gregory_king1

<p>I'm never had any problems with the bokeh of any of my Mamiya 645 lenses. Just shot some last night with my AF 80mm at f/4 on a 22mp back and had no issues whatsoever. It wasn't particularly close-up, however.</p>

<p>Then there's always the 80mm 1.9 to consider, and the f/4 macro, too.</p>

<p>You want "best lenses" or "good glass" for a bargain? Those lists are different. ;)</p>

<p>In my opinion:</p>

<p>The best cheap kit:</p>

<p>Standard zoom: 28-85mm, 35-70mm f/4, or 35-105mm (under $80)<br>

Tele zoom: 70-210mm f/4 (under $150)<br>

Prime: 50mm 1.7 (under $80)<br>

Tele prime: 100mm f/3.5 macro (Cosina/Promaster/etc) "Plastic Fantastic" (under $100)</p>

<p>But if you want "best" classic lenses....look for the 28/2, 35/2, 100/2, 200/2.8 and the 28-135mm</p>

<p>Ditto. I shoot MF (and not 35mm) because it's so easy to scan.</p>

<p>Harry, I didn't know Costco developed 120 film. Are you sure?</p>

<p>I get mine done at Costco for dirt cheap, but I don't bother have them scanning it since every cheap develop-and-scan place is worse than my cheap V500 scanner.</p>

<p>Mauro, the answers are both yes and no. What did YOU expect from the forum? ;-)</p>

<p>Film will give you a different "look" than digital, regardless of the image size or display medium. Likewise, medium format lenses will give a different look than 35mm lenses. </p>

<p>I just scanned some 645 E-6 last night, and have the results in front of me. The tonality would be difficult to match with digital, even RAW. C-41 would be different, but in different ways.</p>

<p>Is it "better"? No. But my wife seems to pick a higher percentage of my film shots than digital, compared to how many I shoot.</p>

<p> </p>

<p>I use my Phase H10 back on my RZ67 Pro II with a Leaf 17 adapter, slightly modified. It would work on a Pro as well...the backs are interchangeable.</p>

<p>The Phase backs require a wake-up cable which I have. Leaf backs don't require it. The ZD back cannot be woken up (as far as I know), so it wouldn't be compatible. Maybe it would be with the Pro II D.</p>

<p>The advantage is faster shutter speeds with flash, but at ISO50, 1/125 on the 645AFD isn't too unmanageable. ISO25 from some Leaf backs would get you f/8 or below in bright light.</p>

<p>PS...if we don't agree on this topic, we never will. If we do agree, then obviously our inability to communicate via semantics won't be fixed anytime soon.</p>

<p>Either way, there's no point in continuing this discussion. Only one person here seems to think tiny formats produce shallow DOF, and he won't defend his position. :-)</p>

<p>So, I'm gone. I've got VC160 to burn. Peace out.</p>

<p>Desmond,</p>

<p>The sad part is...you think that changing focal length without changing image size is the same as changing focal length AND changing image size. It's not.</p>

<p>The sadder part is...I gave you a detailed technical link that explained it, and you were too lazy to read it.</p>

<p>The saddest part is...you are arrogant enough to impune others with childish comments as a result of your ignorance.</p>

<p>I'll say it one last time, but I don't expect it to sink in. For the same framing and aperture, you can change focal length all you want, but it won't change depth of field. You can shoot a head shot at 20mm f/2.8 (close up) or 200mm f/2.8 (far away) and the DOF will be THE SAME. The background will look different, but the zone of acceptable focus won't change.</p>

<p>So your example was misleading at best, and fully incorrect at worst. Maybe go read the link I presented, and play around with a DOF calculator to prove me correct.</p>

<p>If this is what you were trying to cover your ass on on your longwinded, equally flippant explanation, so be it. It's still not helpful.</p>

<p>Desmond,</p>

<p>Of course it's off the original topic, but YOU were the one guilty here. You just posted two shots from the SAME CAMERA, using different lenses, did you not?</p>

<p>I was just trying to limit the confusion you were perpetrating. </p>

<p>The original topic got lost LONG LONG AGO.</p>

<p> </p>

<p>Desmond/Jens,</p>

<p>Sigh...here we go.</p>

<p>You took different photos by not moving. You changed your field of view. Therefore, comparing DOF is rather moot.</p>

<p>Had you taken the same photo (moved back for the 200mm), the change in subject distance would have resulted in balancing the DOF. Yes, the nature of the OOF areas would change due to telecompression, but the DOF would be the same.</p>

<p>In short, head shots taken with the same camera will have similar DOF at the same aperture, regardless of focal length. Going to 200mm will not decrease DOF over using the 50mm, since the 50mm made you stand closer.</p>

<p>http://toothwalker.org/optics/dof.html</p>

<p>Look at the segment on "background blur"</p>

<p>Taking photos of flat objects and cropping photos isn't the best way to demonstrate the concept. ;)</p>

<blockquote>

<p>Circumstances that are never met in real life.So why do you bother?</p>

</blockquote>

<p>Q.G...that is the most nihilistic explanation I've ever heard. Let me see if I can top it. ;-)</p>

<p>Reality is false, nothing is real. Don't bother taking photos in the first place... they are just bastardized representations of microseconds in time, incorrect in all aspects and fleetingly ephemeral. Two-dimensional surrogates which do no justice to an entire dimension of human existence.</p>

<p>Eschew photography and live in the moment.</p>

<p>I guess asking for the "tiny format DOF is the same as large format" is futile, eh? ;-)</p>

<blockquote>

<p>Hey Gregory, so you just got a MFDB? Congrats! Which one? Is this replacing the tethered-only one you had before?<br>

(Notice how I skilfully avoided even mentioning D**...you know, <em>that </em>word)</p>

</blockquote>

<p>Ray, </p>

<p>Yep, I stumbled on a 22wi. We'll see if it'll still have to be tethered or not. Supposedly it can be self-powered and "self-tethered" to an Ipaq PDA. Whether or not this will work, or whether it'll shoot untethered and unviewed (stored directly to digital magazine without the Ipaq) remains to be seen.</p>

<p>Couldn't pass up that 36x48 sensor...and all the shallow DOF it provides. ;)</p>

<p>Dave,</p>

<p>I'm not sure whose definition it is, but you better get on Google ASAP and get started correcting the ignorant masses. Of the entire first page of hits, I found only one that asked for print size. The rest shockingly left it out.</p>

<p>So it seems a lot of people have become comfortable with a "standard". Perhaps it's the same people who make the DOF scales for camera lenses...who knows? Must be...since one of the "sloppier" websites offered up this explanation:</p>

<blockquote>

<p>It should be noted that an 8x10 inch print viewed at arm's length has long been considered the standard on which most lens manufacturers base their lens' depth of field guidemarks.</p>

</blockquote>

<p>By the way, since you're being so picky. you forgot "viewing distance". It's not just print size, remember? Gotta factor in viewing distance too...lest we confuse anyone. :-)</p>

<p>Don't worry, Jose...your English is better than most native speakers. ;-)</p>

<p>And it's obvious you know your stuff. As does Q.G. We're like three overeducated nerds discussing minutiae, so much so that we scared the original poster off. ;-)</p>

<p>So I humbly suggest we suggest a truce and end the bickering over DOF, viewing distance and resolution, because I'm pretty sure we all think the same thing, regardless of how we express it.</p>

<p>Now, if we can put the tiny sensor issue to bed, we can go off fat, dumb and happy and take some photos. And maybe I'll send back the MFDB I just bought, since Q.G will show me how to take the same shallow-DOF photos with my P&S. ;-)</p>

<p>All that arguing about semantics, and you still didn't get to the good stuff. Bummer. :-)</p>

<p>You find it silly to put a common standard on DOF. I don't. I get your point. I need no further explanation.</p>

<p>You'd apparently rather we say "Medium format systems provide a much narrower region of acceptable sharpness for similar shooting conditions , when printed under proper printing conditions, and viewed under proper viewing conditions, by the same viewer on the same day in the same mood.</p>

<p>I'd prefer to just say "Medium fomat systems provide narrower DOF".</p>

<p>Six of one, a quarter dozen multiplied by the cube root of 64 divided by the hypotenuse of a right triangle divided by a leg squared of the other.</p>

<p>I think it's much more useful to define it using a common set of standards, just like nearly everything else in human society. Stairs, railings and counters are built to standards. Heck, even the definition of 20/20 vision is empirically based. Does that make it less useful?</p>

<p>I suppose you'd rather we had no scales on camera lenses, or online DOF calculators, because that would be too...simplifying? There are just too many variables, so we might as well avoid the issue altogether?</p>

<p>I have to go now. I plan to speed home. If I get stopped by a cop, I'll just tell him that the speed ratings they put on the road don't apply to me, since obviously they weren't aware of the capabilities of my car and my incredible driving skill. ;)</p>

<p>And to drag us back kicking and screaming to the OP...Mario Andretti will still be a better driver than me, no matter what measurement you use.</p>

<p>And furthermore, to extend the temperture analogy...</p>

<p>A few comments were made like "Well, if you wear a thick jacket in NYC, you can feel as warm as you do in Miami". Okay. </p>

<p>But actually, they were in the reverse, which made them make less sense. No, running around naked in Miami won't make you feel (again, in the majority of cases) as cold as you'd be in NYC. There are limits to how much you can adjust your temperture given the limitations of your "equipment".</p>

<p> But you'd look silly. ;)</p>

<p>Yes, in other words, the OP said "Wow, Miami is hotter than New York City" and somehow, this got off onto a discussion of where you draw the line between "hot" and "cold". Even though no one disagrees that Miami is indeed hotter than NYC, with rare exception.</p>

<p>And now, you seem to be discussing resolution. I never said anything about that.</p>

<p>And I never said viewing distance didn't affect percieved sharpness. I said it was standardized for the purposes of defining DOF. But I'm repeating myself as nauseum.</p>

<p>Perhaps you'd like to tell me how they put the DOF scale on my lenses, then? The lens manufacturer has no idea what size I plan to print my photos, and how far away to view them.</p>

<p>And (back to the original OP), why do the DOF scales on my medium format lenses show less DOF than my 35mm lenses?</p>

<p>So to clarify, <em>acceptable</em> sharpness is subjective (I forgot to put in a word before).</p>

<p>Pick a definition for acceptable, be it yours or someone else's. Using that definition, you can calculate a DOF. Now...it's not subjective. (PS...I grasp the concept of viewing distance quite well. It's rather basic.)<br>

<br />Keep the same definition (no cheating now) and a larger format camera will give you shallower DOF....regardless of how large you print.<br>

<br />Not sure how we got off on that tangent...must have to do with people standing so close to posters printed from point and shoot cameras that they look blurry. ;)</p>

<p>Jose,</p>

<p>You can disagree all you want, but it won't make you correct. ;-)</p>

<p>Fine, your DOF calculators do take final print size into account. Good. Many just default to the standard, for simplicity.</p>

<p>They also take into account STANDARDS for visual acuity...ie. so many arcseconds of resolution, blah blah blah. Yes, they don't take your personal preferences into account. If you think of a way to program everyone's personal preferences into a DOF calculator, patent it. You'll be rich. </p>

<p>Sharpness is subjective, DOF is not. It is DEFINED to allow us to make comparisons, without the hinderances of your personal preferences.</p>

<p>In any case, you are off topic, because it doesn't have anything to do with the original post. Whatever you choose to define YOUR definition of DOF, a larger format will have less DOF under similar circumstances. Agreed?</p>

<p>And Q.G's comment about printing tiny format prints at the same DOF as large format will still be incorrect.</p>

<p>Fine, I'll bite...slow day at work. :)<br>

<br />Okay, Q.G...do tell us. Why is everyone else wrong and you are correct?</p>

<p>PS...my example doesn't say why they are wrong. It explains why they are RIGHT, based intrinsically on the definition of DOF. You can create your own definition, but you've got a lot of people to convince before the world will accept it.</p>

<p>I got a good idea...let's agree there is no such thing as DOF, since by law, nothing is in focus. The focal plane is by definition a plane, and has no depth, so nothing three-dimensional can be truly in focus. Will that satisfy you?</p>

<p>Dave,</p>

<p>Just to clarify...your statement is entirely true. However, the standard definition of DOF is calculated <em>irrespective of print size</em>. It assumes a standard viewing distance (I believe 8x10 at arm's length, for example) which changes with print size.</p>

<p>As we all know, DOF calculators don't ask you what size you plan to print...nor how good your eyesight is.</p>

<p>How about next time we just refer to the wiki? ;-)</p>

<p><a href="http://en.wikipedia.org/wiki/Depth_of_field">http://en.wikipedia.org/wiki/Depth_of_field</a></p>

<p>John,</p>

<p>"For some reason"?? LOL...don't say that. We'll get confused again. ;-)</p>

<p>Well stated. But my point was that they should be comparing similar photos, which means that indeed FOV is a better comparison than equal focal lengths. People use a standard lens for standard photos...whether that's 35mm on APS-C, 50mm on FF, 80mm on 645, 110mm on 6x7...you name it. Heck, that's why so much is advertised in "35mm equivalent focal length".</p>

<p>Yes, the math is more straightforward if you use the same focal length, but in the real world, as the OP noticed, more than one variable usually changes. The result (for all intents and purposes) is reduced DOF for larger formats.</p>

<p>I was worried someone was going to mention that the DOF on larger formats is actually DEEPER for certain conditions (but which are overwhelmed by the greater effect of change in focus distance, etc.), or that acceptable DOF is a function of viewing distance, but I didn't want to go there. :-)</p>

<blockquote>

<p>DOF has absolutely nothing to do with the size of print you have or the size of the format. It's all in the aperture and focus distance.</p>

</blockquote>

<p>Sigh...except that focus distance is a function the size of the format, because you get closer with a larger format with the same focal length lens.<br>

<br /><br />Ergo, it has "absolutely SOMETHING" to do with the size of the format.<br>

<br />I give up. Too many optical physicists on here hellbent on showing off rather than helping out.</p>

<p>Jose,</p>

<p>Right...those examples are correct. But you're going the wrong way.<br>

<br />Remember the comment was:</p>

<blockquote>

<p>Yes, if you print a tiny format camera image the same size as you print an 8x10", DoF will be the same."</p>

</blockquote>

<p>So, if we go the other direction, most P&S cameras have about a 6x crop factor. So, we'd be using a 8mm lens or so. To get the same DOF, we'd need the same aperture size, or around 50/1.4 or about 35mm. That would require an f/stop of around f/0.25. Now we all know that doesn't exist, and is probably physically impossible to build, at any cost.</p>

<p>To pick an example from large format, my calcs say the smallest f/stop of f/64 will result in an aperture of around 4mm. That would require an f/stop of a bit over f/2 on the P&S camera. Almost all P&S cameras I know of don't go to f/2. A few better ones might be able to, and/or have larger sensors. But we've essentially ruled out nearly all instances where the DOF can be made equivalent...certainly any "normal" examples at common f/stops.</p>

<p>Ergo...to make blanket comments as above that DOF "will be the same if a tiny format image is printed the same size" are misleading at best and physically impossible to create in most conditions at worst. And you'll notice in my math...nothing is said about print size, so that's a moot point which adds confusion.</p>

<p>Looking back to the original post, that sort of answer isn't at all helpful. </p>