Another Olympus E-M1 and SONY a7 walkabout test, high ISO

Started 8 months ago | Discussions
MrGubrz
Contributing MemberPosts: 743Gear list
Like?
Re: Another Olympus E-M1 and SONY a7 walkabout test, high ISO
In reply to Daniel Wee, 8 months ago

great write up and read!

thanks for a lovely distraction from work!

i cant recall, but in your 35equiv post, did you make mention of the user experience of the 2 different bodies?

i recently purchased one of these cameras after heading to the photo shop in town to purchase the OTHER. after handling them both, there was no way i could leave the shop with the camera i had originally intended to purchase.  it just didnt feel right to ME.

do you have any similar experience? or are you just as comfy with either body?

 MrGubrz's gear list:MrGubrz's gear list
Sony RX1 Olympus E-30 Olympus E-M1 Sony Alpha 7S Olympus M.Zuiko Digital 17mm 1:2.8 Pancake +9 more
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Blue Skies misleading again.
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I saw in another thread where you admitted the difference between the E-M1 and A7 is NOT 2 stops, and when I went to DxO's site to verify this I saw the difference in noise was usualy about one to one and a half stops and the difference in dynamic range was almost always only 1/2 stop and maybe less.  Are you now saying DxO is wrong?   I'll take the camera with more dynamic range that can has a focus system that works over one that is very unreliable, had slightly less noise, but also less dynamcic range.  I am just glad I can use the E-M1 to take pictures of kids in action with a lens over 70mm. 

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
You are rigtht and BS is try to sell Sonys
In reply to skyglider, 8 months ago

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area.  This is because they both have the same exposure.  Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
But that is wrong.
In reply to skyglider, 8 months ago

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now.  I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor.  Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field.  If you check the results from DxO tests, the difference is much less.  A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100.   It would even be the same on your smartphone!

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
quezra
Senior MemberPosts: 2,439Gear list
Like?
Re: But that is wrong.
In reply to Lab D, 8 months ago

Why don't you refer to T-stop then, since that is clearly what you're actually talking about.  F-stop is just a ratio of aperture opening to the focal length, it gives you an approximate idea of light gathering but it varies from lens to lens.  Daniel here has actually quite by accident shown how the T1.8 of the PanaLeica is equal to the T1.8 of the FE 55 - when both lenses are wide open (f1.4 vs f1.8), and this is backed up by DxOmark.

 quezra's gear list:quezra's gear list
Sony Alpha 7 Sony FE 55mm F1.8 Sony FE 28-70mm F3.5-5.6 OSS Sony Alpha NEX-5N Voigtlander 35mm F1.4 Nokton +7 more
Reply   Reply with quote   Complain
Advent1sam
Senior MemberPosts: 1,210
Like?
Re: Thanks Daniel
In reply to Daniel Wee, 8 months ago

Reply   Reply with quote   Complain
assaft
Contributing MemberPosts: 858Gear list
Like?
Re: Another Olympus E-M1 and SONY a7 walkabout test, high ISO
In reply to Daniel Wee, 8 months ago

Daniel Wee wrote:

I think, in all fairness, that could be more an issue of the a7 AF in low-light than a lens issue. For those two shots, I had to use AF because I had the camera on the ledge of a building and it was inconvenient for me to MF them. In this case, I suspect it was due to the a7 missing the focus while the E-M1 nailed it.

Thanks for the reviews - they were clear and enjoyable to read.

I think that the CZ lens doesn't perform so well. The PL looks better to me in the center, and more so on the sides (taking into account that the noise might affect the judgement somewhat). If I were you, I would have tested the CZ very seriously while I can still replace it. The following are crops from the city scape, I think that the crop from the center indicates that focus was OK.

PL vs CZ, center.

PL vs. CZ, sides.

 assaft's gear list:assaft's gear list
Olympus PEN E-PL2 Olympus OM-D E-M10 Olympus M.Zuiko Digital ED 9-18mm 1:4.0-5.6 Panasonic Lumix G 20mm F1.7 ASPH Panasonic Lumix G 14mm F2.5 ASPH +5 more
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: Blue Skies misleading again.
In reply to Lab D, 8 months ago

Lab D wrote:

blue_skies wrote:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I saw in another thread where you admitted the difference between the E-M1 and A7 is NOT 2 stops, and when I went to DxO's site to verify this I saw the difference in noise was usualy about one to one and a half stops and the difference in dynamic range was almost always only 1/2 stop and maybe less. Are you now saying DxO is wrong? I'll take the camera with more dynamic range that can has a focus system that works over one that is very unreliable, had slightly less noise, but also less dynamcic range. I am just glad I can use the E-M1 to take pictures of kids in action with a lens over 70mm.

Lol, just how many aliases are you using all over these forums?

You throw in DR and other variables to get nitpicking on what is going on here. Please also start talking true ISO and true resolution and RAW vs RAW with same JPG engine flows. Please ...

You keep saying f/2.8 is faster than f/4.0, and we keep telling you 'it ain't so', at least not in the way that you make it sound like...

Grow up, will ya?

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: You are rigtht and BS is try to sell Sonys
In reply to Lab D, 8 months ago

Lab D wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area. This is because they both have the same exposure. Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

Please re-read. No one is stating anything different.

The discussion was wrt/ different noise level, and how exposure compensation can be used to match that.

f/2.8 = f/2.8 = f/2.8 across formats - same exposure. WE AGREE. You see? BUT THE NOISE LEVELS ARE NOT THE SAME.

If you understand sensor noise and equivalence, you begin to understand the discussions. Please re-read.

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: But that is wrong.
In reply to Lab D, 8 months ago

Lab D wrote:

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now. I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor. Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field. If you check the results from DxO tests, the difference is much less. A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100. It would even be the same on your smartphone!

Sorry, but you have been whining about this for years now (longer that this new alias of yours exists).

Scroll back a few posts, and look at the images that I compared - they appear rather different.

Again, exposure = exposure and equivalence = equivalence. These are different. AND YOU DON'T GET IT, OR DON'T WANT TO GET IT.

In your analysis, m43 = FF for all practical purposes, other than for DOF. Well, I hate to break your bubble, but IT AIN'T SO.

And no - I have no interest in starting another long back and forth with you to produce deleted threads.

Just grow up a bit, will ya?

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
You never let facts get in the way :)
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I saw in another thread where you admitted the difference between the E-M1 and A7 is NOT 2 stops, and when I went to DxO's site to verify this I saw the difference in noise was usualy about one to one and a half stops and the difference in dynamic range was almost always only 1/2 stop and maybe less. Are you now saying DxO is wrong? I'll take the camera with more dynamic range that can has a focus system that works over one that is very unreliable, had slightly less noise, but also less dynamcic range. I am just glad I can use the E-M1 to take pictures of kids in action with a lens over 70mm.

You throw in DR and other variables to get nitpicking on what is going on here. Please also start talking true ISO and true resolution and RAW vs RAW...

You never let facts get in the way do you.  DxO normalizes for ISO (makes sure it is the same for cameras tested) and only compares RAW files because JPEGs are modified and can be misleading.  So when they comapre apples to apples, the difference in dynamic range is about 1/2 stop and the difference in noise is much less than 2 stops, and you know this.

I didn't say F/2.8 is equal to F/4 either.  You said that to distract eveyone.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Re: You are rigtht and BS is try to sell Sonys
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area. This is because they both have the same exposure. Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

f/2.8 = f/2.8 = f/2.8 across formats - same exposure. WE AGREE. You see? BUT THE NOISE LEVELS ARE NOT THE SAME.

Yes, and you know noise levels are NOT 2 stops different and dynamic range is NOT 2 stops different for these cameras.  Dynamic range is about 1/2 stop for the majority of ISOs DxO tested.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Re: But that is wrong.
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now. I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor. Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field. If you check the results from DxO tests, the difference is much less. A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100. It would even be the same on your smartphone!

Again, exposure = exposure and equivalence = equivalence.

And you know in this case equivalance does not tell us the facts.  Admit it, there is NOT a 2 stop difference for noise or dynamic range at almsot all the ISOs DxO tested.

Just admit the truth for once.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: You never let facts get in the way :)
In reply to Lab D, 8 months ago

Lab D wrote:

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I saw in another thread where you admitted the difference between the E-M1 and A7 is NOT 2 stops, and when I went to DxO's site to verify this I saw the difference in noise was usualy about one to one and a half stops and the difference in dynamic range was almost always only 1/2 stop and maybe less. Are you now saying DxO is wrong? I'll take the camera with more dynamic range that can has a focus system that works over one that is very unreliable, had slightly less noise, but also less dynamcic range. I am just glad I can use the E-M1 to take pictures of kids in action with a lens over 70mm.

You throw in DR and other variables to get nitpicking on what is going on here. Please also start talking true ISO and true resolution and RAW vs RAW...

You never let facts get in the way do you. DxO normalizes for ISO (makes sure it is the same for cameras tested) and only compares RAW files because JPEGs are modified and can be misleading. So when they comapre apples to apples, the difference in dynamic range is about 1/2 stop and the difference in noise is much less than 2 stops, and you know this.

I didn't say F/2.8 is equal to F/4 either. You said that to distract eveyone.

ok, I repeat your first post:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

and I repeat my answer again:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I read, again, that you claim that the Oly 12-40/f2.8 gets you one stop faster than the Sony 24-70/f4.0.

And I answer again, that is IGNORING the sensor format. Add in the sensor, YES AT 4X RATIO, or 2 STOPS DIFFERENCE, and you are one stop slower (f/5.6 at FF).

Why deny the simple logic? If DxO points out that it is 1.65x stops or 1.5x stops, it does NOT CHANGE the general thoughts - and your analysis remains WRONG !!!!

http://www.dxomark.com/Cameras/Compare/Side-by-side/Sony-A7-versus-Sony-A7R-versus-Olympus-OM-D-E-M1___916_917_909

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: But that is wrong.
In reply to Lab D, 8 months ago

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now. I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor. Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field. If you check the results from DxO tests, the difference is much less. A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100. It would even be the same on your smartphone!

Again, exposure = exposure and equivalence = equivalence.

And you know in this case equivalance does not tell us the facts. Admit it, there is NOT a 2 stop difference for noise or dynamic range at almsot all the ISOs DxO tested.

Just admit the truth for once.

http://www.dxomark.com/Cameras/Compare/Side-by-side/Sony-A7-versus-Sony-A7R-versus-Olympus-OM-D-E-M1___916_917_909

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: You are rigtht and BS is try to sell Sonys
In reply to Lab D, 8 months ago

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area. This is because they both have the same exposure. Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

f/2.8 = f/2.8 = f/2.8 across formats - same exposure. WE AGREE. You see? BUT THE NOISE LEVELS ARE NOT THE SAME.

Yes, and you know noise levels are NOT 2 stops different and dynamic range is NOT 2 stops different for these cameras. Dynamic range is about 1/2 stop for the majority of ISOs DxO tested.

http://www.dxomark.com/Cameras/Compare/Side-by-side/Sony-A7-versus-Sony-A7R-versus-Olympus-OM-D-E-M1___916_917_909

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Thanks for admitting it finally.
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

Aperture is the same.

Think of it this way:

A fat lady and a thin supermodel are laying on the beach. Who will get sun burnt faster? Answer: both will burn/tan the same despite the fat lady having 4x the skin area. This is because they both have the same exposure. Anyway, Four Thirds is the hot supermodel.

F/2.8 is the same for a Nikon 1, an RX100, the E-M1 and the A7.

f/2.8 = f/2.8 = f/2.8 across formats - same exposure. WE AGREE. You see? BUT THE NOISE LEVELS ARE NOT THE SAME.

Yes, and you know noise levels are NOT 2 stops different and dynamic range is NOT 2 stops different for these cameras. Dynamic range is about 1/2 stop for the majority of ISOs DxO tested.

http://www.dxomark.com

-- hide signature --

Cheers,
Henry

Here is what you link shows.  As we agree, from ISO150 to ISO10000 (the most common range), there is maybe 1/2 stop.  Interestingly, I didn't see before that sometimes it is only one third.

Thanks for this, and thanks for admitting the truth. If you adjust for the difference in the F/2.8 and F/4 lenses, we can see which the better camera is.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Thanks for the truth!
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now. I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor. Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field. If you check the results from DxO tests, the difference is much less. A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100. It would even be the same on your smartphone!

Again, exposure = exposure and equivalence = equivalence.

And you know in this case equivalance does not tell us the facts. Admit it, there is NOT a 2 stop difference for noise or dynamic range at almsot all the ISOs DxO tested.

Just admit the truth for once.

Henry showing the difference between sensors

-- hide signature --

Cheers,
Henry

You are right with the DxO link.  The difference is really negligible.  There is not a 2 stop difference almost all of time here.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
Lab D
Senior MemberPosts: 4,012Gear list
Like?
Right.
In reply to blue_skies, 8 months ago

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I saw in another thread where you admitted the difference between the E-M1 and A7 is NOT 2 stops, and when I went to DxO's site to verify this I saw the difference in noise was usualy about one to one and a half stops and the difference in dynamic range was almost always only 1/2 stop and maybe less. Are you now saying DxO is wrong? I'll take the camera with more dynamic range that can has a focus system that works over one that is very unreliable, had slightly less noise, but also less dynamcic range. I am just glad I can use the E-M1 to take pictures of kids in action with a lens over 70mm.

You throw in DR and other variables to get nitpicking on what is going on here. Please also start talking true ISO and true resolution and RAW vs RAW...

You never let facts get in the way do you. DxO normalizes for ISO (makes sure it is the same for cameras tested) and only compares RAW files because JPEGs are modified and can be misleading. So when they comapre apples to apples, the difference in dynamic range is about 1/2 stop and the difference in noise is much less than 2 stops, and you know this.

I didn't say F/2.8 is equal to F/4 either. You said that to distract eveyone.

ok, I repeat your first post:

Lab D wrote:

Thanks for the samples, they are very helpful.

I would remind everyone that Olympus has wider aperture lenses and IBIS too. This means if you use the Olympus 12-40mm F/2.8 as a walkabout lens, not only will you have a greater range and more uses (also a great close-up lens), but you will get 1 extra stop of light over the new Sony 24-70mm F/4 lens.

and I repeat my answer again:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

You can expose on the Oly one stop faster (at f/2.8), but the sensor difference nullify this.

I read, again, that you claim that the Oly 12-40/f2.8 gets you one stop faster than the Sony 24-70/f4.0.

Correct. Let's look at the picture from your link.  Since the F/2.8 lens gets you an extra stop, you can shift the E-M1 results 1 stop (ISO) to the right.   When you do that, it gives you more dynamic range than the A7 or A7R.  Anyone claiming there is a 2 stop difference for those ISOs is not telling the truth.

 Lab D's gear list:Lab D's gear list
Panasonic Lumix DMC-FZ1000 Nikon D600 Panasonic Lumix DMC-GH4
Reply   Reply with quote   Complain
blue_skies
Senior MemberPosts: 7,060Gear list
Like?
Re: Thanks for the truth!
In reply to Lab D, 8 months ago

Lab D wrote:

blue_skies wrote:

Lab D wrote:

blue_skies wrote:

Lab D wrote:

skyglider wrote:

blue_skies wrote:

skyglider wrote:

blue_skies wrote:

How so: in equivalence terms, the Oly 12-40/f2.8 becomes 24-80/f5.6 versus the Sony 24-70/f4.0?

Hi Henry,

I understand how the Oly 12-40mm is equivalent to 24-80mm in 35mm terms because of the 2x crop factor of the micro 4/3 sensor. But AFAIK, the aperture remains the same.

IOW, if an Oly 12mm lens could be used on a full frame (35mm) sensor, only the center 1/4 of the sensor area would be illuminated which is equivalent to 1/2 the horizontal and vertical pixels. Thus the crop factor of 2x. But the aperture remains the same so the same amount of light is hitting that portion of the sensor by the F2.8 aperture. So the aperture does "not" become equivalent to a F5.6 aperture.

Is my understanding incorrect?

Thanks,
Sky

Hi Sky, no your understanding is correct.

In terms of ISO, aperture and shutter speed, the exposure is the SAME on the small and the larger sensor.

If you are after (fast) shutter speed, you only care about the lens speed, and your thinking is correct.

But in terms of noise, the larger sensor allows to operate at a much higher ISO level and produce the same amount of noise: in m43/FF this is a 4x ratio, or 2 stops. This means that eg. m43 at ISO 1,000 is as noise as FF at ISO 4,000.

So, if you want to produce comparable images, you would shoot the FF image with two stops slower aperture and at two stops higher ISO. This is equivalent exposure.

Ironically, the same metric applies to DOF - you roughly see about the same DOF in both images as well.

Thus, shooting the Oly at 12mm f/2.8, ISO 1,000 as 1/60th is equivalent to shooting the Sony at f/5.6, ISO 4,000 and 1/60th. Aside from the resolution, the two images will appear similar.

If you use the same exposure on both, you are comparing the FF at ISO 1,000 versus the Oly at ISO 1,000. The FF image will have a lot less noise, ie. be much cleaner, but the DOF will also be reduced. The images are not equivalent at that point.

On FF you can trade noise for DOF, assuming you have a fast lens. There is a 2 stop delta to play with.

In the example, using the Sony lens at f/4.0 implies that the ISO goes to 2,000. This is one stop below the equivalent values of f/5.6 and ISO 4,000, so, with more shallow DOF, you will have a less noisy image on the FF.

-- hide signature --

Cheers,
Henry

Hi Henry,

I think I understand your point now. I wondered how many stops difference there was between a micro 4/3 sensor verses a full frame sensor. Now I know it's a 4x ratio or 2 stops difference.

That only applies for Depth of field. If you check the results from DxO tests, the difference is much less. A good example is dynamic range where the E-M1 is only about 1/2 stop different than the A7 for most of the ISO settings DxO tested.

Remember if you need F/2.8, 1/60th sec shutter speed, and ISO800 on the E-M1, you will need the SAME settings on an A7, a Nikon 1 and a Sony RX100. It would even be the same on your smartphone!

Again, exposure = exposure and equivalence = equivalence.

And you know in this case equivalance does not tell us the facts. Admit it, there is NOT a 2 stop difference for noise or dynamic range at almsot all the ISOs DxO tested.

Just admit the truth for once.

Henry showing the difference between sensors

-- hide signature --

Cheers,
Henry

You are right with the DxO link. The difference is really negligible. There is not a 2 stop difference almost all of time here.

?????

Please go take ISO 6400 pictures with your EM1 then

You conveniently deleted that I stated that it is immaterial whether it is 2x, or 1.65x, or 1.5x stops. It is immaterial, imho, as I would not use a smaller sensor camera at higher ISO. Why not? Because the image quality degrades too much. I would rather use longer exposure and lower ISO, if possible.

And we have had this discussion so many times already. Why the nitpicking?

Lower the ISO, and both cameras are great. They both have their pros and cons.

-- hide signature --

Cheers,
Henry

 blue_skies's gear list:blue_skies's gear list
Canon PowerShot S95 Sony Alpha NEX-7 Sony Alpha NEX-6 Sony Alpha 7 Sony a6000 +30 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads