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UdonUdon · 09-28-2011, 10:56 AM

Originally posted by rawr

Half a stop of light loss doesn't sound much, but it looks like this:

(screencap from Digitalrev review of the A77):
Sony Alpha SLT-A77 Hands-on Review - DigitalRev.com

It also means your expensive fast glass will meter half a stop slower, so won't be fast glass anymore

Your expensive glass will meter the same on an A77. When sony calibrated the ISO levels they included the mirror as a factor. If Sony didn't do this, then many long-time photographers "internal light meter" would be skewed up and, just like you said, lenses wouldn't meter the same. Plus, it is called "International Organization for Standardization" for a reason.

If you are wondering, here is DxOMark's measurement of the A77's ISO sensitivity compared to nominal ISO sensitivity. It's pretty close, it is nearly exactly the same as the Nikon D7000, and it is much closer than the Canon 7D. Also, yes the A77 was tested with the mirror down.

So, yes, metering will be the same on A77 as other DSLRs; it's just that the SLT has taken a step back in terms of high ISO performance.

What Kai of DigitalRev should have done is compared a bare-body shot of the A77 with the mirror down to bare-body shot of a regular DSLR with the mirror up (obviously).

falconeye · 09-29-2011, 08:47 AM

Originally posted by RonHendriks1966

What is the gain in goin 14-bit instead of 12-bit?

Theoretically, the gain should be marginal. It should show mostly where DR (in screen resolution) exceeds 12EV. Then 14Bit can provide a slight increase in DR over a 12Bit camera.

Consulting DxO, you'll see that K-5 benefits from its 14 Bit at ISO 100 vs. the A-580 which gives it its little extra boost in DR. But this little extra boost let it win the APSC competition...

However, the A-77 has more pixels and therefore, the pixel-DR doesn't barely exceed 12 EV. With more pixels, you don't need as many bits per pixel.The A-77 sensor doesn't seem to need a 14Bit engine.

RonHendriks1966 · 10-25-2011, 03:49 PM

The DPreview report is in. When I look at some measurements then it looks like that sensor is going back to K-7 performance.

elho_cid · 10-25-2011, 04:20 PM

2 stops worse noise performance than K-5? That can't stand in world of today. Too bad. Let's wait for what Samsung will have in NX200.

BTW funny how dpreview is still trying to compare DR of jpg files. What a pointless exercise!

Winder · 10-25-2011, 06:59 PM

You guys realize that the 24MP sensor is being enlarged 30% more and it is losing 1/2 a stop of light from the mirror. You can not judge how the 24MP sensor will perform in a Pentax. Look at how the K-5 outperforms the NEX-5N even though they have the same sensor. There are way too many variables.

My guess is that the 24MP sensor will perform exactly like the 16MP when it comes to S/N ratio, but because it has more "pixels" it will generate a better looking image everything else being equal.

garyk · 10-25-2011, 09:31 PM

I am looking at the Sony Nex-7 an interesting camera. As i get older this is appealing to me.

ogl · 10-25-2011, 10:58 PM

Just Posted: In-depth Sony SLT-A77 review: Digital Photography Review

Pictures in RAW is rather noisy to say honest.

Emacs · 10-25-2011, 11:03 PM

Steve Huff found nex-7 being noisier than nex-5n

RonHendriks1966 · 10-26-2011, 02:24 AM

Originally posted by Winder

You guys realize that the 24MP sensor is being enlarged 30% more and it is losing 1/2 a stop of light from the mirror. You can not judge how the 24MP sensor will perform in a Pentax. Look at how the K-5 outperforms the NEX-5N even though they have the same sensor. There are way too many variables.

My guess is that the 24MP sensor will perform exactly like the 16MP when it comes to S/N ratio, but because it has more "pixels" it will generate a better looking image everything else being equal.

Well is it possible to make a picture like this one with that sensor?

Because if we can't then it wont be my next camera. With the performance I'm looking at with the a77 I don't think it will hit the market hard.

**Schraubstock** · 10-26-2011, 03:43 AM

Hi

Allow me to throw this into the mix; With ever present dust flying around in an changeable lens camera how would an SLT be effected by it. Would the dust or crap that settles on the mirror be too far away from the sensor to be a problem? And if it is how does one clean the mirror, presumably the mirror surface is not as sturdy as a sensor surface? Even if it is not a big problem and cleaning is not required (I could not imagine that this would be a possibility) I can see that over time the mirror would get pretty filthy.

I cannot find any reference or write ups about it and I am just interested to know.

Has anybody had any experience with this?

Greetings

Winder · 10-26-2011, 06:02 AM

Originally posted by RonHendriks1966

Well is it possible to make a picture like this one with that sensor?

Because if we can't then it wont be my next camera. With the performance I'm looking at with the a77 I don't think it will hit the market hard.

Until we see what Pentax can do with it we wont know. Pentax cameras have been running a stop better than the Sony versions with the same sensor and you can not really compare 100% crops of sensors with significant pixel density because the 24MP sensor is enlarged 30% more than the 16MP sensor.

I think Pentax realizes that simply dropping a new sensor into the next model is not going to entice people to upgrade from the K-5. I would assume the next body will have other significant upgrades.

Supernaut · 10-26-2011, 06:49 AM

Originally posted by Winder

I think Pentax realizes that simply dropping a new sensor into the next model is not going to entice people to upgrade from the K-5. I would assume the next body will have other significant upgrades.

+1

That would be the least interesting release ever :ugh:

Emacs · 10-26-2011, 06:53 AM

Originally posted by Supernaut

+1

That would be the least interesting release ever :ugh:

It can be the MOST interesting release for the K-mount lenses owners ever: just put the 36x24 there

eddie1960 · 10-26-2011, 07:22 AM

right now there won't be any models from anyone using sony sensors

the plant is one of the Sony plants under water in Thailand.

Winder · 10-26-2011, 07:30 AM

Originally posted by eddie1960

right now there won't be any models from anyone using sony sensors

the plant is one of the Sony plants under water in Thailand.

But the 20MP Samsung is made in Korea.....

A large number of these sensors have already been made (A77 & NEX-7). I would assume that if Pentax or Nikon have a camera ready for Spring announcement that the sensors have already been shipped. Hopefully Pentax ordered theirs a few weeks early so they have time to clean all of the stains off of them.

10-25-2011, 11:03 PM	#293
Emacs Veteran Member Join Date: Oct 2010 Location: Moscow Posts: 1,223	Steve Huff found nex-7 being noisier than nex-5n Last edited by Emacs; 10-26-2011 at 12:58 AM.

10-26-2011, 07:30 AM	#300
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	Originally posted by eddie1960 right now there won't be any models from anyone using sony sensors the plant is one of the Sony plants under water in Thailand. But the 20MP Samsung is made in Korea..... A large number of these sensors have already been made (A77 & NEX-7). I would assume that if Pentax or Nikon have a camera ready for Spring announcement that the sensors have already been shipped. Hopefully Pentax ordered theirs a few weeks early so they have time to clean all of the stains off of them. Last edited by Winder; 10-26-2011 at 07:58 AM.

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09-28-2011, 10:56 AM	#286
UdonUdon Forum Member Join Date: Jan 2011 Location: Texas Photos: Albums Posts: 90	Originally posted by rawr Half a stop of light loss doesn't sound much, but it looks like this: (screencap from Digitalrev review of the A77): Sony Alpha SLT-A77 Hands-on Review - DigitalRev.com It also means your expensive fast glass will meter half a stop slower, so won't be fast glass anymore Your expensive glass will meter the same on an A77. When sony calibrated the ISO levels they included the mirror as a factor. If Sony didn't do this, then many long-time photographers "internal light meter" would be skewed up and, just like you said, lenses wouldn't meter the same. Plus, it is called "International Organization for Standardization" for a reason. If you are wondering, here is DxOMark's measurement of the A77's ISO sensitivity compared to nominal ISO sensitivity. It's pretty close, it is nearly exactly the same as the Nikon D7000, and it is much closer than the Canon 7D. Also, yes the A77 was tested with the mirror down. So, yes, metering will be the same on A77 as other DSLRs; it's just that the SLT has taken a step back in terms of high ISO performance. What Kai of DigitalRev should have done is compared a bare-body shot of the A77 with the mirror down to bare-body shot of a regular DSLR with the mirror up (obviously).

09-29-2011, 08:47 AM	#287
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by RonHendriks1966 What is the gain in goin 14-bit instead of 12-bit? Theoretically, the gain should be marginal. It should show mostly where DR (in screen resolution) exceeds 12EV. Then 14Bit can provide a slight increase in DR over a 12Bit camera. Consulting DxO, you'll see that K-5 benefits from its 14 Bit at ISO 100 vs. the A-580 which gives it its little extra boost in DR. But this little extra boost let it win the APSC competition... However, the A-77 has more pixels and therefore, the pixel-DR doesn't barely exceed 12 EV. With more pixels, you don't need as many bits per pixel.The A-77 sensor doesn't seem to need a 14Bit engine.

10-25-2011, 03:49 PM	#288
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	The DPreview report is in. When I look at some measurements then it looks like that sensor is going back to K-7 performance.

10-25-2011, 04:20 PM	#289
elho_cid Veteran Member Join Date: Dec 2007 Location: Prague Photos: Gallery Posts: 1,199	2 stops worse noise performance than K-5? That can't stand in world of today. Too bad. Let's wait for what Samsung will have in NX200. BTW funny how dpreview is still trying to compare DR of jpg files. What a pointless exercise!

10-25-2011, 06:59 PM	#290
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	You guys realize that the 24MP sensor is being enlarged 30% more and it is losing 1/2 a stop of light from the mirror. You can not judge how the 24MP sensor will perform in a Pentax. Look at how the K-5 outperforms the NEX-5N even though they have the same sensor. There are way too many variables. My guess is that the 24MP sensor will perform exactly like the 16MP when it comes to S/N ratio, but because it has more "pixels" it will generate a better looking image everything else being equal.

10-25-2011, 09:31 PM	#291
garyk Inactive Account Join Date: Feb 2010 Photos: Gallery Posts: 488	I am looking at the Sony Nex-7 an interesting camera. As i get older this is appealing to me.

10-25-2011, 10:58 PM	#292
ogl Banned Join Date: Dec 2007 Location: Sankt Peterburg Photos: Gallery \| Albums Posts: 8,382	Just Posted: In-depth Sony SLT-A77 review: Digital Photography Review Pictures in RAW is rather noisy to say honest.

10-26-2011, 02:24 AM	#294
RonHendriks1966 Banned Join Date: Jan 2009 Photos: Gallery Posts: 9,675	Originally posted by Winder You guys realize that the 24MP sensor is being enlarged 30% more and it is losing 1/2 a stop of light from the mirror. You can not judge how the 24MP sensor will perform in a Pentax. Look at how the K-5 outperforms the NEX-5N even though they have the same sensor. There are way too many variables. My guess is that the 24MP sensor will perform exactly like the 16MP when it comes to S/N ratio, but because it has more "pixels" it will generate a better looking image everything else being equal. Well is it possible to make a picture like this one with that sensor? Because if we can't then it wont be my next camera. With the performance I'm looking at with the a77 I don't think it will hit the market hard.

10-26-2011, 03:43 AM	#295
Schraubstock Site Supporter Join Date: Oct 2010 Location: Melbourne Photos: Gallery Posts: 3,386	Hi Allow me to throw this into the mix; With ever present dust flying around in an changeable lens camera how would an SLT be effected by it. Would the dust or crap that settles on the mirror be too far away from the sensor to be a problem? And if it is how does one clean the mirror, presumably the mirror surface is not as sturdy as a sensor surface? Even if it is not a big problem and cleaning is not required (I could not imagine that this would be a possibility) I can see that over time the mirror would get pretty filthy. I cannot find any reference or write ups about it and I am just interested to know. Has anybody had any experience with this? Greetings

10-26-2011, 06:02 AM	#296
Winder Veteran Member Join Date: Apr 2010 Location: Tennessee Posts: 6,617	Originally posted by RonHendriks1966 Well is it possible to make a picture like this one with that sensor? Because if we can't then it wont be my next camera. With the performance I'm looking at with the a77 I don't think it will hit the market hard. Until we see what Pentax can do with it we wont know. Pentax cameras have been running a stop better than the Sony versions with the same sensor and you can not really compare 100% crops of sensors with significant pixel density because the 24MP sensor is enlarged 30% more than the 16MP sensor. I think Pentax realizes that simply dropping a new sensor into the next model is not going to entice people to upgrade from the K-5. I would assume the next body will have other significant upgrades.

10-26-2011, 06:49 AM	#297
Supernaut Veteran Member Join Date: Sep 2008 Location: West Coast , Sweden Posts: 467	Originally posted by Winder I think Pentax realizes that simply dropping a new sensor into the next model is not going to entice people to upgrade from the K-5. I would assume the next body will have other significant upgrades. +1 That would be the least interesting release ever :ugh:

10-26-2011, 06:53 AM	#298
Emacs Veteran Member Join Date: Oct 2010 Location: Moscow Posts: 1,223	Originally posted by Supernaut +1 That would be the least interesting release ever :ugh: It can be the MOST interesting release for the K-mount lenses owners ever: just put the 36x24 there

10-26-2011, 07:22 AM	#299
eddie1960 Veteran Member Join Date: Aug 2010 Location: Toronto Photos: Gallery \| Albums Posts: 13,667	right now there won't be any models from anyone using sony sensors the plant is one of the Sony plants under water in Thailand.

Pentax version of the Sony a77 coming ?

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