October 30, 2014, 07:43:20 PM

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Messages - heptagon

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16
Canon General / Re: DRones vs. anti-DRones: how to resolve the controversy
« on: September 25, 2014, 05:37:46 PM »
why don't they establish a thread specifically for this topic and leave it there.

Because this currently is the most pressing issue for about 50% of the people here. People can cope with artificially dumbed down camera software - magiclantern alleviates some of that pain. People can deal with ergonomics. People can deal with lenses - most are fine and many 3rd party alternatives are available cross platform. But people cannot deal with an image which cannot be processed in the way they like because of high shadow noise. Then they look over to their neighbor and despite all the shortcomings of the other camera systems his image shows a higher resolution and less noise. Many of us often hit this barrier.

This is not the reason why there is complaining... that will never stop... but it is the reason why this one topic is so prevalent.

17
EOS Bodies / Re: Canon Says Higher Resolution Sensors Are Coming Soon
« on: September 25, 2014, 10:27:29 AM »
I indeed have a problem to hear the DR topic repeatedly.

Another solution would be to accept that Canon cameras only provide 2nd grad sensors for photos below ISO 1000 and high resolution photos. Sure, this is good enough for journalists and they are not here to complain. Sure, Birders can use crop cameras and teleconverters (along with the associated loss in image quality). But what about enthusiasts who save a big chunk of money to buy the best camera system they can afford? Could they live with a 5D Mark I? Has that camera gone bad over the years? No, they want the best. Canon has some of the best lenses with the best resolution but no full frame camera to go with it. I mean the cameras are not bad, they don't get worse over time but people want the best and Canon sensors simply are not the best anymore. We could say they are second best, but virtually any other manufacturer now uses better sensors for their new models. Sure, focus systems are important and if you have time you can light the scene and stitch your panoramas and do multiple exposures for HDR. But why not use the technology that is on the table. Why not give the users what they want? Why not simply buy the same Sony sensor as Nikon does for a studio/landscaping camera? Take the 5D3, rip out the old Canon sensor and put in the Sony sensor. It's not THAT hard to do for Canon. They had years of time and the only thing holding them back is greed for money because people are reluctant to switch. But trust me, nobody switched back from Nikon because of the sensor. Many things are different or wrong with Nikon systems but the camera sensor is not one of them.

18
EOS Bodies / Re: Canon Says Higher Resolution Sensors Are Coming Soon
« on: September 25, 2014, 10:11:24 AM »


in looking at DR... Is it just more at ISO 100 to 200 that you all want or higher consistent DR across the whole range..? Some of the higher DR cameras  really start to drop off as ISO increases...

High DR at high ISO is physically NOT POSSIBLE.

Currently, Sony sensors that Nikon uses have a slight disadvantage at ISO >1000 but that seems to be fixed with the A7R. With these sensors you could basically shoot everything at ISO100 and lift in post which gives a lot of headroom to recover highlights.

The only way to gain some significant quality at high ISO is the use of layered sensors with higher quantum efficiency. With Silicon only this seems not possible but there are other material combinations in development which will make this possible in some years.

What can be done with current technology is a) higher pixel density (up to the 200-800 MP range for full frame) and b) lower ISO for even more dynamic range.


19
EOS Bodies - For Stills / Re: Posting about sensors and DR!
« on: September 24, 2014, 10:46:06 AM »
Neuro would you please care and lift some of the shadows in that picture of yours?

20
EOS Bodies / Re: Sample Images From the EOS 7D Mark II
« on: September 21, 2014, 03:58:21 AM »
Color and pattern noise give us an idea about sensor performance, but they are not taken into consideration when calculating DR. So you should leave Noise Ninja checked on at default setting too (chroma NR 50) and look at the luminance noise. Make sure that Detail slider is set to zero as it tends to enhance noise. Now throw in D7100 (DR 13.9 according to DXO) in the mix and see what happens. You won't see much difference in noise. So, I don't know if we can take this test too seriously to get an idea about DR. We need proper shadow lifting and read noise measurement. Other caveat is that 7DII is not supported officially by any RAW converter yet, we can't really rely on these tests. 
Something else I have noticed and not sure what to make of this. Take this 3 cameras, do above adjustments, but leave the shadow slider at zero. Export the JPEG files to LR or CS and adjust exposure by +1 (or save as JPEGs and open again with PN and adjust exposure by +1). Now look at the cup, it is darker in 7DII file compared to other two cameras. Look at the whole scene, everywhere 7DII retains more color and detail (except for overblown areas) compared to 7D and D7100. Is it because 7DII scene is slightly underexposed? Lighting has changed? RAW converter needs fine tuning? Something else?

Ok, I agree, lifting the shadows might not do what i expected it to do. For a proper comparison we should use other programs where whe know better what happens. Also the scene here doesn't contain the amount of dynamic range we need for a proper comparison. The bright shadows of the 7D are weird, maybe the program has a wrong offset for black... don't know.

What we can say for sure though, is that the 7DII has better shadow noise than the 7D.

21
EOS Bodies / Re: Sample Images From the EOS 7D Mark II
« on: September 20, 2014, 12:08:01 PM »
Test images:

7D2:
http://www.imaging-resource.com/PRODS/canon-7d-mark-ii/E7D2hSLI00100NR0.CR2.HTM
7D:
http://www.imaging-resource.com/PRODS/E7D/E7DhSLI00100_NR_0.CR2.HTM

Program: Photo Ninja
http://www.picturecode.com/download.php

Settings:
Only the first three checkmarks on:
* Demosaic
* Color correction
* Exposure and detail
(no extra sharpness/color/noise correction)

Everything on default except in Exposure and Detail:
* Exposure offset +3
* Shadows +1

Now you see the colored noise in the cloth and cup at the right bottom.

22
EOS Bodies / Re: Sample Images From the EOS 7D Mark II
« on: September 20, 2014, 02:09:30 AM »
I opened the CR2 files at 100ISO of the 7D and 7DII in PhotoNinja, turned off all noise/color enhancements and pushed the shadows:
* Pattern noise seems to be gone.
* Shadows are still noisy. Maybe 1/3rd Stop or 1/2 Stop more dynamic range than the 7D. But more useable due to the lower Pattern noise.

So, it is the same sensor technology with little enhancements.

23
EOS Bodies / Re: A New EOS Pro Body With 46mp Next Month? [CR1]
« on: September 18, 2014, 06:34:37 AM »
Reply to the 30MPix nonsense.

Current sensors have a bayer pattern providing with only 1/4th resolution in red/blue. So make that makes the 30MPix into 120MPix if you want a color sensor. But it doesn't stop there. Look at the resolution of the 300mm 2.8 IS II. It outperforms current sensors when using the 2x extender on crop. That'd be 18 MPixels times 4 (extender) times 2.56 (crop to FF area) resulting in 184 MPix. This times 4 because of the bayer pattern is 737 MPix for full color resolution.

Even though most lenses will only provide this resolution in the center of the image at the optimum aperture (<<f/8) we're far from "too many pixels on this sensor".

Admittedly fewer and fewer people will benefit from more pixels in fewer and fewer situations since you need super fast shutter speeds, perfect focus, optimum lighting etc. but if technology provides more pixels at moderate cost, why not take it to get those 10% of the shots you couldn't with the old tech?

In the end the real loser will be the 1.4x and 2x extenders which are just a magnifying glass and crop cameras for tele which just use a smaller imaging circle.

24
This simply means that Canon and maybe many of the other Camera manufacturers have not done their (law/patent) research properly and now need to pay for a license and a fine to use technology others have invented and patented in the USA (and probably other countries).

This probably makes DSLRs more expensive but in the end is no big deal.

25
EOS Bodies / Re: A New EOS Pro Body With 46mp Next Month? [CR1]
« on: September 18, 2014, 05:14:54 AM »
A quick 2 questions: 

1) Has anyone asked Canon directly why they don't offer a higher-mpixel camera?  Asking someone other than a marketing guy, that is.

2) Has anyone from Canon provided a clear, reasonable reply to why their current product offering is as good, if not better than Nikon/Sony at 36mpixel (rumored to soon go to 46mpixel)?

A link to something (Presentation?  Whitepaper? Engineering paper?) would be great.  I'd like to take the time to understand (as best I can) why Canon is "stuck" in it's current position.

1) Only public relation persons are allowed to speak to the public. If an engineer answers he'll lose his job and possibly get a big lawsuit.

2) It still sells well enough, so it must be good enough. Looking at the sensor alone, Canon is way behind in some important areas. In my opinion they should adapt a Sony sensor for a high density studio/landscaping body. This would make many people happy.

26
EOS Bodies / Re: How excited are you about the new 7D II?
« on: September 16, 2014, 03:25:59 AM »
I guess it depends on your purpose of purchase. As a photographer, I can see the idea of this camera, although…. why not either boost the sensitivity of the chip to compete with Sony's A7s or boost the pixels so you don't feel like you are licking the 5D3 in the ass….

What could really make the Canon 7D II look like bullshit is the Samsung NX1 which was just announced:

http://www.nofilmschool.com/2014/09/samsung-nx1-new-4k-mirrorless-shoots-h265

Quote
The specs:

28.2MP BSI APS-C CMOS sensor
4096 x 2160: 24 fps
3840 x 2160: 30 fps
1920 x 1080: 60 fps, 30 fps, 24 fps, 50 fps, 25 fps
1280 x 720: 60 fps, 30 fps, 24 fps, 50 fps, 25 fps
640 x 480: 60 fps, 30 fps, 24 fps, 50 fps, 25 fps
Clean HDMI 4:2:2 (8-bit)
H.265 Codec applied to 4K and UHD video files
Tiltable 3.0″ HD 1036k-dot touchscreen
205 phase-detection AF points
15 fps burst mode
1/8000 Max Shutter Speed
ISO range from 100 to 51,200
Camera can utilize UHS-I or UHS-II-SD-type memory cards
1/8" Headphone, 1/8" Microphone, HDMI D (Micro), USB 3.0
802.11b/g/n/ac Wi-Fi capability coupled with Bluetooth 3.0 technology
Samsung NX Lens Mount
Price: $1,500 Body Only, $2,800 with 16-50mm f/2-2.8 S ED OIS Lens

Unfortunately the NX mount is made incompatible to the EF mount.

While the NX1 has better specs and the better sensor it lacks one thing and that is the advanced phase AF of the 7DII. If Samsung made an NX1 with an fully functional EF mount it would win hands down in all categories except maybe low light sports.

27
EOS Bodies / Re: Video Review: Canon EOS 7D Mark II
« on: September 15, 2014, 01:18:16 PM »
Review? More like professional commercial spot.

28
Is this relevant for focusing speed? (E.g. Supertele+Extender @ f/8)

If no, then it's pretty irrelevant for the target audience because the sensor is too small for low light action shots.

29
EOS Bodies / Re: Canon EOS 7D Mark II Specifications Confirmed
« on: September 12, 2014, 11:12:28 AM »
This is how I shoot low light on my 30D..  I stop at ISO800..   here's the implied readout noise levels from the DxO data...  on the D800 looks like ISO200 is worth having but benefit rapidly drops beyond that.

Coincidentally the D810 now has native ISO64 because to improve DR and SNR.

For studio and landscape cameras the way to go is more Megapixels and lower ISOs.

30
EOS Bodies / Re: Canon EOS 7D Mark II Specifications Confirmed
« on: September 12, 2014, 10:06:51 AM »
If you shoot raw, then stick with ISO100 and be prepared to "underexpose" then fix in post.


well that's not good advice! :D

Care to explain why shooting at ISO100 but underexposed by 2 stops is worse than shooting at ISO400 on a Nikon 800/600 series?

Numbers are useful here.


You have two main sources of noise at low ISO:
1) Quantum noise
2) Readout noise

Quantum noise is due to the fact that photons behave like particles and if you on average expect 10000 photons in a pixel in reality you get sometimes more and sometimes less leading to a Poisson distribution around that average value. The quatum noise is the square root of the number of photons e.g. 100 for 10000 photons and 10 for 100 photons.

The readout noise is various electronic noise and depends on the amplification factor and other interference. With the new Sony sensors the readout noise is virtually the same on ISO 100 to ISO 6400 e.g. 5 electrons. With the canon sensors the readout noise is better for high ISO e.g. 3 electrons but worse at low ISO e.g. 30 electrons at ISO 100.

If you look at a bright pixel you get 10000 electrons from the photons +-100 electrons due to Poisson statistics (even a perfect sensor will get that). The S/N ratio is 100.

If you look at a dark pixel you get 100 electrons from photons and +-10 electrons from Poisson statistics. The S/N ratio is 10.

Now factor in the read noise.
- Bright pixel:
-- Canon: 100+30, S/N 77
-- Nikon: 100+5, S/N 95
- Not much difference.

- Dark pixel:
-- Canon: 10+30, S/N 2.5
-- Nikon: 10+5, S/N 6.7
- Almost a factor of 3!

If you do the same calculation at high ISO, the Canon sensor gets a little advantage.


From this we can conclude that BRIGHT pixels have the SAME QUALITY with a Canon and a Sony sensor.
But DARK pixels suffer from readout noise and here the Sony sensor is much better.

So if you do not underexpose or lift the shadows in your pictures, you will be OK with current Canon sensors.


Oh boy....


I do this stuff every day for work.

Yes poisson noise is also present, but as the two situations I'm comparing here have the same light levels, the poissn noise is identical, so we can drop it out of the equations.

Also you don't just add the noise.   it's an RMS..  (in volts) so that changes the maths a little,  Sqrt(Noise A+ Noise B)

Yes, I should have used RMS addition of the independent noise.

No, the Poisson noise is important to calculate the S/N value which considers all noise sources.


After all, this exactly explains why cameras with the same sensor size have the same SNR18% performance (in print mode) on DXO. Also it explains why the dynamic range is worse on Canon sensors compared to new Nikon/Sony sensors. Also it explains why Canon has equal or better high ISO performance.

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