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Topics - Marsu42

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Lenses / AFMA & distance?
« on: November 07, 2013, 01:10:25 PM »
Since my good ol' 60d doesn't have afma (thanks, Canon!) I'm new to this with my 6d and would like to ask some people with more afma experience for advice.

I just adjusted my lenses with Magic Lantern's dot_dune module which is basically a free in-camera version of FoCal and found that neither of my f4 zooms need afma (well, the 17-40L +1) at all at either end, at least not at the distance I could test them with in my room. I wonder...

1. My 100L seems to need more afma the longer the lens-subject distance gets. Did I do something wrong, is this normal behavior so I actually arbitrarily need to pick my favorite distance I'd like the lens to af? Do I need to test my 70-300L at longer distances than the 2m right now for accurate results?

2. I don't understand the scale of the afma values - does for example make the +5 of my 100L @1m a difference at the dof of f2.8 in real life? Or is this overcompensated by the camera's and my human's focusing variance anyway unless I shoot on tripod (and in this case would use focus peaking or contrast af)?

If a shot was framed too tight and I'd like to add some space around it, for example for print and framing - what options are there?

Is there a plugin to extrapolate the edge of the frame a bit so that the extension becomes less visible than a plain color, or a plugin to do a non-linear stretch so that the outer sides of the frames are stretched while most of the inner part remains the same (I know for the latter there is a plugin with this idea for AviSynth video processor)?

How do you do it? Thanks for any insight :-)

EOS Bodies - For Stills / 6D af tracking: experiences & usage cases
« on: October 15, 2013, 03:40:14 PM »
So I've at last bought a 6d and am fine with it because I knew what I was getting and what for. Still, Canon didn't dare to cut tracking completely - so the 6d does have an "ai servo"ish feature. After trying to use it a bit I'm not yet convinced I've got the best settings and handling method and would like to ask for your experiences.

1. Single af point tracking. So far I've found the outer points are bad for single point tracking, certainly worse than my 60d which has crosspoints and also up to +0.5lv light sensitivity. The 6d has trouble locking focus on low contrast areas like horses' foreheads, which also shows in stills shooting but really becomes a problem when trying to track in portrait position. Any different experiences?

2. Multi af point tracking: From 5d2->6d Canon didn't only reduce the af points from 15 (inc. tracking helpers) to 11, but also cut the firmware hook to select focus patterns through Magic Lantern - so you're stuck with either all or one af point.

My short experience indicates that when not tracking an elephant running towards you the 6d does a bad job choosing the af points and for some weird reason tends to ignore the good center point. If "center point with outer point tracking helpers" would work, the close af spacing could be a blessing in disguise - but somehow I found the selection to be rather erratic. Is this due to a not optimized Canon firmware, do I have the wrong settings or was I just unlucky so far?

3. The 5d3 has "af cases" which link the af settings to neat packages. With the 6d, you're on your own to find the best combination for different uses. I was trying to track running horses (from me, to me, parallel to me) - what do you track and what settings do you find work best?

  • Tracking sensitivity: I'm using "responsive" since I try to keep the object in the center af point - what's your experience with multipoint af, is "responsive" too erratic?
  • Accel./decel. tracking: I'm using higher values, or does this in your experience generate a too erratic behavior with the mediocre 6d af points?
  • AI Servo 1st image priority: I'm using "release" because I'd rather get an out of focus shot than lose a good one - or do you find the 6d is reliable enough to determine when the first shot is in focus?

Disclaimer: This thread is intended to help 6d users with tracking and multipoint af, if you don't have something helpful to add feel free to participate in another thread about the 6d's greatness or regressions vs. the 5d3.

EOS Bodies - For Stills / Is ff metering more aggressive than crop?
« on: October 07, 2013, 02:44:11 PM »
I've recently bought the 6d and expected the metering to be just the same as on the 60d - but that doesn't seem to be the case(?), though both use the same 63-zone metering system.

To me, the ff metering system seems to be more aggressive, and I'm more often running into blown highlights than with my 60d - esp. since the amount of highlights "hidden" in the raw and only accessible in postprocessing is much smaller on the 6d.

This is an important difference, because esp. with flash & ettl you're really depending on the camera metering system, and I see me using -ec, spot/partial metering, exposure & flash lock more often than with the 60d where eval metering and "shoot away" usually worked.

Question: Is my impression correct and ff/crop metering is different, or have I've gotten it wrong during my rather short time with the 60d?

Some time ago, I've been told by an alleged pro photog that real photogs don't crop, or at least only do minor angle correction. I am wondering if this is true, or it is an old-school fairy tale from the analog age that falls into the category "real photogs don't use auto iso and only shoot in full m".

I've gotten much better framing my shots, but I wonder if squeezing the last pixels out of your camera makes sense all the time. If I have a hard time framing a wildlife shot just right to get max. resolution, the Nikon guy next to me just shoots 24 or 36 mp and then crops some, gaining flexibility (aspect ratio, different framing) while probably not loosing much iq for usual print/screen sizes.

When shooting raw stock you cannot crop, or with 1000+ shots of an event you of course don't want to crop some pixels from every one - so a 100% vf (which my 6d doesn't have) makes sense in these cases.  But I also have recently experienced some situations where a couple of pixels to one side could have really helped in postprocessing, but I always have this nagging feeling that leaving more space around a subject simply isn't considered "proper".

Thus the question: How do you do it - better safe than sorry, or go for the full "no cropping, please" experience?

EOS Bodies / 6D: LCD protector w/o air bubbles?
« on: September 29, 2013, 04:12:53 PM »
Canon didn't grace the 6d with the swivel screen of the 60d (turn to protect) or a glass lcd like the 5d3, so I'd like to invest the money Canon saved in a 3rd party glass protector...

... Problem is: As a result of the natural and smooth, round 6D finish (edit: Amazon reviews state that) the screen is not planar but slightly bent, esp. on the top right. I currently have a thin plastic lcd cover, and it does show air bubbles in this region.

Did anybody manage to find a glass or comparably sturdy 6D lcd protection that applies *without* air bubbles beneath?

Esp. anything *glued* to the screen seems to have this problem (see attached image with black glue border), what *might* work is a much more expensive glass cover that only electrostatically attaches (image with "hama" brand). Any experiences?

Technical Support / 5d3/6d silent shutter: faster, slower or equal wear?
« on: September 25, 2013, 04:07:45 PM »
If shutter lag time isn't an issue: Does shooting in silent shutter mode protect the camera since it's moving the mirror slower(?), i.e. putting less physical stress on the components? Or is the max. shutter rating due to the curtains failing, meaning silent or normal shutter doesn't matter? Thanks!

I'd like to get a "as cheap as possible" android phone for 6d remote control and would like to ask for advice here. I've never gotten a smartphone before, I don't really need any smartphone capabilities, it's really just for this one purpose and voice telephony.

Are there any experiences with different phone types that don't really work with eos remote, what are you using?


Edit: It seems a tablet would be really better suited for me, so I extended the topic to match this change.

EOS Bodies - For Stills / How does read noise actually affect image quality?
« on: September 20, 2013, 05:31:44 PM »
Since somehow every sensor thread seems to degrade quickly into gibberish and brand fanboyism, I'm a bit embarrassed to admit that I still don't get how the real world impact of a camera's read noise is.

My current understanding: traditional non-Exmor sensor designs have higher read noise at low iso which also affects max. dynamic range (but this thread isn't about dr). Also read noise doesn't equal banding artifacts, see the lower 7d figures - but this model has higher banding due to the dual readout channels.

sensorgen.info says: @iso 100 / 200 / 400 / 800:
7d: 8.4 / 4.7 / 3.3 / 2.8
60d: 13.2 / 8.4 / 4.4 / 3.2
5d3: 33.1 / 18.2 / 10.6 / 6.1
6d: 26.8 / 14.6 / 7.9 / 5.1

Question: Except for long time astronomy exposures, when (if at all) does this mean that shooting at higher iso might/will give better iq than at the lowest iso setting? Thanks for explaining!

Lenses / What (nd) filter to put in the 17-40L back filter holder?
« on: September 20, 2013, 05:01:53 AM »
I recently realized my 17-40L has this back filter holder :-p and I now even have though of a use for it: With my 10x glass screw-in nd filter I don't get long enough shutter times for cloud blur in bright daylight, so I'd like to add another gel nd filter.

Question: What nd gels do I get to put behind the 17-40L?

Lenses / Effective iq for same dof on ff vs. crop @ same shutter speed?
« on: September 19, 2013, 06:03:33 PM »
This is a thought experiment I've been wondering about, I hope I understand the basics correctly :-p ...

Let's say I want to have a certain depth of field and use a full frame and a crop camera with the same shutter speed. When going from crop to ff, I'd need to close the aperture to get the same dof for the same field of view. At the same time, I could raise the iso to counter this light loss with the ff and to remain at the same shutter speed.

Question: Which iq (noise, ...) is better: crop with lower iso or ff with higher iso? When shooting handheld with a macro lens at macro distance, maybe shooting with a crop is even better than ff if a large dof is wanted?

Technical Support / How to fix a physically broken sd card?
« on: September 19, 2013, 04:02:02 PM »
After 3 years of pulling it out of the camera and putting it into my laptop, my trusty ol' 32gb sandisk finally broke - the front part with the pins fell out because the plastic sandwich construction came loose.

However, I only then realized that the front part *is* the actual sd card, there's nothing but empty plastic in the back part - if I tape the thing together again, it works in my laptop, but won't fit into the camera.

Question: Is there any way to get hold of a replacement sd "chip" holder so I can continue using the front part that obviously works perfectly fine? If I'd bought a micro-sdhc with sd adapter the solution would be simpler...

Lenses / AF hit ratio with 100L and portraits?
« on: September 18, 2013, 02:51:15 PM »
I was recently practicing portrait photography with my old 60d and the 100L, usually set to f2.8. Unfortunately, I find the af misses a lot, much more than in macro photography - am I doing something wrong?

I was using focus & recompose on the eye due to the lack of af points on the 60d, and in good light the lens missed about 1/3rd (some near misses, some real out of focus), and in bad light the af hit ratio was a sheer catastrophe but that's simply because the 60d doesn't af in dim light. I wonder:

* Is my technique wrong? The 100L has a very slow af as a macro lens, but is 1/3rd misses in focus & recompose with aperture wide open what I should expect... I waited for the af confirm after all? For macro, I nearly never shoot wide open.

* Is my camera af broken or maybe dirty? I recently also find my 70-300L @f4 missing somewhat more often than I remember. Btw I never tested the lenses for afma since my 60d hasn't got it anyway.

Edit: I could add some sample pictures if that helps, I didn't throw the bad ones away yet.

Lighting / Please explain how multi-group ettl preflash works?
« on: September 14, 2013, 03:37:48 PM »
I know what ettl2 is and what the preflash does in general, what I'd like to understand is how multiple groups work.

* Is it that every group does successive pre-flashes on their own so that the camera can determine what ettl ambient/flash ratio to set?

* Is this also the reason why pre-2012 don't work in group mode as they are only able to meter two pre-flashes (a:b and c) and rt requires up to five (a-e)? However, even if so Canon could at least have made it possible to use groups a+b in ettl and d-e in m flash mode (not to bash Canon, just for my understanding of the system)?

I'm wondering: What's the use of the new wifi remote control in practice, given that you cannot move the camera/lens itself? And with the upcoming 70d you can just the swivel screen for awkward angles...

... Is the wifi app just an enhanced self portrait gadget or has anybody managed to pull off some shots that wouldn't have been possible otherwise, for example shy wildlife? None of the Canon marketing examples really convince me :-\ but I'd be not surprised if there were creative uses I currently cannot think of.

Btw one of the shortcomings seems to me that as usual there is no sdk, so we cannot expect 3rd parties like Magic Lantern to make use of this feature for focus stacking, timelapse, motion detection, trap focus ... and the Canon apps seems to be limited to p&s.

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