[Trickortreat]

I can assure you Trickortreat my experience is not anecdotal. Now you are just either being rude or ignorant.

Should I remind you of your words and who is rude and ignorant?
Numbers dont lie. Your experience is anecdotal. Have a nice day.

[Chris Mak]

"No autofocus motors" means driving customers away, because the screw drive is both noisy and imprecise.
One of the reasons Pentax has so little market share is the "no autofocus motors" in too many of their lenses.

Hit the nail on the head there!
The "no autofocus motors" bit sort of went in tandem with an increasing lag in AF capabilities of the Pentax system.

I was and am convinced that good in-lens AF motors are the core of any current camera system. The best lens in the world will only produce mediocre images if they are not spot-on in focus, and it does not help if you have to take 10 images to get one actually critically in focus. This issue really fully surfaces with the long super telelenses with paperthin DOF.

Chris

[BigMackCam]

The lens-related discussions in this thread are interesting in that they confirm what we've already known for decades... You just can't please everyone all of the time.

Produce a big, heavy, fast, full-frame 50 with thoroughly top-notch performance, and some people won't like the size, weight and / or price. Produce a small, affordable, high quality screw-drive 21mm f/3.2, and some will find it too slow or noisy. Offer a really nice 70-200 f/2.8, and some folks want an f/4 instead. A 43mm with beautiful rendering, and some don't like the border performance at faster apertures.

I'm not criticising anyone who wants something different or additional to what's already on offer... My own preferences and requirements are as unique and personal as the next man's.

But... No manufacturer - least of all a relatively small player such as Pentax - can hope to fulfil the wishes of every customer. And whatever Pentax does in future, I'd bet there'll be roughly the same number of people who are delighted with the offerings, those who would have liked some differences, and a few who just don't like many of the lenses at all...

[Mountain Vision]

Amen!

[Rico]

Should I remind you of your words and who is rude and ignorant?
Numbers dont lie. Your experience is anecdotal. Have a nice day.

So you are being both ignorant and rude.

I was already having a nice day.

Thanks any way.

[Trickortreat]

So you are being both ignorant and rude.I was already having a nice day.Thanks any way.

Glad we agree you are just wrong. BB now...

[BigMackCam]

In the digital age they could phase out the FA31. 28mm makes better sense for the reasons mentioned. 28mm fits better for both FF and APS-C.

I have an A-Series 28mm ƒ2 that was my most used lens on APS-C. It has stayed in my bag moving to the K-1. It replaced the M-20 ƒ4 I was using for APS-C. The secondary advantage a similar DFA 28mm ƒ2 design should bring over a DFA31 is size.

They could, sure... but for an operation that has to carefully choose where to focus its financial and human resources, I wonder if that would be a smart move - at least, in the near future. A 28mm lens might be smaller, but the approximate field of view is more-or-less catered for by the FA31.

How quickly we forget... Until the K-1 came along, the FA31 was one of the most revered and talked-about lenses in Pentax's line up. The field of view and optical quality were deemed outstanding by many folks here - and these are primarily APS-C format digital photographers we're talking about, not film. Were it not for the price here in the UK, I'd have joined the many fans and bought one myself. As it is, I took the economy option and bought a Sigma 30mm f/1.4 Art which I love... It has (to my eye) beautiful rendering... but is undoubtedly inferior to the FA31 in terms of optical performance (and it's not FF compatible either).

Don't get me wrong - if Pentax released a DFA 28mm f/2, it would certainly pique my interest. I just don't think they need to at this point, when there are so many other things to attend to...

---

Last edited by BigMackCam; 01-09-2019 at 02:05 PM.

[BigMackCam]

Folks... Once more, let's keep these discussions respectful and cordial, or infractions and thread bans will follow. Thank you...

[Kunzite]

There isn't anything more silent and precise than Quickshift focusing. If people are leaving because of autofocus lens motors than they are not really interested in photography. Good photography has nothing to do with autofocus motors. What the design of the FA and DA LTD bring is high quality at a reasonable price. Increased price through over design will drive away customers.

Quickshift focusing? You mean manual focus?

I'm not talking about photography as art. I'm talking about how screw drive AF is noisy (not equally so in all lenses, of course) and how it's less precise - the gearing requires some degree of slack. This can become significant as the sensor resolution increases, and for AF-C.
What few people realize, a screw drive lens is getting more imprecise as it's aging. Do you know the fix? Grease.

To be clear, I'm not saying screw drive AF is useless; just that it's less good than a good in-lens AF.
And...

You Tube

You Tube

[Rico]

They could, sure... but for an operation that has to carefully choose where to focus its financial and human resources, I wonder if that would be a smart move - at least, in the near future. A 28mm lens might be smaller, but the approximate field of view is more-or-less catered for by the FA31.

How quickly we forget... Until the K-1 came along, the FA31 was one of the most revered and talked-about lenses in Pentax's line up. The field of view and optical quality were deemed outstanding by many folks here - and these are primarily APS-C format digital photographers we're talking about, not film. Were it not for the price here in the UK, I'd have joined the many fans and bought one myself. As it is, I took the economy option and bought a Sigma 30mm f/1.4 Art which I love... It has (to my eye) beautiful rendering... but is undoubtedly inferior to the FA31 in terms of optical performance (and it's not FF compatible either).

Don't get me wrong - if Pentax released a DFA 28mm f/2, it would certainly pique my interest. I just don't think they need to at this point, when there are so many other things to attend to...

I never got the FA31 for the same reason primarily price. Plus once I found the A-Series 28mm ƒ2 I never felt like I needed to get one. The other factor was the FA LTD's do not have QuickShift focus. One of the first lenses I bought when I got the K-10 were the DA40 and the FA77. I quickly regretted getting the FA77 for the lack of QuickShift which the DA40 demonstrated the absolute utility of it. When I moved to the K-1 I reluctantly bought the FA43 to replace the DA40 as it was passed to a family member along with my K-5.

In no way am I saying the FA31 43 or 77 are bad lenses they just need to be modernized for the digital age. Like I have said before these three lenses should have been modernized for the release of the K-1. Instead they focused on the DFA1530 and 2470 ƒ2.8 zooms.

For an operation that has to carefully choose where to focus their financial and human resources over the last five years the development of the DFA*50 and DFA*85 has focused those efforts in creating lenses for a niche segment of their already niche market share.

[BigMackCam]

For an operation that has to carefully choose where to focus their financial and human resources over the last five years the development of the DFA*50 and DFA*85 has focused those efforts in creating lenses for a niche segment of their already niche market share.

With respect, I'm not sure I agree. To have a credible full-frame offering, a manufacturer arguably needs to have fast, high quality, normal and portrait prime lenses at classic focal lengths (50 and 85 respectively). The FA50 f/1.4, much as I like my own copy (for use on APS-C, admittedly), is a nice low-cost normal lens, but even I would admit that it shows its age, and there was undeniable justification to produce something that could leverage the quality of the K-1 and K-1II sensor. For now, the FA77 Limited fills the portrait niche, but however good it may be, I don't think Pentax can credibly pair it with the D FA* 50. So I see the justification for the D FA* 85 too. I could also see sense in D FA* 28 and 35 lenses to round out the set. A K-1 / K-1II (or whatever current incarnation of Pentax full frame camera) plus the D FA 24-70 f/2.8 and 70-200 f/2.8, plus fast D FA* 28, 35, 50 and 85 (or any subset thereof, depending on use case) would be a formidable professional arsenal indeed...

[Rico]

Quickshift focusing? You mean manual focus?

I'm not talking about photography as art. I'm talking about how screw drive AF is noisy (not equally so in all lenses, of course) and how it's less precise - the gearing requires some degree of slack. This can become significant as the sensor resolution increases, and for AF-C.
What few people realize, a screw drive lens is getting more imprecise as it's aging. Do you know the fix? Grease.

To be clear, I'm not saying screw drive AF is useless; just that it's less good than a good in-lens AF.
And...
New vs. Old Pentax 55-300mm Autofocus Test - YouTube

QuickShift focus in my experience is both silent and precise all while in autofocus mode.

I don't see the tolerances between screw drive and motor drives having any major impact to focus point in real world situations. Getting "focus" is entirely technique whether you focus manually or use autofocus.

[BigMackCam]

I'm talking about how screw drive AF is noisy (not equally so in all lenses, of course) and how it's less precise - the gearing requires some degree of slack. This can become significant as the sensor resolution increases, and for AF-C.
What few people realize, a screw drive lens is getting more imprecise as it's aging. Do you know the fix? Grease.

To be clear, I'm not saying screw drive AF is useless; just that it's less good than a good in-lens AF.

I don't see the tolerances between screw drive and motor drives having any major impact to focus point in real world situations. Getting "focus" is entirely technique whether you focus manually or use autofocus.

I agree with both of you to some extent

Until a few months back, I'd have said a screw-drive AF mechanism without mechanical wear was just as accurate as an in-lens electronic mechanism.

But, recent experiences in periodic re-calibration tests of my lenses on each body changed my view - though only slightly. It's now clear to me that a screw-drive lens with short focus throw (or fast gearing), focused at very short distances, at an aperture resulting in shallow depth of field, can have a small but significant degree of inconsistency - both in phase and live view contrast detect AF (which suggests the lens rather than in-camera AF algorithm is at fault).

Examples here would be the DA40 f/2.8 Limited, with it's short focus throw, compared to the DA35 f/2.8 Macro Limited (which has longer focus throw at the close focus end of the range) - or the DA70 f/2.4 Limited versus the D FA 100 f/2.8 WR Macro (the latter, again, with long throw at closer ranges). I don't see any inconsistency with the DC-driven DA20-40, for example.

Yet this is a pretty narrow use case - shooting wide open at or near the minimum focus distance. We can't discount the effect, as some people will use the lenses in this way for good reasons... But for much day-to-day shooting at more forgiving subject distances, the minor inconsistencies will have little (if any) impact...

EDIT: Of course, if we were talking about f/1.4 or f/1.2 lenses, the screw-drive "slack" could have more impact on perceived AF accuracy, especially at short distances

[mtgmansf]

For about £1000 less you can get the Irix 15mm in F (or K) mount and over a stop more light capture at similar weight to the Z 14-30. Most of the other wide zooms you quote are APSC lenses. Alternatively, the Pentax 15-30 WR is available now, and not shabby on the optical side.

Not a zoom and, therefore, less flexibility. Also, I made it clear that I am not an astro-photographer, so the bigger f-stop is a much less desirable feature for me....
(never fun exchanging lenses in damp, wet, cold, and severe condition!)

---------- Post added 01-09-19 at 02:33 PM ----------

He is looking for a camera not yet developed and a lens to match it not yet on the market........

That will never change, because the next generation of gear will be the one he is seeking for!

Yes, thanks for pointing that out. I have plenty of quality equipment now, but I am always looking ahead at at new tech that can improve my vision.

[Kunzite]

QuickShift focus in my experience is both silent and precise all while in autofocus mode.

I don't see the tolerances between screw drive and motor drives having any major impact to focus point in real world situations. Getting "focus" is entirely technique whether you focus manually or use autofocus.

Sorry, but I don't get what you mean by "QuickShift focus in autofocus mode".
QuickShift, of course, is just a full-time manual focus implementation. Do you mean manual focus? Or manually pre-focusing at/near the target, then using the autofocus to do the rest? Or something else?

Anyway, if it works for you... great. That doesn't mean it's better for everyone, including the occasional birder or even the untrained customer wondering why only the Pentax cameras make loud noises during AF
(I'll continue with a more personal point of view in a response to Mike's post)

---------- Post added 10-01-19 at 01:08 AM ----------

I agree with both of you to some extent

Until a few months back, I'd have said a screw-drive AF mechanism without mechanical wear was just as accurate as an in-lens electronic mechanism.

But, recent experiences in periodic re-calibration tests of my lenses on each body changed my view - though only slightly. It's now clear to me that a screw-drive lens with short focus throw (or fast gearing), focused at very short distances, at an aperture resulting in shallow depth of field, can have a small but significant degree of inconsistency - both in phase and live view contrast detect AF (which suggests the lens rather than in-camera AF algorithm is at fault).

Examples here would be the DA40 f/2.8 Limited, with it's short focus throw, compared to the DA35 f/2.8 Macro Limited (which has longer focus throw at the close focus end of the range) - or the DA70 f/2.4 Limited versus the D FA 100 f/2.8 WR Macro (the latter, again, with long throw at closer ranges). I don't see any inconsistency with the DC-driven DA20-40, for example.

Yet this is a pretty narrow use case - shooting wide open at or near the minimum focus distance. We can't discount the effect, as some people will use the lenses in this way for good reasons... But for much day-to-day shooting at more forgiving subject distances, the minor inconsistencies will have little (if any) impact...

EDIT: Of course, if we were talking about f/1.4 or f/1.2 lenses, the screw-drive "slack" could have more impact on perceived AF accuracy, especially at short distances

Mike, "to some extent" is fine - I'm not talking in absolutes, and I wouldn't want my posts to be read in absolutes
The screw drive AF is obviously good; it worked (and still works) well for so many people. But the in-lens AF is better.

There are far more experienced people here, but these are things I've noticed (after owning a few screw drive lenses, old-style SDM, DC and now ring-type SDM - the PLM I've only briefly tested):
- yes, you can feel the slack; screw drive lenses tend to "micro-hunt", it's not really bad but noticeable once you work with in-lens AF lenses. You can also measure its effect - perhaps an idea for a future Pentaxforums article; the D FA* 50mm would be interesting, as it lacks any gearing.
Apparently some lenses (not necessarily newer) are more prone to that than others. I wouldn't call any of my lenses "bad"... but in my limited experience, in-lens AF motors are more consistent.
- obviously the noise. Doesn't matter if you're shooting rock concerts and it varies wildly with the lens so once again it's up to each of us to decide how much is too much.
- I've seen a lens (an FA 35mm, in good condition) not being able to focus at a certain distance; the mechanism was simply not precise enough to attain it to the AF system's satisfaction (it continued to hunt around it). On an easy target.
Of course, a slight altering of the distance did the trick.