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02-09-2014, 06:07 PM   #226
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QuoteOriginally posted by Uluru Quote
It will work well on Digital and Film cameras too.
The 100mm doesn't work well on my MX film camera! The aperture is always too small.


QuoteOriginally posted by Uluru Quote
Like the 100mm/2.8 macro. There are plenty of Pentax film cameras available and people using them.
I get what you're saying, but some lenses are DFA... 100% of those cover full-frame.
Lenses that are DA were introduced with APS-C lenses... and some of those cover full-frame.

I don't blame other people for there confusion, I blame Pentax. Pentax made this bed, not the 'users'.

QuoteOriginally posted by Uluru Quote
That was very clear during the introduction of the DA560, for example. Pentax product manager clearly stated the lens was optimised for digital Pentax DSLRs, and that Pentax does not guarantee its optimum performance on Pentax film cameras.
The 560 is beyond comment in many ways.

---------- Post added 02-09-14 at 05:14 PM ----------



^^Pentax is (clearly? un-clearly?) specifying DA lenses as 'optimized for APS-C'.

02-09-2014, 06:27 PM   #227
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Pentax is definitely guilty for some confusions. Let's name that recent one about the compact camera branding, which we finally got it clearly stated — after so many years!

But the users and endless full-frame despair are the real culprits in this case.

The real truth behind the nomenclature is somewhat ambiguous. As it should be. DA lenses are indeed optimised for APS-C, to deliver best image quality for APS-C (or the new digital format). APS-C is de facto embraced digital format from first days — not the so called FF (derived from 135 film format).

However, if in some cases — due to characteristics and overlapping of optical designs — DA lenses may be used on 135 format film bodies and (eventually) 135 format full frame sensor cameras because the performance of the lens using a digital format is same or very similar to its performance on a 135 film format.

It is about tolerances.

To some users the quality of the final image may be fine and tolerable in either case, but to some more concerned individuals, it may not be the case. DFA just states that manufacturer believes optical design is good enough for 135 film format (and eventually 135mm sensor size format). However, it is firstly optimised for best use for digital format. Therefore DFA, instead of FDA nomenclature.

The letter F in FA coincides with both Film, and Full-frame. That adds to overall confusion, but users are guilty of it.

Last edited by Uluru; 02-09-2014 at 06:37 PM.
02-09-2014, 06:38 PM   #228
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The DFA 50 Macro retained its useability for generally ALL Pentax digital and film cameras, while the new 100 Macro WR left out the older ones. I guess Pentax has a grudge on age sometimes too. What are the chances of the DFA 50 being refreshed to a non-aperture-ringed version, and more probably HD?
02-09-2014, 07:47 PM   #229
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QuoteOriginally posted by Alizarine Quote
The DFA 50 Macro retained its useability for generally ALL Pentax digital and film cameras, while the new 100 Macro WR left out the older ones. I guess Pentax has a grudge on age sometimes too. What are the chances of the DFA 50 being refreshed to a non-aperture-ringed version, and more probably HD?
Very likely.
From the info I've heard, it is a plan to refresh and update all Pentax lenses (with HD, etc.) before the end of 2015.

02-09-2014, 09:36 PM   #230
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I hope they will include their FA'S too, including the fast ones.
02-09-2014, 10:03 PM   #231
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QuoteOriginally posted by Uluru Quote
Very likely.
From the info I've heard, it is a plan to refresh and update all Pentax lenses (with HD, etc.) before the end of 2015.
No problem with that but if they could do this with an aperture ring...
* not gonna happen, I know ...*
02-09-2014, 11:11 PM   #232
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QuoteOriginally posted by audiobomber Quote
I thought the S was designed for shorter focal length lenses (under 300mm) and L for longer focal lengths.
Indeed the L converters (I own both of them the 1.4x-l, and the 2x-l) are documented for use on 300mm and longer glass. I've tried
the short distance viewing as the text.

The next thing I did was try out a very long distance shot ---this solved some of the focus issues, but introduced camera shake issues.
I've got my findings on my website at "http://www.vannattabros.com/photo7.html" and "http:/www.vannattabros.com/photo11.html".

this is a non-commercial site, and not copyrighted if you want to borrow some of it.
I'm not sure I convinced myself whether optical cropping or photoshop cropping is best. I think it sort of depends.

It's very clear though---when you get very long (as stacked converters (I tested among otherthings a 2x-L stacked with a 1.7x auto adapter

the shake becomes a big deal.

a few observations: Converters eat light -- lots of it. if light is marginal --- photoshop crop.
major distractions on the shot (things other than your target) will cause exposure problems on the target--- use
the converter to trim them in the camera.

Buy a K-3. --- the high ISO options --- I use up to ISO 6400 and don't feel bad as can still get a good photo
This was taken with a Pentax FA-300 f2.8 @f-11 at Iso 6400 with a Pentax
1.7x adapter. ---- If you look at the metadata it will tell you differently, but just before that I had tried my Pentax-A f/2.8 and it wouldn't
quite focus closely enough for that location so I switched to the FA300 and the adapter so I could focus more closely.

What you see in that bird photo is a 'full frame' -- i.e. uncropped.

My bottom line---there is no right answer, use what you have, and if you have choices try them. --- Small birds, really close don't work
well with the Pentax A 400 or the FA-600 because of minimum focusing distance issues. (4 meters and 6 meters respectively).
the FA 300 f/2.8 foucuseddown to 2 meters), which with the 1.7x adapter made this full frame shot possible at about 3 meters or so.
02-10-2014, 06:13 AM   #233
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From the Ricoh US website:

A-series - An older Pentax K-mount lens is capable of having it's aperture controlled automatically. Features an "A" (auto) setting on the lens aperture ring. These lenses will work on a digital or film camera.

F or FA - A lens that is capable of having it's aperture and focus controlled automatically. These lenses will work on a digital or film camera.

FA J - A lens that is capable of having it's aperture and focus controlled automatically. J series lens do not feature an aperture ring and aperture cannot be adjusted manually. The camera can only control the aperture automatically. These lenses will work on a digital or film camera.

DA - A lens that is capable of having it's aperture and focus controlled automatically. These lenses are optimized for use on a digital camera and will not work correctly on a film camera.

D FA - A lens that is capable of having it's aperture and focus controlled automatically. These lenses are optimized for use on a digital camera, but will still work correctly on a film camera.


According to the above, DA lenses will not work correctly on a film camera, the D FA 100 WR (with no aperture ring) will. It seems pretty clear that they are saying DA is for APS-C image circle only, but that does not explain the results people have shown, or the patent info on the DA*200 and 300mm. No wonder we're confused.
.

02-10-2014, 06:24 AM   #234
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You have the same convention with the 645 lenses. All are FAs or DFAs but one: the 25mm f/4 which exists in two versions, a DFA 645 sold in Japan only (where there are plenty of film Pentax 645 bodies) and a DA 645 sold in the rest of the world and which is limited to crop sensors such as the 33x44mm sensor in 645D. Note in particular the longer hood of the DA.

smc PENTAX D FA 645 25mm F4 AL [IF] SDM AW



smc PENTAX-DA 645 25mm F4 AL [IF] SDM AW

02-10-2014, 06:42 AM   #235
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QuoteOriginally posted by Uluru Quote
It will work well on Digital and Film cameras too.
Like the 100mm/2.8 macro. There are plenty of Pentax film cameras available and people using them.

That was very clear during the introduction of the DA560, for example. Pentax product manager clearly stated the lens was optimised for digital Pentax DSLRs, and that Pentax does not guarantee its optimum performance on Pentax film cameras.
The issue is that Pentax's nomenclature to this point has not included full frame digital cameras. Updates of FA designs would just have the D put in front of them, but the DA naming to this point has indicated that the lenses don't have aperture rings, have digital coatings and are guaranteed to work on APS-C sensors.

If/when Pentax comes out with a full frame camera, lists will be necessary from Pentax to indicate which lenses are really full frame compatible, as the DA naming doesn't say how usable a lens will be on such a sensor.
02-10-2014, 06:44 AM   #236
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Probably they'll have a list similar with the one for the rear converter, splitting the lenses into:
+ compatible
+ compatible with limitations
+ compatible only in crop mode?
02-10-2014, 08:13 AM   #237
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QuoteOriginally posted by Kunzite Quote
Probably they'll have a list similar with the one for the rear converter, splitting the lenses into:
+ compatible
+ compatible with limitations
+ compatible only in crop mode?
Actually the lists shouldn't be necessary for the DA style lenses. I believe they have sufficient telemetry between the lens and
the camera body for the camera to know what lens has been attached. With that information the camera body can determine
via an internal lookup table what size the lens is and simply adjust to an APS-C mode when a small lens is attached.

One of the realcomplexities of this sort of software would be a protocol of how it worked with a converter
02-10-2014, 09:04 AM   #238
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It would be for the users, not for the camera.
02-10-2014, 11:56 AM   #239
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QuoteOriginally posted by Kunzite Quote
Yes, the 3rd was scaled digitally so the edges are better defined - but it has less details.
You are right...I stand corrected.
02-10-2014, 11:57 AM   #240
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QuoteOriginally posted by rvannatta Quote
Actually the lists shouldn't be necessary for the DA style lenses. I believe they have sufficient telemetry between the lens and
the camera body for the camera to know what lens has been attached. With that information the camera body can determine
via an internal lookup table what size the lens is and simply adjust to an APS-C mode when a small lens is attached.

One of the real complexities of this sort of software would be a protocol of how it worked with a converter
Not need for telemetry. Lens ID is enough.
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