February 28, 2015, 11:09:28 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Neutral

Pages: 1 [2] 3 4 ... 8
When I read Lula review of Samsung NX1 sensor I was really impressed and I was much interested to see how it compares with other cameras (including FF). I am also as much impressed as MR and Jrista about NX1 sensor technology, not only low noise level but by AF capabilities and the fact that AF points cover 95 percent of the screen.
   This AF tracking technology is my dream for many years for sport/action medium format camera – especially for acrobatic events. With Canon 1Dx and tele zoom lens I can get close to the performer but movements are so fast and so erratic that it is not possible to track that manually – performer always jump out of the view. With MF camera (around 80mp) and NX1 tracking technology it is possible to have much wider angle of view , camera will track object without need to move camera and then you can do required crop  of the shot and get high quality resulting image .  With this it would not be required to use long tele lens. I hope to see that in a couple of years in coming Mirrorless MF cameras
Now back to NX1 sensor noise levels at high ISOs and comparisons with Canon 5Dm3, 7Dm2 and Sony A7.
I did that using DP Review studio –shot comparison tool and below are screen snapshots for comparisons of Samsung NX1, Canon 7DII, Canon EOS 5D M3 and Sony A7S, and also one with Sony A7 at ISO3200 from.
-   At  ISO3200 NX1 is very close to 5Dm3, a bit more of luminance noise but noise structure is better than 5Dm3 – less blotchy and easier to clean up.
-   At ISO6400 5Dm3 looks better than NX1 which could be expected for FF compared to APS-C sensor.
-   At both iso3200 and ISO6400 NX1 is better that Canon 7DM2
-   King of low light in FF segment is still Sony A7S, at ISO6400 it has less noise than Canon 5Dm3 at ISO 3200..
At ISO 12800 A7S is also noticeably better than 5Dm3 at IS06400.
From comparison it is easy to see that A7S is about 1.5 stop better than Canon 5Dm3.
   I bought A7S recently (could not resist temptation) and since then enjoy it to great extent – it makes impossible possible especially in combination with DXO Optic Pro 10 PRIME noise reduction. Getting very clean images (in shadows areas) that were shot in very dim light at ISO up to 20000 which was almost unbelievable even 1 year back. Now using 1Dx much less than before.

 What is interesting and bit surprising that at ISO3200 and especially at ISO6400 and ISO12800  Samsung NX1 crop sensor is significantly less noisier than full frame Sony A7 sensor.
Good for Canon 7Dm2 owners - at ISO3200 and ISO6400 it also has less noise than FF 24mp Sony A7. And in general it is not far behind 5DM3 in noise performance. So Canon really did some improvements in 7Dm2 sensor technology.


I think this technology could make it possible to create affordable compact mirrorless medium format camera using optimized pancake lenses which would require less optical elements in design (e.g. 3-4) elements instead of typical 10 -17 elements). So lens could be much smaller and cheaper which would result in significant cost reduction of overall medium format system. This could be breakthrough in medium format cameras design and could allow MF to take more market share from FF DSLRs

Lenses / Re: Canon TS-E 17mm f/4L Tilt-Shift Lens - your thoughts?
« on: April 10, 2014, 05:03:37 PM »
Though TS-E is perfect optical system it need to be used with care.
I've seen many images with TS-E when it was not used properly.
It like working  with HDR - if not use carefully than it easy to overcook.
Some people are overcooking prospective correction with lens shift  and make vertical lines  on image strictly vertical  and parallel to the picture sides and this breaks overall image prospective  - image does not look natural   - as if turned upside down.
When you look at the image upper side looks bigger than down side though they are equal .
This is optical illusion  because our mind uses it's own prospective correction .
So it is important  always to leave some prospective proportions on the  image and do not do it fully square

Lenses / Re: Canon TS-E 17mm f/4L Tilt-Shift Lens - your thoughts?
« on: April 10, 2014, 04:48:48 PM »
Neutral, that second crop is downright scary.  Wow, insane detail.  Very, very impressed with your work, technical skills, and the Sony+TS-E 17 combo results.

+1 on privatebydesign's comments, TS-E require a completely different style of shooting.  LiveView has made it a lot easier, but it's no substitute for the 16-35 unless you're using the 16-35 like a TS (i.e. architecture and other slow, deliberate type work).

Such kind of combo  TS-E 17+ Sony a7R  combo was always my dream.
Now it became reality. Thanks both to Canon and Sony.

 As for 16-35 I do not think it is really needed for anyone  who  already has Canon EF 24-70 f/2.8 M2 which is also perfect on both bodies.   
Canon EF 24-70 f/2.8 M2  is enough for most of short zoom needs, and  TS-E 17 is perfect complement to that when high quality wide angle shot is required. And both work perfectly on 1DX and a7R.
Here are also some image samples of   Canon EF 24-70 f/2.8 M2 on a7R and 1Dx: 

  With this set  EF 24-70 f/2.8 M2  and TS-E 17 I  really no need  16-35 any more  and to my view  IQ from 16-35 is far below  compared with IQ from EF 24-70 f/2.8 M2 and TS-E 17  even on 1Dx body let alone a7R, so I was never  fully satisfied with 16-35

Lenses / Re: Canon TS-E 17mm f/4L Tilt-Shift Lens - your thoughts?
« on: April 10, 2014, 03:50:31 PM »
Canon TS-E 17  is perfect optical system in all respects.
Once I bought it I stopped using my older 16-35 II 
It is easy to use, even handheld.
I used it initially with 1Dx but  1DX resolution was not enough ,so  I bough Sony a7R specially to use with TS-E 17.
Together they give amost MF IQ.
Here is example of TS-E 17 on a7R with Metabone MIII adapter.
First image - is almost all frame - just a little bit of cropping.
The other two are 100% crops from different image area.

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

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
"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.

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)"

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.

The A7r user is gonna want to print some big pictures to gain an advantage.

  This is most common confusion and misunderstanding repeated all over different forums from person to person and this resulted that this is taken as granted by majority of the of people who are arguing about value of high MP sensors

In fact this is totally wrong.

Downscaling high MP image to the lowest resolution camera image in comparison and viewing results will never demonstrate how high MP image will look on real print. Viewing this results on the PC monitor is the same.
This is actually what many people are complaining about DXO sensors comparisons when they are normalizing  images to 8mb.  At these days it would be better to normalize images to 24mpx which is de facto common reference point now.

Now coming  to high MP image printing.

Here are A4 and A3 printouts resolutions at fine 720dpi and superfine 1440dpi

A4  8.3 x 11.7 inches
Pixel size  for 720 dpi   = 11.7x720  x8.3 x720    equal to  8424 x 5976 =  50.34 MP
Pixel size  for 1440 dpi   = 11.7x1440  x8.3 x1440  equal to  16848 x11952 = 201.367 MP

A3 11.7 x 16.5 inches
Pixel size  for 720 dpi   = 11.7x720  x 16.5 x720 equal to  8424 x 11880  = 100.077 MP
Pixel size  for 1440 dpi   = 11.7x1440  x 16.5 x1440  equal to  16848 x 23760 =400.3 MP

  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. On printout every dot is compete pixel . For Buyer sensor effective resolution is about 60-80%  of actual pixel count. So only Phase One IQ180  image could match in resolution to  fine quality 720 dpi A4 printing  resolution  and far below of fine quality 1440 dpi A4 print  let alone A3 printouts.

So difference on IQ and resolution between 24mp and 36mp will be clearly seen even on A4 printout.
Even on small screens difference in resolution is very noticeable.
This is why people want to have retina displays on their smartphones  and now new trend is 4K screens on the smartphones , let alone TV set.

 As for big prints at very high resolution  - they give you feeling of the real reality. From far distance you see overall image, when you get closer and closer you see more and more  details - the same as in real life. On big landscape print  from 400mps image you get very close and you would be able see even bee on the flower and flower petals texture and fur on the bee belly.  And you will fill  this as it is real reality

How about posting the A7 with EF 24-70 sized the same as the 1Dx.
OK, here is comparison  of A7R with EF 24-70 sized the same as the 1Dx with Canon EF24-70F/2.8 M2 on 1Dx
a7r with Canon EF24-70F/2.8 M2 looks a bit better even if  downscaled to 1Dx size

Fair enough.
How about posting the A7 with EF 24-70 sized the same as the 1Dx.
I already posted  a7R with Canon EF24-70F/2.8 M2  which shows how much it is superior compared to Sony 24-70 on a7R
It could be  easily downscaled  to the 1DX size in any photo editing program to see the difference.
Result of normalizing image to lower resolution is obvious - perceptually it will be the same or bit better  IQ only with less resolution.
So it would be a bit  better that 1Dx with Canon EF24-70F/2.8 M2

very interesting results  :o

I already knew 24-70mkII is excellent lens, but I'm very excited about results on A7R. One think I'd like to ask is AF performance. You already mentioned AF is slow, but both pictures look spot on. Were there no trouble with missed focus? Especially handheld?
Canon EF24-70F/2.8 M2 AF with Metabones M3 adapter on a7R is slow but accurate.
I had no missing shots at all.
In fact Metabone focusing algorithm is very simple but solid:
It takes two passes from - to + calibrating lens and finding AF peak  and then goes back and does final move to the lens focus peak
I think that ultimate  resolution power of Canon EF24-70F/2.8 M2 help much in this process as focus peak could be easily detected by contrast AF system. With blurry lenses this would be a bit more difficult

Some more interesting test  results

Canon EF24-70F/2.8 M2  on Canon 1Dx body compared to Sony Zeiss 24-70 f/4 OSS on a7R body

 Again two 100% crops , no adjustements, a7R crop when exported from C1 to JPEG was downscaled to 1DX resolution.
No worry abot handheld as shutter speed in both cases is around 1/1600 so camera vibration does not  affect results

 At 24 mm images looks close to each other though Canon EF24-70F/2.8 M2  on Canon 1Dx perceptually looks a bit better. When 1Dx image upscaled to a7R resolution  the a7R image resolution difference is visible but perceptually  1Dx image overall is still slightly better to me eye

At 70mm   Canon EF24-70F/2.8 M2  on Canon 1Dx  is significantly better than Sony Zeiss 24-70 f/4 OSS and this difference is very obvious.

  This results just illustrates the point that the sensor resolution is only part in overall system performance. If lens is mediocre then even  image from higher resolution sensor  is less quality than from sensor with twice less resolution but using high quality optic.
These test actually correleate with DXOMark measurement results fo both lenses.

   I think it might also be interesting to compare image quality of  Canon 1Dx with Canon EF24-70F/2.8M2  to that of  Sony a7R with Sony Zeiss 24-70mm-F4-ZA-OSS - which would  be more pleasant to the eye perceptually.
Which system will win ???

Wow, now I feel better about the money I spent on it and I'm more confident about how it will work on a high MP sensor in the future.  Thanks for the test.
Yes, it was also WAW for myself.

I  was expecting to see some  difference between them  but no to such huge extent.
   Pictures taken using Canon EF24-70F/2.8M2 looks like pictures taken by MF system  - not only razor sharp up to single pixel on a7R sensor  but also by the quality of color rendering which looks perfect to my eye (the same is applied  for Canon TSE17).
   Also I was surprised by quality of autofocus using  Metabone III adaptor for a7R, I thought that I would have to use manual focus get best focusing results.

  Pictures taken using Sony Zeiss 24-70 looks as if they were  taken by cheap  average camera system, and colors look a somewhat "dirty" - as if there is something not very clean and transparent  between the camera and the object  so results are not very pleasant  to the eye.
  By looking at DXOMark test results  http://www.dxomark.com/Lenses/Sony/Sony-FE-Carl-Zeiss-Vario-Tessar-T-STAR-24-70mm-F4-ZA-OSS I knew that they are not in the same league as Sony Zeiss 55 F1.8  or Canon EF24-70F/2.8M2 and perceptual resolution is low  (15mpx)  but  I expected better actual performance than I saw in my tests.  Even DXO Optic Pro  9  lens correction does not help much to bring image quality close to that of Canon EF24-70F/2.8M2. It makes image a bit better but still far below of IQ when using Canon EF24-70F/2.8 M2.
I was expecting a bit more from  Sony Zeiss 24-70  at least in color rendering quality.
This lens doesn't  not match a7R sensor performance  at all, despite the fact that Sony claimed just the opposite.
Even not up very much to the a7 sensor resolution
So Sony Zeiss 24-70mm-F4-ZA-OSS  usability is limited to general walk-around average point and shoot requirements when image quality is not an issue and person just need light camera for easy carry around.

But  Canon EF24-70F/2.8M2 on a7R is almost perfect combination when image quality is main concern.
a7R could be considered as high quality digital back for high quality Canon lenses including EF24-70F/2.8M2  and TSE 17 and TSE 24. The only one perfect native lens for a7R is Sony Zeiss 55 1.8 which is extremely good and allow to use all a7R resolution capacity.

Pages: 1 [2] 3 4 ... 8