Messages

31

EOS Bodies / Re: How can lens focus ever be "off" in a way that AFMA fixes it?

« on: April 19, 2013, 07:19:38 PM »

Canon cameras contain information about all the EF lenses and the commands to send to them.  Third party lenses tell the camera that they are a Canon lens and then translate the command they receive to their lens.  This can cause even another step that adds to inaccuracy, but it can be adjusted by AFMA as well.
 
Its a lot more complex that a person might think.

Again, all of that would be solved by closing the loop. Then all you'd need is a correction for sensor/vs AF array, which would be body specific and programmed by Canon at the factory.

It is sounding like the whole phase detect AF system is fully open loop, which really surprised me. Is Nikon like this too? Do they also have an AFMA type feature on their bodies?

Wish there were a Canon engineer I could speak to this about, would be a fascinating discussion!

Even with a closed loop, you may not be able to guarantee that it will always be correct since there's long term wear and tear, if the body is sent back to be cleaned and things shift slightly...plus it'll be different if you're using it in cold weather vs hot weather since parts expand/contract and at different amounts.

32

EOS Bodies / Re: How can lens focus ever be "off" in a way that AFMA fixes it?

« on: April 19, 2013, 04:30:20 PM »

If it was closed loop, with a second look, we would be only a few steps away from a self-learning AFMA built in into the camera. Now that would be nice, wouldn't it.

More than nice ... it'd be AWESOME!

The problem is you can't really, unless you also look at the actual image projected onto the sensor. AFMA fixes the situation where the AF detects "in focus", while due to small differences between lens + body combinations, the image projected onto the sensor is not quite in focus. So if the lens mount on the body is every so slightly thicker than the specs but still within tolerances, and the sensor is positioned ever so slightly closer to the back, then while the AF might be in focus, what is projected onto the sensor is just slightly off leading to images that might be a bit software than the might otherwise be. This is most obvious when you have a very shallow DoF, because the plane of focus is very thin where being slightly off from the focus is noticeable.

33

Software & Accessories / Re: LR 4/5 output - jpg is warmer(more reds) than LR edit screen - why

« on: April 19, 2013, 12:32:19 PM »

You say your monitor is uncalibrated? And then you export as JPG to sRGB I'm guessing? Is your image viewing application color aware? Sometimes when shifting between color spaces and your viewing application doesn't have any concept of color space, the viewed image can be off from what it really is.

34

Lenses / Re: 24-70mm upgrade?

« on: April 17, 2013, 12:30:05 AM »

I've rented the Tamron 24-70 a few times now (still saving up for it) as needed, and it's quite a good lens. AF can sometimes be a touch slower to get going than most of the rest of the L lenses I have, but in general it's quite good. Heavy though, but so is the Canon 24-70 v2.

35

Software & Accessories / Re: Adobe Lightroom 5 Public Beta Available

« on: April 16, 2013, 02:51:48 PM »

It's slow going due to general buggy-ness

My experience when trying it is quite the opposite: LR5 feels like turbo-charged, as if the build a wait loop into LR4 to make people wish for an upgrade :-> ... this and some new features like the heal/clone brush are enough to upgrade, let's hope the RC phase doesn't take the better of a year's time.

Out of curiosity: OSX or Windows? I've thus far only used it on Windows 7. May load it up on my Mountain Lion machine this evening.

It does feel peppier than 4, and I'll note that I always work each photoshoot in its own fresh catalog, so there's no "few hundred versus tens-of-thousands" effect at play.

What I meant was: getting through the entire set is slow going, because I have to restart LR every couple of frames. Most common failure has been the adjustment brush. It repeatedly stopped working, i.e. I'd select the tool but when I clicked to place it it merely zoomed in an out. Restarting the software remedied it. Other times it crashed outright.

Ouch, that sounds quite buggy. If I keep hearing this, I might wait for the next beta or RC before trying it out.

36

Lenses / Re: EF 200-400 f/4L IS 1.4x Availability

« on: April 16, 2013, 01:33:29 PM »

So over 8 lbs? Yikes.

Holy cow, not that I'd be in the market for a 10k lens, but I'm wondering what users Canon has in mind - at this weight, most photo-journalistic or quick action shots seem to be impossible?

But probably it's really a small pro sports (and maybe wildlife?) market, and those few people are fine to shell out that money for top notch iq & reach flexibility.

Until you put it on a monopod/tripod and shoot from the side of a major sports event or out stalking wildlife. Or you're a paparazzi and needs to be able to go from shouting "Hi there" to being so far away as to be unnoticeable.

37

EOS Bodies - For Stills / Re: Confusion about Macro Photography

« on: April 16, 2013, 12:39:29 PM »

The definition I've heard is when your subject is reproduced on your recording medium (film or digital sensor) near or at 1:1 or better. So if your subject is 5mm long, it's near or at 5mm long on your recording medium. Or possibly more, so if it's 2:1 magnification, it's 10mm long instead of 5mm.

38

Technical Support / Re: MacBook Pro : Best RAW Processing Software?

« on: April 16, 2013, 12:36:26 PM »

Well, there's RAW processing, and then there's assent management (e.g. keeping track of all those photos you're taking). DPP is pretty decent software for general RAW processing. Not fantastic, but for a free tool it's quite good. Then there are other standalone processors like Photoshop (really Adobe Camera RAW which imports into Photoshop). Finally, there's full image processing & catalog management such as Lightroom, Aperture, and Capture One. Most people choose Lightroom or Aperture, although having just checked Capture One actually isn't too expensive at $300, but from my understand it's definitely geared towards the working professional and tethered capture for photoshoots.

For myself, I use Lightroom with very occasional edits in Photoshop.

39

EOS Bodies - For Video / Re: Results: Filming 720p 60fps at super high shutter speeds

« on: April 16, 2013, 12:27:27 PM »

You're welcome! Comes from hanging around film guys too much. Sometimes it seems that's all there is here in LA, but really just the friends I have.

I'm in L.A. too. I hear you... seems like half my friends are either shooters, editors, or screenwriters. After years of resisting the dark side, I'm looking at getting into the business myself. But I still have a lot to learn.

Good luck, there is some _expensive_ equipment out there for video. Even more so than for stills, especially if you start going cinema lenses and such. I've flirted with it a bit here and there, but so far mostly stayed away unless my friends said "hey, we need your help", which really means I have a 5d2/5d3 and they want to borrow them

40

Software & Accessories / Re: Adobe Lightroom 5 Public Beta Available

« on: April 15, 2013, 08:03:01 PM »

From what I read it looks like performance in general, and especially in the Develop module has been a major focus of this version. Definitely going to check this out!

41

EOS Bodies - For Video / Re: Results: Filming 720p 60fps at super high shutter speeds

« on: April 15, 2013, 07:36:35 PM »

I'm a video noob. And I'm curious... What's wrong with shooting at 60fps?

I understand how ND filters work with aperture, but if slo-mo is what you want, why would you shoot at 30fps with an ND filter, rather than 60fps without one?

Nothing wrong with shooting at 60fps, in fact it's often used so that in post-production you cut the output framerate in half to get 30fps output so you double the time it takes, which give slow-motion.

Beyond that, the general rule in video is to get a 180-degree shutter which gives a nice, smooth look you shoot at 1/(shutter speed * 2). So for 30fps you shoot with a shutter of 1/60, and with 60fps you shoot at 1/120, or as close to that as you can get (so 1/125 on most DSLRs). So the only way to control exposure is with ISO or aperture, or to use ND filters to cut the amount of light. Since the OP wanted a very shallow DoF he needed to use some ND filters to cut the light to allow his aperture to be wider since he undoubtedly had his ISO set very low (100-200). Since he had no ND filters, he had to raise the shutter speed significantly. This can give video a more stilted look, since every frame is much 'sharper' and there won't be any motion blur like you can sometimes get with the slower shutter speeds.

Very well explained! Thank you. I'm saving up for a variable ND filter.

You're welcome! Comes from hanging around film guys too much. Sometimes it seems that's all there is here in LA, but really just the friends I have.

I'd take a look at http://www.canonrumors.com/forum/index.php?topic=14219.0 thread in which there's a good video about variable-ND filters. They may be useful, but they also have their downsides.

42

EOS Bodies - For Video / Re: Results: Filming 720p 60fps at super high shutter speeds

« on: April 15, 2013, 07:34:38 PM »

i don't know much about video, but i've heard of a 180degree rule, but it had nothing to do with shutter speed.

See https://en.wikipedia.org/wiki/Shutter_speed#Cinematographic_shutter_formula, it comes from the mechanical rotary shutter traditional video cameras have used. I suppose it's not really called the 180-degree rule, it's just that's what stuck with me in my head from the traditional 24fps @1/48s shutter speed.

43

EOS Bodies - For Video / Re: Results: Filming 720p 60fps at super high shutter speeds

« on: April 15, 2013, 05:47:53 PM »

I'm a video noob. And I'm curious... What's wrong with shooting at 60fps?

I understand how ND filters work with aperture, but if slo-mo is what you want, why would you shoot at 30fps with an ND filter, rather than 60fps without one?

Nothing wrong with shooting at 60fps, in fact it's often used so that in post-production you cut the output framerate in half to get 30fps output so you double the time it takes, which give slow-motion.

Beyond that, the general rule in video is to get a 180-degree shutter which gives a nice, smooth look you shoot at 1/(shutter speed * 2). So for 30fps you shoot with a shutter of 1/60, and with 60fps you shoot at 1/120, or as close to that as you can get (so 1/125 on most DSLRs). So the only way to control exposure is with ISO or aperture, or to use ND filters to cut the amount of light. Since the OP wanted a very shallow DoF he needed to use some ND filters to cut the light to allow his aperture to be wider since he undoubtedly had his ISO set very low (100-200). Since he had no ND filters, he had to raise the shutter speed significantly. This can give video a more stilted look, since every frame is much 'sharper' and there won't be any motion blur like you can sometimes get with the slower shutter speeds.

44

EOS Bodies - For Video / Re: Results: Filming 720p 60fps at super high shutter speeds

« on: April 15, 2013, 05:10:39 PM »

Quite nice, and a very good job keeping the focus where you wanted it at f/2. What supports/focus puller/etc did you use?

45

EOS Bodies - For Stills / Re: 5D mark III problem - 32gb sandisk extreme pro destroyed

« on: April 13, 2013, 03:29:27 PM »

what makes you think the canon broke the card?

counterfeit sandisk cards (approximately one third are fake says sandisk) show this behavior quite often.

The card was bought from an "authorised store"  and was pretty fast. I do not think it was a counterfeit one.

And I think that camera broke the card because did the same think when tried with another card.

Perhaps time to contact Canon Support? If you have another camera you can take a video with, maybe take a video and show exactly what you are doing and the way in which are doing it.