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Messages - Meh

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601
Canon General / Re: Birders don't use Canons?
« on: October 20, 2011, 11:03:35 PM »
One thing I bet makes us all laugh is the photo editing software on cop shows or spy shows. I like how they will bring up a totally blurred image and type a couple of keys and suddenly the image creates data that was not there and suddenly the image looks great. Or when they magically hit a single key and the editing software turns an object around or creates a face that is behind a post or tree or something.

apparently they have access to the Adobe de-blurring tool!  http://tv.adobe.com/watch/max-2011-sneak-peeks/max-2011-sneak-peek-image-deblurring/ ... I still can't believe this is real, but Adobe seems to be pretty serious about it.

There are a few algorithms that can sharpen images but most likely this is just an implementation of a Richardson-Lucy Deconvolution.   Already available for free in RawTherapee.  It works best for simple camera movements that caused the blur... it's less effective or non-effective for complex or multiple movements (for example camera shake + lateral movement).

602
EOS Bodies / Re: The EOS 1D X Sensor Demystified...
« on: October 20, 2011, 10:24:32 PM »
Larger pixels giving more Dynamic Range is not a myth just an oversimplified statement because there is more to it than just pixel size.  It is true when those other things are equal.  DR is the ratio of the largest signal to the lowest signal that can be measured .  That ratio can be expressed as a simple ratio, stops/EV, or dB.

The maximum signal is the most electrons that can be stored in the photosite (one electron is release for each photon absorbed).  This is also referred to as saturation value or full-well capacity.  Note that it's the size of the photosite that matters... the area of each pixel that is sensitive to light which in the past I believe has been as low as 30% but in recent years was up to about 50%.  This is called the fill-factor 

The lowest signal is taken as the noise floor.. which is the read noise at whatever ISO your using.  Most CMOS sensors up until the most recent generation actually had higher read noise at ISO 100 but the Sony sensor used in the D7000 greatly improved on this and the read noise is fairly constant with ISO settings.

The Sony also has much higher full-well capacity even though the pixels are smaller.  This is most likely because they were able to increase the fill-factor... i.e.  a higher percentage of the pixel area is used for the photosite.  In other words, even though the pixels are smaller the photosites are larger (higher max signal).  Combined with the lower read-noise at ISO 100 (lower noise floor) the ratio of largest to smaller signal is much larger giving the very high 13.9 stops of DR.

Hopefully, we'll see these advances in the 1DX sensor as well but there are many other tradeoffs in designing a sensor to optimize for speed, heat, minimizing blooming (current leakage), etc. that the Sony sensor may have sacrificed... I don't know that's the case just stating the possibility.




603
EOS Bodies / Re: What's Next?
« on: October 19, 2011, 10:57:55 PM »
I thought that the 200-400 1.4X was a reality?

Yes, I am confused too. It's a lens that was announced some time ago, just that the release date is delayed (much like what happened with the 8-15 fisheye).

What I want to see: 24-70 f/2.8L with better optics and 14-24 f/2.8L

What I personally wish to have: FF with pentamirror or mirrorless. Just want to have a cheap, low weight Rebel type FF camera. :) That's just me.

I believe the 200-400 was announced to be "in development" and as yet not an officially announced product.

604
EOS Bodies / Re: What's Next?
« on: October 19, 2011, 04:22:08 PM »
I have been waiting to transition into DSLR filmmaking.  My holding out for the 5DmkIII is over...  I will get the 7D and some better glass while I wait for mkIII.  Then sell back the 7D.

At least wait until Nov 3rd. It's only 2 weeks away. Trust me as someone who has shot a lot of DSLR video the last few years. The moire and alias and soft video image can drive you crazy. It was good when it came out 3 years ago, but now compared to Sony and Panasonic, it's very dated.

Just give it 2 weeks before you buy. I think something good will come.

It may not change your mind about DSLR film making, since the alternatives are prohibitively expensive, but check out the 3-part series "The Great Camera Shootout 2011" at www.zacuto.com

The third in the series shows the motion artifacts that DSLRs are prone to due to the rolling shutter of CMOS sensors.  It will be interesting to see if what Canon announces on Nov 3rd will address this issue and if they announce something affordable for indie film makers or only cameras to compete with RED.

605
EOS Bodies / Re: What's Next?
« on: October 19, 2011, 04:05:15 PM »
Common 14-24 lens!

+1. I think we're the biggest fans of this idea.

I must be missing something. The 14-24 is a common lens?
Nikon makes one, but does anyone else?

I think it was mean to say "come on 14-24 lens" ?

606
So, after a useful discussion I think we are coming to an understanding/consensus that the DxOMark tests are representative of the DR the sensor is actually capable of and the DPR tests are an attempt to test what DR we can expect in final images but may be coming in low by somewhere in the range of 1-2 stops due to testing limitations, in particular the use of jpegs that by definition lose some detail in the shadows and highlights.  And perhaps the rest of the difference is due to say another half stop on either end (shadows and highlights) that the sensor can detect but can't be seen anyway.

The original comment that started this conversation was that DR has been Canon's Achilles heal.  In both sets of measurements it would seem that they are in fact behind by about a half to a full stop of DR when comparing sensors from the same point in time and that is most likely due to Canon's emphasis on higher resolution.  The 1DX will likely change that though.

Does that sound about right?




607
EOS Bodies / Re: What's Next?
« on: October 19, 2011, 02:14:34 PM »

The whole thing is pure comedy, becasue as I've been saying Nikon and Canon are switching. All the Nikon shooters are used to low MP sensors. All the Canon users are used to high MP sensors. And the two companies are going in opposite directions.

Unless both Canon and Nikon have each realized that there is a need, and more importantly a market, for both high resolution sensors and lower resolution sensors (along with the inherent trade offs of each) and will now try to have both types in their respective lineups?

It would be interesting to know what conversations happened in the engineering and marketing departments at each of Canon and Nikon as recently as 5-6 years ago.  You can almost imagine both companies with a concept of an ideal digital sensor (high res, low-noise, high DR, etc.) that technology couldn't deliver and laying out a road map of what properties to focus on first with the intent of improving over time towards the ideal.  Canon went with working on increasing resolution and Nikon went the other way.  Each marketed their choice as "better" and "more important" but knowing it's really just a matter of how an image would be used that defined what mattered most.

608
Last time looked, DPR's numbers for DR were based on in-camera JPG shots of a step wedge. If that's no longer the case, happy to hear it. If they're still doing that...need I say more?

Actually that´s (imho) closer to reality then the 12-13 Stops from DXO Mark.

8.x EV (9.x with Raw Headroom) seem to be what i can achieve with my 1D MK4.
But i sure come nowhere near the 12 Stops from DXO Mark.

Quote from: DPreview
Our Dynamic Range measurement system involves shooting a calibrated Stouffer Step Wedge (13 stops total range) which is backlit using a daylight balanced lamp (98 CRI). A single shot of this produces a gray scale wedge from the camera's clipped white point down to black (example below). Each step of the scale is equivalent to 1/3 EV (a third of a stop), we select one step as 'middle gray' (defined as 50% luminance) and measure outwards to define the dynamic range. Hence there are 'two sides' to our results, the amount of shadow range (below middle gray) and the amount of highlight range (above middle gray).



Quote
That would explain why every camera was measured to have around 8 stops of DR... no matter what the actual dynamic range recorded by the camera they are all converted to the standard jpg file format with 256 levels per colour channel.

Sonys Sensor is measured with 9.4 EV.

I think the point is more about the fact that DPR is using jpeps for the test rather than the fact they're doing a real world visual test by shooting the step wedge and counting the number of stops above and below middle gray before detail is lost.  My understanding (and feel free to correct me if I'm wrong) that the jpeg transfer function sacrifices shadow and highlight detail in favor of preserving detail in the middle tones.  Something has to be lost to reduce file size and highlight and shadow detail is the least important.  The earlier clipping of the shadow and highlights reduces the DR that was captured in the RAW file and this is precisely why by shooting RAW we can pull more detail out of the shadows in post than working with the in-camera jpegs.

When I stated that all the DPR results all came in at 8.x stops I was making the point relative to the numbers in Gothmoth's post (I have not looked for the DRP results for all cameras) and my point was that they were all reduced to about the same level lower than the DxoMark tests.  If the Sony sensor was measured 9.4 then perhaps it started with more DR in the RAW file, perhaps the Sony in-camera jpeg applied a less aggressive transfer curve?  I don't know, I'm asking because you seem to know about the details of their testing?

Another question I have is, if DPR is shooting the wedge and visually counting the stops what are they viewing it on (monitor, print) and what is the DR of that viewing medium.  This I have no clue about so perhaps you know more about that.  My understanding though is that modern sensors can record more dynamic range than can be printed and only very high-end expensive monitors can display DR greater than about 10 stops which perhaps DPR was using.

Since you imply you've tested what you can achieve with your 1D4, how did you do your test?  Do you have access to a monitor that can display more than 8-9 stops of DR?

609
Can you point me to where you're getting those numbers from.  I've seen higher numbers quoted but possibly none are the definitive source.

sorry forgot to give the source...  ::)

they are from dpreview.
numbers as mentioned at base iso.

Last time looked, DPR's numbers for DR were based on in-camera JPG shots of a step wedge. If that's no longer the case, happy to hear it. If they're still doing that...need I say more?

That would explain why every camera was measured to have around 8 stops of DR... no matter what the actual dynamic range recorded by the camera they are all converted to the standard jpg file format with 256 levels per colour channel.

610
I must not be thick skinned enough to participate in online forums because I don't like getting smited when I think I'm just politely commenting or responding to other people's posts.  Ouch, it hurts.  LOL

611
Where do people see 16 bit images in the specs??  I see14 bit images in the specification, and 16 readout channels.

The previous model had 8 readout channels and 14 bits, and Nikon D3S has 12 readout channels and 14 bit images.

I'm not sure that the number of readout channels has much to do with the bit level of the image, I thought it was just pulling data from the sensor in parallel streams data can be read faster.

Doesn't the A/D converter determine the bit depth?

http://www.prophotowiki.com/w/index.php/CMOS

http://news.cnet.com/8301-17938_105-20121138-1/canon-loads-eos-1d-x-with-new-tech-hopes-and-dreams/

wasn't saying that the 1D X shot 16-bit.  I was saying that I would very much like to see it shoot 16-bit.

Ivar had said there was relatively little difference between 12-bit and 14-bit files, and I was strongly disagreeing with that sentiment, as well as paying a shout-out to a personal wish list item, which is the desire for 16-bit RAW files in the future.  hope that clears that one up

Kubelik, I can't speak for Mt. Spokane, but I did read your comment the way you meant it.  The mention of "16-bit" was made in several comments at least one of which I think has been deleted.

612
Hopefully it will be close to the recent Sony sensors that are all over 13 stops.

source?
the diagram at dpreview is 13 stops overall and i did not see that sony exceeded this diagram..

Dxomark.com or Sensorgen.info

613
hopefully the new sensor electronics for the 1DX brings forth improvement in dynamic range, Canon Achille's heel

Nikon D3S = 8.3 EV

Canon EOS 1D Mark IV = 8.7 EV

Canon EOS 5D Mark II = 8.4 EV

Nikon D3 = 8.6 EV

Nikon D300S = 8.4 EV

all at base iso.

so not really a overall achilles heel i would say.
if you mean DR in high iso ... well that looks not so good.

ok sony beats them all but .. sony is still no competition in the pro sector.
i rarely have a professionell customer who buys sony.

Can you point me to where you're getting those numbers from.  I've seen higher numbers quoted but possibly none are the definitive source.

614
A quick check revealed the 1D3 and 1D4 had 8 channel output

Hopefully the new sensor electronics for the 1DX brings forth improvement in dynamic range, Canon Achille's heel

I would expect so.  Technology has advanced... read noise is down even lower than 1D4 according to press release and in general the chip electronics have shrunk making more room for the photosite in each pixel.  Those advances combined with larger pixels should result in more DR.  Hopefully it will be close to the recent Sony sensors that are all over 13 stops.


615
Where do people see 16 bit images in the specs??  I see14 bit images in the specification, and 16 readout channels.

The previous model had 8 readout channels and 14 bits, and Nikon D3S has 12 readout channels and 14 bit images.

I'm not sure that the number of readout channels has much to do with the bit level of the image, I thought it was just pulling data from the sensor in parallel streams data can be read faster.

Doesn't the A/D converter determine the bit depth?

http://www.prophotowiki.com/w/index.php/CMOS

http://news.cnet.com/8301-17938_105-20121138-1/canon-loads-eos-1d-x-with-new-tech-hopes-and-dreams/

Yes, the press release stated that the 1DX will have a 14-bit ADC and that the new sensor will have 16 channel readout.

Yes, The maximum bit-depth is determined by the ADC.   A 14-bit ADC can encode 2^14 (16,384) discrete levels for the voltage at each pixel.

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