Richard Butler

Richard Butler

DPReview Administrator
Lives in United Kingdom Seattle, United Kingdom
Joined on Nov 7, 2007

Comments

Total: 2944, showing: 21 – 40
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On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

Like this, for instance: 16MP D7000 vs 36MP a7R. [Alternate between full size and 'Print' resolution to see thee effect of scaling to a common output size](http://www.dpreview.com/reviews/image-comparison/fullscreen?attr18=daylight&attr13_0=sony_a7r&attr13_1=nikon_d7000&attr15_0=raw&attr15_1=raw&attr16_0=6400&attr16_1=6400&normalization=full&widget=170&x=0.034839129400584874&y=0.4957593209940143)

The full story is, of course a little more complex, but this illustrates the point that the broader point works in the real world, not just in theory.

Direct link | Posted on Apr 10, 2015 at 18:38 UTC
On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

For photographic examples of this topic, [please read this article](http://bit.ly/equivap).

But let's imagine this situation:
36MP Full frame camera, 150mm F4 lens
16MP APS-C camera, 100 F2.8 lens

Both cameras have essentially the same pixel density. Shot from the same position relative to the subject, they have the same field of view. This should be fairly uncontroversial.

Set both lenses to F4 and they will both project the same intensity of light onto their sensors, so every pixel will receive the same amount of light. The pixel-level noise performance will be identical.

However, one of them captured 36million points of data, the other only 16million. Take the 36million pixels and down-scale them to 16MP and you'll generally end up with a cleaner image (The noise averages as you downscale, so you end up with cleaner images).

Direct link | Posted on Apr 10, 2015 at 18:36 UTC
On Samsung NX1 Review preview (1145 comments in total)
In reply to:

DGrinb: No in-body image stabilization, proprietary lenses....how come it's good??

I think we're using different definitions of the word 'proprietary.'

The Micro Four Thirds mount is owned by two companies, rather than one, but it's still owned and controlled by those companies.

Direct link | Posted on Apr 10, 2015 at 17:34 UTC
On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

Because the primary source of noise in an image is often shot noise (the randomness inherent in light), the total amount of light captured is often *the most* relevant factor in noise performance.

And, because total light is *strongly* dependent on sensor size, it ends up being the most significant factor in image noise in most situations (assuming contemporary sensor design).

To stress the impact of pixel density (at large sensor sizes), the Sony 16MP and 24MP APS-C sensors produce essentially the same noise, when scaled to a common size, and Sony's a7R is less noisy than its a7II, despite a higher pixel count. It may play more of a role in high pixel count, tiny smartphone sensors, but that's not the topic in hand.

Direct link | Posted on Apr 10, 2015 at 17:30 UTC
On Samsung NX1 Review preview (1145 comments in total)
In reply to:

DGrinb: No in-body image stabilization, proprietary lenses....how come it's good??

Which camera brand doesn't use proprietary lenses?

Direct link | Posted on Apr 10, 2015 at 17:15 UTC
On Samsung NX1 Review preview (1145 comments in total)
In reply to:

Albert Silver: Just a few notes:

1) Judging by the noise seen in the Real World DR comparison, the NX1 appears to be about a full stop worse than the D5500. Whether this qualifies as almost as good is of course subjective, but it is still a distance away.

2) As of this comment, the ISO-invariance at the end is broken, and no image appears when trying to compare with other cameras.

3) The AF performance results are all over the place when scrutinizing reviews, which suggests that Samsung has considerable work to do.

It is fascinating to see Samsung enter the DSLR market precisely now, when everyone is biting their nails on what the future holds.

I'm not sure what you mean when you say the ISO-invariance section is broken. Could you please send me a private message and I'll try to get to the bottom of any problem.

It's also worth noting that AF performance has improved significantly with some of the more recent firmware updates, so any reviews based on v1.0 are likely to tell a very different stories to test being conducted today.

Direct link | Posted on Apr 10, 2015 at 17:07 UTC
On Canon XC10: What you need to know article (229 comments in total)
In reply to:

John C Tharp: Some goofy points:

-305Mb/s is still possible on the faster SD cards
-That baseplate looks like it will get in the way of gearing for zoom and focus pulling
-The type of AF motor used isn't mentioned- if it's a USM-type with direct manual override, cool, but if it's an STM-type, focus pullers will likely be frustrated!

@John C Tharp: as in the example I gave above, the SanDisk card you quote can write at *up to* 90MB/s. It's the minimum sustained write speed (which isn't always published), that's the issue.

Direct link | Posted on Apr 10, 2015 at 17:02 UTC
On Opinion: Why the Canon XC10 is a big deal article (809 comments in total)
In reply to:

The Squire: CORRECTION?

In the comparison table with the FZ1000 and RX10 it lists the Canon as featuring "2X oversampling for HD video", but none of the other cameras do this.

The RX10, at least over-samples - It does a full sensor scan to create the HD image - No pixel bining. No centre of sensor crop.

Or do you mean something else?

If you look at the Sony a7S's 1080 video, you'll see it is essentially moire-free because it captures 3840 x 2160 footage (1920\*2 x 1080\*2), and intelligently downsamples it.

This means it is shooting at a the precise resolution that allows 1080lph to be represented, without aliasing (1080 is the Nyquist frequency of 2160).

The RX10 and others may perform full sensor readout (at still higher frequencies), but what they don't manage to do is intelligently reduce this to moire-free 1080.

The '**2X**' aspect is relevant, here and the XC10 supposedly gains the same downsampling system Canon developed for its C500, so it's reasonable to expect it to be very good, in much the same was as the a7S is and the RX10 and FZ1000 aren't.

Direct link | Posted on Apr 9, 2015 at 18:47 UTC
On Canon XC10: What you need to know article (229 comments in total)
In reply to:

jtan163: @Barney Britton - any news on the video toolset - e.g. zebras, focus peaking (for those of us who don't trust the AF), vector scopes and the like?

I like it, I can't afford it, but I'm very tempted anyway.

It has zebras (70-100%), peaking (three colours), markers, time code and colour bars (EB/SMPTE on the PAL versions, at least).

Direct link | Posted on Apr 9, 2015 at 01:06 UTC
On Canon XC10: What you need to know article (229 comments in total)
In reply to:

John C Tharp: Some goofy points:

-305Mb/s is still possible on the faster SD cards
-That baseplate looks like it will get in the way of gearing for zoom and focus pulling
-The type of AF motor used isn't mentioned- if it's a USM-type with direct manual override, cool, but if it's an STM-type, focus pullers will likely be frustrated!

As I say, it's quite possible that some of these cards are capable of such speeds. The problem is that there's not yet a standard stringent enough to guarantee it.

Yes there are UHS-II cards that say '280MB/s' on the front. These say they can write at *up to* 250MB/s, but the U3 symbol on the front only *promises* that they won't dip below 30MB/s.

Direct link | Posted on Apr 9, 2015 at 01:01 UTC
On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

The thing I find interesting is that people recognise the relationship between sensor size and focal length (and are quite happy to use equivalent focal lengths), they also recognise the relationship between aperture and sensor size (increased depth-of-field) and they recognise the relationship between ISO and sensor size (noisier images on smaller sensors), but some people are fiercely resistant to following the logic through and acknowledging the pattern.

(Not that I'm suggesting using equivalent F-numbers for anything other than identifying the different *potential* of different camera/lens systems). JPEG-based ISO is also limiting for Raw photographers, but that's another matter entirely.

Direct link | Posted on Apr 9, 2015 at 00:42 UTC
On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

Hack is probably an exaggeration. My point is that, in order to provide comprehensibly consistent exposure between cameras with different sensor sizes, it ends up obscuring the fact that the effect of 'F2' changes depending on what format you're shooting on. On top of this, the current standard is really woolly and allows so much leeway that it's almost meaningless.

However, while everyone realises that a full frame camera, a Micro Four Thirds camera and a 1/2.3"-type sensor compact will all end up with different image quality (if shot with the same ISO, F-number and shutter speed), the way ISO works obscures the *reason* for this difference: each format is making its image from different amounts of total light.

Direct link | Posted on Apr 9, 2015 at 00:36 UTC
On Fujifilm X100T Review preview (646 comments in total)
In reply to:

FodgeandDurn: Apologies for putting this here instead of the 'report issues' button wherever that is - the intro says this has a "23mm f/2 lens". This actually got me excited, but unfortunately it is an error. If you've divided 35 x 1.5 to give some 35mm equivalence wouldn't it be 50mm equiv?

Lou P Dargent: you need to specify more of the assumed conditions in order to draw a conclusion.

On the same sensor, your point about a 23mm F2 and 35mm F2 is correct = the 23mm F2 will capture light from a wider field-of-view, in direct proportion to how much smaller its physical aperture is, meaning you get the same amount of light *per unit area*.

The problem comes when you use a smaller sensor and don't collect all the light projected by the lens. A 23mm F2 lens on an APS-C camera still projects the same light intensity as a 35mm F2 lens on full frame, but your sensor doesn't see all of it. (You have the same light per unit area but only sample a smaller area). Or, to refer back to your first case: the smaller sensor can't 'see' the wider field of view from which the 23mm would capture the additional light.

At which point, the 23mm on APS-C and the 35mm on full frame are seeing the same view and the same number of photons per square mm. But the full frame sensor has more sq mm

Direct link | Posted on Apr 8, 2015 at 23:50 UTC
On Opinion: Why the Canon XC10 is a big deal article (809 comments in total)
In reply to:

regordyoll: Why a 1" sensor when a Sony A7 has a full frame sensor or a Sony A6000 has an APS-C sensor? I'd like to understand the reason. Thanks!

Lots of popular high-end camcorders are based around much smaller 1/2.8"-type chips. A Super 35/APS-C camera with a 27-270mm equiv zoom would be much larger, a Full Frame camera with one, still larger.

Direct link | Posted on Apr 8, 2015 at 20:52 UTC
On Opinion: Why the Canon XC10 is a big deal article (809 comments in total)
In reply to:

Bjorn_L: This reads like it was written by a fanboy not an analyst.

If you need 4k, then the lack of stabilization would seem to be a deal killer on this. Particularly when combined with the slow lens. The Gh4 simply seems a better solution. It too has all-in-one solutions which cover the same range but don't give up stabilized 4k video. Sealed lenses too, if you want that. Plus you have the option of using f/1.4 or even f/0.95 lenses and high end add-ons. Ultimately the gh4 seems to be a better solution and while you can add many $1000s in add-ons to it, to achieve the modest specs of the xc10 you could do so at a lower price point.

If you don't need 4k video (and very few really do) then the Sony rx10 seems a better solution. The lens takes in 4x as much light at the long end. It is wider and about as long. The rx10 has the same DR & bit rate, stabilized zoom, sealed lens.

I fail to see how this is worth considering by anyone not just in love with it because of the brand.

It's written by someone with a video background who is enthusiastic about the *concept* or the product and what it represents (another step towards convergence).

I wouldn't extrapolate from that to assume fanboyism of this particular product, less still the brand. I believe Dale would have written the same thing, regardless of which company produced it.

Direct link | Posted on Apr 8, 2015 at 20:50 UTC
On Canon XC10: What you need to know article (229 comments in total)
In reply to:

John C Tharp: Some goofy points:

-305Mb/s is still possible on the faster SD cards
-That baseplate looks like it will get in the way of gearing for zoom and focus pulling
-The type of AF motor used isn't mentioned- if it's a USM-type with direct manual override, cool, but if it's an STM-type, focus pullers will likely be frustrated!

The current fastest speed class is the U3 rating for UHS-I and II cards. These only promise that they can maintain *at least* 30MB/s, which is some way short of the 38MB/s that 305Mbps represents.

So some SD cards might be able to cope with those data rates but there's no way of being certain, at present.

Direct link | Posted on Apr 8, 2015 at 19:40 UTC
On Canon XC10: What you need to know article (229 comments in total)
In reply to:

ttran88: Sony sensor? Good camera!

Sony doesn't currently list a 12MP 1" type sensor as being available to customers (though this isn't always immediately made public).

We've not seen a 4:3 aspect ratio 1-type sensor before, which is what this camera's currently using.

Direct link | Posted on Apr 8, 2015 at 18:44 UTC
On Lensbaby introduces Velvet 56mm f/1.6 article (166 comments in total)
In reply to:

mosc: weren't soft portrait lenses 85mm?

56mm is an 84mm equivalent on APS-C (nearer 90mm equiv on Canon).

Direct link | Posted on Apr 7, 2015 at 21:19 UTC
On Opinion: The myth of the upgrade path article (1454 comments in total)
In reply to:

jefrs: The aperture controls the amount of light. If you use the same shutter speed and the same f-stop and the same focal length(!) then the same amount of light hits the sensor irrespective of its size.
The F-stop is defined as focal.length / iris.diameter. It's simple optical physics and I am a professional physicist: it's like a funnel where the smallest hole determines how much stuff goes through it, it has nothing to do with the size of the bucket below.
You reviewers really, really, really need to get this or go back to school to learn your stuff.

I'm afraid I don't understand what you're trying to say, here.

If you wish to continue this conversation, please send me a private message - it will avoid the huge lag between responses and won't add clutter to the bottom of an article that's about something else.

Clearly I don't feel the examples I gave were misleading, or I'd not have linked to them. Regardless of whether you like the 'equivalent aperture' terminology, the actual f-numbers are stated and it should be clear that there is *a difference* between what the same F-number means on each format, and that this difference is directly proportional to sensor size.

Direct link | Posted on Apr 2, 2015 at 22:28 UTC
On Opinion: The myth of the upgrade path article (1454 comments in total)
In reply to:

Yuvalm: So, the bottom-line of this whole discussion is that in terms of Noise-Level, any DSLR with bigger sensor-pixels is better, be it FF or APS-C, or any other crop format.

In that sense of Noise-Level, bigger formats do have an advantage, as long as their given resolution, is not over it's advantage-limit, overshot by smaller sensor-pixels.

Still, bigger formats, suffer from expensive, bigger, heavier gear, which is an innate disadvantage to field photography (studio photography excluded), and not with noticeably better picture-quality than smaller formats, given the same size of sensor-pixels, and lens optical quality.

Since on my current 16 and 18 megapixel APS-C cameras, I use APS-C, FF and medium-format lenses with great results, my previous FF had a more limited choice of optics, and since my APS-C gear only use the central portion of the image on my FF and bigger lenses (as seen on any MTF), I'm in fact able to get sharper overall results, than I could on my previous FF gear.

No.

A 36MP full frame sensor will produce a cleaner, more detailed image when compared with a 16MP APS-C sensor, despite both cameras having the same pixel size.

But you're right in saying that a larger format sensor will tend to be bigger, heavier and more expensive. I make reference to there being a size/price/image quality trade-off between formats (and consequently the 'sweet-spot' will vary, person-to-person and situation-to-situation).

Direct link | Posted on Apr 2, 2015 at 22:22 UTC
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