Richard Butler

Richard Butler

Lives in United Kingdom Seattle, United Kingdom
Works as a Reviews Editor
Joined on Nov 7, 2007

Comments

Total: 2502, showing: 1 – 20
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On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

vscd: You will *never* get the same picture on the Crop as with a 200mm @f2.8 on fullframe. Yes it's bigger gear... but why do you all scream for size? If you nail a pin you use a hammer, not a spoon.

@EinsteinsGhost - priorities are entirely in the mind of the individual making the decision or taking the photograph.

If your priority is greater reach, then a longer lens is going to be preferable.

Since I want to be able to use such a lens for portraiture as well as full-zoom telephoto work, a lighter lens with a range that was traditionally considered to be sufficient is preferable to something with a bit more reach that I've found too heavy to carry with me.

Direct link | Posted on Sep 22, 2014 at 18:01 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

supeyugin1: You also forgot Pentax Q 15-45/2.8, it's an equivalent of 69-207 on Pentax Q7. The weight is 90g/3.17oz and the length is 56mm. The quality is excellent, and the price is only $300. I've got it as a part of a bundle, so it's cost was $200 for me.

I didn't forget it, it's just that the Q system uses sensors so much smaller than APS-C that you don't get the same control over depth-of-field of the lenses I'm talking about, so I don't really consider it to achieve the same thing.

For instance I like these 50-150mm F2.8s for portraiture, where shallow depth-of-field is often thought to be desirable.

Not that I have anything against the 15-45mm, it just doesn't achieve the same things, so I haven't included it in this article.

Direct link | Posted on Sep 22, 2014 at 17:56 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Just another Canon shooter: "I owned a 70-200mm lens for several years and rarely used it, because I couldn't face carrying it around.

However, a 50-150mm (in this case the first-generation, 770g unstabilized Sigma) was light enough that I had it with me and was able to quickly grab a shot when I bumped into the then National Circuit Race and World Track Team Pursuit champion."

The Canon 70-200/4 IS is 10g lighter.

@Just another Canon shooter - I didn't explain every single caveat of that statement because it's a picture caption, not a scientific paper.

In an article that is almost exclusively about APS-C, it's reasonable to assume I'm talking about APS-C.

Since both those shots were taken wider than F4, then a 70-200mm F4 would have been a poor substitute for the lens I used.

I make clear in the article that a 70-200mm F4 *on full frame* makes as much sense as these ~50-150mm F2.8s do on APS-C, but I don't *personally* consider a 70-200mm F4 to be as useful, on APS-C.

Direct link | Posted on Sep 22, 2014 at 17:47 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

sans culotte: "Equivalence theory" pushed by some guys is absurd cause it's never used to really compare systems. Why Richard Butler uses his "equivalence" only when talking about m43? Why he doesn't use it when talking about APS-C? Why he doesn't compare FF to medium format? If you wish you could call it DOF equivalence, but not equivalent aperture. Just cause aperture is focal length divided by diameter of entrance pupil. There's much easier to understand camera+lens capabilities dealing with some real physical numbers like Aperture, Focal length, ISO, not their pseudo-"equivalent" distorted versions.
Why is Pana 35-100 f/2.8 comparable to FF 70-200 f/5.6? To match the exposure I would need to push ISO 2 stops higher on FF which would result in higher noise despite all "light capture", is it somehow equivalent?

As an aside: we don't refer to it a depth-of-field equivalence because it isn't just about depth-of-field, as I tired to illustrate in [this article](http://bit.ly/equivap), using real-world examples, not just theory and calculation.
Look at it this way: the aperture in the Panasonic 35-100mm lens it 1/2.8th the focal length. (12.5-35.7mm diameter)

However, as soon as you think of the lens as behaving like a 70-200 on full frame (which [Panasonic does](http://www.panasonic.com/ca/consumer/cameras-camcorders/interchangeable-lenses/h-hs35100.html), on its website), then that same 12.5-35.7mm aperture diameter range would be 1/5.6th of 70-200. And the physics works as if it were, too (depth-of-field, diffraction, total light etc).

Direct link | Posted on Sep 22, 2014 at 17:32 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

sans culotte: "Equivalence theory" pushed by some guys is absurd cause it's never used to really compare systems. Why Richard Butler uses his "equivalence" only when talking about m43? Why he doesn't use it when talking about APS-C? Why he doesn't compare FF to medium format? If you wish you could call it DOF equivalence, but not equivalent aperture. Just cause aperture is focal length divided by diameter of entrance pupil. There's much easier to understand camera+lens capabilities dealing with some real physical numbers like Aperture, Focal length, ISO, not their pseudo-"equivalent" distorted versions.
Why is Pana 35-100 f/2.8 comparable to FF 70-200 f/5.6? To match the exposure I would need to push ISO 2 stops higher on FF which would result in higher noise despite all "light capture", is it somehow equivalent?

Actually the two stops higher ISO almost certainly wouldn't result in higher noise (assuming you're using contemporary sensors), but that's not really relevant here.

This article is almost solely about APS-C and comparing within that format - hence equivalence isn't relevant.

However, in the two places it is relevant: the box about Micro Four Thirds 70-200mm equivalents and the reference to using a 70-200mm F4 on full frame, it is referenced.

Direct link | Posted on Sep 22, 2014 at 17:28 UTC
In reply to:

rufusrm44: This statement is false:

"Quite simply, the smaller sensor will receive less light at matched exposures (same shutter speed and aperture) and this means more noise."

It's only true if the pixel pitch is lower (meaning the pixel density is greater.) But if the number and size of the pixels are identical, that less light received on the m43 sensor is equivalent to the 'more' light gathered by full frame because the full frame requires more light to cover the larger sensor.

Imagine if you had a sensor that was cut 1/4 the size of the full frame sensor. That means it only needs the same shutter speed and aperture to produce the same quality of image, but that image would be only 1/4 the pixels of the ff sensor, and would therefore only need 1/4 the light.

As was said further up, if you just use the APS-C crop from a full frame sensor (with the conditions you suggest), then yes, those two image should be identical.

However, if you use the whole of the full frame sensor then you'll have more light-collecting area (and hence lower noise when you consider the entire image).

Direct link | Posted on Sep 22, 2014 at 16:59 UTC
On Hands-on with Panasonic Lumix DMC-LX100 article (300 comments in total)
In reply to:

DerekWillmott: The specs sheet shows 2.7 megadots on the EVF. This article says 2.3.

Equivalent in a different sense.

This EVF produces resolution of 1280 x 720 pixels which, if you used one red, one green and one blue dot at each pixel, would be 2.7m dots.

This is a field sequential display: it displays red, then green, then blue information, in quick succession, so offers the same resolution as a 2.7m dot display would, but actually only has 1/3rd that many 'dots.'

Direct link | Posted on Sep 21, 2014 at 02:24 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

StevenE: The Sigma 50-150mm F2.8 weighs as much as a full frame 70-200 2.8, and that's a turn off. I might as well carry the FF.

I have owned a Tokina 50-135 f/2.8 (APS-C lens) for many years and it's a great lens, except it doesn't have IS. It's parfocal too, which is great for video!

I'm sorry, I mis-read the original comment (I read it as 'Samsung').

Yes, the Sigma 50-150mm is too big and heavy - it appears to be built in the same body as the current 70-200mm - which totally undermines the point of the lens, in my opinion.

Direct link | Posted on Sep 20, 2014 at 19:31 UTC
In reply to:

camerosity: You forgot the Nikon Coolpix A. Typical dpreview

[Really?](http://www.dpreview.com/articles/8545740747/opinion-why-the-death-of-the-point-and-shoot-benefits-photographers?slide=4)

Direct link | Posted on Sep 20, 2014 at 18:43 UTC
In reply to:

Jefftan: I have a question for someone in the know
Can lens filter be used on any of these 3 cameras? RX100 m3, G7X, LX100?
thanks

LX100 has a 43mm filter thread. Neither the Sony nor Canon has. Sony offers an accessory to add filters, this may also work with the Canon.

The RX100 III and G7 X both have built-in ND filters.

Direct link | Posted on Sep 20, 2014 at 18:38 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Mark Chan: I wonder why you didnt't try to put the 35-100mm and 40-150mm f2.8s of the m43 system into this - yes I know you are discussing APS-C, but shouldn't such discourse include m43 too given that the photo quality is now there similar.

There is a section about the 35-100mm F2.8 towards the bottom of the article.

However, probably because it doesn't share a mount with a full frame system, you don't see mFT owners using or asking for 70-200mm lenses.

Direct link | Posted on Sep 20, 2014 at 17:54 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Knine: I like the fact that you now post equivalents of the focal length and aperture in you camera reviews. I wish that you would carry this over to other reviews like this lens review. Wouldn't the 50-150 be an equivalent of 75-225 on a 1.5 crop factor camera? And, the 70-200 would be 105-300? But more importantly, the F-2.8 would be more like F 3.8. I feel that by not showing these numbers you are perpetuating the sales myth that manufactures exploit. Please keep posting these numbers.

@phazelag - It is unfortunate that 135 film became the default reference point for describing angles-of-view in terms of the focal lengths that offer them. It's understandable, given that format's dominance in the film era, but it's unfortunate in that it appears to (falsely) imply the superiority of one particular format.

Ultimately all formats are a size/image quality (and usually price) balance. If you *only* care about image quality then the larger you can go, the better, and the Pentax 645Z's sensor is 60% bigger than full frame...

Direct link | Posted on Sep 20, 2014 at 17:27 UTC
On Hands-on with Panasonic Lumix DMC-LX100 article (300 comments in total)
In reply to:

DerekWillmott: The specs sheet shows 2.7 megadots on the EVF. This article says 2.3.

My mistake.

It's 2.7m dot *equivalent*.

Direct link | Posted on Sep 20, 2014 at 17:13 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

quezra: "But any cost benefit of buying a 70-200mm F4 rather than an equivalent zoom is lost if you have to buy a full frame camera to gain access to that capability."

... unless there's an A7 in that mix, which you completely forgot about. The 70-200/4 is $100 less than the Fuji and Samsungs, both the A7 body and the FE70-200/4 weighs less than the APS-C versions, so the total system cost is very close against their flagships (X-T1 and NX1), and overall weight is less. And is FF, so for other things is much better. But that would spoil your prose wouldn't it...

The entire article is written about people who already own APS-C and why they would probably be better off with lenses designed for the format they're using.

My point still stands - the 70-200mm F4s are slightly cheaper (including the Sony), but if you need to go out and buy a new camera to use them. You'll notice I only say that there's a cost advantage - I'd have said there was a weight advantage, too, but I remembered the Sony, so didn't say that.

Direct link | Posted on Sep 20, 2014 at 16:49 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

SHood: The new Olympus 40-150mm f2.8 is an interesting lens. It provides the same DOF on m43 as the Samsung and Fuji lenses while providing greater reach. Since it starts at 40mm you are not giving up much at the wide end either. And it weighs only 760g.

It does not provide the same depth-of-field as the Fujifilm and Samsung lenses.

Stand in the same location and shoot with the same framing (both reasonable conditions) and you won't be able to match the depth of field of the APS-C lenses. You will, however, have greater reach.

This article is about APS-C, and how APS-C users have traditionally often had to put up with full frame lenses that aren't necessarily ideally suited to APS-C. This has not been the case with Micro Four Thirds, which is why it's only mentioned in passing.

Direct link | Posted on Sep 20, 2014 at 16:42 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Knine: I like the fact that you now post equivalents of the focal length and aperture in you camera reviews. I wish that you would carry this over to other reviews like this lens review. Wouldn't the 50-150 be an equivalent of 75-225 on a 1.5 crop factor camera? And, the 70-200 would be 105-300? But more importantly, the F-2.8 would be more like F 3.8. I feel that by not showing these numbers you are perpetuating the sales myth that manufactures exploit. Please keep posting these numbers.

Almost the entire article is talking about APS-C, so inter-format equivalence isn't particularly relevant. I've added a sentence a the beginning to make this clearer.

Where I do talk about other formats (a reference to 70-200mm F4s on full frame and the 35-100 on Micro Four Thirds, I've mentioned equivalence).

Direct link | Posted on Sep 20, 2014 at 16:36 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Albert Silver: You are wrong about the cutting costs, since although Canon and Nikon models are priced like Rolls-Royces, you can get fantastic value in the Tamron 70-200 VC, which you have neglected to review, and costs $1499 (checked now on Amazon). DXO has it as the absolute best lens of this kind for the Nikon D610.

http://www.dxomark.com/Reviews/Best-lenses-for-Nikon-D610-Short-telephoto-and-standard-focal-lengths/Best-zoom-lenses-for-the-Nikon-D610

I included the Sigma into my tables to show that third-party 70-200 F2.8s can be cheaper - there isn't the page width to show it's also true for the Tamron. The own-brand Fujfilm and Samsung are aiming for Canon and Nikon levels of build and optical quality, so it seemed reasonable to *primarily* compare those prices, while including a third-party lens to show the fuller picture.

But I maintain that, while it probably is very good on the D610, I'd still rather have a dedicated 50-150mm if I were shooting APS-C (the Tamron is 197mm long and weighs 1470g, so it considerably bigger and heavier).

Direct link | Posted on Sep 20, 2014 at 16:34 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

wolfloid: This whole article is based on a very basic misunderstanding. The lenses are the 'equivalents of 70-200 f4 lenses. NOT f2.8 lenses. Depth of field on APS-C at f2.8 is 'equivalent to f4 on full frame. Any light gathering advantage of f2.8 on APS-C is mitigated by the larger sensor of FF, which, if the sensors are of the same quality, will have half the noise of APS-C.

So, the Canon 70-200IS f4 is actually the lens to compare these new lenses with, and that, of couse, is smaller and lighter.

@Wolfloid - there's no misunderstanding on my part. I've added a sentence near the beginning of the article to make clearer that I'm talking about APS-C almost exclusively. I'm not comparing 50-150mm F2.8s on APS-C to 70-200mm F2.8s on full frame - I'm comparing them to 70-200s on APS-C.

I've brought inter-format equivalence up only where it's relevant.

Direct link | Posted on Sep 20, 2014 at 16:27 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Andr3w: The Pentax 50-135 f/2.8 has been out since 2007 and is very well regarded. Unfortunate that it gets written off because it "doesn't sell very well". Any data to back this statement up? It is the second most rated Pentax lens on B&H.

I can't imaging Fuji or Samsung will sell significantly more anytime soon since Pentax has had a 7 year head start.

My intention wasn't to write it off (I even mention that it's one of the things I look forward to when reviewing a Pentax DSLR).

However, this is an article about the new lenses for mirrorless systems. I tried to acknowledge that such lenses already exist for APS-C and thought I'd given Pentax due credit.

Direct link | Posted on Sep 20, 2014 at 16:24 UTC
On Opinion: Bring on the 70-200mm equivalents article (254 comments in total)
In reply to:

Vignes: I standardise to EF lens. I can use it for FF and crops sensor bodies. Not sure whether I want to collect EF-S lens if lets say Canon went along this path.
Companys like Samsung, Fuji, Pentax may develop crop sensor lens but this is where they run into a 'brick wall' when they want to develop FF cameras. They have to re-develop or do what Sony and Nikon does - reduce the MP. Can't see Fuji jumping in FF system, Samsung may do it (they have the money), Pentax may do it to please their customers with legacy lens. Pentax has been saying this for some time but haven't materialised yet.

If you've decided that full frame is the only size/image quality balance you're happy with, then it makes sense to only buy a full frame camera and lenses.

However, the idea that it's the optimal format for everyone is false, at which point the idea of an 'upgrade path' is arguably more of a benefit to the manufacturers than it is to the photographer.

Direct link | Posted on Sep 20, 2014 at 16:21 UTC
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