Messages

31

Software & Accessories / Re: ColorChecker passport, what's wrong?

« on: April 25, 2013, 09:26:42 AM »

At a guess (I don't claim any specialist knowledge here) I think you have to be pretty accurate on your exposure when shooting the colour chart - if any of the patches are blown out in any of the channels the resulting colour profile won't be 100% accurate. Maybe better to underexpose slightly when shooting the chart than to overexpose? I usually bracket my shots and then choose the best exposure to create the profile from.

I really thought an external lightmeter would get the exposure perfect. Although I have seen that the CC gets exposed differently under different light even if I use the meter, not sure why.

But the patch with red, purple pink etc are very far from being blown (the others also). I also use low iso settings to avoid color contamination.

32

Software & Accessories / Re: ColorChecker passport, what's wrong?

« on: April 25, 2013, 08:49:41 AM »

I tried underexposing the image to see what happens to the red, and then boosting saturation it really comes out great. I think the purple/pink issue, at least to a pretty big extent, is that the reds are overexposed. I got the idea from when I overexposed a shot with my iPhone and the red turned bright pink.

So what does that mean, I can't really underexpose just the reds, and why isn't the CC correct any way? All my wb-samples and the CC-shots are done with a lightmeter.

Here's the same shot only underexposed:

33

Software & Accessories / Re: ColorChecker passport, what's wrong?

« on: April 25, 2013, 07:55:02 AM »

I've never had this issue with my Ds3 and 1D3 nor with the 1DsII before it...and I shoot a lot of product with reds, both high and low key and everything in between. I have had some issues before the passport with a regular colorchecker, but only when the light I was illuminating the calibration shots had an excess of a certain wavelength. That includes late afternoon sun (more reds) and cloudy days (more cyans).

When I calibrate using studio lights, there is never an issue...

i have to add i noticed this on outside shoots.

but well.. i bought it not for the easy stuff, i bought it to get correct colors under difficult conditions.

+1 !

34

Software & Accessories / Re: ColorChecker passport, what's wrong?

« on: April 25, 2013, 05:35:17 AM »

can´t help you because it´s the same here.

some red or deep oranges go nuclear and very violet here too.

That's interesting, which camera body do you use? I used to own the 5d2 and it never had this issue, but both my old 5d3 and the 1dx have this problem.

35

Software & Accessories / ColorChecker passport, what's wrong?

« on: April 25, 2013, 04:18:24 AM »

Hi guys, simple question. Why is it that it is only my flash-color profile that gives me the correct reds?
Every ambient-profile, dual-illuminant or single, outdoor/indoor, sun/shade everything, the sampled wb and the CC-shot gives me reds that are WAY off and purple. All people's lips looks blueish, and red sweaters looks purple. See example:

CORRECT COLORS (flash): I understand it's very hard for you guys to see if it's right colors or not, not having the subjects in front of you, but this one is highly accurate.




WRONG COLORS (overcast): Here you can see the reds turns to some nasty purple. I've tried this a thousand times, same results. I was quite surprised to see the flash profile work last night.



And to me at least, the wb of the right shot is a bit warm, and I've seen that several times, that the greycard built into the CC passport gives to warm wb (why?) but that doesn't explain the purples, correcting the wb makes it even more purple.

And this one is gone completely mental, notice her skin also:



Any ideas folks?

36

Lenses / Re: Rubber Seal 24-70 f2.8 L

« on: April 24, 2013, 02:18:04 PM »

Concern is what. To do with the other places the water can come in. It took my 85L out in the rain once and it rained right through the focus distance window, the mount was dry between camera and back if the lens.

That's the exact problem with stuff like the dust donut - it can only attempt to fix the leak at the lens/body join and does nothing to seal up the rest of the holes in the lens. However, the 24-70 mk I is a weather sealed lens, so all those other potential water ingress points should be covered. Presuming yours only has damage to the rubber gasket at the lens mount, it should work - but as to whether its anywhere near as good as the genuine $211 Canon seal, I couldn't say. And I guess there will be a bit of a wait seeing as it's still at the kickstarter stage.

For now I think I'll just use the 50L for the rainy days . Perhaps even remove the seal as it is pretty chewed up.

37

Lenses / Re: Rubber Seal 24-70 f2.8 L

« on: April 24, 2013, 01:55:39 PM »

Is this one of those rare occasions where a dust donut makes sense?

http://www.kickstarter.com/projects/77243737/dust-donuttm-add-a-weather-seal-to-the-mount-of-an

Thanks I'll look into that. Cool stuff on Kickstarter.t
Concern is what. To do with the other places the water can come in. It took my 85L out in the rain once and it rained right through the focus distance window, the mount was dry between camera and back if the lens.

38

Lenses / Re: Rubber Seal 24-70 f2.8 L

« on: April 24, 2013, 01:47:21 PM »

$211 ... DAMN!

And that was sold as a spare part from the serviceshop. Ridiculous !

39

Lenses / Re: Rubber Seal 24-70 f2.8 L

« on: April 24, 2013, 12:49:52 PM »

1.   Call Canon directly.  They will sell parts to owners.  Its best if you have a part number, but they will try to help.

2.   Call a third party authorized distributor like Midwest Camera, Precision Camera, ...

You can Google for Authorized Canon Camera Repair Depot

Thanks a bunch! I'll try those

40

Lenses / Rubber Seal 24-70 f2.8 L

« on: April 24, 2013, 09:30:30 AM »

Hi guys!

Anyone know where I can get the rubber seal that's on the back of the mount of a 24-70mm f2.8 mk1?

I asked my local Canon-shop if they could send me one for me to fix myself, and they could, only it was 211 USD! I tried looking on eBay, but couldn't really find one.

Thanks!

41

EOS Bodies / Re: 1DX Autofokus did not work when really cold -20 C

« on: April 23, 2013, 02:41:24 AM »

I've used in -20 it's a normal winter temp here, but haven't used like you have spending days only outside, so can't really say something. I have been out for a few hours and the camera was certainly what I would call very very cold, but it worked normal except a bit more resistance when pushing
Buttons and the smaller lcd's responded a little slow. Battery capacity wasn't much to brag about, but we know that is a problem.

IMO though, the AF should work in places WE don't work, so I find that strange.

42

Third Party Manufacturers / Re: Sigma 18-35 f/1.8 DC?

« on: April 18, 2013, 07:21:42 AM »

Judging from the way other ultra-large-aperture zooms are designed (e.g. the Oly 35-100 f/2) I'd guess that the design is basically a 35-70 f/3.5 with a reversed 2x teleconverter at the back.

I imagine that an FF version of this concept would weigh well north of a kilogram (& cost well north of a kilobuck).

Kudos to Sigma for being innovative once again.  Hopefully this will show C & N that there's real demand for more large-aperture lenses.

I've said this before and I'll say again, do we really mind a 1.4 kg lens that covers 24-70 at f1.8? We carry the 70-200 with that weight with no issues, so why not a 24-70?

43

Reviews / Re: Review - Sigma 35mm f/1.4 DG HSM

« on: April 16, 2013, 05:17:06 PM »

The results from the Sigma do look good; I've never really been an ultra shallow DOF shooter so perhaps that's why I can't think of any situations when you'd be shooting at f1.4 and require critical corner sharpness.

Can someone post a real picture which has razor thin DOF but requires corner resolution ?

you will never get critical corner sharpness at 1,4 but it shows that sigma in this case is much better than canon at 1,4 which not can be bad parameter.

Last pictures regarding the  bokeh issue, to me they are very equal

Well, I will wait to agree with that until after I get
The Zeiss 55 

44

Reviews / Re: Review - Sigma 35mm f/1.4 DG HSM

« on: April 15, 2013, 12:51:57 PM »

The results from the Sigma do look good; I've never really been an ultra shallow DOF shooter so perhaps that's why I can't think of any situations when you'd be shooting at f1.4 and require critical corner sharpness.

Can someone post a real picture which has razor thin DOF but requires corner resolution ?

Here's a quick example shot at 1.2 to show the need for corner sharpness. Aimed at his eyes.

45

EOS Bodies - For Stills / Re: How do you prevent buttons from being accidently changed on Canon 1DX?

« on: April 13, 2013, 10:00:43 AM »

I the same issue, i use a black rapid and when the camera hangs not being used and I lift it too my eye I'm more
Often than not on f22 as I have bumped and turned the top dial. For
Me I have the time to change it back, but to have that happen to two or three cameras in a journalist situation must be the worst. If I come up with a good solution I'll let you know.