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Author Topic: 645D vs 5Dmk2 part 2  (Read 10190 times)

mhecker*

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645D vs 5Dmk2 part 2
« on: January 22, 2011, 03:04:55 pm »

This time some full daylight outdoor testing under landscape conditions

Sunlight, Detailed landscape, ISO 100, RAW

5dmk2, 24-70mm zoom lens @ f8    autofocus   34mm focal length
645D,   45-85mm zoom lens @ f11  autofocus   45mm focal length

After capture daylight color balance in LR, no sharpening.
Sharpening in CS5 5D shot USM 350,0.4,1   645D USM 250,0.4,1

A little more sharpening on 5Dmk2 because of its AA filter

A little use of adjust shadows command in CS5 to open shadows   about 15,30,50 settings


Links.

5Dmk2  http://wyofoto.com/Pentax_645D/House_35mm_5Dmk2.tif
645D    http://wyofoto.com/Pentax_645D/House_35mm_645D.tif

Warning big files 5DMk2 is 39MB,  645D file is 67MB

You'll need Photoshop to open the TIFF's.

I feel the wide dynamic range and fine random detail of this real world shot very revealing.

Cowabunga dude!   ;D



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ErikKaffehr

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Re: 645D vs 5Dmk2 part 2
« Reply #1 on: January 22, 2011, 05:00:53 pm »

Hi,

I guess that you are not complaining...

Would be nice if you could share some raw images, too.

The studio shots were much closer in color, but the resolution advantage of the P645D is very clear on these samples, too.

THANKS FOR SHARING!

Best regards
Erik

This time some full daylight outdoor testing under landscape conditions

Sunlight, Detailed landscape, ISO 100, RAW

5dmk2, 24-70mm zoom lens @ f8    autofocus   34mm focal length
645D,   45-85mm zoom lens @ f11  autofocus   45mm focal length

After capture daylight color balance in LR, no sharpening.
Sharpening in CS5 5D shot USM 350,0.4,1   645D USM 250,0.4,1

A little more sharpening on 5Dmk2 because of its AA filter

A little use of adjust shadows command in CS5 to open shadows   about 15,30,50 settings


Links.

5Dmk2  http://wyofoto.com/Pentax_645D/House_35mm_5Dmk2.tif
645D    http://wyofoto.com/Pentax_645D/House_35mm_645D.tif

Warning big files 5DMk2 is 39MB,  645D file is 67MB

You'll need Photoshop to open the TIFF's.

I feel the wide dynamic range and fine random detail of this real world shot very revealing.

Cowabunga dude!   ;D




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Erik Kaffehr
 

tsjanik

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Re: 645D vs 5Dmk2 part 2
« Reply #2 on: January 22, 2011, 08:12:49 pm »

I have the impression you like the camera.   ;D  I had mine out for two hours today, unprotected at 90 Fahrenheit, worked without a hitch.   Red pines and actual pixel crop, 45-85mm
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DeeJay

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Re: 645D vs 5Dmk2 part 2
« Reply #3 on: January 23, 2011, 07:04:21 am »

Thanks for sharing the pics, very nice. It's a very clean image from the Pentax isn't it? The extra DR is certainly apparent. THose Canon shadows looks rather hideous in comparison.
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MrSmith

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Re: 645D vs 5Dmk2 part 2
« Reply #4 on: January 23, 2011, 07:55:38 am »

the pentax files look great.
the 5DII looks oversharpened to me and there is some ugly shadow noise probably down to bad exposure or processing? if you shot at 160asa (as i said in the previous thread) you will not see pattern noise like this.

i did look at at one particular area in photoshop. you can see the pattern noise quite clearly
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mhecker*

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Re: 645D vs 5Dmk2 part 2
« Reply #5 on: January 23, 2011, 11:55:51 am »

I like this setup as a test shot because of its extreme dynamic range.
Light colored siding in full sun to black objects in deep shadows.
The 645D is clearly showing its superior dynamic range here.

You certainly can see the pattern noise there in the 5Dmk2 shot when the shadows are pushed.
Part of the problem is the 5Dmk2 does not have as wide a dynamic range as the 645D.
I think that will become even more apparent with thorough testing.
So the signal to noise ratio is less and as you view the shadows with a reduced signal, the noise becomes visible.

Why will shooting 160 ISO remove the pattern noise?

As I understand it the pattern noise is do to mismatched amplifiers on adjacent pixel channels or green filters with differing optical transmission characteristics.  Canon of course doesn't admit it exists. How will gathering less photons offset what is a physical problem inherent in the electro-optical system?

At ISO 160 you are merely shooting at ISO 200 and overexposing 1/3 stop.

See http://canonphotogroup.com/misc/5DM2-ISO-Noise-POTN.jpg

In return for a tiny bit cleaner shadows you lose 1/3 stop headroom on the high end.
That's okay in the studio with a limited range of light, but not so okay outdoors with a huge range of light levels.
You could de-rate the 5D and shoot at ISO 50 and do better shadow wise, but that would also loose you 1 stop range on the high end.  The highlights would start blocking up.

« Last Edit: January 23, 2011, 03:44:49 pm by mhecker* »
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MrSmith

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Re: 645D vs 5Dmk2 part 2
« Reply #6 on: January 23, 2011, 12:54:28 pm »

160 is the chips native iso.


you can see the cleanest iso's are 160, 320, 640, 1250
the square pattern noise and noise in general is much cleaner at 160, i have not seen a 1stop loss in DR from 100-160 only cleaner files?
this graph suggests the same. (though not a fan of DXO as they don't take into account a chips native iso)


a 160 asa comparison would be a fair one against the 100 of the pentax as this is comparing the iso's with the best image quality. the 5dII examples you show don't give a good indication of what the camera is capable of imho.
« Last Edit: January 23, 2011, 12:56:35 pm by MrSmith »
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adammork

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Re: 645D vs 5Dmk2 part 2
« Reply #7 on: January 23, 2011, 02:04:54 pm »

160 is the chips native iso.

This is also my findings, and others, often filmmakers... From my testing the 160 iso gives a bit more grain in the files but more clean and a little better DR

/adam
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ErikKaffehr

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Re: 645D vs 5Dmk2 part 2
« Reply #8 on: January 23, 2011, 02:18:40 pm »

Hi,

I don't really think ISO matters that much as far as the image is correctly exposed to the right. Something I have noticed is that new raw processing pipeline in LR 3 seems to enhance noise on Canon but be beneficial on Sony.

It would be very nice to have some raw-files to play with.

In general I have the impression that the Pentax images are much better. To begin with, the lens is much better, the Canon is not very impressive in the right top corner.

Best regards
Erik


I like this setup as a test shot because of its extreme dynamic range.
Light colored siding in full sun to black objects in deep shadows.
The 645D is clearly showing its superior dynamic range here.

You certainly can see the pattern noise there in the 5Dmk2 shot when the shadows are pushed.
Part of the problem is the 5Dmk2 does not have as wide a dynamic range as the 645D.
I think that will become even more apparent with thorough testing.
So the signal to noise ratio is less and as you view the shadows with a reduced signal, the noise becomes visible.

Why will shooting 160 ISO remove the pattern noise?

As I understand it the pattern noise is do to mismatched amplifiers on adjacent pixel channels or green filters with differing optical transmission characteristics.  Canon of course doesn't admit it exists. How will gathering less photons offset what is a physical problem inherent in the electro-optical system?

At ISO 160 you are merely shooting at ISO 160 and overexposing 1/3 stop.

See http://canonphotogroup.com/misc/5DM2-ISO-Noise-POTN.jpg

In return for a tiny bit cleaner shadows you lose 1 stop headroom on the high end.
That's okay in the studio with a limited range of light, but not so okay outdoors with a huge range of light levels.
You could de-rate the 5D and shoot at ISO 50 and do better shadow wise, but that would also loose you 1 stop range on the high end.  The highlights would start blocking up.


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uaiomex

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Re: 645D vs 5Dmk2 part 2
« Reply #9 on: January 23, 2011, 03:59:15 pm »

Surprised to know iso 160 is native in 5D2. In this comparison I can see clearly the Pentax advantage in resolution. The receded foliage on the right part of the pic turns to mush in the 5D2 (I'd like to believe it's the lens :D) but not at all in the 645D. In dynamic range I don't see much difference. I like better the overall color in the Pentax but it might be just processing.
I don't see how the 1DS line can hold its asking price now that the Pentax came with ths 645D for a mere $2K more. On behalf of the 5D2, again I say it's the best buy in the photo world.
Thanks for sharing
Eduardo
 
« Last Edit: January 23, 2011, 04:01:45 pm by uaiomex »
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Leping

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Re: 645D vs 5Dmk2 part 2
« Reply #10 on: January 23, 2011, 04:43:44 pm »

the 5DII looks oversharpened to me and there is some ugly shadow noise probably down to bad exposure or processing? if you shot at 160asa (as i said in the previous thread) you will not see pattern noise like this.

No matter what RAW converter you use it is the same.  I actually own a 5DII and I tried them all almost.  It is readout noise clearly seen in the DxO curves.  ISO 160 you will net a bit less but not no it will not eliminate the stuff.  ISO 1250 noise less than ISO 125???  Really hard to believe the chart.

And it is what digLloyd found and reported almost two years ago when he compared 5DII to D3x in shadow pattern noise.  Huge huge difference.

Just never try to drop in fill lights to open up 5DII near blacks.  They accused Nikon to clamp the back point (to zero) but at least they did that cleanly.
« Last Edit: January 23, 2011, 08:30:06 pm by Leping »
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PierreVandevenne

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Re: 645D vs 5Dmk2 part 2
« Reply #11 on: January 23, 2011, 07:04:51 pm »

Nice chart. Wells could be minimal quantization errors.
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ondebanks

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Re: 645D vs 5Dmk2 part 2
« Reply #12 on: January 24, 2011, 10:47:45 am »


You certainly can see the pattern noise there in the 5Dmk2 shot when the shadows are pushed.

As I understand it the pattern noise is do to mismatched amplifiers on adjacent pixel channels or green filters with differing optical transmission characteristics.  Canon of course doesn't admit it exists.


This is a good thread - thanks for the various links and learned discussion!

The 5DII's "pattern noise" - if it really is an additive, fixed bias pattern - should be cleanly removable by subtracting an averaged bias frame, like we do in astronomical imaging. Or if the problem arises in CFA filter transmission variations, then likewise, we normalize the pixel responses by dividing by a flatfield. It's something that I'm going to look into, as I have a 5DII on the way soon.

Nikon's blackpoint clipping (and lack of pattern noise) could be explained by them doing this bias subtraction internally, before writing out the RAW file. They really shouldn't mess with the RAW: it is scientifically damaging, but it would look cosmetically better.

Ray
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ErikKaffehr

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Re: 645D vs 5Dmk2 part 2
« Reply #13 on: January 27, 2011, 01:09:47 am »

Hi,

I'd suggest that it's preamplifier circuitry. Canon has double preamps on advanced models. They have an additional preamp to produces intermediate ISOs.

Best regards
Erik



Nice chart. Wells could be minimal quantization errors.
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