November 27, 2014, 02:15:41 AM

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Messages - rs

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16
Great. So each colour is sampled at a different time, as the colour filter physically moves in front of the pixel. This will be great for tripod based static scene shots, but will result in colour tearing - much like a field sequential display does. Bad news for video, bad news for stills of anything that moves as there will effectively be three exposures taken at different times for red, green and blue, and then all merged into one.

Plus the exposure time for each colour cannot be more than 1/3rd of the total exposure time, so I'd hazard a guess that the sensitivity isn't increased either by these larger pixels for the same resolution. And as the filter can't transition instantly between the colours, its less than 1/3rd of the exposure time available to each colour.

17
Lenses / Re: Canon 100-400 mk ii (with/without 1.4 ext) vs sigma 150-600
« on: November 11, 2014, 06:12:40 AM »
We have MTF charts to go by for now, but these are of course from two different manufacturers, each tested to their own methodology.

Sigma Diffraction MTF:


Sigma Geometrical MTF:


vs Canon MTF:


Feel free to make your own conclusions based on the above. My take is the 100-400 looks very impressive with TC's, but we need to wait for reviews before any meaningful comparisons to the Sigma can be made.

In terms of AF, the 100-400 with 1.4x TC results in an f8 combo at the tele end. While bodies like the 1D X, 5D III and 7D II AF at f8, you don't get all the AF points. The Sigma should AF on any f5.6 body with its f6.3 aperture, but its effectively cheating the system as well as being reversed engineered. So its a tough one to call on the same body.

Due to it operating well within the lenses, AF systems and the OEM manufacturers standards, the 100-400 on a 7D II (equivalent to 160-640/7.2-9 with the crop factor) should theoretically outperform the Sigma on a 1D X or 5D III when it comes to AF performance.

18
Lenses / Re: Canon 85mm f1.2 or Sigma 50mm f1.4 Art?
« on: November 10, 2014, 12:49:22 AM »
If you're thinking of buying either of these lenses to shoot wide open for a narrow DoF, the two really don't compare.

From purely a numbers point of view, the Sigma has a 36mm aperture, while the Canon has a 71mm aperture.

19
EOS Bodies / Re: Canon 7D Mark II - DXOMark Review
« on: November 05, 2014, 05:41:02 PM »
Oh, wait...there are.  ::)

Considering that old ballasts sold for scrap net more money for the copper in them then new electronic ones cost...guess I'm more drawn to the rational.
The harsh reality is most photographers tend to turn up at a venue to shoot without taking the time to modernise the entire lighting system first. I've been guilty of that myself, and have been forced to choose between using shutter speeds too slow to freeze action, or be left with a whole load of editing on most of the shots, sometimes even going as far as using a graduated WB/exposure in PP for the shots that are really worth keeping. What a waste of time this 7D II is. Next time I'll just do things properly and spend days modernising each venue before I shoot. ???

20
Third Party Manufacturers / Re: One Samsung Camera to Rule Them All
« on: November 03, 2014, 12:40:37 PM »
EVF will always be more laggy than OVF. But is that really so important? More important than the 35-55ms minimum shutter lag (1DX numbers) in a DSLR because the mirror needs to move away before you can take pictures? With electronic shutters mirrorless cameras can totally beat that.
If you have a DSLR with zero lag in the viewfinder and small shutter lag vs a mythical mirrorless with small viewfinder lag and (somehow) zero shutter lag, that viewfinder lag has a two pronged effect: firstly, you're viewing everything after it happened, so no matter how fast the shutter, the camera induced delay between observing the decisive moment and the shutter firing is still there. And secondly, the viewfinder delay also negatively impacts tracking.

21
On the other hand, it's entirely possible that Sony facilities are used to fabricate the sensor but sensor design comes from Canon.

what about industrial espionage?
would that not be a problem?

buying a finished sensor is no problem but handing out all your technical stuff to a competing company so they can produce your latest and greatest?

i mean sony is not like other companys who could produce sensors for canon, they are a direct competitor.

it´s not like apple is handing out chip production to TSMC.
TSMC does not produce phones or tablets.
Apple also get Samsung to produce many components for them such as processors and displays, and they do produce phones and tablets.

22
EOS Bodies / Re: Modular DSLR Coming from Canon? [CR2]
« on: October 30, 2014, 05:55:42 PM »
Hmmm, I wonder if the following is possible? ..... In theory, if Canon wanted to preserve backwards compatibility with EF lenses for a future "main" mirrorless system, I suppose they could make a FF mirrorless camera mount, give it the form factor of an SLR (like the mirrorless Samsung NX1 or Sony a3000) and include a modular adapter/box that has a mirror, a pentaprism, phase detection sensor, and an OVF. Without the "box", the camera is a FF mirrorless which can mount its own unique lenses; with the "box", it accepts EF lenses and turns the mirrorless into an SLR.

This has already been done before: The Sony A7x mirrorless series has an adapter, LA-E4, that has an SLT mirror inside to allow the mounting of Sony SLR lenses, with continuous phase detection autofocus. Add a modular grip in addition to the adapter, and voila, mirrorless becomes SLR-like
Nice idea, but Sony's SLT system is a far cry from an SLR. All the drawbacks of an EVF, coupled with a stop gap workaround before on sensor phase detect AF was mainstream, resulting in a significant reduction in light transmission.

A bolt on SLT mount adapter makes no sense with current mirror less tech, and a bolt on SLR mount adapter would be much more complicated.

An interchangeable EVF/OVF with a conventional EF mount and mirror box built into the body makes more sense, but I see no reason why a true hybrid EVF/OVF cannot be done - after all Fuji have had a rangefinder style version of this in production models for some time.

23
Lenses / Re: Canon 6d vs 24-70mm mark ii
« on: October 30, 2014, 05:10:08 PM »
My recommendation us the 6D. For me, your lenses have a slightly awkward range on crop, and make a whole load more sense on FF. Plus the lower pixel density if the 6D is less fussy about the resolving power/finite focusing issues of your lenses.

Your focusing issues could possibly be resolved by another body and/or AFMA. If not, a good service is more than worth a shot.

24
Lenses / Re: Why does a 2x TC lose 2 stops?
« on: October 29, 2014, 06:48:57 PM »
Such an adapter would not be practical for two reasons:  first, because the image circle is reduced in proportion to the conversion scaling factor, and because most if not all EF lenses are designed to only project an image circle roughly large enough to cover the 24x36mm imaging sensor, the result of such a converter in an EF-to-EF system would be large sections of black, unexposed sensor in the image periphery.

Naturally, but note that many people don't mind cropping (D800/600, probably many sony models will do it in camera), and may be willing to give up peripheral pixels in exchange for brightness.

That said, there likely isn't a major market for it.
Same quantity of light (if you exclude transmission losses), resulting in a brighter projection on a smaller area. If you take advantage of the extra light by lowering the ISO for a higher S/N ratio, remember that the cropped image requires magnified further to match the size of the full frame, which lowers the S/N ratio. Back to square one.

Instead, what you've ended up with is a smaller viewfinder, worse AF, less light transmission, more aberrations, less resolution, more post processing, and of course more weight, size and expense.

25
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 10:29:55 AM »
I don't agree with this "amount of light" argument. Consider a full frame sensor and an APS-C size sensor with pixels the same size as a full frame taking photos with the same lens at the same f-stop and the same distance from the subject. The signal to noise ratio for each pixel in the APS-C sensor will be the same as the S:N ratio as the corresponding pixels in an APS-C sized area of the ff.

True, but the 2.56x greater area of the FF sensor will gather more total light.  Comparing noise at the pixel level isn't the same as comparing noise at the image level.

You lost me on the image level noise, Neuro. It seems that an APS-C sized crop of the FF image and the APS-C image in this case would be identical. The number of photons hitting each pixel is the same and assuming the downstream operations are identical, what's the difference?

I don't know about you, but as a photographer, I strive to compose correctly, and I look at the image as a whole myself. Your above scenario doesn't make a huge amount of sense as the resulting photos would be very different. I'd start off by using an appropriate focal length on each format to capture the chosen image, not to mention choosing an aperture to achieve the desired DoF, and an ISO to achieve the desired shutter speed/exposure.

If you truly do use the same length lens, settings and distance from subject with the larger format, it would require cropping in post to achieve the framing you've strived towards with the APS-C body. Now we're left with the same image as an APS-C body would have taken - just under 40% of the image. In other words, just under 40% of the light. So to enlarge this small crop up to the same viewing or printing size that you would have wanted should the whole frame of that FF body have been filled correctly, you've now magnified what signal is left by 2.56 times. And strangely enough, the noise has been magnified by that exact same amount too.

If we could just keep cropping with no enlargement penalties such as additional noise, why would anyone bother with these huge telescopes in Hawaii? Surely we can just equip the optics in an iPhone with a sensor 10,000 times smaller than the 1/3rd inch sensor they currently have? We could see the most distant galaxies with unimaginable magnification and clarity, all from a device in your pocket? After all, it is an f2.2 lens  ;)

26
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 23, 2014, 03:58:21 AM »
Sure, if you are doing portraits, where DoF matters, you'll go with FF. The same holds with low light where you want to minimize noise.  However, if I were going to visit Alaska or Yellowstone, I think I'd buy a MFT camera and the Zuiko 300/2.8 lens rather than the 600/5.6 for my Canon.  The combo will be cheaper, lighter, smaller and unless I'm shooting at dusk or dawn, the grizzlies will show the same size (and probably comparable IQ) on the same size print, or my screen.

Indeed.  Because we all know having deeper DoF makes for better wildlife images.  For example, the first image is much better than the second, it's much better that all the distracting stuff behind the subject is decently sharp focus.   :o





Oh c'mon neuro, DoF certainly matters, but this is a shot at 55mm with f/5.6 and a downward angle. Nobody would expect it to have a shallow DoF.  If anything, this shot is an argument against the significance of sensor size, because the following shot I did with my crop sensor and it has a much nicer bokeh.
The amount of background blur isnt just a function of sensor size and aperture. Relative distance between camera, subject and background all play a very important part too, so that owl shot has no relevance to the bear shots with a telephoto.

I can even get some notable separation with my iPhone if I'm shooting a subject at minimum focus distance with a background at or near infinity.

27
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 22, 2014, 05:18:10 PM »
Crop vs. Full frame.

As a 6d owner - my first full frame- im very unimpressed at its low iso quality. There is no 3d-ish POP that i have seen in so many 5d2/5d3 images over the years - image quality that i could easily see was not reproducible on my crop cameras.

To these ultra pixel peeping eyes, the 6d is only slightly better at dynamic range than my t2i.  High Iso handling is generally FANTASTIC, which is why i figure the low iso takes an image quality hit. Low light photography is a whole other ball game compared to my crop bodies.

So while i enjoy my 6d, its nowhere close to the full frame experience i thought it would be. Still dreaming of a 5d3 and non-ancient AF.  :(



-
What lenses are you using?

28
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 22, 2014, 05:16:27 PM »
I must have misread. I was under the impression that some people were arguing that 2.8 lens let in the light of an f8 when on the micro 4/3 mount.
Jarrod
As Neuro said, two stops (f5.6), not three.

To understand this, you need to understand the difference between total amount of light, and the intensity of light. Think of a shaft of sunlight - use a magnifying glass to concentrate that light into a smaller area - you get no more light, but the intensity is increased. Just shrouding more of the light to make a narrower shaft leaves the intensity the same, and reduces the total amount.

A greater intensity of light is what's needed to make a smaller area receive the same amount of light. Simply cutting/cropping out some light, and then magnifying/enlarging what's left afterwards results in less light captured. That's otherwise known as a lower signal, which requires more amplification/enlargement, typically resulting in more noise.

rs, you might be right about light, but you are at 666 posts, so you got to post again to avoid being evil :-)
Good point. Ok, here's one to sort out the number.

The Canon 300/2.8 is about the same price as the Olympus 300/2.8, yet the Canon is smaller, and even with the extra heft of the 2x TC and bulkier FF body, lighter. Plus it doubles up as a 4/3rds equivalent of a 150/1.4

I know which I'd rather buy (not taking into account the dropped 4/3rds mount) and carry with me  ;)

29
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 22, 2014, 05:05:00 PM »
I must have misread. I was under the impression that some people were arguing that 2.8 lens let in the light of an f8 when on the micro 4/3 mount.
Jarrod
As Neuro said, two stops (f5.6), not three.

To understand this, you need to understand the difference between total amount of light, and the intensity of light. Think of a shaft of sunlight - use a magnifying glass to concentrate that light into a smaller area - you get no more light, but the intensity is increased. Just shrouding more of the light to make a narrower shaft leaves the intensity the same, and reduces the total amount.

A greater intensity of light is what's needed to make a smaller area receive the same amount of light. Simply cutting/cropping out some light, and then magnifying/enlarging what's left afterwards results in less light captured. That's otherwise known as a lower signal, which requires more amplification/enlargement, typically resulting in more noise.

30
EOS Bodies - For Stills / Re: How to differentiate crop vs. FF
« on: October 22, 2014, 09:13:26 AM »
the Zuiko is as fast as a 2.8.
You are correct, it is f2.8. And by that exact same premise, the Zuiko is 300mm long too.

What I'd like to know is, if small sensors lead to smaller, lighter systems, how come this lens designed for only a quarter of the frame size manages to weigh in at close on 50% more than the Canon 300/2.8? Even with a 2x TC and bigger body, there's a massive weight saving for the large sensor system, not to mention better handling.

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