the 25mm lens

Adam · 03-13-2018, 11:49 AM

Originally posted by texandrews

Interesting, so, really a QC problem, less tight tolerances. I wonder who was manufacturing it. One of the most notable things about what Sigma has done in the past few years was the upgrade of their testing and QC system in house, from the ground up. They said at the time that the demands of the new cameras were such that it had to be done. Flew under most people's radar.

Indeed, a QC problem, specifically related to the glass in the lens. That front element must have had some issues.

Adam
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**rdenney** · 03-13-2018, 12:06 PM

I had heard that the front element was being manufactured by a specialty contractor that was no longer able to supply it. Source for that absolutely unconfirmed, and probably Internet FUD.

But most products fail in the market because they cannot be produced for the cost that provides a profit under what price the market will bear. My bet is that at $7500, the 25 would find fewer than 1000 buyers, and maybe fewer than 100.

A 25 specifically designed for the smaller sensor might be cheaper to produce, but the deep flange distance for the 645 will require a more strongly retro focus design.

Wouldn’t the 35 be wide enough for most on the full film frame?

Rick “wondering if lenses are still being made in Vietnam” Denney

Sandy Hancock · 03-13-2018, 01:39 PM

Originally posted by rdenney

Wouldn’t the 35 be wide enough for most on the full film frame?

I'm hoping so

Sarnian · 03-13-2018, 01:49 PM - **1 Like**

Originally posted by mikeSF

It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured.

I also did this with my D-FA 25mm on a 645Nii and, yes, the image filled the whole 645 frame with no vignetting. The D-FA is seriously wide on the 645N!!

**blackcloudbrew** · 03-13-2018, 03:29 PM - **1 Like**

Originally posted by mikeSF

It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured.
I can reach out to him for more details if you like.

Yep, that's true. Can't recall the images now but it worked just fine on my 645n.

**Ed Hurst** · 03-13-2018, 08:36 PM - **1 Like**

Originally posted by mikeSF

It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured.
I can reach out to him for more details if you like.

Sorry for any ambiguity, Mike. I meant can anyone confirm with certainty that the only difference between the DFA and DA versions is the hood and that the DA version would cover full frame 645 if the hood were trimmed? I did not doubt that the DFA version covers full frame 645.

mikeSF · 03-13-2018, 11:54 PM

Originally posted by Ed Hurst

Sorry for any ambiguity, Mike. I meant ...

ah gotcha. I'll quit posting in here. lol. be well.

2351HD · 03-14-2018, 04:13 AM

I’d love to pick up a 25 as there is a few of them around. I’m just so afraid of it A: dying or breaking and B: the system going nowhere and wasting more money.

mikeSF · 03-14-2018, 12:18 PM

Originally posted by 2351HD

I’d love to pick up a 25 as there is a few of them around. I’m just so afraid of it A: dying or breaking and B: the system going nowhere and wasting more money.

irrational fears, IMO.

texandrews · 03-14-2018, 01:20 PM - **1 Like**

Originally posted by mikeSF

irrational fears, IMO.

It doesn't ultimately matter in this case---this owner should sell off as the dissatisfaction has set in so deeply.

2351HD · 03-15-2018, 03:17 AM

Originally posted by texandrews

It doesn't ultimately matter in this case---this owner should sell off as the dissatisfaction has set in so deeply.

Hold on a sec. Just because you’re in awe doesn’t mean I have to be.

So let’s break it down. The 25mm lens is:

1: rare and only available used
2: not able to be repaired easily in my country.... at all
3: known to be very fickle and just fall apart.
4: expensive
5: doesn’t take filters easily
6: part of a system of which we have no clear plans of where it’s going. DA?? DFA?? Mirrorless??

I absolutely love my 645z, but at the same time it could be well improved. I have taken my best images with it.

Why is it that only glowingly positive discussion and pats on the back are allowed here?

texandrews · 03-15-2018, 03:58 AM - **1 Like**

Originally posted by 2351HD

Hold on a sec. Just because you’re in awe doesn’t mean I have to be.

I'm not in awe of my equipment---which is very good and has helped me enormously, but hardly perfect---or Pentax / Ricoh (and other corporations, truth be told) whom I think are really rather bone-headed on the marketing and support side of things. Iknow that well, as one of my best and oldest friends is an independent rep for them. Looking at the entirety of my comments shows that.

Quote:

I absolutely love my 645z, but at the same time it could be well improved. I have taken my best images with it.

Interesting. That's maybe the second time I've seen you post such a sentiment, against all the other postings.

Quote:

Why is it that only glowingly positive discussion and pats on the back are allowed here?

They aren't. You'll find criticism (including mine) aplenty on these forums. But here the difference is an unending/unrelenting litany of complaint from you that transforms from a quantitative index of known issues stated a few times to a qualitative beating of the proverbial dead horse almost incessantly to the point of rudeness. Furthermore: the Z came out 4 years ago this spring. In 2014 it was already quite clear what sort of company Pentax was, and the troubles they had, and the deficiencies in the products and product line-up. But it seems that you bought into the company expecting it to be something it was not. That's hardly the fault of Pentax. Let me be clear: you've made your point many, many times now. We know how you feel pretty clearly. Enough, already.

And I was in no way being facetious above. Such intense dissatisfaction and angst with the maker of your gear and its future is an unnecessary thorn in your side. Most likely you are an excellent photographer who could undoubtedly make excellent work with another company's products. Let Pentax go down the tubes, so what? You can migrate over to another maker now, or by the time Pentax goes under migrate over to what will be by that time to other incredible imaging devices---well, they're incredible at this very moment.

moroccanimager · 03-15-2018, 05:54 AM

I have the 25mm. It's not a lens I've used a lot mainly down to my style of photography. I find the filter system is fine for a polar and indeed I've been advised the Format Hitech largest filter system works well on it although not a cheap option. For me handling is secure, it feels robust and gives a great angle of view, I just need more subjects for it.

psenior1 · 03-15-2018, 06:45 AM

I was told directly by Ricoh/Pentax UK that the reason for stopping production was indeed the manufacturer of one of the internals going out of business, they didn't know why they couldn't carry on and make the part themselves, but presumably it was down to economic reasons.

Thomas · 03-15-2018, 07:41 AM

I love the 645Z but the lack of a really wide lens is a serious shortcoming; the 28-45mm is not wide enough for some of my uses and its cost, weight and size are real liabilities.
Additionally, I wonder how is it that Fuji can supply a 23mm at half the price of the discontinued Pentax 25mm?
I don't know the answer to Ed's question, but I noted that the D FA 25mm was listed at 1070g (Ricoh) and the DA 25mm is listed at 1040g (B&H). If the only difference in the lenses is a bigger hood and baffling for the DA version,it should be heavier, not lighter, than the D FA.

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03-13-2018, 11:49 AM	#16
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by texandrews Interesting, so, really a QC problem, less tight tolerances. I wonder who was manufacturing it. One of the most notable things about what Sigma has done in the past few years was the upgrade of their testing and QC system in house, from the ground up. They said at the time that the demands of the new cameras were such that it had to be done. Flew under most people's radar. Indeed, a QC problem, specifically related to the glass in the lens. That front element must have had some issues. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-13-2018, 12:06 PM	#17
rdenney Site Supporter Join Date: Feb 2018 Location: NoVA Posts: 635	I had heard that the front element was being manufactured by a specialty contractor that was no longer able to supply it. Source for that absolutely unconfirmed, and probably Internet FUD. But most products fail in the market because they cannot be produced for the cost that provides a profit under what price the market will bear. My bet is that at $7500, the 25 would find fewer than 1000 buyers, and maybe fewer than 100. A 25 specifically designed for the smaller sensor might be cheaper to produce, but the deep flange distance for the 645 will require a more strongly retro focus design. Wouldn’t the 35 be wide enough for most on the full film frame? Rick “wondering if lenses are still being made in Vietnam” Denney

03-13-2018, 01:39 PM	#18
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,267	Originally posted by rdenney Wouldn’t the 35 be wide enough for most on the full film frame? I'm hoping so

03-13-2018, 01:49 PM - 1 Like	#19
Sarnian Senior Member Join Date: Oct 2015 Posts: 101	Originally posted by mikeSF It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured. I also did this with my D-FA 25mm on a 645Nii and, yes, the image filled the whole 645 frame with no vignetting. The D-FA is seriously wide on the 645N!!

03-13-2018, 03:29 PM - 1 Like	#20
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,460	Originally posted by mikeSF It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured. I can reach out to him for more details if you like. Yep, that's true. Can't recall the images now but it worked just fine on my 645n.

03-13-2018, 08:36 PM - 1 Like	#21
Ed Hurst Site Supporter Join Date: May 2010 Location: Sydney Posts: 1,657	Originally posted by mikeSF It has been several years, but blackcloudbrew (Tim) mounted my DFA 25mm on his 645 film body and reported the full image circle was captured. I can reach out to him for more details if you like. Sorry for any ambiguity, Mike. I meant can anyone confirm with certainty that the only difference between the DFA and DA versions is the hood and that the DA version would cover full frame 645 if the hood were trimmed? I did not doubt that the DFA version covers full frame 645.

03-13-2018, 11:54 PM	#22
mikeSF Pentaxian Join Date: Jan 2009 Location: East Bay Area, CA Photos: Gallery Posts: 6,620	Originally posted by Ed Hurst Sorry for any ambiguity, Mike. I meant ... ah gotcha. I'll quit posting in here. lol. be well.

03-14-2018, 04:13 AM	#23
2351HD Veteran Member Join Date: Apr 2013 Location: Brisbane, Australia Photos: Albums Posts: 750	I’d love to pick up a 25 as there is a few of them around. I’m just so afraid of it A: dying or breaking and B: the system going nowhere and wasting more money.

03-14-2018, 12:18 PM	#24
mikeSF Pentaxian Join Date: Jan 2009 Location: East Bay Area, CA Photos: Gallery Posts: 6,620	Originally posted by 2351HD I’d love to pick up a 25 as there is a few of them around. I’m just so afraid of it A: dying or breaking and B: the system going nowhere and wasting more money. irrational fears, IMO.

03-14-2018, 01:20 PM - 1 Like	#25
texandrews Moderator Join Date: Apr 2014 Location: Baltimore Photos: Albums Posts: 3,390	Originally posted by mikeSF irrational fears, IMO. It doesn't ultimately matter in this case---this owner should sell off as the dissatisfaction has set in so deeply.

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03-15-2018, 03:17 AM	#26
2351HD Veteran Member Join Date: Apr 2013 Location: Brisbane, Australia Photos: Albums Posts: 750	Originally posted by texandrews It doesn't ultimately matter in this case---this owner should sell off as the dissatisfaction has set in so deeply. Hold on a sec. Just because you’re in awe doesn’t mean I have to be. So let’s break it down. The 25mm lens is: 1: rare and only available used 2: not able to be repaired easily in my country.... at all 3: known to be very fickle and just fall apart. 4: expensive 5: doesn’t take filters easily 6: part of a system of which we have no clear plans of where it’s going. DA?? DFA?? Mirrorless?? I absolutely love my 645z, but at the same time it could be well improved. I have taken my best images with it. Why is it that only glowingly positive discussion and pats on the back are allowed here?

03-15-2018, 03:58 AM - 1 Like	#27
texandrews Moderator Join Date: Apr 2014 Location: Baltimore Photos: Albums Posts: 3,390	Originally posted by 2351HD Hold on a sec. Just because you’re in awe doesn’t mean I have to be. I'm not in awe of my equipment---which is very good and has helped me enormously, but hardly perfect---or Pentax / Ricoh (and other corporations, truth be told) whom I think are really rather bone-headed on the marketing and support side of things. Iknow that well, as one of my best and oldest friends is an independent rep for them. Looking at the entirety of my comments shows that. Quote: I absolutely love my 645z, but at the same time it could be well improved. I have taken my best images with it. Interesting. That's maybe the second time I've seen you post such a sentiment, against all the other postings. Quote: Why is it that only glowingly positive discussion and pats on the back are allowed here? They aren't. You'll find criticism (including mine) aplenty on these forums. But here the difference is an unending/unrelenting litany of complaint from you that transforms from a quantitative index of known issues stated a few times to a qualitative beating of the proverbial dead horse almost incessantly to the point of rudeness. Furthermore: the Z came out 4 years ago this spring. In 2014 it was already quite clear what sort of company Pentax was, and the troubles they had, and the deficiencies in the products and product line-up. But it seems that you bought into the company expecting it to be something it was not. That's hardly the fault of Pentax. Let me be clear: you've made your point many, many times now. We know how you feel pretty clearly. Enough, already. And I was in no way being facetious above. Such intense dissatisfaction and angst with the maker of your gear and its future is an unnecessary thorn in your side. Most likely you are an excellent photographer who could undoubtedly make excellent work with another company's products. Let Pentax go down the tubes, so what? You can migrate over to another maker now, or by the time Pentax goes under migrate over to what will be by that time to other incredible imaging devices---well, they're incredible at this very moment.

03-15-2018, 05:54 AM	#28
moroccanimager Junior Member Join Date: Jul 2016 Location: Morocco Posts: 47	I have the 25mm. It's not a lens I've used a lot mainly down to my style of photography. I find the filter system is fine for a polar and indeed I've been advised the Format Hitech largest filter system works well on it although not a cheap option. For me handling is secure, it feels robust and gives a great angle of view, I just need more subjects for it.

03-15-2018, 06:45 AM	#29
psenior1 New Member Join Date: Jan 2016 Posts: 18	I was told directly by Ricoh/Pentax UK that the reason for stopping production was indeed the manufacturer of one of the internals going out of business, they didn't know why they couldn't carry on and make the part themselves, but presumably it was down to economic reasons.

03-15-2018, 07:41 AM	#30
Thomas Veteran Member Join Date: Feb 2008 Photos: Gallery \| Albums Posts: 434	I love the 645Z but the lack of a really wide lens is a serious shortcoming; the 28-45mm is not wide enough for some of my uses and its cost, weight and size are real liabilities. Additionally, I wonder how is it that Fuji can supply a 23mm at half the price of the discontinued Pentax 25mm? I don't know the answer to Ed's question, but I noted that the D FA 25mm was listed at 1070g (Ricoh) and the DA 25mm is listed at 1040g (B&H). If the only difference in the lenses is a bigger hood and baffling for the DA version,it should be heavier, not lighter, than the D FA.