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05-11-2009, 11:33 AM   #1
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D FA vs FA?

Pentax states:

The PENTAX D FA series, compatible with PENTAX 35mm film cameras, but built specifically for digital SLRs, utilizes lens coatings, curvature and positioning of optical elements to virtually eliminate flare and ghosting for clear, high-quality images with digital SLR cameras.

The PENTAX FA series is designed for film SLR cameras, but is also compatible with digital SLR cameras. The FA series features full-frame image coverage with full automatic and manual aperture control.

Is sounds to me that they are both for 35 and digital. Are there any limitations with using the FA's on the 10D?

thx

05-11-2009, 11:44 AM   #2
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The only existing DFAs are the DFA50 and DFA100, both macro lenses.

I have used a lot of FA/FA* lenses on all kinds of Pentax DSLRs (*istD, *istDS, K100D, K10D, K20D, K-m) without any problem.
05-11-2009, 12:11 PM   #3
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You might get the occassional flare artifact off the rear element of the lens.
Other than that, no.
05-11-2009, 05:06 PM   #4
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Thx for the feedback. I've purchased a couple of FA's primarily because for the higher speed. I am very happy with them, but wondered a bit why they would specify a difference between DFA and FA. The difference sounds insignificant.


05-11-2009, 06:30 PM   #5
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QuoteOriginally posted by beaumont Quote
Thx for the feedback. I've purchased a couple of FA's primarily because for the higher speed. I am very happy with them, but wondered a bit why they would specify a difference between DFA and FA. The difference sounds insignificant.
I suspect (no evidence, though) that the DFA macro lenses were designed at a time when Pentax was less sure that their future would be APS-C digital and wanted a fallback in case 35mm film continued to survive in the marketplace, or the market moved rapidly to FF digital. In any event the DA and DFA macro lenses, while similar optically, have a quite different lens barrel and mechanical design.

Regards, Jim
05-12-2009, 11:43 AM   #6
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I thought the D-FAs had an "optimized for digital" coating on the rear element (or mabye throughout?)...

The only lens I've used that causes sensor reflections is the Tamron 90/2.5 SP macro 52B...and that happens only at f/8 and smaller. f/8 isn't bad but completely noticeable at f/11-22.
05-13-2009, 12:53 PM   #7
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QuoteOriginally posted by tcom Quote
The only existing DFAs are the DFA50 and DFA100, both macro lenses.

I have used a lot of FA/FA* lenses on all kinds of Pentax DSLRs (*istD, *istDS, K100D, K10D, K20D, K-m) without any problem.
In the case of the D FA 100 macro versus the FA 100 macro, the FA is much superior because it has a focus range limiter.

05-13-2009, 01:05 PM   #8
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QuoteOriginally posted by Canada_Rockies Quote
In the case of the D FA 100 macro versus the FA 100 macro, the FA is much superior because it has a focus range limiter.
in handling during the shooting, but what about the image quality once they both focused on target ?
05-13-2009, 09:35 PM   #9
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QuoteOriginally posted by deejjjaaaa Quote
in handling during the shooting, but what about the image quality once they both focused on target ?
From all I have read, virtually identical.
05-14-2009, 12:30 AM   #10
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As one who has used both the FA and DFA 50mm f/2.8 Macros and the FA and DFA 100mm f/2.8 Macros, there are noticeable differences between two series. First off all are usable on 35mm film and digital (i.e. FF compatible) with an image circle larger than APS-C.

The first thing that is immediately apparent is that the DFA macro lenses have been made more compact and lighter in weight compared to the FA macros. There is plenty of polycarbonate plastic in the construction of the lens barrels. The lens barrels extend outward necessitating the use of the large plastic lens hoods both to shield from glare and to protect the extended lens barrel. The FA macros are more solid in build quality overall. One aspect of the slimming down is that the DFA lenses use the same 49mm filters while the FA 50mm and 100mm macros use 52mm and 58mm filer sizes respectively. No hoods on the FA macros as the front element is recessed.

The smc PENTAX-DFA Macro 100mm F2.8 incorporates the FREE (Fixed Rear Element Extension) focusing system, while the smc PENTAX-DFA Macro 50mm F2.8 features the dependable floating element system. These reduce aberrations at any focusing distance to infinity, a bug bear of older macro lenses which are typically sharper only at macro focusing ranges. No issues with the FA macros in this regard.

Since much of macro shooting requires precise focusing, the DFA's wide focusing barrel and Quick Shift is in practice much better when focusing manually than the FA, which requires disengaging the AF before manual focus can be attempted. With the DFA, one could get the camera to AF first before being overridden with Quick Shift. Due to the long focus travel, both DFA and FA macros can hunt if there is no subject or adequate contrast to lock focus. In this regard, the DFA is a little better, but not by much.

If I had to choose, I still prefer the FA macros over the DFA macros when it come down to optical performance, but only just. The DFA versions have a much snappier, brighter overall contrast, typical of DA lenses whereas the FA version give a much nicer, punchy colour rendition. In extreme high contrast situations like backlighting, there is some colour fringing and highlight blooming at larger apertures for the DFA. In terms of sharpness, there is little to choose as they are all very sharp and aberration free, but the DFA will give the appearance of being a tad sharper due to the higher contrast. On balance, you can't go wrong with either version, though if you shoot for an extended period, the lighter weight of the DFA versions is noticeable and less taxing, particularly the 100mm. If you can look beyond the plastic build quality, the DFA is not a bad option, particularly with the very useful Quick Shift.

PENTAX Press release 2004

Last edited by creampuff; 05-14-2009 at 12:48 AM. Reason: spelling
05-14-2009, 12:42 AM   #11
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QuoteOriginally posted by Canada_Rockies Quote
In the case of the D FA 100 macro versus the FA 100 macro, the FA is much superior because it has a focus range limiter.
Frankly speaking it's a nice to have feature but no great shakes. The focus limiter merely narrows down the focusing range so that the AF will not hunt and rack focus from minimum focusing distance to infinity.
The DFA's Quick Shift feature is in practice far quicker to use, especially with a fast moving subject like a bee moving from flower to flower.
05-14-2009, 05:33 AM   #12
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Thx for the feedback. Other than size, and speed, do you think that the DA's outperform the FA's on the 10D (or vice versa)?
05-14-2009, 07:43 AM   #13
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QuoteOriginally posted by beaumont Quote
Thx for the feedback. Other than size, and speed, do you think that the DA's outperform the FA's on the 10D (or vice versa)?
I'd say whichever Pentax macro you choose, either DFA or FA, they are all very sharp lenses with little distortion. I think there is little to choose from and it boils down to personal preference. I happen to prefer the colour rendition of the FA macros better but practically speaking I'd get the one that is cheapest and most readily available. Bottomline it's not the lens but the shooter's skill and technique that is more important.
05-14-2009, 01:33 PM   #14
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QuoteOriginally posted by creampuff Quote
Frankly speaking it's a nice to have feature but no great shakes. The focus limiter merely narrows down the focusing range so that the AF will not hunt and rack focus from minimum focusing distance to infinity.
The DFA's Quick Shift feature is in practice far quicker to use, especially with a fast moving subject like a bee moving from flower to flower.
Seems to me the main advantage of the focus limited would be for *non-macro* situations, so the lenses doesn't waste its time extending to the macro range when it isn't appropriate. That could make a big difference for someone thinking of getting one of these for ordinary use as well as macro.
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