Medium format shootout: 100% crops are not 100%?

[Joseph Yeung]

Just a quick note to Mike, Mark and Nick about the newly posted 2010 Mini Medium Format shootout.  It's a nice review, the only thing that stands out as a problem is that it's hard to tell whether the 100% crops posted are actually 100%...

Starting with figures 19, 20 and 21, these are described as 100% crops.  But looking at the UI features of Photoshop shown in the edges and corners, these are all different in each in each image, and all heavily shrunk from what one would expect to actually see onscreen.  The UI elements in Fig. 19 and 21 are so shrunk as to be illegible.

If the UI elements are shrunk, the 100% crops shown in the screen capture would also have been shrunk, so what we are viewing on the website would be effectively less than 100%.  Much less than 100%, for fig. 19 and 21.

Looking at Figure 3, Photoshop's ruler marks peek out from the left edge, and I'm not sure, but these also seem to show the effects of resizing, as the ruler marks are not pixel-sharp. (I just compared them to the rulers on my Photoshop)

So...?  

I know Mike and the contributors here discourage people from judging image quality onscreen, but if you provided 100% crops in the review, these were provided for a reason (it is at least possible to judge sharpness onscreen, if not colour and contrast), so they should really be 100%?

[Dick Roadnight]

And bingo - we received an email from Mark Dubovoy suggesting exactly the issue of lens to sensor alignment. If this were really the issue, what it means of course is that we are paying large amounts of money for incredibly well-manufactured sensors and lenses, only to be foxed by inadequate precision of the camera bodies. Mark Dubovoy reminded us of this reason why each Leica is hand-shimmed before it leaves the factory, and why he likes mating his Phase One back with an Alpa – individually shimmed. It all begins to make sense, and it all delivers a message to the other camera manufacturers to get their act together: in this pricing stratosphere, there's no excuse for not going the whole nine yards on technical excellence.

...so can we forgive Hasselblad for their "closed" policy?

I have been thinking of organizing a shoot-out between the H4D-60 and the competition, perhaps including multi-shots... but is is very difficult to come to meaningful conclusions, especially when the performance of the different systems is similar.

If we compared digital backs on view cameras, using the same Apo-Digitar and tethered live view focusing it might be more accurate.

One could include a focusing test... a shot of a rough tarmac road or an oblique shot of a brick wall?

[Mark D Segal]

Just a quick note to Mike, Mark and Nick about the newly posted 2010 Mini Medium Format shootout.  It's a nice review, the only thing that stands out as a problem is that it's hard to tell whether the 100% crops posted are actually 100%...

Starting with figures 19, 20 and 21, these are described as 100% crops.  But looking at the UI features of Photoshop shown in the edges and corners, these are all different in each in each image, and all heavily shrunk from what one would expect to actually see onscreen.  The UI elements in Fig. 19 and 21 are so shrunk as to be illegible.

If the UI elements are shrunk, the 100% crops shown in the screen capture would also have been shrunk, so what we are viewing on the website would be effectively less than 100%.  Much less than 100%, for fig. 19 and 21.

Looking at Figure 3, Photoshop's ruler marks peek out from the left edge, and I'm not sure, but these also seem to show the effects of resizing, as the ruler marks are not pixel-sharp. (I just compared them to the rulers on my Photoshop)

So...?  

I know Mike and the contributors here discourage people from judging image quality onscreen, but if you provided 100% crops in the review, these were provided for a reason (it is at least possible to judge sharpness onscreen, if not colour and contrast), so they should really be 100%?

Joseph,

To clarify: the meaning of "100%" in the context of this article is that for those Figures where it is demonstrated as such, the image you are seeing is a screen grab of what shows on the display when the full-sized image is magnified on display to a magnification factor of 100% in the meaning of Photoshop: i.e. one image pixel correlates with one display pixel, exactly as one does when estimating the impact of sharpening in Lightroom, for example. Therefore the content of the screen grab is indeed the appearance of what one sees on the display of the image segment at 100% magnification; however, the screen-grab itself is resized to suit reproduction requirements for efficient posting and viewing the internet.