Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-28-2018, 06:08 PM   #61
Site Supporter
Site Supporter
Ed Hurst's Avatar

Join Date: May 2010
Location: Sydney
Posts: 1,654
I think if they introduce a full frame 645 sensor size, they should introduce DFA versions of the DA lenses and provide an upgrade programme for those of us who have bought DA lenses (i.e. a scheme by which you can exchange the DA for the DFA version at minimal cost). Since full frame would be a change of direction for the system, this would keep the loyalty of those of us who followed them down the previous 44x33 strategy... Leaving us to buy new DFA lenses at full price would discourage me from upgrading to the new body entirely.

03-01-2018, 03:49 AM - 1 Like   #62
Senior Member




Join Date: Dec 2015
Location: Paris area
Posts: 214
QuoteOriginally posted by Ed Hurst Quote
I think if they introduce a full frame 645 sensor size, they should introduce DFA versions of the DA lenses and provide an upgrade programme for those of us who have bought DA lenses (i.e. a scheme by which you can exchange the DA for the DFA version at minimal cost). Since full frame would be a change of direction for the system, this would keep the loyalty of those of us who followed them down the previous 44x33 strategy... Leaving us to buy new DFA lenses at full price would discourage me from upgrading to the new body entirely.

There are only 2 lenses in DA in the whole line-up : the 28-45 (without equivalent in DFA) and the 25mm, discontinued, which existed in DFA version before. I don't think Pentax would build any strategy of upgrade in case they would go to 54x40 sensor. They would probably just think about wide-angle offer to cover full size sensor, the widest in sales being 33mm if I am correct.
03-01-2018, 06:18 AM   #63
Pentaxian
photoptimist's Avatar

Join Date: Jul 2016
Photos: Albums
Posts: 5,113
QuoteOriginally posted by SylvainB Quote
There are only 2 lenses in DA in the whole line-up : the 28-45 (without equivalent in DFA) and the 25mm, discontinued, which existed in DFA version before. I don't think Pentax would build any strategy of upgrade in case they would go to 54x40 sensor. They would probably just think about wide-angle offer to cover full size sensor, the widest in sales being 33mm if I am correct.
Exactly!

The FA 645 33-55mm f/4.5 AL covers the same FOV on FF645 as the DA 28-45 does on crop645.

And if you put a "crop" lens on a 100MP FF645 camera, you get a 66MP crop image so even the DA lenses get an upgrade in resolution.

Overall, a 100MP FF645 would be an upgrade on resolution, IQ (especially if Pentax adds the accelerator chip), and wider-angle FOV.
03-01-2018, 03:29 PM   #64
Site Supporter
Site Supporter
Ed Hurst's Avatar

Join Date: May 2010
Location: Sydney
Posts: 1,654
My thinking on this is that one of the merits of full frame is getting a wider angle of view from a given focal length. Doing that would require a full frame version of either the 28-45 or the 25 (or something similar - please may we have a 21mm f2.4?). A DFA super wide did not exist as new items when I was investing in a system that had, at the time, concentrated on 44x33mm. If I were to get a full frame camera, it would partly be to get the wider angle of view at that 25-28 end. If doing so involves buying new lenses at full price, I am not sure the upgrade would be worth it.


Last edited by Ed Hurst; 03-01-2018 at 04:35 PM.
03-04-2018, 09:44 AM - 1 Like   #65
Loyal Site Supporter
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Working From Home
Photos: Gallery | Albums
Posts: 26,276
QuoteOriginally posted by Ed Hurst Quote
My thinking on this is that one of the merits of full frame is getting a wider angle of view from a given focal length. Doing that would require a full frame version of either the 28-45 or the 25 (or something similar - please may we have a 21mm f2.4?). A DFA super wide did not exist as new items when I was investing in a system that had, at the time, concentrated on 44x33mm. If I were to get a full frame camera, it would partly be to get the wider angle of view at that 25-28 end. If doing so involves buying new lenses at full price, I am not sure the upgrade would be worth it.
Which PENTAX-DA 645 lenses do you own? How many lenses would you need to abandon if Pentax upgrades 645 to a 54 x 45 sensor?

Suppose they re-work and re-release some version of the discontinued D FA 645 25/4 (the discontinued lens presumably would cover the FF 645 image circle anyway)?

Your post reads as if the entire line of 645 lenses would be orphaned. Would there actually be more than one orphaned 645 lens? Would one lens (that presumably would be functional in Auto Crop Mode anyway) be a valid reason to reject a FF Pentax d645?

Last edited by monochrome; 03-04-2018 at 10:02 AM.
03-04-2018, 11:06 PM   #66
Forum Member




Join Date: Mar 2016
Posts: 84


I saw this conversation on DPReview regarding Pentax's new 50/1.4 for 35 FF (K-1). It might be true. The new 50/1.4 from Pentax looks similar to Tokina's new 50/1.4. Earlier Pentax also had a new 15-30/2.8 for 35 FF, and it looks almost identical to Tamron's 15-30/2.8, including numbers of lenses and groups.

If this is true and Ricoh Pentax no longer has the capability to design high-end camera lenses, I feel very pessimistic about the future of its 645 line. Those who already have a few Pentax lenses that can cover the 50mmx40mm 645 FF might be willing to buy the new 645 FF from Pentax, but that's probably it. Those who are not in the Pentax camp will very likely think twice before they jump in, even if Pentax produces a 645 FF camera. Who will want to buy camera bodies from a company that is no longer capable of producing exciting new lenses to match the need of next-generation high-resolution sensors? I know I won't.

As a Pentax user for more than a decade (Pentax 67, Pentax's astronomical telescopes, and now 645z), I feel quite sad when I saw that.
03-04-2018, 11:52 PM   #67
Site Supporter
Site Supporter
Ed Hurst's Avatar

Join Date: May 2010
Location: Sydney
Posts: 1,654
QuoteOriginally posted by monochrome Quote
Which PENTAX-DA 645 lenses do you own? How many lenses would you need to abandon if Pentax upgrades 645 to a 54 x 45 sensor?

Suppose they re-work and re-release some version of the discontinued D FA 645 25/4 (the discontinued lens presumably would cover the FF 645 image circle anyway)?

Your post reads as if the entire line of 645 lenses would be orphaned. Would there actually be more than one orphaned 645 lens? Would one lens (that presumably would be functional in Auto Crop Mode anyway) be a valid reason to reject a FF Pentax d645?

A lot of my work depends on wide angle coverage - which in landscape usage is not unusual. One of the main usage cases for the 645, IMHO. I have the 25mm DA and the 28-45 DA. Neither of which is designed to cover a FF 645 sensor. Both were expensive purchases and both were made as an investment into a 44x33 system. I would love to follow them into the full frame world and have really spectacular wide angle coverage. But I would feel that I have invested heavily into their old strategy and would not then feel inclined (YMMV) to spend heavily again to get the same coverage on a FF 645 sensor.

"Your post reads as if the entire line of 645 lenses would be orphaned"
That's your interpretation, not anything I said or implied. I reserve the right to express my own opinions, not to defend them based on interpretations that others may make :-)

---------- Post added 03-05-18 at 06:39 PM ----------

And, as you rightly say, many other focal lengths are well served by current offerings, so I am only suggesting that this upgrade path should cover the DA-only offerings.

03-05-2018, 12:51 AM   #68
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 11,254
The only difference between the DA25 and DFA25 is the hood. So with the right hood it *is* a full 645 lens, giving an equivalent field of view to about 15mm on the K-1. So it's *really* wide.

The DFA35 will be plenty wide on full 645. Equivalent to 20mm on the K-1.

The DFA55 is roughly equivalent to the FA31 on the K-1.

I reckon that covers the wide stuff pretty well if we get a full frame 645 body. The old FA 33-45 could have a rebirth for the zoom fans.
03-05-2018, 12:56 AM   #69
Site Supporter
Site Supporter
Ed Hurst's Avatar

Join Date: May 2010
Location: Sydney
Posts: 1,654
I have heard different accounts of whether the only difference between the 25DA and 25DFA is the hood (which in any case is permanently attached and not something you can remove without engineering). Some accounts suggest there are also some internal differences (baffles or similar) that would make the DA vignette on full frame, even if the hood were cut down. Would love to have a definitive answer to that. If it's only a matter of cutting back the hood...

---------- Post added 03-05-18 at 06:59 PM ----------

20mm equivalent is not wide enough for me!

As for the 33-45, not optically up to a modern digital sensor IMHO
03-05-2018, 01:03 AM - 3 Likes   #70
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 11,254
QuoteOriginally posted by whwang Quote
I saw this conversation on DPReview regarding Pentax's new 50/1.4 for 35 FF (K-1). It might be true.
Has it occurred to you that it might NOT be true?

Don't be sad, because it is all complete bollocks. The DFA*50/1.4 is a Pentax design, which it appears they may have licensed to Tokina.
Asahi has not been associated with Pentax for decades. Kirk and Zvonimir have no idea what they are talking about.

---------- Post added 05-03-18 at 06:47 PM ----------

QuoteOriginally posted by Ed Hurst Quote
20mm equivalent is not wide enough for me!
From what I've seen of your superb work, you have managed admirably with the DA25 on crop
03-05-2018, 01:28 AM   #71
Site Supporter
Site Supporter
Ed Hurst's Avatar

Join Date: May 2010
Location: Sydney
Posts: 1,654
QuoteOriginally posted by Sandy Hancock Quote
From what I've seen of your superb work, you have managed admirably with the DA25 on crop
That's very kind of you - thanks :-)

Isn't 25mm on crop roughly equivalent to 19mm? I suppose it's hard to be too exact in these comparisons given the different aspect ratio... But I do feel that wider would be an advantage (and would be one of the things that would encourage me onto FF if it could be done without having to buy wholly new super wide lenses - if they existed!). Imagine 25mm full frame 645...
03-05-2018, 01:39 AM   #72
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 11,254
19.5 by my calculations. Not a massive difference from the DFA35 on full frame, and yes the different aspect ratio does muddy the waters a bit.

I imagine the DFA25 on full frame quite a bit
To be honest, I think I'll sell my 645 kit and stick with the K-1. The only thing that stops me is that prospect!
03-05-2018, 01:52 AM   #73
Senior Member




Join Date: Dec 2015
Location: Paris area
Posts: 214
QuoteOriginally posted by Ed Hurst Quote
That's very kind of you - thanks :-)

Isn't 25mm on crop roughly equivalent to 19mm? I suppose it's hard to be too exact in these comparisons given the different aspect ratio... But I do feel that wider would be an advantage (and would be one of the things that would encourage me onto FF if it could be done without having to buy wholly new super wide lenses - if they existed!). Imagine 25mm full frame 645...

Using 24mm HCD on Hasselblad FF645 body, I kind of know what you mean... There is no such thing as "too wide" angle
On 645Z, I feel sometimes limited with 28-45 zoom, but usually it is indoor or for architecture.
And I agree for focal length equivalence, it is difficult to give accurate figures. I rely myself on horizontal field of view to calculate equivalence, and it is less favourable.
03-05-2018, 03:25 AM   #74
Pentaxian




Join Date: May 2011
Location: All over the place
Posts: 3,534
As far as I understand it, the 15-30 is indeed made by Tamron ( I have had the Sony A version, and it is an excellent lens). Tamron are also rumoured to be the manufacturer of the excellent Zeiss Batis lenses. I don't see how this means that Pentax is incapable of making its own ultra wides. If an ultra wide - 20mm for 44 x 33 anyone? is made to an excellent standard, I'm not particularly bothered who makes it. It was a third party that made the 25 f/4. The build quality would need to be better than the 25 - mine only focuses at infinity - though that doesn't bother me, it's the second faulty unit I have had the other one wouldn't focus at infinity which for an ultra wide is a much bigger issue.

I'd actually quite like it if Tamron made an ultra wide for the 645. I've always found their lenses sharp and well put together.
03-05-2018, 04:08 AM   #75
Forum Member




Join Date: Mar 2016
Posts: 84
I don't mind who makes it, either. It's just harder for me to imagine Tamron or anyone designing/making 645 lenses for Pentax. Pentax pretty much has to do it by itself.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
645d, 645z, accounts, camera, coverage, da, ff, fuji, hood, lens, lenses, line, medium format, offerings, pentax, post, sensor, time
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Architecture Nizhny Novgorod, construction of a stadium for the 2018 FIFA World Cup Chetverovod Post Your Photos! 4 07-07-2018 04:46 PM
Harmless fun: suggestions for new cameras etc. to be available 1 April 2018. pathdoc General Photography 62 02-13-2018 03:01 PM
Tim Walker using the Pentax 645z to shoot the Pirelli 2018 Calendar EdMaximus Photographic Industry and Professionals 28 07-27-2017 11:14 AM
150 MP medium-format chip for 2018 ?? jpzk Photographic Industry and Professionals 19 04-06-2017 11:15 AM
HD D FA* 70-200mm f/2.8 -April, May, June, 2016, 2017, 2018 zapp Pentax News and Rumors 206 04-12-2016 10:07 AM



All times are GMT -7. The time now is 12:02 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top