August 01, 2014, 03:25:42 AM

Author Topic: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body  (Read 2448 times)

Neutral

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #15 on: April 04, 2014, 02:55:06 PM »
...
Here are A4 and A3 printouts resolutions at fine 720dpi and superfine 1440dpi
...
  So from above it is clear that in fact even most Buyer sensor MF cameras can not over perform standard quality 720dpi A4 printing resolution.
...

I dont think you understand what those 720dpi & 1440dpi means

Are you really sure of that ?  :)

DPI means exactly what it means - print spatial resolution  - dots per inch)

  "Dots per inch (DPI, or dpi)[1] is a measure of spatial printing or video dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm)"
http://en.wikipedia.org/wiki/Dots_per_inch

So what I said above is 100% true for BW prints, for color prints it is a bit different depending on  printer model, number of different ink cartridges in printer resulting in required number of dots to reproduce full color in single image pixel.
So for color print pixel to dot mapping is a bit different - more printer dots required per color pixel
But actual printer resolution for fine printing is 2880x1440dpi , so you can redo calculations above for this DPI density and see equivalent BW  resolution for A4 and A3 prints and estimate color resolution

In general these details do not  change much the main the point  - modern color printers are outperforming most of the digital cameras in print resolution even on A4 prints, let alone A3 or A2 prints.
So you can see difference between high MP and average MP image printouts  even on A4 format, but this difference will be almost unnoticeable if high MP image downscaled to average MP image resolution . There is no lossless downscaling - if you downscale image in resolution you will loose fine image details.




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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #15 on: April 04, 2014, 02:55:06 PM »

Sporgon

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #16 on: April 04, 2014, 03:08:36 PM »
...
Here are A4 and A3 printouts resolutions at fine 720dpi and superfine 1440dpi
...
  So from above it is clear that in fact even most Buyer sensor MF cameras can not over perform standard quality 720dpi A4 printing resolution.
...
I dont think you understand what those 720dpi & 1440dpi means

 ;)

It's the old dpi/ppi thing again

Neutral

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #17 on: April 05, 2014, 05:33:28 AM »
It's the old dpi/ppi thing again

Yes , agree there are a number of confusions about that

 In fact relation between  printer output image  pixel resolution  (PPI_print) and  printer Dots Per Inch (DPI) resolution could be expressed in general  (not going deep into details) as follows:

PPI_print = Function (DPP, DPI, Paper_Quality)
DPP (Required Dots Per Pixel)  = Printer_Driver_Mapping_Function(Required_Pixel_quality, Number_of_inks_in_Printer, Avaiability_of_Variable_Droplet Technology, etc. )

  Modern printers (e.g. Epson Stylus Pro 3880  or 4900 and others ) can provide final print resolution above 720 pixel per inch (required output PPI  is set in print settings  dialog box in imaging editing program).
  Here is discussion of printer PPI ( not to be confused with DPI)  - printed images final resolution  using HP 932c
http://forums.adobe.com/message/4266349
"I could see significant reduction in the finest details in the 300 ppi print vs. the three higher resolution prints, and a slight reduction in the 567 ppi vs. 720."

   So the argument  that using Canon EF24-70 F/2.8M2 on a7R   does not give any benefit for printing compared to Canon EF24-70 F/2.8M2 on Canon 1Dx is not correct.
   Though difference would be almost not noticeable when downscaling a7R file to 1Dx size (details are lost in downscaling)   but  when full-res a7R image would be printed  on  A4 or A3  then  difference will be visible especially on A3 print which could not be considered large - if you want to put picture on the wall in your room the best minimum size would be A2
. Also higher quality higher res image gives more flexibility to cropping.
« Last Edit: April 05, 2014, 05:36:06 AM by Neutral »

sdsr

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #18 on: April 05, 2014, 10:54:09 AM »

Test results demonstrate that Canon  EF24-70mm f/2.8 M2 is much superior to Sony Zeiss 24-70 f/4 OSS in resolution and color reproduction and overall image quality .  Especially this is noticable at 70mm focal length .
From test pictures it is obvious that even on 36mpx   Sony a7R body  Canon  EF24-70mm f/2.8 M2 still does not reach it's limit in resolution power.  This combination is perfect one when focus speed is not important.
On the other end  Sony a7R with  Sony Zeiss 24-70 f/4 OSS  is a fairly good combination as general purpose  walk-around point and shoot camera.

I also tested Canon TSE 17  on a7R and image quality , color rendering and resulution is also of top possible quality. 
It seems that Canon TSE 17 the same as Canon  EF24-70mm f/2.8 M2 still does not reach it's resolution power limit on a7R
Canon TSE 17  on Sony  a7R  looks as  perfect  combination for Architecture and Landscape photograpy.

Sony/Zeiss don't seem to have figured out how to make a first rate zoom for their A7s yet.  If you compared the Sony/Zeiss 55mm 1.8 you would have seen a significant difference too (the 35mm 2.8 as well, probably).  But you don't need to attach Canon lens as new/expensive as the Canon 24-70II - you can get fantastic images from many much less expensive Canon lenses on the A7r, even such bargains as the 40mm pancake and 85mm 1.8 - if nothing else, the A7r shows just how good many Canon lenses are!

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #19 on: April 05, 2014, 01:00:45 PM »
Sony/Zeiss don't seem to have figured out how to make a first rate zoom for their A7s yet.  If you compared the Sony/Zeiss 55mm 1.8 you would have seen a significant difference too (the 35mm 2.8 as well, probably).  But you don't need to attach Canon lens as new/expensive as the Canon 24-70II - you can get fantastic images from many much less expensive Canon lenses on the A7r, even such bargains as the 40mm pancake and 85mm 1.8 - if nothing else, the A7r shows just how good many Canon lenses are!
Fully agree  that "Sony/Zeiss don't seem to have figured out how to make a first rate zoom for their A7s yet"
Sony 24-70 proved even worse than I saw in my initial tests.
Did some walk around with this lens on a7R, looked at the images  and found that at short focal length images get blurry at the sides of the frame  though more or less OK closer to the center of the frame.
I am very disappointed with the  Sony 24-70 - seems that this lens more or less could be good for  NEX7 and similar but not a good fit at all  for a7R.
But Sony/Zeiss 55mm 1.8  is just perfect on a7R .

 As for using other cheaper than  EF24-70 F/2.8 M2 Canon lenses on a7R I agree with you  that  excellent results could be achieved with cheaper Canon lenses.  For many people with a7R as second to Canon body  this could be good solution. I just do not have them.  Some of the Canon lenses though  not expensive but are the best in their class
For me my EF24-70 F/2.8 M2  is the mostly commonly lens that was used on my 1DX  recently and now it is also perfect fit for a7R
« Last Edit: April 05, 2014, 01:02:25 PM by Neutral »

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Re: Canon EF24-70mm f/2.8 M2 vs Sony Zeiss 24-70 on Sony a7R body
« Reply #19 on: April 05, 2014, 01:00:45 PM »