Focusing Leica: Merklinger Method

[MTC Photography]

I did not answer Mike's "challange" because I am busy writing up on

<a href="http://www.accessv.com/~martntai/public_html/Leicafile/lfdof/tilt1.html">Scheimplug, Hinge Rules and View Camera DOF</A>, which is

inspired by another Merklinger's great work "Focusing the View Camera"

[roberto_watson_garc_a]

I tend to use small CoC for main object in the frame, with a wider angle lens this becomes less evident, but as said by Appleby, newer asph designs makes OOF-INF diference greater, I understand is the way Leica usage develops.

 

Then lots of philosophy about reasons for in and out of focus decition in a frame, with all my respect to Mr Adams, but is easy to decide every thing must be IN focus when contemplating one of his landscapes, but other tipes of photography requires other decitions, and other limits too.

 

Those who try to take all the advantage of the 5 and 10 lpm in a image, can be less worried about CoC in the OOF areas.

 

But that doesn´t make Martin post less interesting, thank´s for share, but I admit I just couldn´t read all.

[mike_davis]

Andrey,

 

I really appreciate your very lucid example of how a detective might willfully choose to employ Merklinger's method to select an aperture that provides just enough "sharpness" for the task at hand. You explained it very well and it truly makes clear the difference between the traditional method and Merklinger's method.

 

Merklinger himself does not make the distinction you have made - that his method satisfies a "perverse objective"... "rather than for general landscape photography." Indeed, he condemns hyperfocal focusing - see the link I quoted above, where he provides an example landscape photo. And unfortunately, his disciples don't have your depth of understanding about the limitations of his method.

 

Apparently due to lack of time, Martin Tai has still not responded to my questions about how image quality is compromised by Merklinger's method (something which you, at least, have acknowledged via your example). But: Martin has found the time to tell us it's difficult to implement the traditional method.

 

I suppose we'll have to conclude that Martin does indeed prefer to compromise image quality for the sake of convenience. That is certainly his perogative and I defend his right to make that choice, but he seems terribly reluctant to admit that his choice compromises image quality or come up with a defensible rebuttal to that position.

 

I don't have to be a saint to make the choice to use a calculator in the field for each and every shot. This ensures a quality that can not be achieved using Merklinger's method. I deal with the issue of where to focus by using a laser rangefinder. Having measured the Near and Far sharp distances, I calculate both the working aperture and the distance at which I should place the PSF. Then I use the rangefinder again to find a target that is precisely at the calculated PSF distance. I swing my camera onto that target, even if it is outside the intended image space, focus on the target, then re-establish the desired composition to make the exposure.

 

Yes, this technique is inconvenient, but I find it odd that Martin would object to the effort required for such procedures given that he is a large format photographer willing to go to great lengths to determine tilt angle, for example. His comments continue to appear evasive rather than constructive.

 

Unfortnuately, we've offended each other getting to this point. My goal has only been to set straight this thread for the edification of future readers who might jump on the Merklinger bandwagon in ignorance. At this writing, I think anyone who reads the entire thread can conclude that the convenience of Merklinger's method is had at a cost of image quality, that its application is best reserved for odd situations where you specifically want to limit "sharpness" to something less than that which can be resolved by the viewer in the final print at the anticipated viewing distance - a conscious decision to stifle image quality. Let's hope this thread will help prevent others from making an unconscious choice to degrade image quality.

 

Thank you,

 

Mike Davis

[WAn]

Mike, glad to have been of help. EVERY method has its own limitation, either explicit or implicit, and converting the latter to the former is not always a trivial task; here we had to exchange several posts before we've reconciled our positions.

 

 

Any further study that shows that we might have missed something important is welcome.

 

 

Thank you.

[MTC Photography]

In landscape photography, the important object is at distance and

close up objects such as grasses, are not important. <p> Any method

has compromise<p>

<img src="http://www.photo.net/photodb/image-display?photo_id=857465&size=lg"> <p>The above Peggy's Cove pictures was taken with a

Minox 35ML at infinity setting<p> In the foreground, there is a

rope. Why should I chose to make the rope as sharp as possible and

make the fishing hut fuzzy ? I prefer the far zone very sharp

I just don't care the rope shows every strain of fibre<p>

It is a matter of choice.

[mike_davis]

Martin,

 

Your most recent post once again argues that infinity subjects can not be made acceptably sharp without focusing at infinity and you continue to ignore the questions I've asked above - questions which have you backed into a corner. You neither acknowledge nor offer evidence refuting the fact that Merklinger's method compromises image quality for the sake of convenience.

 

Without clearly stating that image clarity is compromised with Merklinger's method, you do the community a disservice by suggesting that Merklinger's method is merely a matter of personal choice. Again, I'm willing to defend your choice to degrade image quality for the sake of convenience - that's certainly your perogative - but I take offense to your unsupported insistence that the convenience can be had without impact to image quality, and much moreso to any suggestion that this convenience can be had while actually improving image quality (vs. that had with hyperfocal focusing).

 

Readers of this thread should beware your implication that hyperfocal focusing is somehow inferior to focusing at Infinity. Merklinger is wrong. You are wrong. I invite them to read this entire thread before drawing any conclusions.

 

Mike Davis

[jerry2]

Martin, In all fairness to Mike, you have a track record in all your threads to ignore what has been written before you and never respond to questions that may doubt your position. This makes forum discussions very difficult for anyone to follow.

[MTC Photography]

Mike, why dont' you show some of your picture showing why do you think

hyperfocal is better in landscape photography.Mik

[MTC Photography]

Bill, I don't know what "track record" your are talking about.

There is a very long discussion thread in LF forum, where I

answered every question to the very end. You were the one

who quit. Not me. That is your track record<p>

 

<a href="http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003Rdn">http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003Rdn</a><p>

 

Mike also tried to mess up without even answering any question

raised in that thread.

[MTC Photography]

Mike, have you really read Merklinger's books and understand what

he wrote ?

Tell us, what he wrote in Chapter 9 of Ins and Out of Focus ?<p>

 

If you want to criticise Merklinger, at least you must read his

books.

[MTC Photography]

Bill

In another related thread

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=003XDC

 

You were so convinced by Graeme, that the DOF limits are curved.

But where were you i hiding when Graeme conceded "checked" at

the very last post ?

<p>

That is your "track record".

[MTC Photography]

Mike wrote:

"Without clearly stating that image clarity is compromised with Merklinger's method, you do the community a disservice by suggesting that Merklinger's method is merely a matter of personal choice"

 

Nonsense !

Merklinger's method GREATLY enhance image clarity in Landscape

photography. You absolutely don't understand what Merklinger is

writing about.

[MTC Photography]

The proof of the pudding is in the eating<p>

 

In thread

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0031ni <p>

 

Richard wrote<p>"

 

I recently read carefully through Merklingers series of articles

on DOF for non LF (i.e. no movements) cameras which are presumably

covered in his book 'The Ins and Outs of Focus'.

After struggling for a number of years with DOF and soft landscapes using

wide angles in 35mm I was enthralled. Being a theoretical physicist I soaked it up,

worked it all out myself and did a bunch of in camera tests.

The result being that I have fundamentally changed the way I think about and take

these kind (large DOF landscape) pictures"<p>

 

In

 

 

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=002JzL <p>

 

Steve wrote"

. Infinity sharpness using hyperfocal settings is just not

as good as having an infinity focus. This is noticable on the

200mm, 300mm, 400mm etc. Even when moving the hyperfocal distance

closer to infinity, the sharpness

at infinity is still not as good as the infinity setting"

 

<p>

 

So Mike, you see, once people through their own experience, find out

infinity focusing provide better landscape picture clarity,

no amount of your shallow theory can change. People can decide

for themselve.<p>

 

<p>BTW, Merklinger's Ins and Outs of Focus is completely sold out.

Mike's drum beat from his corner probably helps

[MTC Photography]

<h3> Most Natural Method </h3>

 

 

Any one watching thing of interest, whether it is near of far

always focus their eyes at object of interest. When you look at

a house across the street, say 50 meters away, your eyes focus

at infinity, not on some "hyperfocal" distance. <p>

Mike said, that is no good, you "compromise clarity". Thou shalt

focus your eyes the hyperfocal way.

[robert_clark]

I have found this thread interesting even though I do not pretend to have understood all of its details. I must admit that I find the Merklinger method counter intuitive, but I am happy to have my assumptions challenged and will give it a try. I have been disatisfied with sharpness at infinity using my (by Mike' standard) sloppy hyperfocal method.

 

Mike has made some challenging and interesting objections (whether he has read all of Merklinger's book or not); though I do find the process of using a laser rangefinder to calculate the critical hyperfocal distance somewhat impractical for all but the most demanding of landscape photographers.( I imply no slur on such admirable high standards) On this point I also wish that Martin would try and address the specific objections that Mike raises without getting too emotionally defensive.

 

The burning questions seems to be 1) why is focussing at infinity going to give better resolution (in all practical circumstances) than Mike's critical hyperfocal method of including infinity well within an acceptable (but critical)range?

2) If there is no practical difference, then why is it not better to use the critical hyperfocal method and get better resolution further into the foreground?

 

From what I understand from Mike's objections to the Merklinger method it seems he has a point in claiming that Merklinger has taken rather a lax and uncritical method of hyperfocal focusing to attack; in other words a bit of a straw horse.

 

Martin, since Merklinger himself has not come along to defend himself, please try to respond specifically to Mike's objections. Your disciplined input would be highly valued.

Thanks,

[MTC Photography]

Robert, nobody explained this topic more clear and convincing then

Dr. Merklinger himself <p>

He explained this in great detail, covering every angle in his

book The Ins and Outs of Focus.<p>

I suggesst you get hold a copy and read it. This book is sold out

but can be found in used book market.<p>

[mike_davis]

Thank you Bill and Robert!

 

It's so nice to have two people come along and join me in asking Martin to get back on track with the debate. Until then, his refusal to address my unanswered questions suggests he knows he is wrong, but it leaves me frustrated at his having left the ring before settling this intelligently.

 

Again, I encourage future readers to absorb this entire thread.

 

Mike Davis

[jerry2]

Martin.... In the other long thread you refer to, everyone in the thread accused you of not responding to specific questions, not just me. In our private correspondence, you randomly would respond to questions making progress impossible. The same applies in this thread....that is the track record I refer to. I think you have had some very valuable input and are very gifted at math, but you seem to evade questions that either you are uncomfortable answering, which makes it appear you can not defend your position. I was not trying to attack you personaly, but rather share my observations. Possibly you should re read some of those posts where everyone kept asking you to answer specific questions, just like Mike above?

 

And yes, in the end, I beleive Graeme was incorrect about DOF lines in tilted lenses. But during the exchange, you made it appear that you were hiding and avoiding his questions... in the end, occassionaly you came through. And to advise you, I was not involved in the nitty gritty at the end of that thread. But anyway, why not take this as constructive criticism and move forward, it certainly was not intended as a personal attack on you. If you perceived it that way, I do apologize. You have made some excellent contributions to these forums and I hope you continue.

 

I am curious to an explanation as why Mike Davis is wrong above. Many of us are open minded, we just want to understand why Merklinger defied the focussing principles (DOF) that existed for 200 years in photography. Although I am a huge Merklinger fan on tilt, I too struggle with his concept about focussing at infinity, and yes I read the entire book, twice! So please try to educate us.... to me, Mike Davis's explanation of his method makes good practical sense.

[MTC Photography]

Bill, in the LF thread, I answered a dozen times Graeme's question

again and again, again and again. He just did not get it. He finally

got it. Graeme has good virtue, his perseverance and willing to learn, that is why I was willing to spent time in answering his questions, because I know he will come through. <p>

As for Mike, forget it. He doesn't even bother read Merklinger's book

If he did, and work throught it. He might get his answer. But I doubt

he knows enough math to read Merklinger, other wise he would grab

the opportunity to join in the "curved DOf" choir and launched another

attack on Merklinger, he kept dead quiet. I knew his knowlegde on LF DOF is 0

 

 

<P> Merklinger's book is the BEST ANSWER to all questions. I am not

Merklinger's spokeperson. I don't even know him personally. If you

have question, read it again and again twice is not enough.

Otherwise, Bill, why would you belongs to "curved dof" choir ?

 

<p> The whole purpose of my thread is a provide a pointer to his

books. That is all. Other people has score to settle, that is not

my problem.

<p>

[jerry2]

Martin.... Otherwise, Bill, why would you belongs to "curved dof" choir? I never felt strong either way on this subject, till I spent the time to work it out. And I am not afraid to admit I had an error in my initial judgement. I am human, I make mistakes, and I certainy am not afraid to admit to them.

 

you wrote.... The whole purpose of my thread is a provide a pointer to his books. That is all. IF that is the case, then you should state that you will not explain Merklingers position, everyone should read the book and draw their own conclusions. In a way, it kind of defeats the purpose of these forums. If you do not have the time or the inclination to do such, that is fair. But most of your threads lead us on, hence the follow up threads... and things get carried away. Since you understand Merklinger very well, if you ever feel the need to educate us less fortunate, I would really like to understand exactly why you feel Mike is wrong. Mike does have a very strong math background, and I think he too would be open to an acceptable argument. BTW, I don't think Merklinger really explained why focussing at infinity is superior over standard DOF. He shows how he did not get results that matched his DOF tables, but that is not sufficient data, as this could have been caused by a multitude of reasons. My gut feeling is, Merklinger threw the baby out with bath water on this one..... once his conventional results failed, he was determined to create a better method. I understand his method, but in certain scenes (as mentioned in several posts above) I just can't comprehend how focussing at infinity can gain more sharpness in the scene! But I can understand how it would create less sharpness.

 

If you ever feel compelled to answer this, be sure to cc me with your response. There is not enough people that understand Merklinger well enough to explain this, but many of us sure are interested in learning.

[mike_davis]

Martin,

 

On what do you base your assessment of my math abilities? And what would my knowledge of large format math have to do with the questions you've refused to answer in this thread? There's no need to lash out at me this way. What we need are answers to questions that you've avoided like the plague for several weeks now.

 

The following are NOT math questions. Can you respond to them intelligently, without being evasive?

 

***

 

(Quoting my original July 10 post)

Focusing at infinity when any portion of the subject space resides at some distance short of infinity is a waste of useful DoF.

 

****

 

(Quoting my July 13 post)

You haven't answered my original question. Here it is again:

 

If the largest circles of confusion seen in the foreground, forward of the plane of sharpest focus, are "acceptable" (i.e. "small enough") when focused at infinity, would circles of this size not be found equally acceptable if they occurred in the background as well, when focused at some point short of infinity?

 

Yes or No?

 

Your "choice" to use Merlinger's method when the scene is predominantly at a distance clearly indicates that some portion of your subject falls short of infinity and you are enjoying at least some near-side DoF if you find the nearest subjects acceptably sharp. If that's the case, why are you choosing to waste the acceptably small, equal-diameter circles of confusion that lie beyond the plane of sharpest focus?

 

****

 

(Quoting my July 16 post)

If we share the goal of making both the near and far CoC's too small to resolve in the final print at the anticipated viewing distance, focusing closer to infinity or at infinity (such that the far CoC will be smaller than the near CoC) will require a smaller aperture than could be used if we instead focused at the hyperfocal distance. Your

preference for making the far CoC's smaller than the near CoC's means that you either permit the near CoC's to be resolvable (visibly out-of-focus) in the foreground so that you can use the same or wider apertures than you would if focused at the hyperfocal distance -OR- you don't tolerate soft foregrounds and do make the near CoC's

unresolvable by stopping down to compensate for having focused beyond the hyperfocal distance. Which is it?

 

Are you allowing foreground subjects to be visibly out of focus so that you can shoot at wider apertures or are you stopping down more than you have to keep the nears visibly sharp despite having focused too long?

 

****

 

(Quoting my July 26 post)

You have several times contended that Merklinger's method is a valid alternative that's a matter of personal choice, but you refuse to respond to my contention that his method compromises foreground sharpness -OR- it compromises shutter speed (by forcing the use of a smaller aperture than would be necessary if you just focused at a

hyperfocal distance calculated to yield acceptable CoC's for the anticipated enlargement factor and viewing distance.)

 

Again I ask: Which compromise do you prefer?

 

No matter how you answer that question, we're left with this one: Why do you tolerate either compromise? Why are you "choosing" to shoot yourself in the foot? You said there was a "great advantage" to using Merklinger's method. Let us hear your explanation of this advantage!

 

****

 

You've also neglected to respond to Robert Clark's August 10 questions, despite having made several posts since then.

 

****

 

(Quoting Robert Clark)

 

The burning questions seems to be 1) why is focussing at infinity going to give better resolution (in all practical circumstances) than Mike's critical hyperfocal method of including infinity well within an acceptable (but critical)range? 2) If there is no practical difference, then why is it not better to use the critical hyperfocal method and get better resolution further into the foreground?

 

From what I understand from Mike's objections to the Merklinger method it seems he has a point in claiming that Merklinger has taken rather a lax and uncritical method of hyperfocal focusing to attack; in other words a bit of a straw horse.

 

Martin, since Merklinger himself has not come along to defend himself, please try to respond specifically to Mike's objections. Your disciplined input would be highly valued.

 

****

 

I can't speak for the rest of the world, but if you continue to avoid these questions, I for one will have to conclude that in your heart, you know I'm right, but just can't bring yourself to admit it.

Merklinger is just a man, Martin. He wrote some great stuff and some bad stuff. You can't believe everything you read just because it's been published and I don't have to quote Merklinger's writings to make the points I've made. The sense of what I've written is speaking volumes to several people.

 

You challenge me to read Merklinger's book, yet just as with the questions I directed at you, you've also not offered a reasonable defense to my July 26 post addressed to Andrey, where I exposed Merklinger's writings at the web site referenced here:

 

****

 

(Quoting my July 26 post)

I fully understand his method. It's a gimmick � a clever shortcut that compromises image quality. Here's a page written by the man himself. (Do read the whole of it at your leisure, but for right now, please consider only the photograph and its caption.):

 

http://home.fox.nstn.ca/~hmmerk/DOFR.html

 

Martin Tai stated he believes using the conventional method vs. Merklinger's method "is a matter of choice." He wrote, "when objects, scenes at distance are predominant then use Merklinger way, focus at infinity."

 

Please examine the photograph at Merklinger's page, above. Is that cannon and the ground on which it is setting "predominantly at a distance"? No it is not.

 

[Agreed Martin?]

 

Now read the caption under the picture. Read it again and again - those are Merklinger's own words. What is there to misunderstand Andrey? [Martin?] Merklinger is WRONG! The statement made in that caption is RIDICULOUS.

 

[snip]

 

Can't you agree Andrey [Martin?] that were we to calculate DoF such that our maximum permissible CoC's were no smaller than those Merklinger has produced in the foreground of this image we could select an aperture that is WIDER than the one Merklinger used to shoot that picture (by focusing CLOSER than Infinity, precisely AT THE HYPERFOCAL DISTANCE, producing comparable results without WASTING the DoF that resides beyond the plane of sharp focus)?

 

Merklinger either finds the foreground CoC's to be acceptably small in that photo or he has sacrificed their sharpness to maximize that had at Infinity. Which is it? He writes in the text that follows the photo: "The foreground is admittedly not tack-sharp." Gee, sounds like a compromise to me!

 

[What do you think Martin?]

 

He goes on to write: "Had I focused at the hyperfocal distance the telephone poles in the village would have been almost erased, and windows in buildings would have been just blurs."

 

Andrey [Martin?], don't you find it conspicuous that Merklinger again fails to qualify his use of the phrase "hyperfocal distance" with the CoC diameter specified for the DoF calculations? In fact, he has failed to qualify a LOT of important variables affecting perceived sharpness!

 

Even with 1/30mm CoC's at the near and far sharps, the ENTIRE image would appear "tack-sharp" if the combination of viewing distance and enlargement factor was not sufficiently demanding to allow the viewer to resolve those CoC's. Right?!

 

[Right Martin?]

 

Give me any combination of enlargement factor and viewing distance and I can come up with a CoC diameter most people will be unable to resolve. DoF calculations made with this CoC diameter will produce images that ARE "tack-sharp" when focusing at the hyperfocal distance (ignoring other factors that limit the total system resolution.)

 

Speaking of ASSUMPTIONS: Please read the last two sentences of Merklinger's "Introduction" section. Merklinger says that if we focus at the hyperfocal distance, we "will have sealed in that 'minimum acceptable standard' ". What standard is he talking about? Higher up he explains that he's talking about a 1/30mm standard for maximum permissible circles of confusion at the near and far sharps.

 

Mr. Merklinger! [Martin!] Will you please tell me what's preventing us from ABANDONDING that standard? Will you please tell me why we can't calculate DoF tables that give us apertures and hyperfocal distances that produce SMALLER circles of confusion than this standard you find so disappointing?

 

Merklinger's entire argument for avoiding hyperfocal focusing is fallacious! Don't you see that he is ASSUMING we are stuck with 1/30mm CoC's? In my opinion, the man knows better. He's just scratching up an excuse with which to argue that his technique will yield better results when the truth is it doesn't work as well as doing things the old fashioned way.

 

Merklinger says we'll be "guaranteed" to have "mediocre" results if we focus at the hyperfocal distance. That's ONLY TRUE if we join him in pretending that 1/30mm is the ONLY diameter CoC we can use in our DoF calculations!

 

[Am I wrong Martin? Can't you see that Merklinger's "guarantee" of "mediocre" results with hyperfocal focusing asks us to believe that we have no ability to choose a finer CoC standard? He woke up one morning with a clever idea that's very convenient to implement and this is how he's trying to pawn it off on people who are unwilling or incapable of discecting his premise!]

 

In the paragraph immediately below the picture on Merklinger's page, he writes: "The hyperfocal distance for a 90 mm lens at f/8 is 106 feet." Harold! [and Martin...] That's the hyperfocal distance for a 90mm lens at f/8 with a maximum permissible CoC diameter of 1/30mm!!! It is not THE ONLY hyperfocal distance! It is one of MANY POSSIBLE hyperfocal distances that could result with various choices of CoC diameter.

 

[Can you nod your head at least?]

 

If I CHOOSE to make my CoC's SMALLER than the 1/30mm "standard" that leaves you [Harold] so "bothered" by the "old story about maximizing DoF by focusing at the hyperfocal distance", I can achieve any degree of sharpness I desire, right up to the limits of total system resolution! And YOU can TOO!

 

[Where is my thinking flawed here, Martin? What can Merklinger's writing's possibly offer to refute this?]

 

****

 

The ball is in your court. Again...

 

Mike Davis

 

[MTC Photography]

Mike,

 

You have being attacking Merkinger's for years.<p>

YOu haven't even read his books ? <p>

What can I say ????<p>

[MTC Photography]

Mike wrote:

"

Merklinger's entire argument for avoiding hyperfocal focusing is fallacious! Don't you see that he is ASSUMING we are stuck with 1/30mm CoC's? "

 

"Don't you see that he is ASSUMING we are stuck with 1/30mm CoC's? "

 

 

"That's ONLY TRUE if we join him in pretending that 1/30mm is the ONLY diameter CoC we can use in our DoF calculations!

 

Am I wrong Martin? " <p>

Mike I am afraid, you are dead wrong<p>

 

You are bound to make a fool of your self, if you pose yourself

as a 'critic,' without even read the author's books.<p>

 

Merklinger made no such assumption.<p> YOU assume that Merkingliner made such asumption.<p>

See P 71 of his book <p>

 

OK !!

[mike_davis]

Martin,

 

I haven't been attacking Merklinger. I've been attacking the quick and dirty of focusing at Infintity and then stopping down further than you would have to if you instead focused at something short of Infinity.

 

No one can find even one statement I've made about Merklinger that didn't relate to this single issue and his position on the subject, written in his own words at http://home.fox.nstn.ca/~hmmerk/DOFR.html, is quite clear.

 

Again, you have avoided the crux of this debate. Surely I'm not the only person wondering why you haven't answered the questions I've summarized for you this morning.

 

You have Merklinger's books, but you've chosen not to quote him. Why?

 

Will you please choose even one of my challenges and tell us why Merklinger is right (on THIS issue)? Why don't you start with page 71? You've suggested that were I to read this page, I would find out that I have made an erroneous assumption. But you don't bother to bring it out here in the open. Why Martin?

 

I'll suspect there's nothing on page 71 or any other page that can erase the FACT (not an assumption) that at this page:

 

http://home.fox.nstn.ca/~hmmerk/DOFR.html

 

Merklinger himself wrote the following caption under his own example photograph: "This scene, the village of Placentia in Newfoundland, was taken with a 90 mm lens set at f/8 and focused at infinity. As explained in the text, to have focused at the hyperfocal distance would have seriously degraded the image of the village, while making negligible improvement to the foreground."

 

Now Martin, can you tell me what unreasonable assumption I've made? No one has to read page 71 of his book to see that Merklinger himself is ASSUMING that the hyperfocal distance is based on a 1/30mm CoC standard he find's objectionable.

 

Where on that web page does Merklinger say, "Of course, if we were to use a hyperfocal distance based on a smaller CoC diameter, we could obtain better results in the foreground, with a wider aperture, without any visible degradation of the Infinity subjects." ?

 

I've made a reasonable assumption Martin. Merklinger is trying to dupe the reader into believing his Infinity focusing technique is superior to hyperfocal focusing.

 

Martin, please tell us what is written on page 71 of his book that can erase his having written THIS on that web page: "What bothers me even more is the old story about maximizing depth-of-field by focusing at the hyperfocal distance. If you follow that advice you will be guaranteed that scenes in the distance will never be resolved any better than mediocre. You will have sealed in that "minimum acceptable standard".

 

It's quite clear to me that Merklinger is suggesing his method is superior to hyperfocal focusing, but his argument ASSUMES that maximum permissible CoC's are FIXED at 1/30mm. Now you may find something where he talks about adjusting CoC diameters, but can you find anything he has written that addresses doing so IN THE CONTEXT of comparing Infinity focusing to hyperfocal focusing?

 

As Robert Clark said, my questions make sense whether or not I've read Merklinger's books. Please stay on track Martin. Answer the questions.

 

Mike Davis

[robert_clark]

Martin, Mike has put in a lot of work tabulating some very specific and interesting questions that he has asked over and over again. They are all now in a single post. Yet you continue to refuse to answer these specific and pertinent objections to this particular theory of depth of field.

 

I assume as photographers we all want to learn more about the issue of depth of field, if there is more to learn. You have brought Merklinger's theory to our attention, but to me it is not whose theory it is that is important, it is what that theory is saying,what it adds potentially to our understanding. Certainly, given what we know of depth of field theory, what Merklinger says is counter intuitive - it goes against what we have learned and what seems to make good sense to us. Combine this with Mike's very cogent challenges, which are begging to be addressed and your refusal to come back to these specific points and it seems you are indeed avoiding rational debate.

 

The refrain: 'read the book, read the book' is simply not an acceptable response. It is like me trying to convince you of certain Christian Scriptural arguments and when you come back at me with reasonable objections to them I just tell you to read the Bible. You would be right to complain, asking why can't we examine the arguments about living or belief without having to take on a theological education.

 

It is the same with this issue: it is the comparitive merits of a 'Critical Hyperfocal Method' and the 'Infity method' relative to better and sharper picture making that is interesting. I do not want to become a Merklinger 'convert'. You made out the case for Merklinger quite forcefully at the beginning of this thread, attempting to explain the theory. When others have raised objections to the logic of the arguments they have been presented with you have been dismissive. Either you have dismissed people for their weakness at maths (surely the worst of unfounded assumptions, as well as insulting) or for their having not read your canonical text. This is tedious and frustrating.

 

You seem not to want to continue arguments that you started when the objections to those arguments become specific and dig into their unexamined assumptions. Your responses since Mike's arguments became very specific, pertinent and interesting seem to have grown weaker, more evasive and more antirational. You seem to be defending Merklinger as an article of faith and have abandoned the reasonable, careful debate that could lead to a deeper understanding useful to photographers of landscape.