July 30, 2014, 06:44:01 AM

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 - Martin

Pages: [1] 2 3 ... 7
1
EOS Bodies - For Stills / Re: 1D-X underexposure
« on: November 14, 2013, 05:10:21 AM »
Hi,

yes, I do experience similar underexposures, but it in my case it depends on the lens e.g

24-70 2.8 L mkI -2/3 EV
70-200 2.8 L mkII 0 EV
Macro 100 mkII +1/3 EV
85 F1.2  -4/3 EV
35 f2.0 mk II 0 EV

of course these are rough averages

Most were shot in  AV mode, around F5.6, evaluative metering.

It would be great if we would have something similar to afma, so an exposure correction by lens ???????


During some tests I have found that the 5d3 and 5D2 underexposes in general by -2/3 stop. Checked with sekonic and other camera (D300). Moreover I observed similar behavior as mentioned above, so it depends somehow on lens:

24-70: -2/3EV
70-200: 0 or -1/3 EV
85 1.8: 0 or even +1/3 (i would rather say it is perfect)
35L: -2/3EV
50 1.4: -2/3EV
135L: -2/3 EV

One more thing which could be strange is that a lot depends on light environment. When I shoot outdoors exposure seems to be much more accurate than in indoors. Almost all indoor shoots are completely underexposed which seems to be strange behavior as a metering system should meter everything as a neutral gray giving histogram peak on the center. Mine is almost -2/3 EV to the left. Once upon I time I run some test with 5d2, 5d3, Sekonic light meter and Nikon D300. I checked metering indoor on neutral even surfaces like white or gray wall. Only canon cameras results were -2/3 stops different from meters. I've sent it to service but they stated all was in line with standards. I spoke with some other users and some of them told me that the use a +2/3 correction all the time. It is a kind of a problem as shadow and dark parts of photos are hard to push with canon's sensors so the tendency should be completely different.

2
EOS Bodies - For Stills / Re: 6D af tracking: experiences & usage cases
« on: November 07, 2013, 08:04:09 PM »
One think u can do for sure is to get rid of canon system and get nikon. One thing is sure for me. Nikon AF, despite faulty D800 units is way better in almost every aspect. I know what is 5D3 in specification list (61 points, many x type points etc.) but try it with one of the outer x type focus points or with center AF under bulbs or fluorescent light-BF or FF. Outer points with mojority of lens just do not wrok (FF)  I have one 5d3 and test two other, different 5d3s-same thing. Reviews and other tests don't shot that. U still has one point in reality. I spent a lot time on testing, trust me or not. Tested different bodies with different lenses, spoke with other users. The new AF system is ok if u use it with center AF, under daylight, with lens adjusted to specific distance, and if the lens are 2.8, if u change one of those factors-it will just not hit the target. That's not the AF system I thought I had paid for. I know how it sounds but it is true, regardless all reviews. Same thing about 6D. AFMA and other service adjustments are useless when u change environment a bit. Check any 5d3 or 6d, LV vs phase detect, then do same test with other camera producer.

Interesting... ::)

I don't why I got MUCH-MUCH more keepers in AI servo with 5D III than 5D II. Must the photographer ;D


"keepers rate"...ok...i am not talking about servo. I am talking about AF precision on all AF points, not about servo at long distance with more DOF and probably stopped lenses. Take 16-35 and check outer points with tripod and well lit target at close distance. Take 135L, adjust it for daylight and than go under different light (fluorescent or bulb). With 70-200 L  at daylight, at 40 meters,  at f3,5 shooting speeding cyclist-I had also a "higher keeper rate than with 5d2" but that's not a revolutionary AF.Old canons users did one funny thing-compare everything to 5d2 as a reference and even now, with 5d3-recompose. I am not a brand lover, I switch system 2 years ago (5d2, then 5d3) but I just regret due to AF. I used to use all AF points before, in D300 and it worked precisely for studio works, even when points were not x-type. Let me say I am kind of experienced user so it's not about skills etc. Just want to share it. No offence, I know you love canon, I tried for two years:) thinking that maybe I had a bad copies. No, i did not. It is only my subjective opinion.

3
EOS Bodies - For Stills / Re: 6D af tracking: experiences & usage cases
« on: November 07, 2013, 03:05:59 PM »
I don't need help, just another camera or a system. The above history is reality. Me and few of my colleagues were really shocked when seeing the results of testing. 

4
EOS Bodies - For Stills / Re: 6D af tracking: experiences & usage cases
« on: November 07, 2013, 11:23:04 AM »
it's not for me to be honest.

5
EOS Bodies - For Stills / Re: 6D af tracking: experiences & usage cases
« on: November 07, 2013, 09:36:06 AM »
One think u can do for sure is to get rid of canon system and get nikon. One thing is sure for me. Nikon AF, despite faulty D800 units is way better in almost every aspect. I know what is 5D3 in specification list (61 points, many x type points etc.) but try it with one of the outer x type focus points or with center AF under bulbs or fluorescent light-BF or FF. Outer points with mojority of lens just do not wrok (FF)  I have one 5d3 and test two other, different 5d3s-same thing. Reviews and other tests don't shot that. U still has one point in reality. I spent a lot time on testing, trust me or not. Tested different bodies with different lenses, spoke with other users. The new AF system is ok if u use it with center AF, under daylight, with lens adjusted to specific distance, and if the lens are 2.8, if u change one of those factors-it will just not hit the target. That's not the AF system I thought I had paid for. I know how it sounds but it is true, regardless all reviews. Same thing about 6D. AFMA and other service adjustments are useless when u change environment a bit. Check any 5d3 or 6d, LV vs phase detect, then do same test with other camera producer.

6
My 5d3 body is extremely faulty but it is not the case in this topic. However I have tested 7 or 8  50 1.4s and ALL of them behave similar. All need AFMA od different distances, all have a lot of of focus shift. As I write in a lot of forums,  below reviews etc-that lens cannot be calibrated properly. Those lens are faulty by design and I have really completely no idea why no one mention this in any review. I am 100% sure that's a problem of all 50mm, and it is not connected with AF inconsistency. This lens cannot be calibrated properly with AFMA as well as with service center. I checked a lot of this.

1/ the AFMA on short distance does not solve problem on long distance (completely different values)

2/ on short ( 50cm-1m) distance when stopping down to ie. f4 there is a focus shift therefore the DOF is way off the desired plane

3/ side AF points behave different than center point (it could be a body problem in my case)

Checked with many 50s and all behave the same way.

7
Lenses / Re: Photozone comparison of Canon 35L vs. Sigma 35mm F/1.4 'Art'
« on: October 01, 2013, 08:59:30 PM »
I dream about 50 1.4 from ART Sigma. I would pay twice the canon price for it. Waiting for those lens so much. Keep my fingers crossed for sigma.

8
Technical Support / Re: Why higher end camera underexposes images?
« on: September 17, 2013, 05:56:17 AM »
Canon cameras, and they are not alone, do not meter at 18% grey, they meter at 12% grey, that is 1/2 stop underexposed for a mid-toned subject.

Take a picture of a grey card on an auto setting and the histogram should have a spike 1/2-2/3 stop below the midpoint.

There is no 18% law, never has been. It was just a number that represented Zone V in the Zone system. Camera manufacturers use 12% as a metered norm for the simple reason that they believe that gives a more consistently "correct" exposure.

Read the small print on a Kodak grey card to see the verbose wriggling even the mighty Kodak do to try to expose an 18% grey card with a 12% meter.


Why the spike should be -1/2 or 2/3EV from center? Take professional external light meter like Sekonic, take other camera (nikon) and check where is the spike. Why do u think it is correct to have the spike more on the left side. That means underexposed image in terms of standards of course. Only Canons meter in that way.

9
Technical Support / Re: Why higher end camera underexposes images?
« on: September 16, 2013, 09:39:08 PM »
  Some time ago, when I switched from Nikon to Canon (D300 to 5d2) I was sure that there is a problem with my new camera (5d2) as all images were underexposed in comparison to what I was used to in Nikon in terms of exposure.
  I tried to convinced myself that maybe its my mistake etc. I am and was aware of mattering and its options however the underexposed images were kind of standard with my new 5d2 and especially indoors.
  I run some tests with "gray card" or any other equally lit surface (white board or wall), I've checked exposure with Nikon D300 as well as with Sekonic meter, and of course with 5d2. Checked it in different environments.
 The well calibrated light meter should give an exposure with histogram with peak in the center. This is standard exposure. It does not matter if u check it on completely black surface, white or gray. The histogram should be the same.
Test results was a little shock to me as Nikon and Sekonic gave me exactly the same exposure, and perfectly centered histogram. Canon 5d2 gave a histogram with off-centered peak (to the left), so it was underexposing obviously by (-2/3 EV or -1/2EV). The 5d2 has an exposure correction up to _+2EV so if u make standard exposure corrected with +2/3 there is not as much room for further correction  (it is but not so much)
Sent it to Canon, they've checked-all in line with standards. Another shock. I've checked another 5d2 and the result was the same.  Now I own a 5d3 and it is underexposing like his older brother.

I have completely no idea why canons are metering  out off the standards. A lot of users just dial +2/3 all the time. Also, have no idea why no one in canon correct this, this looks like kinda design fault, made years ago.
What is more important, canon sensors are bad for pushing shadows as there is much banding or very poor information if any, so there shouldn't be any tendency to underexpose.

10
Reviews / Re: Review - Canon EF 50mm f/1.4
« on: September 12, 2013, 02:08:42 PM »
I not talking about AF issues in general (of course it is not perfect), but about focus shift at close focusing distance while shooting at ie. f3,5 or f4.0. It just cant be a body problem as at f 1.4 there is not problem at all. Stopping down the lens has completely no influence on AF as it being stopped down while pressing shutter, not all the time. As I said, seven different 50 1.4 from different supplies, not at the same time,  adjusted when necessary  with AFMA at 1.4. All of them behave in the same way. In my opinion it just can't be body failure (it hits a 1.4). How is that possible that no one experienced it?

11
Reviews / Re: Review - Canon EF 50mm f/1.4
« on: September 12, 2013, 01:05:36 PM »
I would like to see the results of shooting a kind of test subject with meter or even a normal target from 60cm at 3.5 or 4.0. It is just impossible that the issue deas not exist! I checked so many samples and it was always blurry when stopped down.

12
Reviews / Re: Review - Canon EF 50mm f/1.4
« on: September 12, 2013, 11:47:55 AM »
Ok, guys but the shift focus issuse cannot be realted to camera. I check focus at 1.4. Do not change distance. Change aparture to f 4.0 and the whole DOF is behind the proper point. Always the same behaviour.

Please check it on a close distance. It is not possible thats the camera issue. Thats the way i understand it. I am not talking about tiny shifts. Thats difference beetwen sharp eye or blurred eye on close portrait. I ve checked seven canon's 50s 1.4 and all behave the same.

Also I sent one copy to canon with my camera  2 or 3 times. Always the same result...and i am not crazy.

13
Reviews / Re: Review - Canon EF 50mm f/1.4
« on: September 12, 2013, 10:37:03 AM »
Hi,

I just read 50 1.4 review and completely have no idea why NOONE mentions about its huge problems with AF. I have a 5D3 and tested 7(yes-seven) samples of 50 1.4. First one I just sold after servicing as I thought it's a lens problem or camera, next one I serviced 3 times with my camera. Thought it might be something with calibration, adjustments etc. Then I checked with my local shop another samples so...every 50 1.4 has the same issue!!

Why nobody check this lens AF with different distance??? it has HUGE focusshift at close distance and it is almost unuseble in some circumstances when stopped down. To be more detailed:

When focusing at close distance ie. up to 1m ie. 60 or 70 cm (if u set AFMA perfectly @ F1.4) the lens hits the target  Checked and adjusted with LensCal. Now check the lens at f3.5 or f4.0 at the same close distance. No way u achieve the proper focus. It far away for your desired focus point. Backfocus is really bad. Point "0" is completely out of focus and blurred, the sharpest point is "2" or "3" at the scale.

The lens is completely unusable stopped down at close distance, 1.4 is very soft therefore there is now way the get really sharp photos or desired details. Lens spec. mentions 0,45m as minimum focus distance. Checked it with ie. f3,5 and watch where is focus, sharpness and where is the whole DOF-behind the focus point!

Now do the same with LV-perfect focus, razor sharp, completely different DOF position.

Another problem is focusing in incadescent light-try this with this lens-results are really different from daylight.

Tested a lot of 50 1.4 (seven) from diffrent sources, not is the same time,  and all have the same problem. Why nobody mention about such a issue???

14
Canon General / Re: Desired fantasy gear
« on: May 20, 2013, 09:16:04 AM »
A 5d3 body with perfect working AF (mine is faulty from purchase and being service for a year without solution), with sony sensor ~30, 35 mpix, and good nikon-style DR, no banding etc. + 50 1.4 with perfect AF and all lenses without need for calibrating, checking etc. That's my fantasy gear.

15
EOS Bodies - For Stills / Re: 5D Mark III focus points off center
« on: May 15, 2013, 08:48:14 PM »
I had exactly the same problem and it was real.  After three service visits they exchanged the mirror box. Atfer that repair the AF points' misplacement was corrected however since then I struggle with AF system. Since almost a year from purchase the camera is being serviced all the time without any good solution. My guaranty is almost over and the camera is like piece of crap. I can only suggest you to push the store to exchange it as probably any service will not fix that. I checked 3 canon services and every time if one thing was corrected the other one was not working properly. Right now center and left points are backfocusing and right points are focusing in opposite direction. One year of frustration without taking photos. Unfortunately IMHO if you think your AF points are misplaced-you are probably right. In my camera when I focused on the edge of any target it focused far away. And it was obvious that it happened only in one edge of focus point. It is normal that the real focus point has more area than its layout in viewfinder however not only in one direction. As I said-they fix this but camera probably lost all factory tolerances and now AF is just useless.

Pages: [1] 2 3 ... 7