December 20, 2014, 03:31:48 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 - Aglet

Pages: 1 ... 30 31 [32] 33 34 ... 73
466
EOS Bodies / Re: 70D and Dxomark....
« on: August 30, 2013, 03:16:13 PM »
This makes ZERO sense.  If there is no real world difference the where is the inferiority - or the superiority?  The sensor camera combo is only inferior/superior if there is a REAL tangible REAL WORLD Difference.  If there is no real world difference then logically - one is not greater than the other.  Again, this is photography, people buy images, people hire you because you craft good images - they don't hire/buy because the sensor is better.  And you can even take that to the consumer level - ohhh...thanks for taking some pictures of my sons first birthday, but, I saw that you used a canon so I don't even want to look at the pics because nikon has better sensors?????does anyone in the real world do that?????

The real world also includes hobbyists, who do not buy or sell photos. They are curious about the challenges pros face and about the way the run their business but do not really relate to that.

It is like being a car enthusiast and discussing taxis which professional taxi drivers drive. Every taxi driver would tell you than the clients could not care less about handling, acceleration but they care about space and a smooth ride. The drivers themselves want reliability, trunk space, fuel economy. This automatically excluded the hottest car brands.


+1, well stated analogy.

I have a few "taxis" in my garage which get regular use; a couple 4x4s (d800/e), Austin Mini (Pentax Q), and a few other assorted oddballs including a high performance daily commuter (Pentax k52s). I'm still waiting for an affordable sport coupe (d400 or preferably improved 7d2) to work with long lenses and dim light with high fps.

467
EOS Bodies / Re: 70D and Dxomark....
« on: August 30, 2013, 03:34:56 AM »
OK, put the popcorn away for a minute. :)
Let's do some quick analysis using DxOmark's data.

Putting aside the 70D's sensor-based AF achievement for a moment, let's look at the Signal to Noise Ratio (SNR) of today's 70d, compared with the 20d from 9 years ago, and the 10d from 10 years ago.
As SNR goes, so does DR to a large extent but SNR is a little more telling and when you compare them overlaid you can see how they differ and where the changes in sensor performance are.

The upper blue line is the ISO 100 SNR plot for all 3 cameras.
On all 3 cameras you'll see that the 100% gray scale (white) is at about the same 42dB level.  So all 3 have the same SNR at white.

Where the line meets the bottom axis is where signal = noise and the image information gets lost in the noise and vice-versa. Well, unless there's a pattern that's discernible but DxOmark is still not publishing noise pattern data as far as I know. (I've requested that they do so we can estimate FPN severity of a sensor.)

Anyway, the signal=noise level of 0db is the cutoff level for all ISO measurements.  That is at gray scale 0.052% for the 70d at 100(claimed) ISO.  That's about 10.9 stops of highlite-to-dark range where dark = average noise. (It's late at night, somebody please correct me if I make a math mistake here, auto-correct may also mess up some spelling)

Without getting the specific data points for the other 2 cameras we can see that they also have about the same end points for 0db and white.

Net result.  At a per-pixel level, the 70d's base ISO performance has not improved in 10 years.  But, because it's pixels are about half the total area of the 10d's pixels (likely slightly more because of better fill-factor in modern sensors where more surface is actually actively used but lets go with half as that's in the 70d's favour) the 70d has made a technical achievement of about 1 full effective stop for one full effective pixel.
This may be even better by one more stop because of the way the split-pixel AF system functions but since I have no technical details on how this is really done at the sensor level I'll leave this to other tech types to expound. I'm also not considering each camera's real-effective ISO performance, just the rated level.

If we look at some other ISO levels:

- the 20D has better SNR results at white for all ISO levels.  This is not something that's easy to see in prints since a little noise on a big signal pretty much disappears.  This is also due in part to the physics of larger pixels, which is why full-frame sensors do even better. The 10D is similar to the 20D except for its highest ISO which falls down a bit

- the 20D's curves are ALL higher in every part of the graph, denoting that its SNR is better than the 70D's at all intensities from white right down into very dark shades at matching ISOs.  The 10D's curves are considerably lower; it has worse SNR than the 20D pretty much at every point below base ISO.


SUMMARY.

At a per-pixel level, the 20D was a significant improvement over the 10D which came 1 year before it.  The 70D, at the same per-pixel level, has not improved and is slightly worse than the 9 year old 20D.  Taking into account the smaller pixels of the 70D's sensor, the practical net improvement is less than 1 stop in 9 years. (possibly close to 2 stops, depending on how the dual-sensel-AF-pixels really work)

Compared the 20D to the 60D/7D and Rebel xx0 using 18MP sensors we have an honest improvement of less than 1 stop in the period between the 20D and the 7D's release.

So, if Canon's 70D sensor is read out in such a way as to provide the same level of read noise as a regular single sensel pixel then they may be able to achieve a measurable improvement (nearly 1 stop) in base ISO dark noise which should translate into a similar improvement in total DR of a similar sensor NOT using this new AF system.

So, will the 7D Mark II have no such split AF pixels and offer us slightly improved SNR and DR because of this method or will they do something more akin to the Exmor's superior noise elimination?
Or will they provide these new AF pixels and compromise the stills performance for the sake of video and improved live-view AF?

Please Canon, give us the best possible STILLS camera in the 7D Mark II.  I might then buy one.

468
Landscape / Re: Beautiful sunsets
« on: August 30, 2013, 01:15:17 AM »
out in the back yard watching the sunset and a Great Blue Heron flew past....
I do like when a bird positions itself nicely in the frame for me while I'm shooting a sunset or sky shot. That's a nice shot.

469
EOS Bodies / Re: 70D and Dxomark....
« on: August 30, 2013, 01:11:48 AM »
Well, as innovative as the 70D's new dual-sensel pixels for continuous AF are, the overall signal to noise ratios, as reported by DxOmark, have changed very little.  Hopefully there'll be less banding in dark shadow for those who need to push it but I thought I'd put together some animated gifs to compare the difference between the 70D and the 60D and then the 70D compared to the Nikon D5200.
I hope DxOmark will allow this editorial use of their material here.  If not, it can be removed easily enough.
I find the complete SNR graphs are more useful to see where the low ISO deep shadow SNR limits are and what the highlite end shows for difference, which combined can help indicate DR and more.  Switching between them is a useful way to quickly see the differences.
One take away from all of this though is that somehow they managed to double the number of pixels and add a significantly useful feature (the Dual Pixel AF) without breaking anything.  Of course it doesn't look like they made any significant improvement in the low end noise either -- oh well.  However, I think the jury is still out until we get a look at the back of a lens cap (or something similar) to see what the pattern noise looks like.  I am very curious if any improvement has been made in that area.

+1, the AF development is quite remarkable and accomplished w-o breaking still IQ performance, actually improving on it ever so slightly in some areas.
I'll get some lens cap shots as soon as my local dealer has some stock.  I'm curious about not just what FPN there may be, but whether I can also see where the dual sensels are bordered by the regular ones.

470
EOS Bodies / Re: 70D and Dxomark....
« on: August 30, 2013, 01:08:29 AM »
On my 1DX I just hit a couple of button and bracket, never failed me this far. Generally prefer the results I get from blending exposures over what I get from using sliders on 1 exposure too  :).

Exposure blending's a great work-around, but not always practical. (moving scene elements)

471
EOS Bodies / Re: 70D and Dxomark....
« on: August 30, 2013, 01:06:08 AM »
.. learn how to expose properly, and take some freaking pictures for God sake or sell your gear and jump to sony for all I care... Just stop this nonsense. 

how do YOU "expose properly" for a scene that exceeds your Canon's DR?
Are you content to clip highlites and shadows and live with the out-of-camera tone curve for every shot?
If so, your advice may not register with the more artistic photographers.

Aglet Aglet Aglet ::Shakes head::  I expose the way I expose.  I've been shooting professionally for the last 10 years and been shooting even longer...  I look at a scene, look at what the meter tells me, and I either go with it or call it's bluff and compensate as i see fit.  It's not rocket science.  I get a shot, if it looks the way I want it to, great, if not, I compensate more.  When it's exposed the way I want it, It's good.  If you dont know how to expose, go, get off this forum, and start shooting. 

As far as going into a scene with too much DR... what absolute non-sense...  I've shot back in the days of 4x5 film, shot transparency, medium format, the early canon DSLRs which had what, 5 stops of DR?  If a scene is too dark, brighten it, if you cant brigten it without over exposing something else, use flash, or even better off camera flash, or reflector or some other way to manipulate the light.  Dear god son, this is photo 101, well maybe 102.  This isn't hard.  A real photographer doesn't blame his gear for not getting the shot.  A real photographer knows what needs to be done, and makes the photo even better. As i've said before, a client NEVER has looked at my photos and said "it's a shame there wasn't more DR"... Hell, the average client doesn't even know what noise is.  This is pure pixel peeping madness and it's disgusting.

Well, that was kind of a rhetorical question.  I know the answers. :)

What you seem to be saying is "compromise your exposure" or "manipulate the light" to fit your gear.
Perfectly good advice, that's what has to be done whether it's to fit the limitations of the camera or to change the appearance of the scene.  However, such methods are not always desirable or even possible.  So that advice, good as it is, may also be a bit trite.
I just prefer to have equipment that's less limiting than Canon's, especially since there have been better options available for a few years now and Canon's only improved marginally (base ISO) since their original CMOS sensor hit the scene years before that. They've in fact gone backwards and have only recently returned to where they used to be a few system generations ago when it comes to FPN.

I'm probably not the only one that's not surprised, and also disappointed, that the 70D is not significantly improved for still photography over its predecessor except for an improved AF system.
This simply means we're STILL waiting for Canon to catch up to the competition in the area of basic sensor system metrics.
That said, what they've accomplished with this new sensor-based AF is impressive!  Adding the 7d's PDAF system is a big plus too.

I've still made lots of great images with my Canons, (especially the Digic 3 and older ones) but I've also experienced plenty of situations in landscape shooting where FPN (Digic 4 systems) has shown up, not just in shadows, but in midtones.  Some of this FPN is not just read noise in shadows but also seems to be intra-sensor inconsistency.  Translation, their sensor production lines are not as precise as they need to be.  But I digress…

70d's to be lauded for its AF breakthrough, but not much else as far as I can see.

472
EOS Bodies / Re: 70D and Dxomark....
« on: August 29, 2013, 01:11:53 PM »
As for jumping ship, I think people tend to exaggerate how hard it is.  In the past few years I've jumped ship from Nikon APS-C to Pentax APS-C to Canon FF, bought a second ship (Olympus) and toyed with a third (Nikon FF) before deciding against it after renting a couple.  Each time I switched I sold all the previous equipment I had bought.  Depending on whether I had bought it new or used I received less/more/the same as I had paid for it in the first place.  I may have overall "lost" but I don't look at it that way - I think if it as the (not very high) price of using that equipment during the time I owned it and an extremely useful learning experience.

+1

Quote
Pentax, by the way, provided a rather good example of why DR isn't enough.  I owned a K-5, with a K-x as back-up.  At the time there seemed to be fairly wide agreement that the K-5 had the best sensor of any APS-C camera (the same Sony sensor as the D7000 but run by slightly better software), and it was a good camera in other ways too (esp. ergonomics).  The dynamic range was simply astonishing - when I first bought it I would amuse myself by fooling around with deep shadows in DxO and LR, amazed by what it could reveal (not that the results were worth keeping...); and yes, there were a few times, mainly involving sharply contrasting light in the alleys of Lugano, when it proved useful.  But the relative shortage of first rate lenses with fast, accurate focusing soon became old....

I've added Pentax gear to my kit over the last year.  I really like the k52s, the thing will AF in near dark w-o assist light.  And it likely still does have the best overall low ISO raw performance of any crop body... per-pixel anyway. and the high iso end is also very good.
But I agree, Pentax lenses are a different collection compared to the competition but I've managed to find some that work extremely well for me, tho only my body-driven primes focus super fast.  Their SDM AF is kinda slow on my 16-50/2.8 and that's cost me a few shots.
Still, I use it because I love the images I get with it and the ergonomics and highly customizable interface.  It's a very good photographic tool and has replaced my 60D + 15-85mm as my go-to rig.  If they would bring out a fast lens with more range, like 15-85mm f/2.8-4.5, that'd be even better.

473
EOS Bodies / Re: 70D and Dxomark....
« on: August 29, 2013, 01:01:15 PM »
... awkward when handholding a d800 ..to change the ISO settings (top left of the camera), I could not find how to assign it to any of the other buttons.

?? In Av mode I've got my front control wheel for aperture, rear wheel for ISO

The same to change autofocus points, hard to reach that switch...

short thumb?

Quote
The af-on switch needs too much pressure..

OK, maybe your hands aren't the best fit for a d800
I have mid-size paws and d800 feels perfect in my mitts with a 70-200 hanging off it.

Quote
4fps? really?

5d2 was pretty slow too, who's complaining about that?

Nikon bodies are quite different, you need to spend some time with them to adjust yourself to how to get the best handling with them.  No different than any other mfr.  I have to admit, my long term Canon use gave me a similar bias but no more.
D800 isn't a spray'n'pray kind of camera, it requires more deliberate use.. but has more forgiving (under)exposure latitude

.. learn how to expose properly, and take some freaking pictures for God sake or sell your gear and jump to sony for all I care... Just stop this nonsense. 

how do YOU "expose properly" for a scene that exceeds your Canon's DR?
Are you content to clip highlites and shadows and live with the out-of-camera tone curve for every shot?
If so, your advice may not register with the more artistic photographers.

474
Landscape / Re: Beautiful sunsets
« on: August 29, 2013, 03:16:14 AM »
no ND filter?? wow.  Because I always get either a really bright sky or dark dark landscape.  :/  let me see then... 100 iso, f8-11, and around 1000 shutter?  idk  I guess i just need to practice more..  I live in Montana and only if I could take nice sunsets.  Thank you!

nope, no ND filters on my shots
if you're referring to a graduated ND filter, those can be really useful at times but I don't use them either.
If I have to, I'll pull an ND grad effect in Post (Lightroom does this nicely if needed).
Sometimes you may need to do an NDG filter, sometimes not.
In my examples above it's just a straight shot as is.
I usually start at 100 iso, 1/500 and f/8 (sunny 16) and adjust as required for the conditions.

MO should have some great sunsets!  I used to travel I15 every fall years ago and those dusty skies were sometimes full of color.  Good luck! :)

475
EOS Bodies / Re: 70D and Dxomark....
« on: August 29, 2013, 03:10:17 AM »
Well, as innovative as the 70D's new dual-sensel pixels for continuous AF are, the overall signal to noise ratios, as reported by DxOmark, have changed very little.  Hopefully there'll be less banding in dark shadow for those who need to push it but I thought I'd put together some animated gifs to compare the difference between the 70D and the 60D and then the 70D compared to the Nikon D5200.
I hope DxOmark will allow this editorial use of their material here.  If not, it can be removed easily enough.
I find the complete SNR graphs are more useful to see where the low ISO deep shadow SNR limits are and what the highlite end shows for difference, which combined can help indicate DR and more.  Switching between them is a useful way to quickly see the differences.

476
...I do think the Tamron handles the transition from focus to defocus more smoothly than the Canon.

+1
I was never pleased with the (latest) Canon's rendition of transition areas; went from busy to garish to, "what's that other stuff in there?"
I'm thinking of getting this Tamron in F mount to replace or complement my Nikon 70-200/4vr.  Also a very sharp lens but suffers from similar transitional area bokeh ugliness.  (but it's so small and light..)

Wow, I never thought I will hear this about 70-200 mk II (I hope you guys are referring to that lens) which some here (and elsewhere) consider to be the best canon zoom lens made till date (it surely may be so)! Now day by day my itch of buying the Tamron 70-200 grows exponentially. (now the rose petals will suffer) I should buy it now, I should wait till next year, I should buy it now, I should wait.........

That's the one.
Canon's lens (& Nikon's) may be incredibly sharp and very well corrected for the focus plane, but the out-of-plane areas can look like garbage in some conditions.

see my e.g. here, look at the R side of the apple on the R side and tell me that's a nice bokeh rendition of the branches behind it.  ;)

www.canonrumors.com/forum/index.php?topic=819.210

I've had many shots with busy backgrounds made more ugly by this lens so I got rid of it.
I posted a similarly ugly shot from the Nikon 70-200/4vr somewhere too.

A good lens is not always about ultimate sharpness, those other areas matter too. (Also, Canon's 70-200/2.8L IS 2 has a fair bit of CA in FF corners)
I really like what I saw when just quickly testing the Tamron.  I can see the Canon and Nikon lens trouble areas just thru the viewfinder while racking focus over busy backgrounds.  Do that w the Tam and you won't see nearly as much of that radial bokeh effect.
I'll trade ultimate sharpness for a better-balanced performance on pretty much any lens.  As such, I sold my Canon 2.8 L 2, have been still using my Nikon kit for now and will likely add this Tamron in the future.

477
Canon General / Re: Help design a time lapse rig
« on: August 28, 2013, 12:48:25 PM »
Then you have to take into account how to program it. I can make it so it will slow down during a curve but what if someone moved the position of the curve? Now you have it going fast through the curve and slowing down during a straight portion of the track; programmatically it would suck using a system people can manipulate. I would have to remove the ability to slow down during a turn because the program wouldn't know where the turn was; if that makes any sense.

program could use total track distance as measured (or add up pre-programmed common pieces) and then the director specifies a velocity profile for the entire distance, you'll know where the curve is.

As an alt, use a hardware trigger (optical, mechanical) for telling the controller what section of track it's on.  Could be used for straight and curved, could even ID them with an IR sensor and markings on track.

It should not be significantly more complex.  If someone changes the track, they need to redo the velocity profile with the new track shape & length.

Like I said earlier, being able to adjust aperture isn't going to be possible. The only communication the program will have with the DSLR itself is when to open and close the shutter.

It's just more stepper motor utility channels to control the shaft on a cine lens rig; useful for AE operations.
Again, all these stepper motor channels can be GUI programmed using something like the velocity profile/track length for a simple, consistent interface that's relatively intuitive. (I'm supplying you patentable ideas here! ;) )
Ooops, actually not.  Just hosed that by providing published public disclosure here with witnesses.  :D

Use multiple strip-chart type graphs of the computed total track length in x-axis; display them one above the other so you can see how they all line up and compare the functions relative to each other.

Each chart displays an active dolly-camera function.
- velocity profile on one (top)
- shutter activation period profile (if not constant this allows return to real time as I suggested)
- pan profile
- tilt profile
- focus profile
- aperture profile

MORE OPTIONS - auxiliary function profiles
- more motion channels
- lighting control channels
- filter control channels
- anything anyone could possibly think of adding control channels (binary output trigger points, analog control outputs for light intensity controllers, etc.)

you don't have to incorporate ALL these functions initially, but allow for them.
But if you want to build the best, most cost effective rig, then these FEATURES will really set you apart w-o adding much hardware development cost and the software is all parallel structures to manage these using the time-distance baseline.
VERY DOABLE, very simple interface. checkbox for what function channels you want active, define the curve on activated ones graphically with the option of numerical entry fields to be precise. (Again, national instruments SW does this in its sleep)

I'll stop now.  When I start inventing (this is partly what I do for a living) I don't stop until I've built a Rolls Royce or Bugatti, then I pare it back down to fit the budget. :}

478
...I do think the Tamron handles the transition from focus to defocus more smoothly than the Canon.

+1
I was never pleased with the (latest) Canon's rendition of transition areas; went from busy to garish to, "what's that other stuff in there?"
I'm thinking of getting this Tamron in F mount to replace or complement my Nikon 70-200/4vr.  Also a very sharp lens but suffers from similar transitional area bokeh ugliness.  (but it's so small and light..)

479
Landscape / Re: Beautiful sunsets
« on: August 28, 2013, 04:47:26 AM »
Wow!! No edits? I'm impressed! What settings do you use? Iso? shutter? ND filter? I have the hardest time with sunsets/sunrises.. Tips please!!

for me:
- full manual usually
- no filters
- lowest practical ISO based on focal length and shutter speed
- aperture for required DoF
- shutter speed to expose w-o clipping highlites (you may be over-exposing and losing color and detail if you relay on camera metering)

and it helps to find a location where you can actually get some vivid sunsets/rises!
dusty prairies are great, and the closer to the earth's poles you can get then the longer these events last.
In northern Alberta in summer, sunset colors like this can go on for an hour or so.  Much of it after sunset.

480
Canon General / Re: Help design a time lapse rig
« on: August 28, 2013, 04:41:08 AM »
Might just be me but those great videos made with time lapse and camera movement are starting to all look alike.

Add the ability to do non-linear camera speed on that rail in the process and that'll be a nice feature.
Think like an engineer. :)

Are you talking about having a curved or circular rail? If so, I'm way ahead of you.  ;)

I've thought about curved track but those become "hardware options." (how many different radii can you build and stock?) 
Perfect for some applications, for others, I'd rather the pan-tilt control and as someone else mentioned, build onto that with zoom and focus pull options too.  May as well motorize everything that can be motorized.
And yes, Lego Mindstorm/National Instruments may be a good place to start for such an application.  NI developer edition is bloody expensive but you can then spin off standalone apps that can be sold, maybe by now also compiled for iOS and Android.

Would be nice to accelerate the dolly, along a straight stretch then slow down around a 90 degree curve and come to a decelerated stop.  All the while the camera pans and maintains focus on a nearby subject, like a growing seedling?  Then zoom out while maintaining focus, smoothly adjusting aperture for rapidly increasing depth of field to put the thing into environmental context over a much shorter period of time, actually accelerating back to real-time.

And I'm not even a director ;) - but I can imagine being able to do such a shot would excite a lot of people in the film industry.  Great way to add some zip to a documentary!

Pages: 1 ... 30 31 [32] 33 34 ... 73