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11-03-2009, 01:06 PM   #1
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speculation about FA lenses on FF DSLR

Hello,

I've seen many posts says that FA lenses are old and probably won't work well on a FF DSLR so I started looking at Minolta lenses

on Sony A900.

Several of Sony users like the old Minolta AF.

Works great on A900: Sony SLR Talk Forum:

Digital Photography Review


Minolta AF 20mm 1:2.8 (22)

Is there a reason to think that Minolta engeneering was so much better that Pentax?

Why couldn't Hoya rerelease the old FA primes?

Regards,
Luis


P.S. Sorry if this should have been posted under rumours.
lpfonseca is offline  
11-03-2009, 01:31 PM   #2
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I don't think the engineering was better. Minolta made some great glass though (as do all the major camera manufacturers). I shot Minolta film before I moved to pentax digital.

Hoya could re-release the lenses, but they would have to update the coatings just to ensure a top quality product that is competative in the market.
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11-03-2009, 01:42 PM   #3
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Originally Posted by StephenMerola View Post
but they would have to update the coatings just to ensure a top quality product that is competative in the market.
I think Sony did just that with some primes...
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11-03-2009, 01:44 PM   #4
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as I understand it, the issue might be a function of sensor design.

I have heard that sensors are more sensitive to direct light than light hitting at an angle, and as a result even though lenses worked well on film, the specific design, and how the light hits the edges of the sensor could lead to unintentional vignetting.

of course, if the lens on each sensor element could accomodate for this, there would be no problem, but it is not assured by any means
Lowell Goudge is offline  
11-03-2009, 01:53 PM   #5
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The "problem" is that older lenses are not telecentric. This is mitigated in part by the microlenses on the sensors, and this is not a problem particular to FF.

In fact, there is not problem per se with using an older lens on a FF body. It will perform the same as with a cropped sensor, except of course that corner effects will be more apparent.

A cropped sensor is just that : it uses the center area of the lens. A FF or APS sesor works the same way.
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11-03-2009, 06:55 PM   #6
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i found this video example of a Pentax FA 1,8/31 Ltd. on Canon 5d Mark 2 here.
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11-03-2009, 07:12 PM   #7
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FA's will work,providing Pentax use the same mount system that we all know and love.
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11-03-2009, 07:40 PM   #8
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A lot of the old FA lenses also used lead and manufacturing has to be more eco-friendly nowadays...
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11-03-2009, 07:46 PM   #9
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Originally Posted by Barnster View Post
FA's will work, providing Pentax use the same mount system that we all know and love.
We generally don't doubt they will work; the question is how satisfactorily.

So it's not a yes/no black/white answer, as it depends on each individual's level of scrutiny.
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11-03-2009, 11:11 PM   #10
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Most of the talk on these forums pertains to how well the FA lineup works with today's digi sensors--note several threads holding FA Limited and FA* lenses in high acclaim.

To me, it appears that the "digital optimized" lens engineering worries are largely worries rather than problems. Haven't seen too many "look how bad my FA translates to digital" test photos or examples. The odds seem remote that a larger sensor will somehow finally tip the "angle of light hitting sensor" issue into the realm of "damaged goods" labeling for FA lenses.

Personally, one of the reasons I've enjoyed holding onto my FA lenses is because I know they'll work with full frame sensors whenever that eventuality comes to be. At least they'll work in the sense that the image circle will cover the sensor. I'm not worried that the corners of the sensor will fail to absorb light due to obtuse angles. Hasn't been a problem for various other brands...won't be for Pentax. Current market values for FA lenses--especially FA* and Limited lenses would suggest that the general mood in the marketplace is positive for FA lenses as sensors evolve.
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11-04-2009, 05:29 AM   #11
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Originally Posted by Ron Boggs View Post
Most of the talk on these forums pertains to how well the FA lineup works with today's digi sensors--note several threads holding FA Limited and FA* lenses in high acclaim.

To me, it appears that the "digital optimized" lens engineering worries are largely worries rather than problems. Haven't seen too many "look how bad my FA translates to digital" test photos or examples. The odds seem remote that a larger sensor will somehow finally tip the "angle of light hitting sensor" issue into the realm of "damaged goods" labeling for FA lenses.

Personally, one of the reasons I've enjoyed holding onto my FA lenses is because I know they'll work with full frame sensors whenever that eventuality comes to be. At least they'll work in the sense that the image circle will cover the sensor. I'm not worried that the corners of the sensor will fail to absorb light due to obtuse angles. Hasn't been a problem for various other brands...won't be for Pentax. Current market values for FA lenses--especially FA* and Limited lenses would suggest that the general mood in the marketplace is positive for FA lenses as sensors evolve.
it all comes down to the sensor design, as I noted above, and the need to have light hitting the sensor closer to 90 degrees than on film. This may or may not be a problem.

there is the secondary issue of rear element coatings, to avoid the internal flair from the reflection off the UV and IR filter in front of the sensor, which has a higher reflectivity than film. This will result in reduced contrast.

yes these are "worries" but until you see performance on a full frame sensor you just won't know.

But for me, I don't see the need to go full frame, at the rate of sensor improvement ASP-C does just fine.

I do not, however, understand why pentax has not re-engineered some of the F and FA line up to expand their lens options.
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11-04-2009, 05:47 AM   #12
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I think they'll be fine, but there is no doubt that most lenses look better on cropped sensors. The reality is that corners and edges are the weak parts of most lenses and you don't see them on a cropped sensor. With that said, it is the limiteds and FA* lenses that will shine. If you expect to pick up an FA-J 28-80 and have it impress you, think again.
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11-04-2009, 06:46 AM   #13
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It may very well put some of the third-party manufacturers back in their place. I saw that the much beloved on digital full-frame Tamron 28-75/f2.8 was mediocre at best (per Photozone) on the full frame Canon.
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11-04-2009, 09:57 AM   #14
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No offense Lowell, but my impression is that the lens manufacturers combined with folks with too much "tech time" have created false worries--in particular worries like the need for different coatings on the rear element to reduce reflections off the IR filter. Neat theory, but Pentax multi-coating answers that concern and again--anybody ever seen problems in our brand or any other? This reflection theory would apply to APS-C just as well as FF yet nobody seems to have any problems out there (other than lens manufacturers who want us to spit-can all our lenses and start over with "digitally optimized" lenses). Yes, I've seen an occasional post about reflections, but NEVER seen a credible post nor an industry "proof" of this issue occuring with lenses built in the last few decades. In fact, every lens I've ever seen accused of this reflection issue also exhibits it on film. So crappy lenses are crappy on digital or film...

Same goes for the "angled light" worry. Doesn't hurt any of the larger sensored medium format digi--they still use early Mamiya and Hassy lenses without issues and those lenses in an earlier time often didn't have the quality coatings we've all come to expect for the past 25 years or so. Certainly the sensor filter engineers have factored in any needs for directionality of light. Again, if it's such a problem then what's up with those killer medium format digital systems? Or with Canon, Nikon and Sony FF systems? Haven't seen a wholesale selloff of early Canon or Nikon superteles. In fact, most of the pro supertele guys I run into every year are still using predigi superteles without complaint or issue. (Superwides too btw).

For the OP, you may have seen posts about this stuff, but doubtful that you've seen CREDIBLE posts about it. This is the internet after all and we are all now somehow experts on this stuff that we know little or nothing about. Fact is FA lenses are not old. Some are still being built and most were being built up into about 2005ish. Five years may be old for a computer, but it's not old for optics!

I'm completely convinced that "digitally optimized" as it applies to lenses is marketing hooey with almost no real "on the image" impact whatsoever. And I'm cocky...go ahead and post your proofs (and don't bother posting shots of vignetting to try to convince me. Vignetting has to do with lens image circle most often on zooms ramped wide. That same vignette image with zoom not set so wide instantly "fixes" the problem proving it's a lens image circle issue not a sensor issue." Try it on sensitive slide film and you'll see the same vignetting with no sensor involved...)

Remember when they started selling "digital ready" car stereo speakers 20 something years ago? Or how about "digitally optimized" TV's before the current flat screen era? "Digital Ready" or "Digitally Optimized" have been completely overused marketing terms for decades and until I see actual problems with my images and with my collegues images I give no credibility whatsoever to the worries about FA lenses somehow not working for FF. It's really quite silly!
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11-04-2009, 01:03 PM   #15
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I pretty much agree with Ron. The only issue that might come about with "non-digital" lenses on FF sensors is that the sensors could outresolve the lens. Then again, there's nothing inherently wrong or photo damaging about oversampling an image projected onto a sensor.

Plenty of Sony and Nikon FF photographers are using pre-digital lenses and loving it. There is no reason Pentaxians couldn't do that too. Except for us not having a FF digital camera available

.
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