Sweet Spot

[earleygallery]

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Hi James

if it was possible to see cameras side by side and handle them that would be great, ive handled the X1 and liked it very much but have yet to see a shop with the Fuji in my immediate area so cant make the comparison.But will have a look for the posts you mentioned and have a read.

Thanks vin

 

Hi again, I've played with an X1 but not seen an X100 yet either. FWIW I would choose the X100 for the viewfinder, the more traditional design and it's less expensive. Images from both cameras look fine. The motorised lens on the X1 is a deal breaker for me.

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[ezc203]

So yea, about that sweet spot...

 

Maybe if you spent some time with the camera you can draw some conclusions of your own.....

[Beyder28]

If I was looking for my own conclusions, there would be no point to be on this forum.

[ezc203]

You got me!

[Allnm]

Been looking at the X1 and the new Fuji . Why should i buy the X1 both cameras seem to have quirks and major complaint on the X1 is it is slow and locks up when writing to memory card.

 

Slow? Sometimes a bit slower than you would like when auto focusing. V2 firmware addressed this issue to a great extent. Not many people complain about it on the forums now.

 

Locks up writing to memory? Yes, but only when using raw ( DNG) and generally for about 2 seconds or so on my X1 ( I dont use raw often so I could be wrong here) . If a 2 second wait is going to ruin your day, look elsewhere, but not the X100 because it appears to lock up after any image is taken.

I suggest you read the relevant reviews on Digital Cameras: Digital Photography Review, News, Reviews, Forums, FAQ ) wow, what happened to the link I put in? Just click the red writing) for an idea of how these cameras perform but bare in mind the X1 was reviewed on earlier firmware and the X100 is about due for a major firmware update, already so it works properly!

 

Allan

[tnturnerx1]

I wonder the same thing. I've read in several places the sweet spot is f/5.6 for maximum sharpness, but I wish someone would say why. And I assume this would only be with ISO 100, and shutter speed perhaps determined by the camera.

[Mr_Jones]

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Looking at the aperture on many of the X1 shots that I've taken in Auto with plenty of light, it is 5.6. Perhaps Leica have decided this is optimum for the lens.

 

On the other hand Rockwell has an article stating 8.0 is the sharpest aperture for any lens.

[pico]

Looking at the aperture on many of the X1 shots that I've taken in Auto with plenty of light, it is 5.6. Perhaps Leica have decided this is optimum for the lens.

 

For the X1 that may indeed be true!

 

But speaking in general of the so-called 'sweet spot' might not refer to the sharpest aperture, but to the aperture which Leica designs a particular lens to give its certain character.

 

Claiming that F5.6 (or whatever the middle aperture might be) as sharpest is a convenient rule-of-thumb for most Leica lenses but incorrect because diffraction relates to the absolute diameter of the aperture, and therefore F5.6 (for example) will be larger with longer lenses. I think the general aperture where it kicks in is 6mm. On a large format lens that could be F/64!

 

On the other hand Rockwell has an article stating 8.0 is the sharpest aperture for any lens.

 

He's just being silly.

[01af]

But speaking in general of the so-called 'sweet spot' might not refer to the sharpest aperture ...

It does refer to the sharpest aperture and to nothing else.

 

And why do lenses have 'sweet spots' in the first place? Because there are two effects opposing each other. On stopping down, the lens aberrations will decrease and the diffraction blur will increase. The aberrations are specific to the individual lens; diffraction blur is correlated to the aperture on an absolute scale, i. e. the same for every lens. At full aperture, lens aberrations are at their maximum and virtually always more significant than diffraction blur by several orders of magnitude. So stopping down will improve image sharpness due to reduced aberrations despite increasing diffraction. But at some point, diffraction eventually will take over and reduce image sharpness more than decreasing aberrations may improve it. This point is the lens' sweet spot.

 

For 35-mm format, the sweet spot is somewhere around f/11 for cheap lenses. It's near f/8 for most lenses that are okay but not outstanding. It's around f/5.6 for really fine lenses. It's between f/2.8 and f/4 for truly outstanding lenses. It's at an aperture even wider than f/2.8 for special-purpose lenses meant for industrial, scientific, or military applications.

 

For formats bigger than 35-mm, the sweet spots typically are at smaller spertures; for smaller formats, at wider apertures.

 

 

... diffraction relates to the absolute diameter of the aperture, and therefore f/5.6 (for example) will be larger with longer lenses. I think the general aperture where it kicks in is 6 mm.

The effect of diffraction on image sharpness does not depend on absolute aperture diameter but on relative aperture and image format.

 

 

He's just being silly.

Yes, he definitely is.