guyfawkes: Reading many comments about "equivalence" both here and posted elsewhere, there does seem to me to be one question I'd like to ask: what practical applications are there that one would need to know this?
For example, if one owns a FF sensor dslr, does one really need to know what the so-called equivalence is for DoF for another format? Or turn this around. Would anyone moving from an APS-C system to FF need to know? How on earth would this impact on images they proposed taking?
In my days with film, using anything from sub-min up to 5x4, equivalence never even entered the equation. Photographers simply worked within and knew how to use the tools they used. So why has it assumed a proportion totally out of kilter with its importance now we use digital cameras?
It very much smacks of pseudo science to me.
No, it is not like asking what is the equivalent focal length. Equivalent focal length has a very practical application in digital imaging.
Depending upon how many types of digital camera you've owned, and indeed if you have ever used a 35mm camera, you'd understand. If you have never used 35mm then, understandably, this won't apply to you.
Digital cameras, from small compacts to FF, use a variety of sensors all with physically different sizes. If you check out the actual focal lengths of the lenses on a range of cameras you will likely see see a myriad of quite meaningless figures. On APS-C, for example, you will often see 18-55mm, on 4/3 it will be 14-42, and on small compacts you may come across really short focal lengths such as 4.5-13.5mm, 5.7-17.1mm. What do these numbers mean in FoV terms? How do the lenses "view" FoV. Is the wide end (in equivalent 35mm terms) 24mm, 28mm or 35mm? Without the very useful equivalence you have no idea of knowing.
@ Great Bustard. Thanks for replying.
I fully understand what you say. It is obvious to any intelligent photographer that DoF will be different with sensors (or film) of different formats in achieving the same FoV as the focal length of the lenses needed decreases as the format gets smaller. But what amuses me is that the subject of equivalence when related to aperture occupies so many column inches in articles. This was never so before digital cameras, and it has only in the past few years that its ugly head was raised, right here I believe in dpReview. How does knowing the equivalence aperture rating actually help me as a photographer?
When I used my 5x4 camera with, say, a 150mm Symmar at f8, at distance x, how on earth would it help me to know what aperture I'd need to achieve the same DoF on a 6x6 or 35mm camera with shorter focal length lenses? I'd stop the lens down or use camera movements, for 5x4, to get the DoF I needed on any format camera.
Reading many comments about "equivalence" both here and posted elsewhere, there does seem to me to be one question I'd like to ask: what practical applications are there that one would need to know this?
spencerda: Assuming that the monkey REALLY took it's own photo, I would agree Mr Slater has copyrights.
One he owns the camera and the memory card and process the pictures.Two We as humans do not give animals the right of ownership.Three We as humans have ownership over animals and pets, we are held responsible for anything they might do, so there for Mr Slater has ownership of the copyright, laughing...
But your first point itself isn't necessarily true. A photographer may be commissioned to take a photo where copyright lies with the commissioner. And, of course, if we lend our camera to someone else, they assume copyright over what they take, not the person who lent them the camera.
But whatever, this is a fun story with some very amusing selfies. I wonder if the monkey could be expressing narcissistic tendencies so beloved of the selfie brigade?
In the UK there is a saying that the Law is an Ass. For the most part, people know this refers to the exception rather than the rule. Laws are necessary so society is better able to deal with conflict. This case is an odd exception.
Laws are, or become, deficient with the passage of time or the advance in new technologies that the lawmakers haven't yet caught up with. I don't suppose copyright law ever envisaged a scenario such as this but in my opinion the law as it stands has been interpreted correctly by wikimedia, although the vast majority of us would ever wonder how copyright could be assigned to the monkey in the first case.
The law is there to protect the creative processes and ensure those creating art, or whatever, are protected from pirates who would wish to steal and benefit from others' works. You don't have to look far for evidence of this.
But did the monkey have a sentient knowledge of what he was "creating" and that he could copyright it? I very much doubt it.
HeyItsJoel: He tried to use a typewriter to pay his taxes online. The IRS is looking for him.
I seem to remember that story. (:p(
But wasn't it the English living in Boston who did the actual revolting as they objected, quite rightly, to "no taxation without representation"?
No surprises here!! They ditched their video editing program too a few years back - just when all the Apple users thought it was the best thing!
Adobe is going to love this!! I personally use Silkypix and LR. Very nice program.
It certainly can be counter-intuitive, I agree. I found this when I bought my first Lumix camera, the LX1, and which shipped with a Panasonic only version of Silkypix. Oddball programme? I certainly thought so, and never used it.
But if your Silkypix experience began and ended with the earlier free versions that came with Panasonic cameras, then you could be in for a surprise with the latest edition.
Have a dekko at Pro 6, it you can, and it may surprise you how its interface and GUI have changed a lot. It looks more like Lightroom now on the screen, and only some of the toolbar icons look different.
What I will repeat, though, is for those are serious about Panasonic cameras, this is the software for them.
I gave up Lightroom to move to Zoner for general use, but for Panasonic camera images, especially RAW, it has to be Silkypix. It is no longer as problematic to use as you think.
guyfawkes: It has been known for years that a simple lens images in a plane which is hemispherical. The optical trick in lens design has been to correct for this so-called distortion so that the image looks natural on a planar surface.
Some film cameras tried to overcome this problem with curved film gates, the bakelite Kodak Brownie 127 at the cheap end of the market and the Minox sub-miniatures at the other, being two examples that I know of.
So there is nothing magical in the effect Sony is describing, but its implementation will be. And if it does free lens designers to come up with superior imaging optics, then Sony should be applauded, not attacked.
Whilst I accept that in pure geometry, a plane is flat, and thus my comment may at first seem to be a non-sequitur, I was using it in the world of imaging and where there is often reference to a "flexible and curved focal plane".
Also I couldn't bring to mind a single word to describe what I wished to portray as a projection drawn on the inside of a section of a hemisphere, and which is, of course, more than a simple curve in one axis only.
Yes, you did read my mind as to what I wished to portray, and which I've expanded upon in my reply to JackM above.
JPdeJ: "Frame" - history. Half? Double? Full?(by heart)35mm film originally a cine/movie film format, its frame size was 18x24mm.Leitz introduced the Leitz camera (Leitz + camera = Leica) using that film and doubled the frame size. Look up old pre-WWII National Geographic and you'll see Leica adverts calling the Leica "double frame".After WWII, when Leica was joined by a large population of Kodak, Agfa, Exakta, Zeiss Ikon, Nikon, etc. the "double frame" was forgotten. When Olympus brought the Pen camera, with its 18x24mm recording size, it was called "half frame." Typically a "35mm" thing.Peter
Whilst reference to "double frame" may have been dropped as the use of the 36x24 format had become the de facto standard for 35mm cameras, the use of the label "Leica Film" was used in the 1950's to my knowledge. But this may have been more to do with the fact that Leica's needed to be loaded with film with a pre-cut leader of at least 4".
With the opening back flap introduced with the M3 which made film loading somewhat easier, it can still be a little awkward with the short leader found today. And try loading any earlier Leica without the long leader. But this is the fun, or anguish, depending upon the user, of using Leica film cameras.
Kipplemaster: I like the idea of the Nikon 1 series. Most of the negative points here are the usual Digital Luddite Review classics based on the irrelevancies of the past. I would like to try the 70-300 lens in particular and may well consider one when I go on safari next year (especially as I hope the price will have reduced by then). Fast autofocus is, for things which need fast autofocus, more important than most other factors. (USB charging would also be good!)
No camera is perfect, and if we are sensible we buy the one that most meets our needs and requirements and is within our budget.
Recently, I was looking for a worthwhile replacement for my Panasonic LX3, which is my "casual snapshot" camera, and the new Sony RX100 Mk III took my fancy. However at around £700 sterling it raised serious personal questions about its performance related to cost. Could this be justified, especially as I already use a Sony A7 and Nex 5N?
In the end, I decided it couldn't be so I bought the LX7 instead. In every respect it is an improvement over the LX3, so I was satisfied. And the cost? Just £213 sterling.
But the point I wish to make is my decision was based on an actual appraisal of both cameras related to my needs. And in this respect the "older" technology camera got the vote as it gave me the IQ I was happy with for the purpose to which I would put it.
Bodhi Dharma Zen: To put it in other words. MARKETING people are (professional) liars. They would push a lens as being "2.8" when, in reality, their light sensitivity is a lot less (depending of course of the relative size between sensor and lenses)... There should be LAWS to guarantee that marketing people should be limited to stating FACTS in RELATION to an approved standard.
Exactly. For me, aperture equivalence is a load of rubbish and only serves to confuse matters. Equivalence in focal length, though, has a real place on the spec sheet.
Because the majority of photographers have grown up with 35mm film, they are used to the FoV provided by their lenses. So it makes sense to use these lenses for comparison with digital sensors of differing dimensions and the various focal lengths used with different sensor sizes for the same FoV effect.
One only has to look at the actual lens focal lengths for lenses used with digital bodies to see the myriad differences and which, by themselves, are utterly meaningless. To make any sense of this, equivalent focal length became a must.
Unfortunately, here is another case of the "equivalence" argument when relating to apertures, completely confusing the poster.
An f2.8 lens, is an f2.8 lens irrespective of whichever sensor format it is used on. It is an exposure factor. The total number of photons captured by a sensor and the light intensity are two different things.
For identical light intensity, every camera, regardless of its sensor size will, or should, indicate the same exposure when they are set to the same aperture and ISO. This is why f2.8 is a constant irrespective of sensor size.
"Total light, or photons, captured" is a sensor size factor, so this affects the overall performance of a sensor, which is an electronic device. The more light the sensor can gather, even though the light intensity over area remains the same, means that the gain of individual pixels does not need to be turned up so much, thus resulting in a lower noise threshold.
This must be the silliest argument I've seen propounded in years.
Larry Witt: I would to try this out on my Dad's old German press camera. It's a Carl Zeiss in very good condition, with a leather case which has several thin metal plates, and one thick plate with six black paper pulls, sort of like the tabs we used to pull out of the old Polaroid land cameras. Which plate do I make the hole in? I have been looking for project, and would like to try my Sony a7r with one of these plates. Can someone give me some insight as to which plate to use. I already have an extra adaptor : Larry
As long as your Dad's German press camera has a fully adjustable focusing rail, it doesn't matter, as you would be focusing visually on the screen of the A7r. Therefore, focusing at the plane of the digital sensor isn't an issue, as it could be if the camera's front standard was physically locked when opened and relied on focusing by distance scale only. Then precise location of the sensor would be more important as you may not achieve infinity focus.
If it were me, I wouldn't butcher an original sheet film or plate holder. If it would be possible in your case, I'd use a flat piece of wood and fix the adapter to this.
justyntime: what for?If it had tilt/shift abilities, ok. But in this case: what for??
"But in this case: what for??"
And whilst the camera does not have a swinging or tilt front standard, one can readily see that it has horizontal and vertical shift. This is evident by the two chrome adjuster heads.
It has been known for years that a simple lens images in a plane which is hemispherical. The optical trick in lens design has been to correct for this so-called distortion so that the image looks natural on a planar surface.
A "thumbs up" for Silkypix, especially in the special edition, paid for, version, not the free one, for Panasonic cameras.
If you shoot RAW with a Panasonic camera, this is the editing program you need. Produces results far superior to anything else out there.
flashkube: I just want to say that once you break away from Adobe products you will love it. I suffered for years learning their stuff with disorganized training videos all over the web. Adobe staff are certainly not friendly, either, if you manage to contact them through their convoluted and awful website.
If you have a Mac get Pixelmator for only $25. Much better to use AND the training videos are well organized on their website. After using it for a month I deleted Adobe Photoshop and good riddance, too.
For Windows or Mac try OnOne Software.com Creative Photo Suite. This gem makes me smile and dance when I edit photos. Photoshop always made me grind my teeth and curse under my breath nonstop.
I kind of agree with your sentiment in the first sentence. Adobe products are quite elaborate, much more than many users actually need, I suspect. Once people are prepared to admit that there is life outside Adone and try other products, they will never know what they are missing.
I actually gave up on Adobe after V.3.6 of lightroom and haven't regretted it one iota.
The A7r is all about resolution, but I do wonder how the A7 would have fared in a similar comparison. In some respects it seems the more "all rounded" package the A7 offers is somehow being lost to the extremes offered by the 7s and 7r.
fredrious: Thanks for noting the "Equivalent aperture range" as well. Ridiculously the official introducing video under the following link highlights the lens specifications as: F2.8-4.0/25-400mm* (from 0:40 to 0:48). They convert the zoom range but not the aperture range. To me this is cheating!
I don't think it is cheating, as such, as the "equivalent aperture" calculation is misleading in itself and I don't really understand why reviewers persist in quoting it.
Its interest is only for those who want to know about DoF, nothing more, and is misleading because for anyone else who doesn't really understand apertures, it will give the wrong impression, as here. The FZ200 is a true f2.8 throughout its range, although from the relatively aperture argument, one might get the impression it is very slow indeed, which it most certainly isn't.
I wonder when was the last time you paid UK taxes? It's now officially HM Revenue and Customs, or HMRC.