Andy Westlake

Andy Westlake

Lives in United Kingdom London, United Kingdom
Works as a Technical Writer
Has a website at www.dpreview.com
Joined on Jan 28, 2008

Comments

Total: 692, showing: 241 – 260
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On Olympus PEN E-P5 Review preview (415 comments in total)
In reply to:

Jinks81: How come Fuji cameras are the only ones with practically no chroma noise in RAW?

In every review of every Fujifilm X-Trans camera we point out that the demosaicing process essentially includes noise reduction.

Direct link | Posted on Oct 4, 2013 at 09:39 UTC
On Olympus PEN E-P5 Review preview (415 comments in total)
In reply to:

micksh6: There have been numerous reports about shutter shock (what you call camera/image shake) on E-M5 and other Pens at DPR m4/3 forum.
The shutter shock effect depends on camera body, lens and operator, you were just lucky that you didn't see it on E-M5 (and 17mm F1.8 wasn't available then).

You are wrong that it's caused by shutter button. It's easy to verify this - set up 2 second auto-timer and compare results. I don't see that you did this.
Most people use anti-shock setting - it's more effective than timer. But the shock is caused by shutter curtain movement and it may exist on tripod with timer or remote release.

This is the E-P5, not the E-M5. It's a different camera with a different problem.

Direct link | Posted on Oct 4, 2013 at 00:50 UTC
On Olympus PEN E-P5 Review preview (415 comments in total)
In reply to:

micksh6: There have been numerous reports about shutter shock (what you call camera/image shake) on E-M5 and other Pens at DPR m4/3 forum.
The shutter shock effect depends on camera body, lens and operator, you were just lucky that you didn't see it on E-M5 (and 17mm F1.8 wasn't available then).

You are wrong that it's caused by shutter button. It's easy to verify this - set up 2 second auto-timer and compare results. I don't see that you did this.
Most people use anti-shock setting - it's more effective than timer. But the shock is caused by shutter curtain movement and it may exist on tripod with timer or remote release.

We shot handheld using the touch shutter and didn't see this particular shake pattern. We shot with the camera on a tripod *without* self-timer and didn't see this particular shake pattern. I don't see why you'd think it would come back again, if we turned the timer on.

Direct link | Posted on Oct 4, 2013 at 00:27 UTC
On Olympus PEN E-P5 Review preview (415 comments in total)
In reply to:

reginalddwight: I am surmising you received a defective production copy with the built-in image stabilization.

Did you contact Olympus for a replacement test sample?

We've used about 5 samples of the E-P5 all told, and all show the same thing.

Direct link | Posted on Oct 4, 2013 at 00:18 UTC
On Leica announces Elmarit-S 45 mm f/2.8 ASPH wide-angle lens news story (152 comments in total)
In reply to:

Jogger: Manual focus only, right???

No, the S system is autofocus

Direct link | Posted on Oct 1, 2013 at 14:54 UTC
On Can computer corrections make simple lenses look good? news story (162 comments in total)
In reply to:

ThePhilips: Pretty cool.

Actually, the more interesting research would be have been in the other directions: what optical distortions can be correct well in the software? Some uniform resolution sacrifice is acceptable.

... And after that, the question would be: given the correctable distortions, how can we simplify the lens design, by shifting all the distortions into the correctable range?

Or even more "other way around" approach: how can we make a tiny sensor to perform on the level of the larger sensors? For a tiny sensor, one can always develop potentially near perfect lens of a manageable size.

This has essentially already been done, and widely exploited. Distortion, lateral chromatic aberration and vignetting are all easily corrected in software, which is what allows modern compact cameras to have huge zoom ranges. Mirrorless systems generally employ these corrections too.

Direct link | Posted on Sep 30, 2013 at 19:53 UTC
On Can computer corrections make simple lenses look good? news story (162 comments in total)
In reply to:

Kim Letkeman: Seems like one of those silly binary arguments ... "pixel peepers won't really like it so we expect it to be deploy on smart phones" ... HUH?

How about "it is capable of improving any lens, once the lens has been calibrated to the software so we expect it to be widely used and to lower the bar for professional use" ...

That sounds like a conclusion that matches the article and examples ...

There are existing solutions for not-so-sharp complex lenses, such as DxO Optics Pro or Canon's lens optimiser module in Digital Photo Pro. This work is quite specifically about improving the output from very simple lenses.

Direct link | Posted on Sep 30, 2013 at 19:07 UTC
On Roger Cicala investigates accuracy of lens adapters news story (48 comments in total)
In reply to:

Plastek: Good test. Guys at LensTip.com made similar tests (only never published the results) and came to a similar conclusions - adapters are completely random and getting an acceptable one - perfectly centred with accurate flange distance - is impossible. That's why they test lenses on native bodies instead of comparing all of them in a single body and single sensor (what would allow cross-system comparisons).

So much for all these people thinking that shooting mirrorless with adapters is a valid way for photography.

There's a world of difference between lens testing, and real-world shooting with adapted lenses on mirrorless cameras. For one you need absolutely perfect alignment, for the other, you don't.

It's probably worth bearing in mind that teleconverters and extension tubes will necessarily show the same effect, but that doesn't stop anyone using them. In fact if you look *really* closely, you'll probably find that all of your lenses appear to point in slightly different directions - and it simply doesn't matter.

Direct link | Posted on Sep 30, 2013 at 12:54 UTC
On Miniature wide angle lens under development at UCSD news story (72 comments in total)
In reply to:

Chris Noble: How fast is that lens? f22 or so? Not impressed. Resolving power is a solved problem for most photographers.

The researchers' paper shows an optical design for a 12mm F1.7 that's 20mm long and weighs 16g.

Direct link | Posted on Sep 28, 2013 at 06:30 UTC
On DSCF2003 photo in dpreview review samples's photo gallery (2 comments in total)
In reply to:

Stephen Scharf: Are those spots on the sensor or birds?

Birds

Direct link | Posted on Sep 27, 2013 at 11:10 UTC
On Fujifilm XF 55-200mm F3.5-4.8 R LM OIS review preview (136 comments in total)
In reply to:

kai0815: something wrong with the 100%-crops?

looking at both tree-shots (55mm) at full size (in my browse) it seems to me they are a lot sharper than the 100%-crops show. I have the suspicion those 100%-crops might be a bit more than 100%.

Could anybody check this?

Thanks for the feedback. I've double-checked and can confirm that these are a) 100% crops and b) shouldn't be resized by your browser. (Unless you're asking your browser to magnify the page, of course, which will mess everything up - but I can't do anything about that.)

To be honest, I think you're simply restating my main point. The images from this lens look great until you extract 100% crops and view them in isolation, at which point they look oddly soft, as if they've been upsampled slightly after demosaicing. And it turns out that there's a straightforward explanation for this - they have, due to the process of distortion correction.

Direct link | Posted on Sep 26, 2013 at 10:19 UTC
On Fujifilm XF 55-200mm F3.5-4.8 R LM OIS review preview (136 comments in total)
In reply to:

Henrik Herranen: Um, erm...
Have you ridden your lens reviews of resolution/vignetting/distortion charts? Or is it just for this lens? Or is my browser misbehaving?

Um, erm... it's explained at the top of [page three of the review](http://www.dpreview.com/lensreviews/fujifilm-55-200-3p5-4p8/3)

Direct link | Posted on Sep 25, 2013 at 15:44 UTC
On Fujifilm XF 55-200mm F3.5-4.8 R LM OIS review preview (136 comments in total)
In reply to:

Asylum Photo: Using ACR instead of Iridient or Capture One makes the images look softer than they actually are. YMMV depending on raw converter, and I think it's important to talk about that when reviewing Fuji X lenses.

@siggo: No, that's not what I meant. The context here is about the visual differences in output offered by various RAW converters from any given file. In general, Capture One will apply more sharpening to files from any camera, and therefore make images look sharper. This doesn't mean ACR is wrong - more that it starts from a different aesthetic decision.

Direct link | Posted on Sep 25, 2013 at 14:52 UTC
On Fujifilm XF 55-200mm F3.5-4.8 R LM OIS review preview (136 comments in total)
In reply to:

Asylum Photo: Using ACR instead of Iridient or Capture One makes the images look softer than they actually are. YMMV depending on raw converter, and I think it's important to talk about that when reviewing Fuji X lenses.

I'm sure Iridient Raw developer is great, but I don't use a Mac. Meanwhile, if you actually read the review, you'll see I used Capture One as well as ACR. It applies more sharpening by default, but even so the images with distortion correction applied inevitably look a little soft on the pixel level. And, as I pointed out in the review, this is mainly of academic interest - it doesn't really matter much in practice.

Direct link | Posted on Sep 25, 2013 at 13:27 UTC
On Fujifilm XF 55-200mm F3.5-4.8 R LM OIS review preview (136 comments in total)
In reply to:

Asylum Photo: Using ACR instead of Iridient or Capture One makes the images look softer than they actually are. YMMV depending on raw converter, and I think it's important to talk about that when reviewing Fuji X lenses.

You can, of course, make images look as sharp or as soft as you like in any RAW converter, just by changing the sharpening settings. The ACR conversions shown in this review don't look radically different from the camera's JPEGs.

Direct link | Posted on Sep 25, 2013 at 11:45 UTC
On Digital camera lens buying guide article (58 comments in total)
In reply to:

macmcl: Andy, loved your dissertation on lenses. However, I'm left with a question: Will the whole image of a 35mm camera lens be captured by the smaller-than-35mm sensors used in most digital cameras? Specifically, will the whole image from my 24mm Pentax lens be captured on the sensor of a Pentax K20D SLR if I buy one?

macmcl

The short answer is no - this is basis of the 'crop factor' of digital SLRs. If you put a full frame lens on a K20D the sensor can only 'see' part of the image, and the 1.5x crop factor means that the 24mm lens ends with an angle of view very similar to what you'll get from a 35mm lens on full frame.

You'll often see this expressed in terms of 'equivalent focal length' - in this case we'd say a 24mm lens on an APS-C camera offers an equivalent focal length of 36mm.

Direct link | Posted on Sep 24, 2013 at 18:09 UTC
In reply to:

abortabort: Seriously? The 16-28mm is a great lens, but 5 TIMES the price?! Samyang's cine versions are something like $50 more, if that. I suppose this will still be cheaper than the competition though.

Samyang is very much the exception rather than the rule here. Roger Cicala's recent blog post [There is No Perfect Lens](http://www.lensrentals.com/blog/2013/09/there-is-no-perfect-lens) makes an interesting case for why movie lenses tend to be substantially more expensive than the stills version of the same optical design.

Direct link | Posted on Sep 23, 2013 at 10:37 UTC
On Nikon 1 AW1 preview (587 comments in total)
In reply to:

Jefftan: lens look like can't use lens filter,correct?

Probably best to ask Nikon for clarification on that. But at a guess, it seems most likely that setup isn't considered shockproof simply because the filter won't be. They have a bad habit of breaking when dropped.

Direct link | Posted on Sep 23, 2013 at 10:25 UTC
On Nikon 1 AW1 preview (587 comments in total)
In reply to:

Jefftan: lens look like can't use lens filter,correct?

Not correct. Both lenses have 41mm filter threads.

Direct link | Posted on Sep 22, 2013 at 13:28 UTC
On Nikon 1 AW1 preview (587 comments in total)
In reply to:

jkoch2: Will anyone dare submerge a $1,000 camera and $350 lens to 49'1" or drop it from 6'7", just to see whether the items survive? Will anyone repeat the experience to see how long the seals survive, or degrade?

A relevant test for all such devices would be to drop them multiple times onto concrete and descend them on a line into the local harbor, on two separate dates (and AFTER the drop tests), while shooting video or time lapse. Scuba dives for each test would be too difficult, but perhaps be the only way to confirm whether the control buttons or touch-screen features work at all at any depth.

Maybe the traditional $235 U/W, shock resistant P&S models are a safer gamble. Buyer reviews of these cameras have a larger-than-usual quotient that assign 1 or 2 stars because of failure on the first or second dive.

Fair enough. We'll send Jeff diving with it and see what happens...

Direct link | Posted on Sep 19, 2013 at 17:45 UTC
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