Thoughts while comtemplating my tripod ...

[david j.lee]

Ralph Gibson said that he never brackets exposures and he never uses a tripod, and in case

he did, he would never admit it. he shoots M's.

[wai_leong_lee]

The scientific method only says methods must be objective. It doesn't say you have to use what's currently available in the market. The test set of cameras is disclosed fully. They did their best to control the other variables (by use of tripod, etc).

 

I thus don't see what the issue is, from a scientific point of view.

 

Of course, from a market point of view, people will react as you did-- that these cameras are not state of the art. But then again, Leica isn't state of the art either-- at least, the shutter mechanism has changed little since the 60s.

 

I am familiar with experimental methods, and with scientific method and peer review. One formulates a hypothesis, test it in a repeatable and transparent way, publish verifiable results and subject one's results to peer evaluation.

 

The flaw in this experiment, from a scientific point of view, is that the sample size is too small, ie whether the result is statistically valid is questionable. Classic statistical theory would have you test a minimum sample size of 30 or more before you can draw any conclusion about a population.

 

However, given the impracticalities of testing a large number of cameras, one can argue that mass production makes variations across cameras so insignificant that little gain is obtained from testing a larger sample. For instance, car crash test results and ratings are published by govt agencies without testing 30 samples of each car. It would not be practical for them to conduct so many crashes, and the public understands that.

[wai_leong_lee]

If you have an alternative hypothesis-- that mirror slap does not affect sharpness-- then please conduct an experiment to show it.

[colin_elliott]

"Ralph Gibson said that he never brackets exposures"

 

Depends on one's(or his) definition of exposure.

 

I could define "exposure" as the shutter speed used at a specific aperture. (Or vice versa) Therefore, each "exposure" is unique. If you take another shot at a different setting, then it too is unique.

How do you "bracket" something that is unique. Each exposure is a new one unto itself.

 

Ergo...I never "bracket" exposures!.

[jeroen dommisse]

Wow, you lot are an amazing feisty bunch indeed.

[asher]

Wai-Leong: In addition to what El-Fang wrote, you might enjoy reading "Science Friction" by

Scientific American "Skeptic" columnist Michael Shermer. Science is not as clear cut as you

seem to think it is (and I speak from experience). Have a wonderful day.

[wai_leong_lee]

Sure Asher. What I didn't like about this discussion is the emotions it generated. Why such a simple study should cause so much friction here is beyond me. I suppose the people here had lots of issues with each other to begin with.

[wai_leong_lee]

El--

 

I would say to the lay person, read studies objectively and critically and understand what their limits are. Don't let your emotions cloud your interpretation of test results.

 

Just because we don't shoot test charts does not mean test charts cannot provide objective data about lens performance. And just because we don't shoot Leicas on tripods most of the time does not mean you can obtain an objective test of lens performance by shooting test charts handheld.

[marc_bergman1]

"If you have an alternative hypothesis-- that mirror slap does not affect sharpness-- then please conduct an experiment to show it."

 

Can you find any examples of persons on this forum stating that mirror slap does not affect sharpness.

[david j.lee]

in his book "the edge of darkness", barry thonton shows his results on a test he did shooting

a light with a handheld camera at diferents shutter speeds. then he does the same with the

camera on a cheap tripod, then with a good solid tripod and then with this last tripod and

mirror lock up. this last ones were clearly the best of all.

[david j.lee]

it should read Barry Thornton.

[m_.]

boy...<br><br>

 

<i><bold>Gloria Steinem: The truth will set you free. But first, it will piss you off.</i>

[elmar001]

Ladies and Gentlemen:

 

This is a wonderful discussion about many things, and I applaud your willingness to get into it. Sadly though, I believe it is true that most photographic equipment is better than most photographers. If you believe that you could win awards, get published, or be a photographer on "America's Next Top Model" if you just had better equipment, please speak up and I hope someone would help out.

 

The other sad truth is that the camera industry has, along with the computer industry, buyers panting after the latest new product, while the old product becomes worthless. What digital has done to film is that, in reinventing photography, it capped the ability of the industry to suck more money out of photographic film consumers. Every piece of film gear that ever will be is probably on eBay right now. So no more chasing after gear to make us more successful artists. I am sure this has left a lot out in the cold reality, wondering what next.

 

So hey, go out and make pictures. That is what it is all about. No Leicacameras in my aquariums. They're too full of old Kodaks! LOL

 

Lawrence Christopher

[el_fang]

<i>The scientific method only says methods must be objective. It doesn't say you have to use what's currently available in the market. The test set of cameras is disclosed fully.</i>

<p>In this case it does require it, because of the major differences in the variable being tested (mirror vibration) in currently available units versus 20-year-old ones that few people even use anymore. From Photo Techniques' <a href="http://www.phototechmag.com/current.htm" target="_blank">current table of contents</a>:</p>

<p><i>The Effect of Mirror?Slap on Image Resolution, by Timothy Edberg

At slow shutter speeds, the movement of an SLR?s mirror causes blurring - we investigate how much and at what speeds.</i></p>

<p>The blurb says "the movement of an SLR's mirror causes blurring." The way it's worded implies that all SLR mirrors cause blurring, and, true or not, it is not a valid conclusion that can reached by the scope of Edberg's "experiment." This is an absolute classic example of a flawed abstract that isn't apparent until you read the entire article, and is one of the first thing peer reviewers look for when critiquing scientific literature.</p>

[blakley]

<i>Sadly though, I believe it is true that most photographic equipment is better than most photographers.</i>

<p>

That's the most sensible thing posted in this thread, Lawrence. If I ever take a picture which is even technically, much less aesthetically, as good as my camera is capable of, it'll be a miracle.

[m_.]

<i>El Fang, Nov 02, 2007; 01:01 p.m. ...because of the major differences in the variable being tested (mirror vibration) in currently available units versus 20-year-old ones that few people even use anymore...</i><br><br>

this statement seems to support the very doubt you have that the mirror vibration degrades the sharpness of an image, all things being equal, no?

[el_fang]

<i>For instance, car crash test results and ratings are published by govt agencies without testing 30 samples of each car. It would not be practical for them to conduct so many crashes, and the public understands that.</i>

<p>You're still completely missing the point. To use your analogy of car crash testing, let's say the NHTSA publishes an article this year entitled "Family Cars Are Unsafe." Upon further reading, you discover that they tested a 1981 Yugo GV, a 1975 AMC Pacer, a 1978 Honda Civic and - you guessed it - a 1971 Ford Pinto. None of these cars have airbags or crumple zones. Would it matter if they tested 30 of each? No, what would matter is the article is utterly irrelevant to me, a current car buyer, who is interested in safety information regarding my possible choices between a 2007 Honda Accord, 2007 Volvo S60, or 2007 Toyota Camry - currently available "family cars" with airbags required by law, SRS systems, advanced crumple zones, and accident avoidance technology such as electronic stability control and anti-lock brakes.</p>

<p>The (Edberg article/hypothetical NHTSA study) may be perfectly valid and acceptable for someone who owns or is looking for a 1980's (SLR camera/passenger car) - but completely irrelevant to everyone else.</p>

[el_fang]

<i>this statement seems to support the very doubt you have that the mirror vibration degrades the sharpness of an image,</i>

<p>Oh, I don't doubt at all that mirror vibration degrades the sharpness of an image in old, obsolete and out-of-production SLR cameras like the Canon AE-1, Nikon FA, Nikon N8008s and Nikon F4 - the cameras Edberg tested - in certain limited situations.</p>

 

<p><i>all things being equal, no?</i></p>

 

<p>There's the problem, all things aren't equal in this thing called the real world. Technology changes.</p>

[m_.]

<i>Oh, I don't doubt at all that mirror vibration degrades the sharpness of an image in old, obsolete and out-of-production SLR cameras like the Canon AE-1, Nikon FA, Nikon N8008s and Nikon F4 </i><br><br>

fair enough...

[el_fang]

Debate on the scientific method aside, Wai-Leong - given the Edberg article is published Nov/Dec 2007 - do you have any theories on why he chose to test 20 year old film SLRs over currently available and top-selling dSLR cameras such as the Rebel XTi or Nikon D80?

<p>My guesses?</p>

<p>A) Photo Techniques Magazine pissed off Canon, Nikon and Sony and had to give back the XTi, D80 and Alpha 100 they had on hand for testing and comparison only <a href="http://www.phototechmag.com/articles/articles/200703/0702_Lipson_CanonXTi.pdf" target="_blank">4 issues ago</a> (<i>"I compared the XTi with the Nikon D80 (about $930, body only) and the Sony Alpha 100 (about $640 for the body), and the XTi?s noise is comparable with the Nikon, and much better than the Sony."</i> -page 2) so Edberg was forced to raid the local camera museum for samples to test.</p>

<p>B) Edberg was deliberately trying to sensationalize his article by picking samples he <i>knew</i> would do poorly on his "tests." I predict his next article will be "The Effect of Rangefinders on Inaccurate Focus" in which he tests a 0.58x M7 with a 135mm APO-Telyt.</p>

<p>Any other theories?</p>

[lee hamiel]

"With this in mind, I see no reason not to use a tripod with my M3 or M6 as well as the R4s. It would not be the type of camera that dictates its use, but the objective of the photographer at the time."

 

 

My simple answer is - I see no reason not to use a tripod whenever you see the need.

 

I do whatever I feel like doing as the situation dictates.

 

Not sure if anyone mentioned it but the original threaded opening also accepted accessories like the leather case & later the M-Grip.

 

Nice to see the forum getting more lively these days - it's a good thing

[frank uhlig]

Well, without a tripod (just did not have it along) I can handhold my rangefinder at about 1/2

or 1/4, 1/8 or 1/15 sec any day, if the wind is not too hard ...

 

So, what is the argument? Or rephased, who won this p... contest? Honestly, shame on you!

 

With my SLR, i can see movement blurriness from 1/60 on down with any lens.

[m_.]

i am sure that makes a great commercial line. i would immediately register for the copy right of the phrase before those manufacturers pick it up and run with it...

[wai_leong_lee]

El--

 

You have agreed that mirror vibration affects sharpness in your various posts.

 

It doesn't matter whether the cameras are 20 years old or 2 months old. Any camera maker who makes cameras with lots of mirror vibration today will still face the same result as given in the article.

 

So, end of story there.

 

I may point out that you have said that modern cameras have much less mirror vibration than 20-year old cameras. But have you conducted (or know of) independent scientific tests to validate this? If not, that's still just a hypothesis at this stage.

 

 

As for the choice of cameras, I'd say we should read the full article. I'd expect that the conclusion would say that, hey mirror slap is indeed a factor, which is why SLR manufacturers have invested so much in IS/VR technology, and in other ways to reduce mirror slap, and thus modern SLRs have much less mirror vibration.

 

 

I disagree with you that the choice of cameras is a flaw. To prove a hypothesis about mirror vibration, I must find cameras with mirror slap in the test set.

 

I do agree, however, that the headline for the article could be better. However, as Photo Techniques is a commercial magazine and not a peer-reviewed scientific journal, I can understand that.

 

I accept that the study is useless to you because the cameras are not relevant to you. I accept that. To me, however, it shows what people have said for a long time, that mirror slap degrades performance in SLR's and that's a major part of an RF's advantage.

 

Maybe you should write in when the article is published and ask if they can do a follow-up study using modern SLRs/DSLR's.

[asher]

<p>Wai-Leong wrote: <i>"it shows what people have said for a long time, mirror slap

degrades performance in SLR's and that's a major part of an RF's advantage"</i><p>

 

... when used on a tripod...<p>

 

can of worms: re-opened !