July 24, 2014, 09:09:46 AM

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Messages - dgatwood

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1
Lenses / Re: Buying a used lens from Adorama
« on: July 23, 2014, 09:11:18 PM »

Unless you absolutely can't live without weather sealing, I'd probably just buy the Sigma version instead.  From what I've read, it's sharper, cheaper, and has similar or better build quality....

2
food for thought from another topic ---http://www.canonrumors.com/forum/index.php?topic=21908.msg417183;topicseen#new ---  only 5% of the buying public buys more than 1 lens apparently.  That leaves 95% with a kit lens.  What to venture a bet as to what percentage of that 95% never even take a peek at their manual? What percentage of that 95% even knows what an AF point is?  LOL....that is why AFMA won't be in a rebel!  How many users are in P mode would end up messing with their AFMA because they have blurry shots -  because they don't know their shooting at a slow SS?  Or because the AF is locking on to other things (all point active!!!).  I would love to have more faith in humanity that this wouldn't happen, but, time and time again I get questions from the first time DSLR user and yup, theynever even opened the manual, hell they don't know where it is and ----yeah they look at me like I'm Satan for asking....I paid $$$$ for this and it should just work.  UGGGGGG....no no no no no....AFMA just has no place in the rebel line....


Actually, I'd go the opposite direction.  The Rebel bodies should have their kit lenses pre-AFMAed as part of the initial burn-in and packing process.  That way, non-advanced users won't ever even have to think about it.



and most of those people shoot in "green box" mode.... do you really want them to be doing a complex and precise calibration sequence on a tool that they do not know how to use? AFMA is hard for advanced users to get right....


Only because Canon didn't bother designing an AFMA UI that makes sense for non-advanced users.  There's nothing even slightly complex about AFMA in principle.  The UI just sucks harder than a Hoover. 

Instead, the camera should just provide a one-button-press option to recalibrate the currently attached lens, and should hide the AFMA values from the user entirely.  I would envision something like this:



Would you like to calibrate this lens?


[YES]  [NO]  [DON'T ASK ME AGAIN]



Please set the zoom to its widest setting.


[Waiting]/[OK]



Please put the camera on a tripod and aim it at something more than 50 feet away.

[Too Close]/[OK]




I'm having trouble.  Please make sure the camera is on a tripod, aim it at something far away, then press OK.

[Too Close]/[OK]



No, seriously, you [expletive] dolt, put it on a tripod.

[OK]



Calibrating.

(At this point, it flips the mirror up and down repeatedly, focusing in alternation between live view and normal mode.  Periodically, it kicks the focus way out and repeats this process.  Then, after about twenty flips, it continues.)



Please aim the camera at something about 5 feet away, then press OK.

[Camera goes into servo focus mode.]

[Too Close]/[Too Far]/[OK]



Calibrating.

(At this point, it flips the mirror up and down repeatedly, focusing in alternation between live view and normal mode.  Periodically, it kicks the focus way out and repeats this process.  Then, after about twenty flips, it continues.)



Please set the zoom to its narrowest setting.

[Waiting]/[OK]



Repeat these screens:
  • Please point the camera at something more than 50 feet away, then press OK.
  • Calibrating.
  • Please point the camera at something about 5 feet away, then press OK.
  • Calibrating.



Done calibrating.


[OK]



That's the sort of UI that you need when designing a feature like this for end users.  From there, you calculate the mean AFMA value and the standard deviation.  Then, throw away any outliers, and recompute the mean.  If the standard deviation is too high or there are too many outliers, display the "make sure the camera is on a tripod" screen.  Otherwise, use the resulting mean (with outliers removed) as the AFMA setting.

3
Third Party Manufacturers / Re: Small camera for active kid
« on: July 23, 2014, 02:57:10 PM »
No advice - I just misread the post and it reminded me of my, then, 3 year old grand nephew running around with my 1D4 and 24-105 at Christmas a couple of years ago. The camera was as big as his chest and he found it VERY heavy! He got some cracking shots though!

Was that the lens cracking or the body?  :D

4
You'd think they'd put AFMA in it.  It counts as a good user feature but really it also helps Canon increase user satisfaction by letting owners fix any minor manufacturing boo boos themselves. 

Why wouldn't they do that?  Otherwise most people with slightly out of whack lenses or bodies just suffer with it and tell people their Canon just wasn't very sharp.  Maybe they buy a Pentax next time. 

Then others have to deal with the hassle of sending their body and one favorite lens off for adjustment at Canon which is no fun for either the owner or for Canon, and it is all avoidable if they'd just include AFMA.

If the ketchup companies are smart enough to add "shake well before serving" to their labels, so that the user is more likely to have a positive experience with their condiments, why would a camera maker leave out AFMA?

If I were canon, the thought of allowing afma to the mass population of ma and pa photographers would be terrifying to me and my call centers.  Afma is a great tool for those who know how to use it, but any increase in my call center activity would reduce my profit margin on the rebel line.  Enthusiasts, sure offer this option to allow them to grow with their camera.  Most who can afford a single digit model probably have an idea of what they are doing.  Mainstream usually has no clue what they are doing, but they don't know it.  All they know is that if they screw it up, it would be canon's fault for making such crappy gear and social media would spread that word.

Just bury it deep in the custom functions menu so the newbies won't discover it accidentally.  Better yet, make it mindless.  Have the camera remember each lens it sees, and when it detects a new one, ask the user to set the lens to each end of its zoom range and point it at something close and far away.  Then have the camera calculate the AFMA values by computing the difference between the AF-sensor-computed OOF amount and the DPAF-computed OOF amount several times in rapid succession.

5
Rebel T5 doesn't count? Why?

IMO, Canon hasn't actually updated the Rebel line since 2012.  The T5 doesn't count, because it's basically just a cost-reduced T5i, which in turn is just a T4i with a few firmware changes and a couple of tiny mechanical tweaks (most of which were probably just cost reductions).

6
Don't send it to canon. What you do is you get a pair of tweezers, lift the rubber and put a small drop of superglue on the plastic. Make sure you don't glue the dial in place though and it is probably worth waiting half an hour and doing the same thing on the other side so two points are keeping it in place.

If you're concerned about getting glue in the wrong places, paint on a coating of clear nail polish instead.  The higher viscosity makes it easier to control than glues.  Either that or use rubber cement, which will probably last longer than any other kind of glue.  :)

7
Lenses / Re: What Lenses are missing from Canon's range
« on: July 21, 2014, 01:04:44 AM »
With regards to the 12/14-24 idea, would people prefer f4 and greater sharpness or f2.8 and take a slight hit on absolute sharpness - I don't believe you can have both - personally, I'm holding out for 12-24 to replace my 16-35II, I'd take a hit on absolute sharpness for a f2.8 aparture.

I'm pretty sure you could have both in that range, but it would weigh as much as a big white, and you wouldn't be able to fit any other lenses in your camera bag.  :D

But in all seriousness, f/2.8.  I can always stop down if sharpness is critical, with the exception of last-second "ooh, neat" shots, but nothing can make a slow lens faster (other than cranking the ISO).

8
EOS Bodies / Re: Eos7D mk2, How EXCITED will you be if . . .?
« on: July 20, 2014, 09:29:56 PM »
That said, I still believe that most of the time technique beats gear. It's when we are at the limits that the gear becomes truly important and most people never get that far. People like Jrista are not typical. His bird portraits are at a level where great technique and great gear are needed to get that level of shot. Myself, I am still learning and only occasionally reach the limits of my gear, and to keep things in perspective, remember that most cameras are left in program or "green box" mode. For all those people, technique is far more important than gear.

On the contrary.  I would argue that for those people, gear is more important than technique.  The gear has to be good enough to take a decent shot without the photographer giving it any hints at all.  Among other things, that means that its maximum usable ISO has to be pretty high so that it won't need too long an exposure when shooting moderately moving subjects in poorly lit rooms.  For people who shoot in auto all the time, the gear is most critical.  For people who actually know how to use all those manual and semi-manual modes, the gear matters less (except when we're being lazy).

9
If Canon is listening.......................  Touch screen is nice, but there has to be a way to turn it off and on without turning off the camera.  I am getting to like the touch screen on the M, but if you leave the camera on and the camera bounces around, all your settings have changed.

Did they use a resistive touchscreen or something?

I don't know what type of touchscreen it is.  Or what kinds exist.  But, so far as I know, there is no way to turn it off on the M. So, if you have the M on and bouncing around as you move, some of the settings will change (and you of course don't know which ones).  So I have made it a habit of just turning the camera off between shots when I carry it, but would much prefer being able to leave it on, use the rudimentary controls to take quick shots and then be able to turn the touch on and off quickly to access other settings, etc.

Resistive touchscreens respond to pressure.  Capacitive touchscreens respond to capacitance, which effectively means that you have to touch them with a finger (or something substantially similar) or else they won't detect the touch.  Modern, multi-touch displays are all capacitive.  I'm surprised anybody still uses resistive touchscreens these days.

10
Lenses / Re: Correction Data for Legacy Lenses
« on: July 19, 2014, 04:27:33 PM »

I don't see a Lightroom profile for it, but Lightroom does let you add custom lens profiles for arbitrary lenses.  Just download the Lens Profile Creator app, print the calibration charts, light them appropriately, and go from there.

11
EOS Bodies / Re: DSLR ? - thinking out loud ....
« on: July 19, 2014, 04:23:05 PM »

And you have hit the big problem with mirrorless.... battery life. They increase the power consumption and make the battery smaller.... and for some inexplicable :) reason, battery life sucks! If they kept to LP-E6 they would last longer... or with a mirrorless in a "normal" sized camera there would be room for a larger battery.

For comparison,
70D, LP-E6 battery, 1000 pictures per charge
EOS-M, LP-12 battery, 230 pictures per charge

LP-E6 is 7.2V and 1800mAh
LP-E12 is 7.2V and 875mAh

If you look at in term of pictures per Ah, the 70D is 555 per Ah and the EOS-M is 265 per Ah.... so assuming the same battery capacity you are still at only half the life on the EOS-M as the 70D

Of course, according to the official Canon numbers, the 70D only gets about 230 shots in live view, or 152 shots per Ah.  I can't imagine why its battery life in live view mode is only half that of the EOS-M, rather than being about the same, but there you go.  Either way, the point remains that active displays draw a lot of power.  :)

FWIW, this past week I shot over 500 frames (and a 90 s movie) on a single fully-charged LP-E12 in my EOS M (and I could have shot more, but I swapped in a fresh battery as soon as the red-flashing indicator came on).  I shot about the same number of images on my 1D X, and used less than 35% of the LP-E4N's capacity (no need for the spare battery this trip).


The more useful statistic would be minutes with the screen lit.  Taking the photo is lost in the noise by comparison.  If you shoot photos relatively quickly, you'll get a lot of shots.  If you take five minutes between shots, you won't get very many at all.

12
EOS Bodies / Re: DSLR ? - thinking out loud ....
« on: July 19, 2014, 03:39:38 PM »

And you have hit the big problem with mirrorless.... battery life. They increase the power consumption and make the battery smaller.... and for some inexplicable :) reason, battery life sucks! If they kept to LP-E6 they would last longer... or with a mirrorless in a "normal" sized camera there would be room for a larger battery.

For comparison,
70D, LP-E6 battery, 1000 pictures per charge
EOS-M, LP-12 battery, 230 pictures per charge

LP-E6 is 7.2V and 1800mAh
LP-E12 is 7.2V and 875mAh

If you look at in term of pictures per Ah, the 70D is 555 per Ah and the EOS-M is 265 per Ah.... so assuming the same battery capacity you are still at only half the life on the EOS-M as the 70D

Of course, according to the official Canon numbers, the 70D only gets about 230 shots in live view, or 152 shots per Ah.  I can't imagine why its battery life in live view mode is only half that of the EOS-M, rather than being about the same, but there you go.  Either way, the point remains that active displays draw a lot of power.  :)

13
I love the idea... but I don't want to pay twice as much for a lens because of the infrastructure and added tech.  That's why I lean towards a software issue.

Oh, I meant in the camera body.  Chances are, if they steal the lenses, they're going to steal the body, too, and if you report the theft quickly enough, they'll all be in the same place.

You'd never be able to pull off that sort of tracking in a lens, realistically, for space reasons.  To secure the lenses, I like the idea of providing an unlock code with the warranty paperwork, and programming the lenses so that they won't work with any camera until you authorize that camera by entering the unlock code.  Also provide a way to reset the lens and wipe the whitelist so that store demo lenses don't come preprogrammed with a hundred authorized bodies or whatever.  :)

Oh, and you'd have to provide a global unlock option so that the lens would still work with older cameras that don't support the security feature.  Maybe ship the lens unlocked and program it so that when you first connect it to a camera, if the camera doesn't ask the lens for its lock status within the first ten seconds after asking for the protocol version, the lens sets a flag in nonvolatile storage so that it will stay unlocked until you explicitly lock it.

14
If Canon is listening.......................  Touch screen is nice, but there has to be a way to turn it off and on without turning off the camera.  I am getting to like the touch screen on the M, but if you leave the camera on and the camera bounces around, all your settings have changed.

Did they use a resistive touchscreen or something?

15
EOS Bodies / Re: Canon 6D N
« on: July 19, 2014, 03:09:07 PM »
Then again, I've worked both at Apple and at an embedded Linux startup, so it's possible that I'm just a bit biased against RTOSes.  :)

Interesting observations, though I (I never did rtos programing) like to add this theory: It's easier to debug and build a reliably system because if it works once then it'll work every time sine timing is fixed and this no problem. Do Nikon and/or Sony and other companies use multitasking non-rtos designs in their cameras?

Except that modern RTOSes don't really work that way unless you're dealing with microcontrollers.  If I understand correctly, modern RTOSes are usually a bizarre kludge of multitasking and non-multitasking parts, enforcing partial real-time behavior through scheduling.  The bigger difference between a modern RTOS and Linux is that the RTOS likely has a much smaller kernel footprint, but as a result, has a lot less functionality.

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