September 16, 2014, 07:54:11 AM

Author Topic: 1DX Review  (Read 13328 times)

Meh

  • 5D Mark III
  • ******
  • Posts: 699
    • View Profile
Re: 1DX Review
« Reply #15 on: October 25, 2011, 10:56:35 PM »
@Chris_BC

Good points.  Given the slight drop in MP rather than an increase over the last generation FF sensor, the increase in standard ISO range, the fact that technology has progressed, and Canon's statements I would also hope for more than 1 stop increase.  My comment was meant more generally... that a full stop improvement over a predecessor body is a significant improvement.  Two or more stops would be even better of course.  As far as what body to compare to as the predecessor we could just as easily compare to the 1D4 since that was the most recent 1-series body but your point is still valid because the increase to 18MP FF from 16MP APS-H alone should result in improvements even if there were no other tech advancements.  How much improvement in noise and DR will "cut it" will depend on the user.

canon rumors FORUM

Re: 1DX Review
« Reply #15 on: October 25, 2011, 10:56:35 PM »

Meh

  • 5D Mark III
  • ******
  • Posts: 699
    • View Profile
Re: 1DX Review
« Reply #16 on: October 25, 2011, 11:49:25 PM »
Image noise goes up with higher ISO, fact of life.

Well that's one way of looking at it.

I would prefer to look at it as the noise being reasonably constant (within limits) but the signal being reduced due to the lower light levels available when you have to use higher ISO settings.  The end result is a lower signal to noise ratio (SNR) leading to a noisier image.   The post-capture ISO amplification applied gets you back to the correct image brightness, but as it boosts signal and noise equally, cannot do anything to correct the already impaired SNR, hence the noise that was there all along becomes relatively more visible.

Impaired SNR is the natural result an under-exposed sensor which of course is what you get if you use an ISO setting higher than base ISO.   The exposure meter may say you are not under-exposed, but that is because it is adjusted in advance to allow for the amount of post capture ISO amplification which is going to be applied later.  By going above base ISO you are effectively accepting under-exposure at the sensor.

I would therefore say that high ISO noise performance is a somewhat mythical concept, as in reality the performance at any ISO setting is largely dictated by the SNR ratio at base ISO.  The better this is to start with, then the better the results as you start losing signal due to low light levels. 

Fred

Yes, SNR is what matters most to what we see as image noise and you're absolutely right, ISO amplification happens after the sensor is exposed and amplifies the recorded signal at each pixel which includes the noise component... the camera doesn't know what the true signal was and how it was affected by the noise.  When shooting in low light the input signal is much lower so the SNR is in turn lower and the image looks noisy.

On the issue of thinking of noise as a constant, that depends what kind of noise we're talking about.  There is noise from the electronics (read noise) which is fairly constant and photon noise (aka shot noise) that is not constant.  Both contribute to the total noise (random variation) in the recorded signal.

Photon noise scales as the square root of input so the noise goes up with input signal in absolute terms (not constant) but is a smaller percentage of the input (higher SNR).   With very low light levels (dark shadows, night photos) photon noise can be significant.

Read noise is fairly constant for a given ISO setting and is in the range of around 2-20 electrons for most CMOS sensors.  Again, in dark scenes when the input signal is low (which is when we use higher ISO) the read noise becomes much more significant relative to the input signal (lower SNR) and we can see the noise in the dark areas of the image.

Even when we look at an image we can't "see" or know that a particular pixel (or any area in the image) was supposed to be say 500 photons but was recorded as 495 or 510.  What we see is the unnatural variation in adjacent pixels or groups of pixels that wasn't in the true input.  So say a group of 20 pixels were supposed to all be 500 photons but they were recorded due to noise anywhere from 470 to 530 we can see that variation and because it's random variation we know intuitively that the image isn't supposed to look that way and it's therefore noise.
« Last Edit: October 26, 2011, 12:26:57 AM by Meh »

sbryson

  • Guest
Re: 1DX Review
« Reply #17 on: October 26, 2011, 01:59:09 AM »
I had a quick play with the 1DX at the Canon Pro Solutions show yesterday. Absolute monster.  I wish I could get 100% crops showing noise comparisons the best I could do was take a friend who is a D3S owner.  Going purely by what we could see in the LCD (no memory cards allowed I should have taken the laptop and plugged it into that! And I don't know if the jpg preview on the lcd has noise reduction on or how much) the 1DX at 51k ISO  outperforms the D3S at 12,800.

As for video, I believe each recording mode includes an option to make all frames a keyframe.

I was told by a rep there that the 200-400mm, to his knowledge, is in prototype stage only and might not even actually make production.  This contradicts a canon rumour post from today.  Personally, since Canon had a 200-400mm mock up in a cabinet which was always surrounded by punters asking about info on it I can't see this not making production.

bycostello

  • 1D Mark IV
  • ******
  • Posts: 910
    • View Profile
    • London Weddings
Re: 1DX Review
« Reply #18 on: October 26, 2011, 04:32:49 AM »
I look at canon show yesterday.. very nice...  not sure mrs will let me have one though...

unruled

  • Guest
Re: 1DX Review
« Reply #19 on: October 26, 2011, 04:51:29 AM »
if one looks at every generation of even crop camera's, there is typically about a 1 stop gain in each generation increment. My 40d for example, compared to a 60d.

Fullframe Im sure on this body will easily do 2 stops better with the massively significant changes they have made to signal processing and sensor design. 51k may not be super usable for many people, but for some it will. One also shouldnt ignore how amazingly good noise reduction in lightroom/photoshop have become. ISO is always a compromise, but if you really need to nail a shot in the dark, I doubt theres better than this 1dx or d3s.

keith_cooper

  • Guest
Some other comments from the London show
« Reply #20 on: October 26, 2011, 04:56:09 AM »
Chris Miller shared some of his thoughts about using the 1D X at the show yesterday.

No cards allowed, but he was able to make some (limited) image quality observations

https://plus.google.com/u/0/104131608705810814739/posts/dpDxu2MCCKW

In other comments I've heard, it seems that the Canon people were asked quite often about whether the 1D X was 'really a 1Ds3 replacement' - no revealing answers  I'm afraid... :-)

torger

  • EOS M2
  • ****
  • Posts: 219
    • View Profile
Re: 1DX Review
« Reply #21 on: October 26, 2011, 05:58:17 AM »
For high ISO low light shots most noise is photon shot noise and is unavoidable, it is a physical property of light.

However, the indication that there may be visible pattern noise (read noise from the electronics) worries me, this is a killer concerning useful dynamic range and has been a problem with Canon cameras, for example the 5Dmk2. I really hope that Canon can do as good dynamic range as seen in Nikon's (Sony's) newer sensors, which do not have any significant pattern noise problem.

canon rumors FORUM

Re: 1DX Review
« Reply #21 on: October 26, 2011, 05:58:17 AM »

Mark D5 TEAM II

  • 1D X
  • *******
  • Posts: 1190
  • Proud N0ink 0wnz0r / crApple iFruitcake H4t3r
    • View Profile
Re: 1DX Review
« Reply #22 on: October 26, 2011, 09:50:50 AM »
LOL, you know it's an Engadget "review" when commentators inevitably compare the product to their iFruit. Nothing new here, move along. Pre-production firmware makes the high ISO observations useless at this point.
Nikon NSF16 5-Leaf Dual-Blade Industrial Fan ¦ Nikon NTMFI-H1 Dry Heavy Flat Iron ¦ Nikon Tough Mama NTMRC1-2S Rice Cooker “Limited Edition” ¦ Nikon Tough Mama NTMJK18-S Stainless Electric Kettle Plate Type ¦ Nikon NHT 2-in-1 Curling Iron & Straightener in One ¦ Nikon N4004s Decision Master System™

Picsfor

  • Guest
Re: 1DX Review
« Reply #23 on: October 26, 2011, 10:17:37 AM »
Having now had a play, I can comfortably say the ISO really is something else, the AF is also something else. Ergonomics a nice improvement and that gigabit connector socket is not to be sneezed at. Several other features, but I'll leave it all for my blog :-)

John Thomas

  • Rebel SL1
  • ***
  • Posts: 89
    • View Profile
Re: 1DX Review
« Reply #24 on: October 27, 2011, 03:44:42 AM »
Having now had a play, I can comfortably say the ISO really is something else, the AF is also something else. Ergonomics a nice improvement and that gigabit connector socket is not to be sneezed at. Several other features, but I'll leave it all for my blog :-)
And your blog is... where?

Picsfor

  • Guest
Re: 1DX Review
« Reply #25 on: October 27, 2011, 04:09:58 AM »
I'll post once i've posted...

John Thomas

  • Rebel SL1
  • ***
  • Posts: 89
    • View Profile
Re: 1DX Review
« Reply #26 on: October 27, 2011, 11:16:05 AM »
I'll post once i've posted...

Can you post other things like:

- How is the shutter/mirror sound in comparison with older models? (louder etc.)
  What options do we have WRT this?

- How heavy is / feels?

TIA

Picsfor

  • Guest
Re: 1DX Review
« Reply #27 on: October 27, 2011, 03:03:18 PM »
http://500px.com/Picsfor/blog/17468

Here is the link to my post on both items.

Regards shutter/ mirror noise - it was no louder than older models until you ramped it up to the 12/ 14fps. Then i think the speed of operation just couldn't be overcome. That might be a hindrance with wildlife, golf and tennis, but nothing else. So little did i notice it, i forgot to put in in my review - i was just impressed by the fact you could - and for 10 seconds.

Shutter options came in at single, low speed multiple shooting at 6fps (maybe 7) and hi speed shooting at 12/ 14 fps.

Weight is covered, slightly heavier than a 5D2 with battery grip, but improved ergonomics over come this.

canon rumors FORUM

Re: 1DX Review
« Reply #27 on: October 27, 2011, 03:03:18 PM »

John Thomas

  • Rebel SL1
  • ***
  • Posts: 89
    • View Profile
Re: 1DX Review
« Reply #28 on: October 28, 2011, 04:16:35 AM »
Thanks Andrew for the review and for the clarifications!
One more: Are you just saying that you can leave the AF system 'alone' to choose the subject and track it, without back/front-focusing and/or choosing something else?

Picsfor

  • Guest
Re: 1DX Review
« Reply #29 on: October 28, 2011, 05:09:47 AM »
pretty much.

The trick is the large number of genuine cross hairs - 41 of them. But the real boost is those new additional double cross hairs. These include the usual '+' type of cross hair, but now also include the 'x' cross as well.

This is what really makes the lock so strong. Double the ways of keeping the intended target locked while it is moving. Of course, i couldn't get any one to run around or weave like a footballer, but the speed at which the camera just locked on every thing was just astounding. I was using the 'right cluster' (that is the best way of describing it) as i panned round the hall. Had about 20 focus points in it. The focus points lit up and went out light christmas tree lights and beeped merrily away - hence my statement that 'if their had been music they may have beeped to a rhythm'

But the strangest thing was - they didn't seem to get in the way of the seeing the subject. That was really strange, so much more unobtrusive than the 1D3 AF system.

Must remind you that with AI Servo, the trick is to lock on to the right subject in the first place, but once locked...

canon rumors FORUM

Re: 1DX Review
« Reply #29 on: October 28, 2011, 05:09:47 AM »