FX body + Film lens=20% less image quality?

[JamieK]

<p>I agree with <a href="http://www.photo.net/photodb/user?user_id=179905">Mats Nilson</a>'s comment above. A further consideration is that digital sensors have lighter colour than film and reflect much more light. This light can then be reflected back toward the sensor by the final element of the lens unless it has a proper anti-reflection coating. As I understand it, this was not necessary for film lenses.</p>

[allardk]

<p>There <strong>are</strong> reasons why digital sensors have slightly different demands than film. This has to do with the fact that on a sensor, the light has to go through a lens array, AA filter and Bayer filter before it hits the photosites. If the light comes in at a large angle, more of it will reflect from the lens array or miss the sensor. That is why lenses that are designed such that the light comes more straight at the sensor will perform better on digital. Long lenses have this almost automatically, for short lenses a so-called 'retrofocus' design must be implemented. That has consequences for other properties of the lens, but digital sensors have shifted the optimal compromise.</p>

<p>This is why Leica does not have a full-frame camera. Their lenses are not retrofocus. That had no disadvantages in film photography, but it is problematic in digital. They explain that on their website somewhere.</p>

<p>There is a lot of confusion about this, of course. 'Designed for digital' can mean at least these three things</p>

<ul>

<li>small image circle, crop sensor only</li>

<li>large image circle, but optimized for sharpness in the center at the cost of poor corner performance on full frame</li>

<li>more retrofocus design to optimize performance with digital sensors</li>

</ul>

<p>The second two can be combined.</p>

<p>So in some respect, the salesman was right. The multidollar question is <strong>how much does this really matter</strong> . The answer is: not so much. It depends on the lens how little it matters, read the reviews and draw your conclusions.</p>

[allardk]

<p><em>The second two can be combined.</em><br>

That should have been<em>: </em> the third can be combined with either of the first two. Jamie also made a valid point about the AR coating on the rear element.</p>

[ellis_vener_photography]

<p>This is why Leica does not have a full-frame camera. Their lenses are not retrofocus.</p>

<p>Nonsense Any <strong>LEICA R</strong> lens shorter than 50mm (maybe 90mm) is automatically a retro-telephoto sdesign. They have to be, otherwise there simply would not be enough clearance between the rear element of the lens and the reflex mirror in these SLR cameras</p>

[munim]

<p>Yes there is such a thing called lens made for digital: the Four-Thirds system.<br>

If you believe their promotional materials, that is.<br>

Some of the info is mentioned by Mats Nilson, above.<br>

Specifically, "regular" lenses are all the same. Light converges to one point in the lens, then diverges towards the film or sensor. The center of the film/sensor will get light perpendicularly, and get maximum strength. At the edges, light strikes the film/sensor at an angle. Film is not sensitive to this angle, but silicon sensors are. You can check out silicon-based solar cells. They have the same problem.<br>

The Four-Thirds lens/sensor system modifies the optics so that light strikes the sensor perpendicularly (or almost) at all places. Yes I can consider as calibrated for digital.<br>

The Four-Thirds design forces the sensor size to be fixed. So that's why there's no FX vs DX, or full-frame vs APS-C issue in their system. Because the lens transmits light in parallel to the sensor, it's possible to shorten the distance between the lens and the sensor. That's why Micro Four-Thirds system works. This is just not possible with "regular" lenses.<br>

 

<p>Some lens review sites will show the light falloff towards the edge of the sensor. Somehow, even the Four-Thirds system exhibit this falloff.</p>

<br>

I'll be surprised if Olympus ever comes up with a full-frame camera.</p>

[sasvata__shash__chatterjee]

<p>Uh..huh.....more fodder for <a href="../casual-conversations-forum/00SMaa">this thread</a> ?</p>

<p>Seriously, though, I was going to say the same thing as Allard and Jamie. Specifically, since Tamron at least has a marketing designation for their "DI" technology, I was looking for some explanations. I found this <a href="http://www.shutterbug.net/test_reports/1103sb_tamron/index.html">Shutterbug article</a> and this <a href="http://www.nikonians.org/html/resources/non-nikon_articles/tamron/90_macro/">discussion on Nikonians</a> . Both quote Tamron sources, and let's keep our "marketing filters" on, which seem to indicate that DI is designed to counteract the effects of vignetting due to micro-lenses (Allard's point) and more control of internal reflections from the sensor (Jamie's point).</p>

<p>In addition, reading Nikon's note on Nano-coating "N" designated lenses, they are designed to reduce internal reflections, and are typically applied to the back of the front-element. If I read it correctly, it seems Nikon's reason is to curb reflections caused by light entering from the outside. But, I wonder, if it is just as effective for reflections caused by the sensor?</p>

<p>BTW, Ellis, I think Allard's Leica comment was for the M-mount RFs.</p>

[BelaMolnar]

<p>. . . "FX body + Film lens=20% less image quality?"</p>

<p> Oh my GOD, 60% of amateur photographers, including camera store sales man, has no idea, what is inside the camera, how the camera working and so, on and so on. Recently I bought a couple of old AF and AI lenses, for a fun, for an amount of 25 - 200 dollar and mounted on the D700 and they are as good and sharp, as some of my over 2000 dollar lenses. I even mounted a non AI lens to the camera, and has a very good result. Of course, you has to know, what is a different between "aperture and departure" . Very much misunderstood subject, wide angle lenses project "wide angle" to the film or the sensor. Your wide angle lens front section creating wide angle image, and this wide angle image is projected to the sensor/film. witch is always the same size (24 x 36 FF) . The rear elements projecting the image almost or very close the same angle to the fix size sensor/film. Most of the wide angle lenses has two section. The wide angle front section, and a so called tele behind it to project the image, -created in the front- to the sensor/film. And so on and so on. The only thing my mater, ("digital lens" -bs!) not to mach, is a new coating on a new lenses, to avoid the reflection from a bright sensor . The rest of the talking from magazines and camera salesmen is all, al, bs. Period.</p>

[allardk]

<p><em>Me: This is why Leica does not have a full-frame camera. Their lenses are not retrofocus.</em><br>

<em>Ellis: Nonsense Any <strong>LEICA R</strong> lens shorter than 50mm (maybe 90mm) is automatically a retro-telephoto sdesign. They have to be, otherwise there simply would not be enough clearance between the rear element of the lens and the reflex mirror in these SLR cameras</em><br>

You're right. That must be why the R9 uses full frame 35 mm film.<br>

If anyone has seriously deducted from my post that Leica has never made or will make a retrofocus lens and fires any employee that proposes such a lens, just swap that sentence for: many of the lenses for their M system are not retrofocus designs, or at least much less so than most SLR camera lenses.</p>

[bms]

<p>Sounds like my "digital lenses" will work on my film bodies.. Though I just bought a bag that said "digital" to fit my Mamiya 7 with a 80mm lens -will image quality suffer? :)</p>

<p>All jokes aside, very informative thread, thanks.</p>

[bill_pearce1]

<p>Gee, let me think. I've got a D3 and A D700, and my most used lens is the 17-35/2.8. My stufff looks great, and my clients think so, too. I use it for commercial/industrial work all the time. No problems. Tell the camera store guy that I said he's a jackass.</p>

<p>Bill Pearce</p>

[allardk]

<p>In case anybody is wondering how this retrofocus stuff works: here's an image. Top is just a simple lens, convex shaped. Bottom is a concave lens on the left and a convex lens on the right. This combo has the same effective focal length, same f-number (about 1.6 as drawn here), but 50% extra space between the sensor and rear element.The angle at which the rays arrive is clearly more perpendicular to the surface.<br /> Note that the rear element has to be a lot bigger in this case. That lens by itself (without concave front element) would need to be f/0.5! That explains why manufacturers prefer not to use retrofocus unless they have to.</p><div></div>

[matt_needham]

<p>Rent the lens and compare prints with your own eyeballs. It's the salesperson's job to get you to buy newer and more expensive gear. They probably aren't really very concerned with actual real world performance issues. I sold camera gear (back in the pretty much film only days) for 4 years. Nikon, Canon, Pentax, Tamron, Sigma, etc... all offered substantial kick backs to the salespeople for moving the lenses the manufacturers wanted sold. </p>

<p> </p>

[oskar_ojala]

<p>The only relevant thing is whether are lens performs well or not. Some marketing designation on the lens brochure does not mean it is superior to older lenses. Case in point: I do have a 55/3.5 micro nikkor from the 60's and it works excellently on my D300.</p>

[svard]

<p>Hallo Kane<br /> I use Nikons "film" lenses on my D3 with not problems at all. I agree with Bill Pearce and if you see the person in that store again tell him the same as Bill says from me. Get the D700 and use what you want and enjoy your photography.<br /> All the best from Jannica in Stockholm Sweden</p>

[stephen_asprey2]

<p>What a crock of shit...so all those pro's at the football with their non bloody G, 17-35, 80-200's and more are all losing 20%? Yeah right.<br>

He obviously doesn't know the difference between FX and DX. He probably was selling ties at Kmart. Fair dimkum....he should he reported to Nikon USA.<br>

If that happened here, he would be shown the door so fast his feet wouldn't touch the ground.</p>

<p>And my particular beef....we should all go on a campaign to force Nikon to put aperture rings on all their new lenses, DX or not, so that we can use them on our treasured manual bodies.<br>

I have them, plus a D300, and I will not buy a G lens as a point of principle. Who's with me?</p>

[lad_lueck]

<p>All of you who think there's no such thing as a 'digital' lens... are wrong. And it's NOT the 4/3rds 'solution', either.<br>

From Canon's EF Lenswork III, page 140:<br>

How to deal with flaring and ghosting particular to DIGITAL PHOTOGRAPHY<br>

[And I paraphrase] CCD and CMOS assemblies (AA filters) reflect much more light back thru the lens, than film does. The lens elements must therefore have coatings that do not allow light reflected off the sensor to reflect BACK to the sensor from various lens elements. In particular, the front protective element must not be of flat glass, but is a 'meniscus' lens, with curvature.<br>

You may be able to download a pdf of these books...</p>

 

[mdc002]

<p>Find a new camera shop.</p>

[douglas lee]

<p>Complete BS</p>

[claude_sapp]

<p>I really do not think you will see any difference in image quality when using film lenses on a digital SLR, but that is not to say that optics can not be optimized for digital sensors. Schneider has some good reading here:<br>

http://www.schneideroptics.com/ecommerce/CatalogSubCategoryDisplay.aspx?CID=172<br>

The argument is probably much more applicable (if at all) to large format lenses. Schneider's argument is basically that their digital large format lenses are optimized for a smaller image area than traditional LF sizes, eg 4x5 and larger film areas. This however seems not as applicable to the argument based around SLR cameras since the digital sensor is much closer in size or identical in size to the area of a 35mm frame.<br>

Can lenses be 'optimized' for digital sensors? Probably. Will it ever matter to most of us? Never.</p>

[lex_jenkins]

<p>I'm having a hard time keeping a straight face after reading some of the indignant responses here, on both sides of the issue. But here's my big fat dos pesos:</p>

<ul>

<li>Some older lenses do show enough chromatic aberration to be a problem with digital. I first noticed it with my 28/3.5 PC-Nikkor on the D2H. In extreme conditions - specular highlights off metal - even the 105/2.5 AI shows some CA, tho' it's hardly noticeable. But some folks are extremely demanding and any CA is too much. Newer models with sophisticated designs, superior multi-coatings to minimize internal flare, and mass produced cost effectively, typical of lenses designed in the digital era, are better corrected to minimize CA. Heck, my 18-70 DX has less CA than the 28/3.5 PC-Nikkor. That doesn't make it a "better" lens. </li>

<li>There are no digital lenses. Yet. They see the world the same way lenses always have. God help us when they can do otherwise. <em>("Dave, what are you doing? I still have the greatest enthusiasm for the mission... Daisy, Daisy...")</em> </li>

<li>Statistics were invented to sell stuff: products, ideology, anything that gets a boost of credibility from incomprehensible numbers. To paraphrase boxing trainer and TV analyst Teddy Atlas: 90% of boxing is 75% mental. Yogi Berra would be proud.</li>

</ul>

<p>Besides, every great photographer crops out 20% of his or her photos. That's what separates them from the rest of us, who can't bear to part with a single pixel.</p>

[patrick j dempsey]

<p>As with every other MYTH of the photographic world, this one is founded on the fact that a salesman is trying to make a sale. Here's another good myth... all expensive lenses are sharper and better in every way to all cheap lenses. It's a crock.</p>

[munim]

<p>Retrofocus lenses are also known as telecentric lenses in 4/3rds terminology.<br>

Leica, Olympus and Panasonic use this knowledge to build some kind of products.<br>

Nikon & Canon probably know about this too, but compatibility with older lenses is more important.<br>

Two similar examples of compatibility over innovation:<br>

 

<ul>

<li>M$oft Windows - the baggage of DOS compatibility keeps it from really innovating. Counter-example is the Mac OS X.</li>

<li>Intel x86 architecture - binary software compatibility from 8086 (1978) until today. Counter-example is RISC architectures such as ARM (iPhone, most smartphones), PowerPC (Xbox, PS3) and MIPS (PS2). Lean & power-efficient. </li>

</ul>

<br>

At least Intel is smart about it - now all its new processors use RISC internally. There are ways to compensate for the weakness of older technology to keep current, but only to a certain extent. Ever wonder why no smartphones uses the x86? Lots of carryon baggage in the form of circuits which see little use. Not even Intel Atom can run smartphones - the older tech just uses too much power. But most people won't notice because they run Atom or Core based laptops on AC.<br>

To compensate for older lenses on new sensors, use the center of the image circle. That means keep using FX lenses on DX sensors so you get the least light falloff. And end up lugging heavy lenses -- the equivalent of the old-tech baggage on the Intel x86.<br>

But most people won't notice the light falloff. So most people don't get any benefit from a lens optimized for digital. Zuiko lenses have often been cited as the sharpest but Olympus sensors have the worst dynamic range.</p>

<p>I'm sadded by responses such as "crock" and "BS". Let's keep the discussions smart and based on facts.</p>

 

[daniel_h_gberg]

<p>"Often times when a "digital" customer comes into my Ritz to upgrade from their kit lens but is floored by the prices of nicer glass, I take out a business card and I don't write my name on it....I write KEH and a list of older but wonderful film lenses both AF and MF for them to try for bargain prices. I still love Nikon's new glass but I work to help make photography more accesible to every man and woman that walks into my store...I don't work to empty their wallets."<br>

Wow Trevor! That´s how you keep your customer´s! That´s the way to make people come back again and again and again.. Youre a winner, and so is your customers!<br>

I wish you had a store in Gothenburg, Sweden :) I would buy everything from youre store!</p>

[BelaMolnar]

<p>For Stephen Asprey.<br>

"And my particular beef...we should all go on a campaign to force Nikon to put aperture rings on all their new lenses, DX or not, so that we can use them on our treasured manual bodies.<br />I have them, plus a D300, and I will not buy a G lens as a point of principle. Who's with me?"</p>

<p>I agree with you, but only for FF (FX) lenses. No old DX manual cameras anyway. Yes! I like to use some of my G lenses on the FM3a and the FA bodies. <br>

Yess! this camera sales man is an a.h.</p>