IQ of 7d w 15-85mm Vs 6d w 24-105mm?

Started Mar 8, 2013 | Questions thread
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Re: What about The Digital tests?
In reply to qianp2k, Mar 12, 2013

qianp2k wrote:

schmegg wrote:

qianp2k wrote:

schmegg wrote:

qianp2k wrote:

technic wrote:

ultimitsu wrote:

Corrner performance is very close, neither is great. But since 15mmm F3.5 is more or less close to 24mm F5.6 on FF, 6D at 24mm f5.6 is indeed a lot better than 7D on 15mm F3.5.

P.S.: I'm a scientist, I have my own thoughts about 'mathematical certainties'

For someone who does not understand such basic principle, you must be a scientist of scientology.

mathematical certainties like yours only exist outside the real world, indeed like in scientology.

I have demo a real world 5000-pixel size photo that shows what amazing resolution a FF 5D2 with 24-105L can resolve. Can you please post a 5000-pixel size APS-C (7D or whatever) + 15-85 photo? Let's compare fine details/resolution please.

I'd personally like to see the same 5000-pixel size photo from the 5D (classic) for comparison. I think that might be particularly illuminating.

5D only takes 4368-pixel and delivers amazing 100% cropped. I am still waiting 7D 100% cropped face snapshot or you can downsampling to the same 4368 pixel. If 7D looks so mushy and noisy at 100% cropped, what's the point of 18mp? Therefore I usually never crop my 60D photos more than 50% as they are simply not good.

You are, of course, speaking about your 60D when you talk about the 7D. I think that's valid enough - but it is noted that you choose to speak about the 7D when you have something negative to say, rather than the camera you personally own.

As I said only a few 7D "ze*l0ts" are still arguing, and also review sites only tested 7D resolution with lenses ,so I have to mention 7D. Otherwise I mean to all APS-C. I don't have people using 7D but only with a few boasts unproportionally.

Sure - I believe that (not).

If an 18MP crop looks "mushy and noisy" at 100%, then that's likely due to the fact that you are looking at a more magnified image.

Indeed due to 1.6x crop magnification that inevitably determinates IQ.

Yep - sometimes the crop has advantages, other times it doesn't.

Don't peep and you wont have the problem.

Sorry cannot help. That sounds similar as you trying to tell people IQ and sharpness are not important

I've never said that and I resent you implying that I have.

I've asked you before to not attribute claims to me that I have not made - I will not put up with this again! Please stop.

BTW - that test between the 5D3 and 7D that I've posted a few times shows the 7D at 200% vs the 5D3 at 300%. It's the ultimate in peeping! But it also clearly shows the 7D out-resolving the 5D3. And that's precisely why I don't believe all of what you claim.

See here why you enlarge 5D3 photo? A meaningful test must be down in the same AOV by a) using different length lens; b) adjusting distance; c) both. When you shoot motorsports with your 5D3, I am sure you use a long enough lens, not crop severely. If 400mm is not long enough, get 500L for ultimate much better IQ it can deliver together with 5D3.

An AOV test is only "meaningful" (ie applicable) to certain shooting situations.

And, the fact that you argue otherwise tells me that you still don't understand how one camera may be used to its strengths to provide advantages over the other.

Instead, you continue to argue that there is only one ideal solution.

In fact, what don't you take my macro challenge. Shoot the same highly detailed subject with your 5D, 5D3 and 60D at maximum magnification?

I have 5D macro shots took years ago. And I can show you later that they are very sharp.

Of course they are sharp.

Sharper than fromo 60D that I am sure.

But also less detailed.

A camera with just 16 pixels would be even sharper! It wouldn't capture more detail though.

Not true. My 5D2 photos are almost the same sharpness from 5Dc even at pixel-level but capture lots more details per photo-level. Nevertheless you cannot separate sharpness, clarity from resolution (as you cannot separate details from noises). A very soft and mushy photo cannot deliver fine details.

Your 60D may not be as sharp as your 5D, but it records more detail than it and your 5D2. So, yes, you can separate them as they are different things.

I have not imported them into LR yet. Nevertheless on DXOMark test, 100L or 100/2.8 macro (that I just sold) still have more resolution on 5D than on 7D no mention 5D3. Macro lenses are still 1:1 magnification ratio on whatever cameras, right?

Yep. At max magnification, a macro lens is 1:1, regardless of the size of the sensor. That's why it makes such a good benchmark for comparing resolution.

You'll find that DxO don't test resolution in a way that allows one to sensibly compare sensors of different sizes (as far as I can tell from their limited information on their testing methodology)

Why not as we can compare DR and ISO among cameras, among different brands as ultimately they all generate photos our eyes can see?

I've explained this to you on a number of occasions - you seem either unwilling to understanding.

I've asked you before if you understand their testing methodologies, but you have simply pointed me to their pages which clearly show them testing sharpness (not resolution).

They explain better than me. As I said they just use an easier understanding express unit but didn't change comparison result from previous MTF data that still shows 5Dc outresolves 7D/60D with most lenses.

You clearly don't understand their tests. They show that lenses tested on FF cameras return higher sharpness figures than the same lens on a crop. The tests are lens tests - and sharpness tests at that, not resolution tests.

It's eminently possible for an image to be sharper and also have less detail - this is something I believe you simply don't understand.

It seems to me that, rather than arguing the point continually, you have the resources so you should do the test.

I don’t have that illusion that even I had tests you and a few "arguing persons" will believe my tests? DXOMark, DPR, Photozone are more creditable than any regular individuals.

So - they explain better than you can by doing the tests yourself?

Let see you do it and post the images.

I'd like to see you post the results.

Sure I will. And you will see lots of my macro photos soon with Sigma 150/2.8 OS on 5D3. I sold old 100/2.8 macro. I have not taken macro photos for years.

That would be great. Make sure you include the 5D classic too. I'd genuinely like to see how it does in terms of pure resolution. And I promise I wont have bad things to say when the results come in!

Pure resolution is based on details that human eyes can resolve.

I'm not looking for nor talking about your definition of "pure resolution" - I'm talking about resolving abilities of the different sensors - the ability of those sensors to realise detail from a given projected image.

And an 18MP crop will slaughter a 12MP 5D classic in this respect - no matter what definition of "pure resolution" you care to invent!

BTW - how do you find the 150? Is the OS useful at all for macro work? (I guess you don't know as you say you haven't done any, but I would be interested to know if you try it out)

So far I like Sigma 150/2.8 OS. The reason I didn't buy 100L (with same cost) is 100mm is a bit too short on FF. 150mm is much ideal length. Sure IS/OS is less effective in macro shots than in normal photos but better than nothing. I use ring-adapter flashing anyway in macro shots.

Some 150/2.8 OS macro test shots

Cool. I'll have a good close look at those - thanks. It seems like a good lens from what I've heard - Sigma are doing very well lately. Which is good!

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