ISO Charts confusion

[Raid]

I was playing around with the ISO charts and I didn't realise that the 7D was in the camera selection. I would always select a 1D because I'm comparing lenses, not camera bodies.
I selected the 1Dx & 7D with the 200mm f2 (the best lens Canon has made... so far). As both of these bodies have the same pixel count, just a different pixel size, they also present the same size image.

http://www.the-digital-picture.com/R...mp=0&APIComp=0

What surprised me was how soft the 7D image is when compared to the 1Dx. Could anybody explain this to me?

[neuroanatomist]

Pixel size matters. I suspect that the smaller pixels of the 7D mean Canon chose to use a stronger AA filter to reduce moiré, and that results in a slightly softer image.

[Jon Ruyle]

Smaller pixels also mean any lens flaws are being magnified more. That could have something to do with it as well. (Not that the 200 f/2 has much in the way of flaws...)

[Busted Knuckles]

Ohhhh I think I am going to have another one of those head exploding moments....

The AA filter would be structured for the pixel size? and as such it could be "dialed in" by the manufacturer? Each sensor/AA combo seems to have its own AA characteristics. 5dII vs 5dIII vs 1dx vs 1div, Canon vs Nikon and so on.

I have seen hacks where the user removes the AA filter on a 5dIII - the one I saw did indeed sharpen the image considerably - though at what pixel peep resolution....

I did a quick search and there is a lot of discussion about AA filters. Several commented the the AA filter on 7d is particularly strong.

Mike

[HDNitehawk]

Here is another possibility; the difference is multiple processors gives the 1D X many times the 7D's processing power in camera, plus it costs an extra $5,300 and it should do more.

Let’s not forget the advancements in firmware, and Canon’s marketing making sure a $1,500 camera doesn’t out perform its flag ship body.

When the 1D X was released I went in to the ISO Charts make a few comparisons. What I found is that the ISO Charts are good at comparing lenses, but because of the way ISO charts are made they are really not ideal for comparing camera bodies. It is not a fair comparison.

[cristi]

Hello everybody!
I am new here. I found this thread and I would not open a new one since my question belongs here somehow. Thanks in advance if any of you might have a clue to below observation regarding ISO12233 chart sample images.

When choosing Canon EF 200mm f/2 L IS USM for ISO12233 chart comparison we can compare the sample images from a lot of cameras with this lens mounted. Let us take EOS 1DS3 and EOS 60D, which are the cameras TDP uses in most lens image quality comparisons. What we see is this. Indeed, we observe in this case the image quality difference between image rendered by 1DS3 vs. 60D. Results as expected, 60D sample image shows somewhat less resolution.

But let us take now Canon EF300 f/4 L IS USM on left with 1DS3 and on right with 60D. Like here. Now we see again a lower image quality for the 60D sample image, but in this case the image from 60D is much-much worse than that from 1DS3. I would have expected an image quailty difference on par with what I saw in the Canon EF 200mm f/2 L IS USM comparison above, but 60D sample image shows now a significant lower image quality.

Do you have a clue how to explain this?

[neuroanatomist]

Now we see again a lower image quality for the 60D sample image, but in this case the image from 60D is much-much worse than that from 1DS3. I would have expected an image quailty difference on par with what I saw in the Canon EF 200mm f/2 L IS USM comparison above, but 60D sample image shows now a significant lower image quality.

Do you have a clue how to explain this?

First off, welcome!

The 200/2 delivers much higher optical resolution than the 300/4. So, with the 200/2, you're seeing the maximum resolution from both sensors, but with the 300/4 the lower resolution of the lens is limiting the output 60D's sensor (which has a much higher pixel density than the 1DsIII - a FF sensor with the 60D's density would be 46 MP).

[Dave Throgmartin]

The 7D doesn't look so good, but the 70D is much better.

http://www.the-digital-picture.com/R...mp=0&APIComp=0

In fact the 70D is quite competitive with full frame offerings when using the ISO tool.

http://www.the-digital-picture.com/R...mp=0&APIComp=0

Dave

[neuroanatomist]

In fact the 70D is quite competitive with full frame offerings when using the ISO tool.

The 70D has a rather weak AA filter, which I suspect was necessary for the dual-pixel AF. A weaker AA filter means a sharper image, but it's not free. As a result of that weaker AA filter, compared to the 6D, the 70D has noticeable color moiré in the ISO 12233 crops.

[cristi]

@neuroanatomist:
Thanks.