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10-25-2017, 07:29 PM   #1816
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QuoteOriginally posted by sculptor666 Quote
in 15 years, the new 50 will still be relevant... the 55 maybe not so much.
Based on?
DxO has it rated as the top current Pentax lens, and in 15 years its going to be irrelevant? But all the other lenses rated lower will still be relevant?
Relevant to what?


QuoteOriginally posted by Scintilla Quote
Perhaps one of the conscious compromises in the design is lower astigmatism at the cost of greater Sigmatism?


10-25-2017, 07:44 PM   #1817
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QuoteOriginally posted by normhead Quote
Those are big improvements.

---------- Post added 10-25-17 at 09:19 AM ----------



I'm curious, why would I buy the 50 1.4 instead of the 55 1.4? After all, a longer lens with the same aperture gives you more control of DoF? What do you suppose is the reason they made this so big?
.


The 55 is a great lens, especially on ff, but one issue with the 55 is that it is not quite ff compatible. It vignettes pretty well under certain conditions. The 50 should fix that issue. To some though its not that big of deal.


10-25-2017, 07:50 PM   #1818
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QuoteOriginally posted by Fcsnt54 Quote
It vignettes pretty well under certain conditions.
Take the hood off and try again. Mine works very well. All 50 1.4 lenses from film era, pentax or other makers, vignette quite obviously, and da 55 does not do any worse. Sigma 50 1.4 (pre-art version) shows a little more vignetting under same condition.
10-25-2017, 08:41 PM - 1 Like   #1819
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I am very happy with my DA*55 in FF mode, but I am no kenspo. I would expect the new DFA50 to have much faster and more accurate AF, especially at wide apertures in low light. I find AF is the biggest weakness in the DA55, not the vignetting.

10-26-2017, 01:14 AM   #1820
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QuoteOriginally posted by grahame Quote
Take the hood off and try again. Mine works very well. All 50 1.4 lenses from film era, pentax or other makers, vignette quite obviously, and da 55 does not do any worse. Sigma 50 1.4 (pre-art version) shows a little more vignetting under same condition.


Didnt make too much of a difference, under certain angles, and certain apertures it still vignetted. I was able to get shots with none, but i would not call it by any means a full frame lens. Thus a reason for a 50, besides if it was a full frame lens you should not have to remove the hood, becomes too much of a hassle. it is a crop lens that is close to fully usable on a full frame sensor. Like i said it is reasonable to some. It is a great lens, with great character.


10-26-2017, 01:17 AM   #1821
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QuoteOriginally posted by Scintilla Quote
But at the expense of manual focus precision, one would expect.
Yes - but that's not what everyone complains about - yet
10-26-2017, 02:44 AM   #1822
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QuoteOriginally posted by Kiwipixter Quote
I would expect the new DFA50 to have much faster and more accurate AF, especially at wide apertures in low light. I find AF is the biggest weakness in the DA55, not the vignetting.
QuoteOriginally posted by rawr Quote
Anecdotal reports of 'this lens is better than the other in low-light AF' should be considered with caution. Few of those making those reports use their lenses the same way - same camera, same lens, same scene.

What I mean is that in field use, what impacts the low-light focus performance of a lens might be a wide range of things:

- the camera AF system has to be designed to work below a certain light level, the lens itself hardly matters
- the camera AF settings (AFS, AFC, spot/all AF points, focus assist light on/off),
- the camera metering settings (spot/centre or matrix)'
- the contrast of the scene (generally degraded by low-light),
- the features of the scene (lots of small details, lots of varied light causing problems),
- the type of lighting in a scene (tungsten may still cause autofocus problems with early Pentaxes, for example),
- the T-stop of the lens (some lenses are naturally 'darker' than others),
- the use of 'protection' or UV filters on a lens, often dimming or murking it up,
- the flare and ghosting performance of a lens, which might cloud the lens sometimes'
- whether the lens has been adjusted properly for front or back focus.

etc etc. And often a combination of all of the above.
Accuracy and low light performance depend on the camera AF system, not on the lens.
10-26-2017, 02:45 AM   #1823
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QuoteOriginally posted by Fcsnt54 Quote
Didnt make too much of a difference, under certain angles, and certain apertures it still vignetted. I was able to get shots with none, but i would not call it by any means a full frame lens. Thus a reason for a 50, besides if it was a full frame lens you should not have to remove the hood, becomes too much of a hassle. it is a crop lens that is close to fully usable on a full frame sensor. Like i said it is reasonable to some. It is a great lens, with great character.
Most fast 50s vignette on 35mm. I do find the corners are dark on the 55 wider than f2, but I don't think the FA 50 or DA 50 lenses are any better in that respect. The DFA 50 will be better in that respect, but my big hope would be to have a faster focus motor. The 55 has such a long focus throw and such a slow motor that it can't track any motion faster than a snail crawling up the side of a building.

10-26-2017, 04:03 AM   #1824
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How long, ballpark, does it typically take to go from announcement to availability?
10-26-2017, 04:20 AM   #1825
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I wonder if a hood from a different lens would allow the DA*55 to not vignette on full frame with the hood on.

Someone should loan me a K-1 and a DA*55 for a while so I can test this theory.

p.s. had a good laugh at the concept of the DA*55 being "irrelevant in 15 years". Might be time to take a break with the hot takes for a while.
10-26-2017, 07:24 AM - 1 Like   #1826
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Ricoh Announces Next-Generation, High-Performance PENTAX Star-Series Lens Line

QuoteQuote:
Although final names, specs and pricing will not be released until 2018, here are preliminary key features of the two lenses:

(...)

HD PENTAX-D FA* 50mm F1.4 SDM AW

PENTAX K-mount covering the image circle of a 35mm-format full-frame image sensor
Newly developed ring-shaped SDM (Supersonic Direct-drive Motor) for faster, quieter AF operation
AW (All-Weather) construction to prevent intrusion of dust and rain and ideal for use in demanding shooting conditions
Minimum shooting distance of 0.4 meters
Note: this is an updated version of the reference product shown at CP+ 2017
Availability: Scheduled for the spring of 2018
10-26-2017, 07:30 AM   #1827
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QuoteOriginally posted by Mistral75 Quote
Ricoh Announces Next-Generation, High-Performance PENTAX Star-Series Lens Line
interesting what isn't there - motor and weather-sealing designations on the 11-18 - they do seem to be decided quite late in the process - maybe after testing?
10-26-2017, 07:37 AM - 1 Like   #1828
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The new ring-type SDM is a very good piece of news.
10-26-2017, 07:37 AM   #1829
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QuoteOriginally posted by ffking Quote
interesting what isn't there - motor and weather-sealing designations on the 11-18 - they do seem to be decided quite late in the process - maybe after testing?
All DA*s are WR, all DA* lenses are designated SDM, although as some have pointed out, that is a very sketchy description of unknown technical spec.
10-26-2017, 07:39 AM   #1830
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Spring and summer, 2018....My dear...!
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