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09-21-2020, 05:28 AM   #16
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QuoteOriginally posted by Sakura Quote
The difference is really unbelievable. It really changed it to a full frame lens. It now really has become a D-FA* 60-250.
Despite Pentax's claims that it does not live up to D FA* standards, I do not understand why Pentax did not offer this update (or re-release the lens). My comparison with the D FA 70-210 shows that the 60-250 can hold its own pretty well, even being better in the corners.

09-22-2020, 04:11 AM   #17
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QuoteOriginally posted by bdery Quote
I do not understand why Pentax did not offer this update (or re-release the lens). My comparison with the D FA 70-210 shows that the 60-250 can hold its own pretty well, even being better in the corners.

DA * 60-250 / 4 is better only after:
corners and equally good optical quality throughout the range,
and lags behind DFA 70-210 / 4 in:
focus speed / weight / total size / sdm reliability / higher magnification,
it turns out that DA * has * for optical quality and DFA has "*" for mechanical qualities,
it would be really good if Pentax made a DFA 60-250 / 4 consumer lens with the best features of both mentioned,
for specific / intended needs, DA * 60-250 / 4 and DFA * 70-200 / 2.8 would remain


the ways of the Lord are strange, especially when he associates with the Pentax


unfortunately the Pentax DFA 70-210 / 4 does not give and not offer one "wow which lens for money "

Last edited by mbukal; 09-22-2020 at 04:39 AM.
09-22-2020, 06:26 AM   #18
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QuoteOriginally posted by mbukal Quote
DA * 60-250 / 4 is better only after:
corners and equally good optical quality throughout the range,
and lags behind DFA 70-210 / 4 in:
focus speed / weight / total size / sdm reliability / higher magnification,
it turns out that DA * has * for optical quality and DFA has "*" for mechanical qualities,
it would be really good if Pentax made a DFA 60-250 / 4 consumer lens with the best features of both mentioned,
for specific / intended needs, DA * 60-250 / 4 and DFA * 70-200 / 2.8 would remain
The 60-250 offers better corner sharpness than the 70-210, and that's the most surprising thing for me. Pentax claimed that the 60-250 was not up to STAR expectations, but the sharpness is actually pretty even over the range. So I don't understand Pentax's claim.

Vignetting is well controlled (and could be compensated via software). Bokeh is always wonderful, aberrations are pretty good, etc. The AF system is not on a level with the more recent lenses, but instead of spending R&D money on the 70-210 they could have spent that money on upgrading the AF of the 60-250.

QuoteOriginally posted by mbukal Quote
unfortunately the Pentax DFA 70-210 / 4 does not give and not offer one "wow which lens for money "
Smallish size, center sharpness, superb AF, great optical performances, fair price, these are all perks.The 70-210 is a pretty good lens, it's just that the 60-250 is ALSO very good.
09-22-2020, 09:54 AM   #19
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QuoteOriginally posted by bdery Quote
.... The AF system is not on a level with the more recent lenses, ... it's just that the 60-250 is ALSO very good.

and I repeatedly repeat your words: ".The 70-210 is a pretty good lens"Smallish size, center sharpness, superb AF, great optical performances, fair price, these are all perks but it's just that the 60-250 is ALSO very good", and so I repeat myself about DFA 70-210 / 4 :" does not give and not offer one "wow which lens for money " , a play on words that speaks the truth, and they could only adjust DA* 60-250 / 4 for DFA 60-250 / 4, intentionally omit * due "to them known" optical defects, it would be a lens for that says: "wow which lens and there is only Pentax", something like DFA * 85 / 1,4 but as an ordinary consumer lens it would be a complete hit for the arrival of new consumers and the joy of old ones
this is a kind of awkward compromise for old users but not for attracting new ones, unfortunately

In the FA series, Pentax had for consumer lenses with aperture from f 4 to f 5.8 for 1 x 70-200 + 1 x 80-200 + 2 x 100-300 + 2 x 80-320 (really really pile),
so it could now have both DFA 60-250 / 4 in addition to DFA 70-210 / 4 and DA* 60-250 / 4 (a much smaller and much higher quality pile) ,it would be a real lure for new users and a joy for us old ones
yet that DFA 60-250 / 4 is silver consumer lens === aua which bait with reason


Last edited by mbukal; 09-22-2020 at 11:40 AM.
09-22-2020, 01:38 PM   #20
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some more samples after modification of the lens. Totally no vignetting visable
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09-23-2020, 05:06 AM   #21
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QuoteOriginally posted by Sakura Quote
Totally no vignetting visable
As expected The article explaining how to do the modification, and the review comparing the modified 60-250 to the 70-210, show what one should expect.

Glad you like the modification!
04-28-2021, 10:19 AM   #22
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QuoteOriginally posted by jbrill Quote
I went through this process recently with absolutely no experience or familiarity with 3D printing, materials, or online services.

( - - - )
Following the instructions from article, the baffle assembly was easily removed from the lens and the baffle was easily removed from the plastic ring. Unfortunately, the 3D printed baffle was ever so slightly larger that the ring into which it was supposed to be inserted. Using really fine automotive sandpaper, I slowly worked the outer edge of the baffle until it could be successfully snapped into place. At some point, I removed a little too much of the material and effectively lost the ability to "snap" it into the ring. Since I had a second baffle on hand, I started the process over again using the second baffle. Without a second baffle on hand, I would have been far more careful and deliberate the first time. At some point, the baffle would snap into the plastic ring. The baffle seemed as if it would/could "pop" out a little more easily than I was comfortable with. As suggested in the article, I applied silicone sealer the keep the baffle affixed to the plastic ring. Once the silicone sealer dried, the baffle assembly was cleaned and re-installed in the lens.

I am not particularly handy, so your experience will likely be much smoother/easier. Preliminary tests yielded results consistent with the other threads and I am very happy with the end result.
Thanks for sharing your experience, it is encouraging. Yet, I still have some doubts doing the modification myself. I wonder, how many stories there are ending with a failure? How big a risk would there be to break the lens in a way or another while opening the mount etc and then re-assembling? (You may well conclude I'm not a clocksmith )

04-29-2021, 04:34 AM   #23
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QuoteOriginally posted by 5ks Quote
Thanks for sharing your experience, it is encouraging. Yet, I still have some doubts doing the modification myself. I wonder, how many stories there are ending with a failure? How big a risk would there be to break the lens in a way or another while opening the mount etc and then re-assembling? (You may well conclude I'm not a clocksmith
Well, when writing the article I switched the baffles (and accompanying parts) many times, with no hiccup. The only slightly fragile part is the tab with the two power zoom contacts.

If you're mildly careful, not much can go wrong, I'd say.
07-23-2022, 04:23 AM   #25
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I understand quite well why Pentax does not re-issue the lens as FF and why they promote the 70-210. It is also obvious why the 70-210 cannot carry the * designation.
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