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Messages - seekthedragon

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1
Lenses / Re: General purpose zoom for honeymoon
« on: February 25, 2014, 11:19:19 AM »
I took a 24-70 II to my honeymoon, it matches the L primes in terms of image quality. It served me great, although weight was a little issue when we climbed the Triglav. Other solution may be the Tamron 24-70 f2.8 VC.

2
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 11, 2014, 01:42:05 PM »


I don't buy that. Many things can be corrected in post, and moire isn't one of them. pcpro.co.uk aren't renowned for their photographic expertise. In this case I get the impression they just read a couple of marketing gimmicks and wrote it as fact.

So you would be saying that Adobe's moire correction brush cannot work, right?

Right. It is like P mode: it does this and that, but only takes the intended shot by chance, since the camera has no idea about the current scenario.

If you would like to remove moire, you need to know exactly, what should be on the picture. You can't use the picture for that, as it already contains aliasing. But if you saw the scene, you may know what is wrong, and what is right. If you saw millions of scenes, you may put this knowledge in a computer, and correct these moire errors, if they appear. It may happen, that you make mistakes, as you weren't present at each of the actual shots, and you have only a guess based on your experience. But more or less, it may be useful.

However, there is no way to correct moire using only the picture and having no information about what should be there. It is not technology, not even physics, it is pure mathematics. So it won't change even in another universe.

3
Lenses / Re: DxO Mark
« on: November 20, 2013, 06:38:07 AM »
PS: I really would like to hear more about those notable examples.


Here's one obvious one that I've run across:

When DxOMark first publised their measurements and review of the EF 70-200mm f/2.8L IS II, they stated that the MkI version of the 70-200/2.8L IS was sharper.  They stated that the, "The Canon EF 70-200mm f/2.8L IS II USM offers slightly less resolution with 51 lp/mm compared to the excellent 61 lp/mm of the Canon EF 70-200mm f/2.8L IS USM," and went on to explain that it was due to 'less homogenous behavior across the field'.  They concluded that, "...the overall scores come out slightly in favor of the previous version of the Canon EF 70-200mm f/2.8L IS USM, especially for Travel and Sport photography, which are the main use cases of these telephoto zoom lenses.

That conclusion differed from pretty much every other reviewer/tester who compared the two versions of the lens, and found that the MkII was hands-down the better lens (the f/2.8L IS MkI was considered to be a worse performer optically than both the 70-200/4L IS and the 70-200/2.8L non-IS).   Comments can be added to their review pages, and several people commented that from personal experience with both lenses and reviews on DPR, PZ, et al., had all found that the MkII was the better lens.  A DxO Labs employee replied, "Thanks for bringing this potential mistake to our attention. But, after checking with all our experts in the lab, there isn’t really a mistake...overall the Mark 1 has a slightly higher and more homogeneous resolution. So, it scores better on a full frame camera, like the Canon 5D Mark II used in the review."

The above quotes are copied from the review page for the 70-200 II, which has not been edited.  But, if you compare these two lenses on the 5DII today (screenshot below), you can see that under their new P-Mpix measure for sharpness, the MkII version of the lens performs better than the MkI. They also updated their 'use case scores' so that the MkII is now rated higher for Traval and Sport photography.  So…either they re-tested the lens (a different copy, presumably), or whatever black-box factors applied to convert real units (lp/mm) to units that DxO made up (P-Mpix) were applied in a nonlinear manner that somehow favored the MkII version of the lens.  I suspect the former is the case, but they said nothing about it, did not add any sort of notation to the original review (which would have been appropriate), or do anything else to acknowledge their mistake.

DxO has used the tagline 'Image Science'.  Speaking as a card-carrying scientist, when we discover a mistake in previously published data (it happens), we inform the journal and they publish a correction.  DxO's failure to do so in this case is what I'd call 'Bad Science'.


This is quite serious. Thanks for sharing.

4
Lenses / Re: DxO Mark
« on: November 19, 2013, 06:16:36 PM »
Don't rely on the scores. They reflect the taste of the DxO crew, which may be completely different than yours. You can not describe a lens or a sensor with one number that fits everyone anyway.
However, the measurements are pretty reliable. Check that out.

PS: I really would like to hear more about those notable examples.

5

A actually wrote: The Df will Dfinitely have to seduce me with the ergonomics and overall feel to make me trade a D800 for it tho


That's a valid argument, for the consequences I do apologize.

However, I don't think that frequenting this forum would strengthen your grounds in any way.

6
Which point?

Do I really have to explain? Then I do it really slowly, so you may understand.

A says: "I wish my D800s had this kind of control setup."
B answers: "Interesting that you would change your 36mp D800 for a 16mp DF."

B's answer has nothing to do with A's statement.

Scenario 1: B is simply mentally disabled, and does not understand A. In this case, I really sorry.
Scenario 2: B is so frustrated by something, that he overlooks statements including the D800, and tries to form an answer which proves the camera's utter uselessness, even if doing so is irrelevant or meaningless.

That was my point.

The sad thing that these scenarios may also apply to our conversation.

7
Correct me if I'm wrong, but nobody has talked about resolution. More living proof, that the Nikon D800 is so successful it makes plenty of the Canon users frustrated...

By the way, this DF looks incredibly lovely. The only drawback is the price tag...

The D800 is so successful that the 5DIII is outselling it by a wide margin, and resolution is so important that Nikon builds on the 'success' of their 36 MP camera by bringing out a retrocam with a paltry 16 MP.  None of that frustrates me in the least...   ::)

I'm really astonished that you overlooked the point...

8
The specs are reasonably impressive.
Excellent number of shots from a small battery.
I wish my D800s had this kind of control setup.
And it's LIGHT!  This gets a bit closer to the feel of an old film body just for the reduced weight.
The Df will Dfinitely have to seduce me with the ergonomics and overall feel to make me trade a D800 for it tho, I typically do not need great high ISO performance.
I think this is going to be a polarizing product, love it or hate it.  I think there'll be enough of the former to make it a worthwhile product.
Canon might even copy it. ;)

Interesting that you would change your 36mp D800 for a 16mp DF. More living proof that Nikon really missed the mark with a 36mp sensor.

Correct me if I'm wrong, but nobody has talked about resolution. More living proof, that the Nikon D800 is so successful it makes plenty of the Canon users frustrated...

By the way, this DF looks incredibly lovely. The only drawback is the price tag...

9
Lenses / Re: 24-70mm lens. Which one?
« on: October 20, 2013, 03:00:24 PM »
Best quality: Canon 24-70 II
Best value: Tamron 24-70.

I have the first, and I'm really happy with it, as it is razor sharp wide open. However, if I would buy a new zoom now, I would probably go with the Tamron. Little worse in every aspect, but has IS and is almost half the price.

10
Lenses / Re: 100MM 2.8 USM or THE 100MM L for portrait and macro work??
« on: October 10, 2013, 05:30:34 PM »
I never had any other prime, but the 100L is just awesome for both portraits and handheld macro (jewels, small details, flowers, etc.) I don't think you would regret it. It performs better for portraits than my 70-200 II.

11
Lenses / Re: Next step? New lens?
« on: October 06, 2013, 03:43:49 PM »
Normally I would be on the side of glass first.
But not in this case I think your camera body is old enough to swap up now.

I do all my family pictures and holidays with a 10D + 24-70 II. It is just great. With the 5D mkIII, it is time to upgrade, but I did not fell the need earlier. (It would also replace the 1D mkIII I use at the moment for work).

12
Lenses / Re: Next step? New lens?
« on: October 06, 2013, 03:39:34 PM »
Upgrade the lenses. The old 18-55 and 75-300 zooms are quite weak, the IS version of both would be desirable at a minimum. Or think about a 70-200L, or the Sigma 18-35, based on your needs. Some extra stop of light is going to be extremely useful.

A cheap camera with good lenses offers much better IQ than a good camera with poor glass.

13
Lenses / Re: EF 24-35mm f/2.8L pure wide angle zoom
« on: August 24, 2013, 11:23:22 AM »

What Canon does is marketing the exemplary 24-70/2.8L II albeit with vignetting at the higher range. Tells you instead of 24-35/2.8 + 50() I give you 24-70 with a weaker 50-70 segment. Well, alright, but some of us put quality above "portability". Give us the proper 24-35/2.8L and we'll combine it with a 50/1.2L.

Unless we expect the competitor to make the first move, like the 14-24/2.8.

Give the 24-70 II a try. It is sharper, than the 24 f1.4 or the 50 f1.2. It is just the sharpest lens I ever had. With this lens, aperture controls only the depth of field, you don't need to stop down for more details. By the way, the Tamron 24-70 VC is almost that good, which is incredible for its price. There is no room for a 24-35...

14
EOS-M / Re: Eos M ISO 1600 to 6400 tests and review...
« on: June 11, 2013, 07:17:06 AM »
Thanks for your reply!  Re my statement, would you care to explain why you thinks its incorrect? I am happy to change it if you can give some more detailed explanation....


Read this, for example:

http://www.josephjamesphotography.com/equivalence/#8

There are also heated discussions on other forums, you can google them. I like Joe's essay. He also happens to be a very talented photographer.

In short, the answer is that the high ISO (to be more precise, low exposure, photon) noise is a part of the signal projected on the sensor, and determined by the discrete nature of light.

Here is a more technical explanation:

http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/


Sounds good for a mathematician, but last time, when I was taught microelectronics, total CMOS sensor noise was almost a linear function of pixel count, due to the number of active components required. You can double the SNR by a 2x2 averaging, but using the same technology, the on-chip pixel binning is just better. I don't really see, why all this papers missing this point.

15
This is a common "problem" for people, who are new to either LR or RAW workflow.

Canon (and also Nikon) cameras are embedding the JPEG picture style to the RAW metadata, and when you import your shots in DPP, this picture style becomes automatically applied. The most visible effects of this used to be contrast adjustment and the noise reduction.
Thus, you get a picture, like the in-camera JPEG, made by DPP.

However, Lightroom used to keep almost every settings at 0, when importing, except if you use presets. So you really see the raw picture, and you have to develop it yourself like the in-camera JPEG, if you wish so.

Notice, that during import, the small pictures you see at first are like the DPP ones, and then they become the flat LR ones. This is due to the embedded small JPEGs in the RAW, which LR shows you first, until it creates its own previews. These embedded JPEGs also carry the in-camera picture style.

After all, the "issue" is just the way things work here.

(By the way, if you check that garbage collector like stuff on the right side of your pictures, you really see the detail loss due to the noise reduction applied by DPP, just to confirm what I said.)
 

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