January 31, 2015, 04:13:05 PM

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 - John Thomas

Pages: 1 2 3 [4] 5 6 7
46
Lenses / Re: Which 24-70 to buy for weddings & events?
« on: June 21, 2012, 02:44:24 AM »
Quote
Quote from: John Thomas on June 20, 2012, 01:11:25 PM
And there are plenty of situations in which one needs VC at weddings.

Are there? Plenty? All I'm all in favor of a "free" IS of a Tamron lens that performs like the Canon mk1 and is much cheaper, and I'll use the IS for my personal spare time shots. But except for totals of the church and such no situations would spring to my mind that wouldn't involve people, thus rendering the IS advantage nearly moot at these focal lengths?

Yes, there are plenty of situations, at least in my case. It is not only the fact that the low light forces you (ok, me) to IS becasue I cannot obtain 1/70s at longer end, there are cases in which you (I) suddenly see "the shot" and because I'm in rush to catch it, my hand isn't steady enough. IS compensates this as well.

Also, perhaps is better to say my humble opinion about "useless" IS on slow shutter speeds because "human subjects are constantly moving" - there are (at least) two things to consider here:

1.) there are enough situations in which your subject (candid scene / portrait) can be catched at 1/20, even at 1/10.

2.) From our experience we know at what shutter speed we can freeze a moving man (and how much we want to freeze from his movement), depending on what he does. This, at (my) events is usually between 1/30 till 1/60-1/80. I preffer to have the camera near to the lowest shutter speed possible in order to have lowest ISO possible. And IS helps here.

just my2c & HTH

PS: Perhaps is better to mention that I preffer to shot mood, atmosphere shots and go to select events. Harsh, bright (neon) lights aren't my kind. But perhaps I'm mistaken.

47
Lenses / Re: Which 24-70 to buy for weddings & events?
« on: June 20, 2012, 01:11:25 PM »
I'd get the tamron, The original 24-70 is a good lens but a bit long in the tooth. The tamron is better in every way except built quality, Plus VC.

Unless you have the budget for the MK2, the tamron is the obvious choice.
+1
If I didn't have my Canon 24-70mm MK1, I would get Tamron 24-70mm VC now.  Many reviews say Tamron 24-70mm overall is better than Canon 24-70mm MK1.  For wedding Canon 24-70mm MK2 may be the best; however, it's not out yet.

+1 -0.5

-0.5 is about Canon 24-70 Mk II. It has no VC. And there are plenty of situations in which one needs VC at weddings. I rather preffer not to use flash for many reasons - one of the most important being that the people must be natural in order to get "the shot" and the flashes of the flash break the intimate atmosphere of a wedding.

+1 also for 50mm primes.

48
EOS Bodies / Re: New 5D Mark III Firmware Before the End of May [CR2]
« on: June 19, 2012, 04:14:33 AM »
Quote
Sorry, I cannot follow re. spin control .. what would that lookk like ... got a picture? 

I do not have the impression that Nikon's fine-tune feature is logarithmic ..  but I agree with you, that users should have even more direct control over Auto-ISO behaviour ... which parameter (Av,Tv,ISO) should be adjusted first, which second, which third and under which circumstances (min - max ranges, focal length used, IS active or not).

Having the Nikon UI metaphor means that you are limited by the screen in showing values (see the attached image), while a spin edit (a box which increments or decrements values based on dial movements) allow much more values to hold inside. See for example the 2nd (animated) picture from the top at

http://www.dpreview.com/reviews/canon-eos-5d-mark-iii/10

...besides that, yes, the real solution is to provide a professional GUI for exposure cuboid adjustments and save them as settings. What is exposure cuboid (aka incorrectly as "exposure triangle") see Matthew Miller's answer here:

http://photo.stackexchange.com/questions/6598/what-is-the-exposure-triangle#12441

Any takers in how this GUI/workflow would be?

49
EOS Bodies / Re: New 5D Mark III Firmware Before the End of May [CR2]
« on: June 19, 2012, 03:51:43 AM »
Quote
That having said, all customization of current dslrs is a joke given the fact that you've got an embedded computer in your hand. Even on my 25 year old eos620 with date back, I could program in custom shutter-aperture curves!

How did you that?

...btw, the "embedded computer" from our hands is a monster, (especially if we talk about DiGIC 5) with a screen which has 1,040,000 dots. Remember, desktops and after that laptops had for many years a resolution of 1024x768 which means 786,432 dots...

I think that their main problem is that they are locked in pre-iPhone mindset. We have a super-CPU to do just one thing and it can do just in one way. Today the cameras are digital but still built with a mechanical mindset.

Guys, unlock that potential...

50
EOS Bodies / Re: New 5D Mark III Firmware Before the End of May [CR2]
« on: June 18, 2012, 01:52:04 PM »
...And to take in account IS. The AutoISO doesn't take in account the IS. Think 70-200 f/2.8 IS. What Tv should I choose for AutoISO? 70? 200? Auto? But "Auto" raises the ISO on 1/(FLength) basis (ok, more or less) thus mitigating the advantage of having an IS on your lens.
They need to implement also an option like "Exposure Bias" in 1/3 stop in/decrements to handle this.
Just sayin'

I will not go through this endless loop again. Please read up on how exactly Auto-ISO is implemented on the Nikon D4 and D800 (http://www.dpreview.com/reviews/nikon-d800-d800e/16). This is as good as it gets currently. Although it is not complete or "perfect" either.

Read it, thanks for the link. However I think that having much more precise control (ie. in +/- 1/3 stops or 1/2 stops, WRT Lens' Focal Length) is better than having a 5 step scale of -0.5xF, -0.25xF, 0, 2xF, 4xF - where F is the lens' focal length like the Nikon has.

Also, I think that my proposal is much more open to the future cases (being linear) compared with Nikon's which seems exponential / logarithmic.

As for GUI implementation, rather than a slider, I would propose a spin edit control (for ex see http://documentation.devexpress.com/#WindowsForms/clsDevExpressXtraEditorsSpinEdittopic) which is much more compact space wise and can "hold" much more values than a slider. But if Canon want to use sliders like in AFMA screen, no problem for me. Just to implement it.

just my2c

51
EOS Bodies / Re: New 5D Mark III Firmware Before the End of May [CR2]
« on: June 18, 2012, 04:14:01 AM »
The M with autoiso and ec is available in the 1D4

we are talking about the 5D 3 and a possible FW Update for it. So forget your stupid 1D 4 for a while and its totally awkward scratch-yourself-on-the-back-of-your-head implementation of pseudo Auto-ISO.

The 5D III and any other Canon EOS camera needs a firmware with a full and unfettered implementation of Auto-ISO. 

This means:
* user-settable upper and lower limits for 1.) ISO 2.) shutter time and  3.) aperture - to be used as required in   various exposure modes [Auto], P, Av, Tv, M
* plus regular operation of exposure correction in M with Auto-ISO on
... anything less is unacceptable and total crap.

oh ... and just to make sure: we want it NOW and we do NOT want it hidden away under unlabeled custom functions 91,92 to 99 plus safety shift enabled and CTRL-ALT-DELETE-DIRECT-PRINT-button pressed simultaneously ... oh no, we want it readily and easily accessible!

...And to take in account IS. The AutoISO doesn't take in account the IS. Think 70-200 f/2.8 IS. What Tv should I choose for AutoISO? 70? 200? Auto? But "Auto" raises the ISO on 1/(FLength) basis (ok, more or less) thus mitigating the advantage of having an IS on your lens.

They need to implement also an option like "Exposure Bias" in 1/3 stop in/decrements to handle this.

Just sayin'

52
The issue I have reported is that this check is done when the camera power is OFF...which may lead to some interesting power drain issues if the camera is left off for an extended period of time (the camera has to check for some condition when the power is off to detect the door opening).  However Canon could not confirm that this impacts the charge on the battery.


1 Series already does this and that has no battery problem

I think this is a non issue from a battery drainage point of view

EOS 1Ds Mk II has it.

53
Lenses / Re: Canon 17-40L lens for $500...good deal?
« on: June 07, 2012, 02:56:36 AM »
Much better than 17-40L is Tokina 16-28 f/2.8 at the same price. See

http://www.photozone.de/canon_eos_ff/595-tokina162828eosff

and

http://www.fredmiranda.com/forum/topic/1117411/0#10675636

HTH

54
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 06, 2012, 02:43:10 AM »
Quote
The ideal CMOS RGB sensor design is really Foveon...layered pixels with blue, green, then red layers. This kind of sensor design normalizes pixel distribution...eliminating the distributed bayer pattern that results in 1/2 red and blue pixels relative to green. It uses Silicon's natural filtration effect to filter out wavelengths as it penetrates deeper into any given pixels tri-color pixel well. Because every pixel is sensitive to the full range of light wavelengths, your QE is naturally higher, and a layer of microlensing could improve QE even more. The lack of a bayer pattern generally eliminates the need for a low-pass filter (which are usually used to avoid COLOR moire in bayer sensors)...you will still encounter some luminance (monochrome) moire, but you'll generally encounter that regardless anyway with or without a low-pass filter (except in the case of upscaling). Canon's best competitive move would really be to buy Foveon from Sigma, and put it to some truly good use. They could greatly improve IQ that way, and if they could improve resolution to current standard ranges (18-22mp), they could make a killing, and get competitive again. I figure that a backside illuminated design, and further copper-based/high conductivity activate and read wiring BSI would be necessary to increase Foveon-style sensors to current resolutions, however BSI designs are becoming rather academic at this point.

Also I do think that Foveon-like multi-layer sensors are the future. However:

1. Now, they behave poorly at high ISOs (layers response etc.). In how much amount of time do you think that they will be able to compete with Bayer on 800-6400 ISO?

2. I don't know if you're aware but it seems that Canon has a better patent than Foveon & Exmor for a multi-layer sensor:

http://www.canonrumors.com/forum/index.php?topic=1209.0

In fact, in order to stay on topic  ;), this was the sensor which I've expected in 5D3/1DX. However it seems that it isn't.   :'(

3. OTOH, related to this, there are reports that 5D3 works without the AA (OLPF) filter. And I mean it works well. (No moire etc.).

Do you think that this thing really stands? An 5D3/E? An 5D3 without AA filter?

55
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 05, 2012, 02:35:03 AM »
ehhh what?  ??? :P

Well, to summarize:

BSI:
Backside Illuminated Sensors (BSI) only offers significant benefits when your pixels are ultra tiny...say 2 microns in size or less (many point and shoot/phone camera sensors have pixels as small as 1.9 microns, possibly even smaller these days, what with 40mp+ phone cameras floating around...!!) For comparison, a 7D has 4.3 micron pixels, the D800 has 4.6 micron pixels, the 5D II has 6.4 micron pixels and the 1D X has 6.95 micron pixels. Readout wiring is in the range of hundreds nanometers (fraction of a micron), so it isn't usually a problem until your pixels are around 2000 nanometers or less (where a couple hundred nanometers is a significant percentage of your pixel area).

Noise:
Sony Exmor mondo badass hardware noise removal.
Canon uber suckass hardware noise removal (well, ok..SO-SO mediocre hardware noise removal...to be fair ;) I am a Canon user after all. )

Why do you think that Nikon D800's Exmor sensor settled at 36 Mpix?

Wouldn't be a much better solution WRT noise removal a, let's say, 22-24 Mpix sensor? Now I'm thinking that if Nikon would had a 18-24Mpix Exmor then the 5D3 would be in serious trouble, because Exmor's NR hardware correlated with a rather big pixel size would have an amazing output even at high ISOs.

What do you think?

I don't really think there would be that much of a difference, honestly. Pixel size has more to do with QE, or Quantum Efficiency, than with noise. Improvements to QE have the side effect of improving noise characteristics, however outside of the lowest ISO settings (and even then, only to a slightly lesser degree), the very vast bulk of "noise" is photon shot noise, rather than electronic forms of noise. Photon shot noise is a matter of physics, due to the random and otherwise unpredictable nature of light packets (photons.)

All things being equal, once you eliminate most electronic forms of noise (such as is the case with Exmor sensors), more pixels is always a good thing. Higher spatial resolution at that point is always better than lower resolution, regardless of diffraction. At some point you reach a spatial resolution where even the finest details that you could possibly photograph require representation by many pixels (i.e. the smallest aspect of detail requires at lest 10x10 pixels to be represented.) Assuming little or no electronic noise, there is a HUGE benefit to that, because now noise is a SUB-DETAIL level issue, and noise removal is now largely and intrinsically a detail-neutral process.

Hence the Megapixel Race will start again?

...However a very interesting effect is to be seen: Acording to DxO measurements (CIIW), while the EXMOR has an amazing Dynamic Range on very low ISOs, this falls linearly whereas 5D3's (and Nikon D4's) has a logarithmic(?) falloff having as a net result that the 5D3's DR is actually better (speaking at 100% crops) than Exmor's.

Another related question: Having so many Mpixels, perhaps is better to have an RGBW sensor rather than a RGB one? (I don't think so, but I'm asking anyway).

Thanks a bunch for your info,

John Th.

56
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 04, 2012, 12:50:45 PM »
More about 1dx.

The 1dx firmware is 7.1.1 B0.9

so close now!!!

:D

1. Aha! They have a firmare in late Beta. Very good! They're working on it.

It is very very good for the community to know this. Also I presume that the 5D3's firmware is update accordingly, where applicable, isn't it? :)

2. > "So close now!!!"  ...hmmm.... from WHERE do you know?  :)

Usually these sorts of things are shipped "when is/are ready" (TM). A small hurdle can keep the team for enough time stuck. What makes you to say "So close now!!!" (with three exclamation marks)

OTOH, someone very close to the team knows such things. (I don't think that's very bad to say that you know more - in fact it would help us, the guys which are left in the twilight zone) Especially if we can help with something and/or is something which affects many (eg. it is related also to 5D3 - for ex. a wide-impact update) or affects few (eg. a niche feature which is related only to 1DX - eg. Ethernet card).

3. Did you just received a new firmware for your 1DX? :)

Thanks in advance for your response!

In addition, mid June is still the target date.
From the sample pic there, the high iso is not really cool as Canon said before.
3200 is acceptable.
U can c so many noise when push to 6400...
A little bit disappointed about that...

However, this machine is still on the top of Canon camera tree.
Nikon's high iso is always better, but Canon's color is better!!!

Am I right? :D

Thanks for the info.

OTOH, regarding to ISOs - Hmmm... I don't know. 5D3 is MUCH better at high ISOs in 100% crops than its competitor (D800). Also, I expect that 1DX to be better than D4, but we'll see. The thing is debatable.

Also, I preffer the Canon's "better colors". On scientific side, tough, while D800 has an amazing DR on low ISOs, this falls quite abruptly at high ISOs and Canon is better there by a sensible margin. I would say that 5D3 has a good 3200, very usable 6400 and an usable 12800. Also, if you really want a shoot, 28500 can do also your job, but you can loose enough details there.

57
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 04, 2012, 04:53:39 AM »
More about 1dx.

The 1dx firmware is 7.1.1 B0.9

so close now!!!

:D

1. Aha! They have a firmare in late Beta. Very good! They're working on it.

It is very very good for the community to know this. Also I presume that the 5D3's firmware is update accordingly, where applicable, isn't it? :)

2. > "So close now!!!"  ...hmmm.... from WHERE do you know?  :)

Usually these sorts of things are shipped "when is/are ready" (TM). A small hurdle can keep the team for enough time stuck. What makes you to say "So close now!!!" (with three exclamation marks)

OTOH, someone very close to the team knows such things. (I don't think that's very bad to say that you know more - in fact it would help us, the guys which are left in the twilight zone) Especially if we can help with something and/or is something which affects many (eg. it is related also to 5D3 - for ex. a wide-impact update) or affects few (eg. a niche feature which is related only to 1DX - eg. Ethernet card).

3. Did you just received a new firmware for your 1DX? :)

Thanks in advance for your response!

58
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 04, 2012, 04:30:56 AM »
ehhh what?  ??? :P

Well, to summarize:

BSI:
Backside Illuminated Sensors (BSI) only offers significant benefits when your pixels are ultra tiny...say 2 microns in size or less (many point and shoot/phone camera sensors have pixels as small as 1.9 microns, possibly even smaller these days, what with 40mp+ phone cameras floating around...!!) For comparison, a 7D has 4.3 micron pixels, the D800 has 4.6 micron pixels, the 5D II has 6.4 micron pixels and the 1D X has 6.95 micron pixels. Readout wiring is in the range of hundreds nanometers (fraction of a micron), so it isn't usually a problem until your pixels are around 2000 nanometers or less (where a couple hundred nanometers is a significant percentage of your pixel area).

Noise:
Sony Exmor mondo badass hardware noise removal.
Canon uber suckass hardware noise removal (well, ok..SO-SO mediocre hardware noise removal...to be fair ;) I am a Canon user after all. )

Why do you think that Nikon D800's Exmor sensor settled at 36 Mpix?

Wouldn't be a much better solution WRT noise removal a, let's say, 22-24 Mpix sensor? Now I'm thinking that if Nikon would had a 18-24Mpix Exmor then the 5D3 would be in serious trouble, because Exmor's NR hardware correlated with a rather big pixel size would have an amazing output even at high ISOs.

What do you think?

59
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 02, 2012, 05:25:15 AM »

I had in mind that they could try NOT to put a "last-minute improvement" (significant or not) but to include a "big" improvement which they have behind the closed doors - something like a BSI sensor - they have the technology...


A BSI sensor, if it ever be true, will place Canon at the same starting line as Nikon/Sony, and should be worth of the long bitter waiting period...

BSI primarily benefits sensors with small pixel pitch, and the aim is to increase QE (quantum efficiency), which only might affect noise levels as more of a byproduct of its primary job. (BSI basically "flips" the fabricated sensor upside down, putting all the R/C activation and readout wiring behind the photodiode, and therefor out of the light path from the pixel/microlens.) The pixel pitch on the 1D X sensor is relatively very large, and it would benefit little from a BSI design. The D800 does not use a BSI design either...it is still FSI.

The difference between Sony cmos sensors and Canon cmos sensors is that Sony integrates FAR more hardware-level noise reduction technology than Canon. Currently, to my knowledge, Canon sensors only employ CDS, Correlated Double-Sampling...however I believe their patents date back nearly a decade. Sony sensors employ a newer and more effective form of CDS, a form of transistor differential compensation to reduce FPN, integrated column-parallel ADC (a smaller, slower ADC for every column of pixels built right into the sensor...slower ADC's produce less noise of their own, and having one ACD per column also helps reduce FPN), and a few other smaller improvements that I currently can't find the patents for. Its these explicit noise reduction features that make a Sony Exmor sensor produce cleaner pictures than a Canon sensor.

Canon could benefit from a BSI sensor in their compact and bridge cameras, but the improvement to QE in a large sensor with a very large pixel pitch like the 1D X would be very small...maybe 1-2%...definitely not enough to put them in the same league as a Sony Exmor. (It should be noted that Canon uses a gapless "microlens" sensor design...but the pixels themselves still have gaps between them...most of the activate and readout wiring exists within the spaces of the gaps, with minimal intrusion into the light path from a pixel. If this were not the case, as might indeed be the case with a very high density full-frame camera (say 60mp or more, the 2-3 micron pixel pitch range), then a BSI design would probably benefit a full-frame high resolution sensor as much as it benefits a tiny point and shoot sensor.)

Your post needs more acronyms  ;D

Nope. It was quite informative as it was.  :P

60
EOS Bodies / Re: Canon EOS-1D X Delays [CR2]
« on: June 01, 2012, 03:45:42 AM »
Given the target market, the price and the fact that their reputation in the professional market rides on this camera, is it any wonder that Canon wants to make sure the thing is as close to perfect as possible before releasing it?

If they think this, they must be really desperate - engineering is always a compromise between dev time and product lifecycle, thus making "near perfection" an idea for geeks, not for a commercial company. It's much more likely that they found flaws (f8 af?) they couldn't get away with given the competition, so rather than "near perfection" its more like "good enough".

1.) By improving 1DX to not leave the impression that 5D3 is abandoned.
Abandoned customers will abandon the brand.

Are you suggesting that Canon would be well-advised not to put any significant last-minute improvement in the 1dx, because it may make the 5d3 look bad? Geez, this is the way of technology - and Canon will hardly stop development because some 5d3 users are a bit touchy when they hear "Nikon" and could not stand internal Canon competition, too. Didn't tons of 5d3 threads establish that the 5d3 is a great body at any price and nothing else matters, esp. not other alternatives :-o ?

I had in mind that they could try NOT to put a "last-minute improvement" (significant or not) but to include a "big" improvement which they have behind the closed doors - something like a BSI sensor - they have the technology, put the link bellow in the Google Translate to see:

http://egami.blog.so-net.ne.jp/2012-01-23

...also have a look here:

http://photorumors.com/2012/01/23/sony-develops-next-generation-back-illuminated-cmos-sensor-with-rgbw-coding-and-hdr-movie-function-canon-files-a-patent-for-a-large-bsi-sensor/

For an expensive product with a long life cycle like 5D3/1DX the early adopters are one of the most valuable assets of a company. It they will feel betrayed then they will betray - a damage which is very hard to repair after. I know this from many years of experience.

Having a camera being twice as expensive and two or even three times better it is understandable. But having a camera ten times better just because they wanted to fool the early adopters and enthusiasts with 5DMk3 - this will backfire. Too few will think that they had a stiff competition from Nikon/Sony and they needed to throw everything against them. The ones who purcased an comparatively over-priced 5D3 will feel cheated and next time who will dare to commit?

OTOH, from my small experience, as I stated elsewhere and it seems that I'm not alone, they now try to overcome some design issues and to improve to the max the firmware (this includes also end-user features like black AF thing but also the internal processing engines like ADC / noise handling etc.). The risk is way to big (imho) to redesign hardware now.

But I think that's critical for them to crowdsource their problems even in the form of "rumors" (this is one the best ways to keep the brand goodwill untouched) because more eyeballs will see better and perhaps a solution will appear from "nowhere" (if it didn't appeared already ;) ).

JustMy0.02c++

JohnTh.

Pages: 1 2 3 [4] 5 6 7