another way. If I use an F:2.8 FF lens on a APS-C body, it is still an F:2.8 lens and the picture taken (at same aperture/speed/ISO AND PIXEL SIZE) is just a crop of the FF sensor. The APS-C area of the FF sensor gets the same amount of light (either total or per area unit) than the APS-C sensor and thus the signal-to-noise ratio is the same...

Except for the fact that the A-PSC sized sensor didn’t use all of the light that passed through the front element of the lens. It is true that each pixel still receives the same amount of signal. However, the signal to noise ratio is lower since some of the signal got thrown away and yet the shot noise is still the same.

Direct link | Posted on Apr 28, 2015 at 19:10 UTC
In reply to:

mpgxsvcd: In order to believe this article you have to accept that shot noise is a significant factor in short exposure photography. That fact is stated in the article. However, it really isn’t demonstrated. I think that is where some people are getting hung up. They can’t accept that fact without seeing it.

It would be really cool if you showed how much noise is contributed from shot noise vs. read noise in each review. You could stack out the read noise with Dark Frames leaving only the shot noise from a very dark scene.

Very good information there Mike. Thanks for that.

Direct link | Posted on Apr 28, 2015 at 15:47 UTC
In reply to:

mpgxsvcd: This is the first time that I have seen shot noise factored into the argument that the larger the sensor the better the noise characteristics are. That is why I was finding it so difficult to accept this as fact before.

@Felix E Klee

Actually that isn’t true. Your mistake is that you assumed that the smaller sensor uses all of the light that the aperture can provide. If the lens illuminates the entire full frame sensor then the smaller sensor will literally discard a portion of that light because the light falls outside of its area. That will also decrease your signal to noise ratio because you are discarding some of the light and the shot noise and absolute aperture haven’t changed.

I made the same mistake in one of my questions as well.

Direct link | Posted on Apr 28, 2015 at 15:13 UTC

In order to believe this article you have to accept that shot noise is a significant factor in short exposure photography. That fact is stated in the article. However, it really isn’t demonstrated. I think that is where some people are getting hung up. They can’t accept that fact without seeing it.

It would be really cool if you showed how much noise is contributed from shot noise vs. read noise in each review. You could stack out the read noise with Dark Frames leaving only the shot noise from a very dark scene.

Direct link | Posted on Apr 28, 2015 at 14:27 UTC as 99th comment | 5 replies
In reply to:

mpgxsvcd: “There are three factors that affect how much light is available for your sensor to capture: your shutter speed, f-number and the size of your sensor.”

I am confused about the statement above. The aperture diameter determines how much light is available to your sensor, right? The focal ratio just determines how concentrated that light is. The focal ratio does not affect the total amount of light that is available at all. The aperture diameter does that.

The focal ratio only affects the light per unit area. However, your statement refers to total light available. Or am I reading that wrong?

I see where my mistake is now. You were implying that the lens was identical in both situations so the total light and the shot noise through the lens was equal in both situations. However, the smaller sensor literally discards a portion of that light because that light falls outside of its area.

When looking at it like that then yes the sensor size is what causes the light loss and therefore would decrease the signal to noise ratio.

Direct link | Posted on Apr 28, 2015 at 14:13 UTC
In reply to:

mpgxsvcd: “There are three factors that affect how much light is available for your sensor to capture: your shutter speed, f-number and the size of your sensor.”

I am confused about the statement above. The aperture diameter determines how much light is available to your sensor, right? The focal ratio just determines how concentrated that light is. The focal ratio does not affect the total amount of light that is available at all. The aperture diameter does that.

The focal ratio only affects the light per unit area. However, your statement refers to total light available. Or am I reading that wrong?

“when you shoot two different sized sensors with the same shutter speed, f-number and ISO, the camera with the smaller sensor has to produce the same final image brightness (which the ISO standard demands) from less total light.”

I guess where I was getting confused was that you didn’t specify that the focal lengths were the same in the above statement. The shutter speed, f-number, and ISO could all be the same but if the focal length for the m43 sensor was half that of the full frame sensor then both would be seeing the same total light because the aperture diameters would be the same.

Should the statement above also say that the focal lengths or aperture diameters are the same as well? If either one of those is different then the sensors could see the same amount of light despite their size difference.

Direct link | Posted on Apr 28, 2015 at 14:04 UTC

“There are three factors that affect how much light is available for your sensor to capture: your shutter speed, f-number and the size of your sensor.”

I am confused about the statement above. The aperture diameter determines how much light is available to your sensor, right? The focal ratio just determines how concentrated that light is. The focal ratio does not affect the total amount of light that is available at all. The aperture diameter does that.

The focal ratio only affects the light per unit area. However, your statement refers to total light available. Or am I reading that wrong?

Direct link | Posted on Apr 28, 2015 at 13:47 UTC as 102nd comment | 3 replies
In reply to:

mpgxsvcd: I agree with everything you said for short exposure photography but what about long exposure photography like astrophotography(Several minutes or more)? There longer exposures increases the electrical read noise and decreases the shot noise because the signal is more consistent over the longer period of time.

It would be interesting to find the shutter duration at which shot noise is surpassed by electrical read noise in particular cameras.

In addition stacking light exposures along with dark frames can reduce the shot and read noise by using some form of averaging with multiple frames. Since the noise is random the difference between each frame is the “unwanted signal”.

It might be really interesting to add a new section to your reviews for long exposure photography. It would be great to not only know what ISO is best to use but also what shutter speed is most desirable. If you have a stationary scene then it could be possible that using a longer exposure than you normally would use might improve the shot noise even at the same ISO value.

Direct link | Posted on Apr 28, 2015 at 13:31 UTC
In reply to:

mpgxsvcd: I agree with everything you said for short exposure photography but what about long exposure photography like astrophotography(Several minutes or more)? There longer exposures increases the electrical read noise and decreases the shot noise because the signal is more consistent over the longer period of time.

It would be interesting to find the shutter duration at which shot noise is surpassed by electrical read noise in particular cameras.

In addition stacking light exposures along with dark frames can reduce the shot and read noise by using some form of averaging with multiple frames. Since the noise is random the difference between each frame is the “unwanted signal”.

I think there are really two categories of long exposure astrophotography. There is the amateur component where we are typically focused on the Messier objects and the like. Those objects(M42, M31, M27, M16, M8, …etc) are fairly bright. From my experience with those objects shot noise is really not as big an issue as read noise once the exposures pass a few minutes.

Then there is semi-Pro and Pro astrophotography where they are trying to get the stuff that is extremely dark. There every single photon counts and those cameras are typically super cooled with extremely low read noise characteristics. I doubt there are many people using an off the shelf DSLR for this type of work. Usually this doesn’t involve pretty pictures. It just involves gathering and analyzing very specific data to the nth degree.

Direct link | Posted on Apr 28, 2015 at 13:31 UTC
In reply to:

mpgxsvcd: I agree with everything you said for short exposure photography but what about long exposure photography like astrophotography(Several minutes or more)? There longer exposures increases the electrical read noise and decreases the shot noise because the signal is more consistent over the longer period of time.

It would be interesting to find the shutter duration at which shot noise is surpassed by electrical read noise in particular cameras.

In addition stacking light exposures along with dark frames can reduce the shot and read noise by using some form of averaging with multiple frames. Since the noise is random the difference between each frame is the “unwanted signal”.

Have you ever done any astrophotography Rishi? I think you would really enjoy it if you haven't. You can get a great setup for about $1500 if you choose the components with a budget in mind.

Direct link | Posted on Apr 28, 2015 at 13:20 UTC
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