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Author Topic: DxO article series on lenses for D800  (Read 5526 times)

Fine_Art

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Fine_Art

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Re: DxO article series on lenses for D800
« Reply #1 on: March 14, 2013, 04:39:39 pm »

One thing I cant understand is the very low P-Mpix ratings of the best primes.

I use the Sony 50, 100 on a 16MP APS-C. DxO claims those have 14P-Mpix on the A900 which is a 24 MP camera. The Nikon 105 which is supposed to be quite good, is rated at 16P-Mpix on the D800 36MP camera!

Here is their P-MPix explained http://www.dxomark.com/index.php/Publications/DxOMark-Reviews/Looking-for-new-photo-gear-DxOMark-s-Perceptual-Megapixel-can-help-you. It seems fairly straight forward.

I know I have tested my primes against Bart's 144cycle Siemens star (sinusoidal version). They are near nyquist on my camera. DxO seems to be claiming the higher res sensors have no benefit. Having downloaded the raws for comparison I can say there is more than 16MP resolution on the A900,99 or D800!


Where is the beef resolution?
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ErikKaffehr

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Re: DxO article series on lenses for D800
« Reply #2 on: March 14, 2013, 04:51:56 pm »

Hi,

Sorry what is the issue?

Best regards
Erik


One thing I cant understand is the very low P-Mpix ratings of the best primes.

I use the Sony 50, 100 on a 16MP APS-C. DxO claims those have 14P-Mpix on the A900 which is a 24 MP camera. The Nikon 105 which is supposed to be quite good, is rated at 16P-Mpix on the D800 36MP camera!

Here is their P-MPix explained http://www.dxomark.com/index.php/Publications/DxOMark-Reviews/Looking-for-new-photo-gear-DxOMark-s-Perceptual-Megapixel-can-help-you. It seems fairly straight forward.

I know I have tested my primes against Bart's 144cycle Siemens star (sinusoidal version). They are near nyquist on my camera. DxO seems to be claiming the higher res sensors have no benefit. Having downloaded the raws for comparison I can say there is more than 16MP resolution on the A900,99 or D800!


Where is the beef resolution?
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Erik Kaffehr
 

Fine_Art

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Re: DxO article series on lenses for D800
« Reply #3 on: March 14, 2013, 10:55:23 pm »

Hi,

Sorry what is the issue?

Best regards
Erik



The issue is they are saying the D800 with top primes is delivering 16-22MP of resolution. I have converted the raws, there is far more resolution than that. The same issue on the Sonys or presumably the Canons. My expectation for precetual resolution would be 90-98% of stated resolution.

They also say zooms are 20-30% less than primes. I can buy that, but not with their very low stated numbers.
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BernardLanguillier

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Re: DxO article series on lenses for D800
« Reply #4 on: March 14, 2013, 11:12:40 pm »

The relative value is probably more relevant than the absolute number.

This being said, I have used many of the lenses they are reporting on and have to agree with their findings.

In particular I am falling in love all over again with the 85mm f1.4 AF-S. It really is an outstanding piece of glass!

Cheers,
Bernard

Fine_Art

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Re: DxO article series on lenses for D800
« Reply #5 on: March 14, 2013, 11:37:16 pm »

The relative value is probably more relevant than the absolute number.

This being said, I have used many of the lenses they are reporting on and have to agree with their findings.

In particular I am falling in love all over again with the 85mm f1.4 AF-S. It really is an outstanding piece of glass!

Cheers,
Bernard


Sure, that makes sense to me.

Still the absolute number seems strange. Here is the D800 ISO 3200 file from Imaging Resource again, yes the under exposed one. The lens is the Sigma 70 macro. Granted this is a new version of Raw Therapee set for Color/Lab based NR (they made it real after we discussed it on their website following the discussion here), Richardson-Lucy deconvolution sharpening.

I am impressed by the thread level detail in the cloths at ISO3200! Now if that was really 16MP of resolution it would look binned 2x2.

« Last Edit: March 14, 2013, 11:47:11 pm by Fine_Art »
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Vladimirovich

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Re: DxO article series on lenses for D800
« Reply #6 on: March 15, 2013, 01:06:04 am »

I am impressed by the thread level detail in the cloths at ISO3200! Now if that was really 16MP of resolution it would look binned 2x2.
why ? just because you are "impressed" and say so ? now that is a good argument  ::)
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ErikKaffehr

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Re: DxO article series on lenses for D800
« Reply #7 on: March 15, 2013, 01:56:46 am »

Hi,

Binning 2x2 would reduce resolution to 6 MP.

Anyway, most decent lenses resolve well beyond 36 MP. The question is how much contrast they transfer and how god the weak areas are, corners, field curvature.

The resolution of the D800 is alway 36 MP, it is just a question of 36 MP of what?

Best regards
Erik


Sure, that makes sense to me.

Still the absolute number seems strange. Here is the D800 ISO 3200 file from Imaging Resource again, yes the under exposed one. The lens is the Sigma 70 macro. Granted this is a new version of Raw Therapee set for Color/Lab based NR (they made it real after we discussed it on their website following the discussion here), Richardson-Lucy deconvolution sharpening.

I am impressed by the thread level detail in the cloths at ISO3200! Now if that was really 16MP of resolution it would look binned 2x2.


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Erik Kaffehr
 

Fine_Art

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Re: DxO article series on lenses for D800
« Reply #8 on: March 15, 2013, 02:20:55 am »

why ? just because you are "impressed" and say so ? now that is a good argument  ::)

You have made it clear before you work for a competing developer. You don't want anyone saying good things about other products.
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Fine_Art

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Re: DxO article series on lenses for D800
« Reply #9 on: March 15, 2013, 02:37:25 am »

Hi,

Binning 2x2 would reduce resolution to 6 MP.

Anyway, most decent lenses resolve well beyond 36 MP. The question is how much contrast they transfer and how god the weak areas are, corners, field curvature.

The resolution of the D800 is alway 36 MP, it is just a question of 36 MP of what?

Best regards
Erik



9MP actually. 6MP 2 across by 2 high is 24.

Yes, I agree decent lenses, especially primes, can handle the 36MP with few difficulties. There may be a bit of smearing in the corners, so what, that is usually OOF anyway. If you need the corners to be good stitch 2 shots. Problem solved.

They make an issue in the article about the OLP filter. It would be interesting to see what their numbers are for those lenses with the E version of the camera. I guess I have gotten so used to using deconvolution with a weak filtered camera I forget how bad pixel level detail can be. Ive said before images look more realistic downsampled 50% so I guess I can understand where they are coming from. Squaring that with the sample images I have seen is not straight forward. The detail looks pretty good!
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hjulenissen

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Re: DxO article series on lenses for D800
« Reply #10 on: March 15, 2013, 04:42:41 am »

DxO seems to be claiming the higher res sensors have no benefit.
I believe that they are claiming the opposite:
"So is switching from the 24megapixels of a D3X to the 36 megapixels of a D800 really worth it? Well, in overall terms, the average improvement in P-Mpix score of a lens on a D800 compared to a D3X, is around 10%. This is not a negligible improvement and should therefore not be ignored. However, bare in mind that this is an average performance increase, so some lenses such as the high-end prime models will show a greater improvement, while lower end zoom and super zoom models will not benefit anywhere near as much."

http://www.dxomark.com/index.php/Publications/DxOMark-Reviews/Which-lenses-for-your-Nikon-D800
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Hulyss

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Re: DxO article series on lenses for D800
« Reply #11 on: March 15, 2013, 05:03:33 am »

Guys ...

Go foveon and stop ranting !!  ;D
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BernardLanguillier

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Re: DxO article series on lenses for D800
« Reply #12 on: March 15, 2013, 05:18:29 am »

Guys ...

Go foveon and stop ranting !!  ;D

I love my DP2m, but I cannot mount my 85mm f1.4 AF-S on it... nor the Leica 180 f2.8 APO... nor...  ;D

Cheers,
Bernard

kers

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Re: DxO article series on lenses for D800
« Reply #13 on: March 15, 2013, 09:17:38 am »

The DXO lens scores make some comparison possible, but for instance sharpness is only one number covering all apertures - that is not very informative...
An 1.4 lens is made to be used wide open and central sharpness is more important while a TS lens is made to be used at d8-11 and has to be sharp from corner to corner..
Also they use a MPIX number for sharpness that makes not much sense - the center of a lens can be easely above 50 MP while the sides suffer..
Af speed is not included- the 1,8G 50mm Nikkor is almost as sharp as the 1,4G at 1,8 but it has a much faster AF. That was for me the reason to choose it...etc
Their information on lenses is so general that i would prefer other test-sites like Photozone etc...
The sensor database i find more interesting for it is the only good reference on sensors as far as i know...

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ErikKaffehr

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Re: DxO article series on lenses for D800
« Reply #14 on: March 15, 2013, 10:45:40 am »

Hi,

IMHO there is a lot of data in the DxO data base, but the simple figure of merit hey have is pretty uninformative.

You need to check all diagrams for each lens.

Best regards
Erik

The DXO lens scores make some comparison possible, but for instance sharpness is only one number covering all apertures - that is not very informative...
An 1.4 lens is made to be used wide open and central sharpness is more important while a TS lens is made to be used at d8-11 and has to be sharp from corner to corner..
Also they use a MPIX number for sharpness that makes not much sense - the center of a lens can be easely above 50 MP while the sides suffer..
Af speed is not included- the 1,8G 50mm Nikkor is almost as sharp as the 1,4G at 1,8 but it has a much faster AF. That was for me the reason to choose it...etc
Their information on lenses is so general that i would prefer other test-sites like Photozone etc...
The sensor database i find more interesting for it is the only good reference on sensors as far as i know...


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Erik Kaffehr
 

Vladimirovich

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Re: DxO article series on lenses for D800
« Reply #15 on: March 15, 2013, 11:47:45 am »

You have made it clear before you work for a competing developer.
competing developer ?
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Fine_Art

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Re: DxO article series on lenses for D800
« Reply #16 on: March 15, 2013, 12:02:49 pm »

I believe that they are claiming the opposite:
"So is switching from the 24megapixels of a D3X to the 36 megapixels of a D800 really worth it? Well, in overall terms, the average improvement in P-Mpix score of a lens on a D800 compared to a D3X, is around 10%. This is not a negligible improvement and should therefore not be ignored. However, bare in mind that this is an average performance increase, so some lenses such as the high-end prime models will show a greater improvement, while lower end zoom and super zoom models will not benefit anywhere near as much."

http://www.dxomark.com/index.php/Publications/DxOMark-Reviews/Which-lenses-for-your-Nikon-D800


Ok, it is vastly diminishing returns.
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Fine_Art

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Re: DxO article series on lenses for D800
« Reply #17 on: March 15, 2013, 12:08:10 pm »

competing developer ?

You do contract work for Adobe, yes? If I have to state the obvious LR is the big player. Raw Therapee is a small group of open source developers.
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Vladimirovich

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Re: DxO article series on lenses for D800
« Reply #18 on: March 15, 2013, 01:46:35 pm »

You do contract work for Adobe, yes?

absolutely not ! I do not qualify at all... I merely use ACR and PS and that's it.
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Fine_Art

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Re: DxO article series on lenses for D800
« Reply #19 on: March 15, 2013, 01:56:32 pm »

absolutely not ! I do not qualify at all... I merely use ACR and PS and that's it.

My mistake then. Sorry.
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