[biz-engineer]

Coating doesn't seem to require lens redesign, as shown for the HD FA 35 f/2 , HD 10-17 and D-FA 70-210, but greatly improves CA and flare resistance. Prime lenses are smaller and faster than the new D-FA zooms designed for the Pentax K1. It is surprising that Ricoh Imaging, given limited resources, haven't immediately after the launch of the Pentax K1 re-coated the FA Limited (FA31, FA43, FA77) primes into digital versions (HD-FA) since the Pentax K1 was released. What are they doing actually since 2016 ?

I'm thinking Pentax own high-end aerobright coating on the FA limited, should deliver unique image output, sold at a good price of course, but those lenses are already expensive.

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Last edited by biz-engineer; 02-26-2020 at 11:50 AM.

[luftfluss]

Coating doesn't seem to require lens redesign, as shown for the HD FA 35 f/2 , HD 10-17 and D-FA 70-210, but greatly improves CA and flare resistance. Prime lenses are smaller and faster than the new D-FA zooms designed for the Pentax K1. It is surprising that Ricoh Imaging, given limited resources, haven't immediately after the launch of the Pentax K1 re-coated the FA Limited (FA31, FA43, FA77) primes into digital versions (HD-FA) since the Pentax K1 was released. What are they doing actually since 2016 ?

I'm thinking Pentax own high-end aerobright coating on the FA limited, should deliver unique image output, sold at a good price of course, but those lenses are already expensive.

Has another production run of the FA Ltd's been required since the introduction of the K-1? If not, then Ricoh hasn't had a need to reformulate those lenses yet.

[BigMackCam]

Coating doesn't seem to require lens redesign, as shown for the HD FA 35 f/2 , HD 10-17 and D-FA 70-210, but greatly improves CA and flare resistance.

I wasn't aware that the HD coating improves CA... would you mind sharing the source for that?

As for flare resistance, reviews suggest it definitely improves things a bit - but greatly? I'm not so sure I'd go that far...

Prime lenses are smaller and faster than the new D-FA zooms designed for the Pentax K1. It is surprising that Ricoh Imaging, given limited resources, haven't immediately after the launch of the Pentax K1 re-coated the FA Limited (FA31, FA43, FA77) primes into digital versions (HD-FA) since the Pentax K1 was released.

I wouldn't call HD lenses "digital versions", as such. There's just an improvement in coating performance, and whilst certainly welcome, it's not a huge difference. My guess is, Ricoh has some (perhaps significant) remaining stocks of SMC-coated elements with which to manufacture more FA Limiteds, or a stock-pile of already-manufactured lenses... and when those stocks run low, it'll re-release them with HD coatings. As I understand it, SMC coatings are no longer produced, so the choices would be to switch to HD or replace the lenses with entirely new models...

What are they doing actually since 2016 ?

Only Ricoh can answer that. Speculation on our part would be baseless and pointless. I'm sure they've been busy enough, though

[aslyfox]

not sure if this helps

this article compares the DA Limiteds

HD vs. SMC Pentax Limited Primes
Introduction
At Photokina 2012, Pentax announced a brand new lens coating which they named the "HD Coating". This coating is slowly starting to replace the conventional "Super Multi Coating" (SMC) on high-end Pentax glass. According to Pentax, the new HD coating greatly reduces reflectance without making any sacrifices in terms of durability. This kind of coating isn't new to the industry, however: Pentax digital medium format lenses have been treated with a slightly less durable variant called Aero Bright coating ever since their debut, and other manufacturers have been using "nano" coatings on their premium lenses for several years.

The modern SMC coating that DA lenses have been using for about a decade now isn't the same as the SMC coating that Pentax originally launched in the 1970's. In fact, most DA lenses have been said to have a "ghostless" coating, so while we don't expect the difference between SMC and HD coating to be be a game-changer, it should certainly still be easy to observe.

Pentax HD Limiteds mounted on the K-3The 5 New Pentax HD Limited Primes

In this review, we will be taking a look at the five new "HD Limited" primes Pentax announced in August, 2013: the HD Pentax-DA 15mm F4, HD Pentax-DA 21mm F3.2, HD Pentax-DA 35mm F2.8 Macro, HD Pentax-DA 40mm F2.8, and HD Pentax-DA 70mm F2.4 Limited. These are among the latest lenses to be treated with the HD coating. In the Pentax world, the term "Limited" simply refers to the fact that these are compact pancake-style lenses sporting an all-metal build and top-shelf image quality. The term does not imply a short or limited production run.

Read more at: HD vs. SMC Pentax Limited Primes Review - Introduction | PentaxForums.com Reviews

[jatrax]

I suspect the key here is whether there has been another production run or are they still using old stock?

Once current stock runs out Ricoh will need to make a decision:
1) Discontinue the FA Limiteds
2) Re-issue as HD-FA with new coatings
3) Redesign a new line of DFA Limiteds

No way to know how they will decide but with the current camera market I do not have a lot of confidence in seeing anything except #1.

[stevebrot]

I wasn't aware that the HD coating improves CA... would you mind sharing the source for that?

My question as well. There is no doubt that HD is an amazing coating techonology, but I sincerely doubt that it can "correct" aspects of intentional lens design.

I wouldn't call HD lenses "digital versions", as such.

Agreed. The whole matter of "digital" coatings has always been largely irrelevant for higher quality multi-coated SLR lenses where internal surfaces and the rear element have typically been given the same treatment as the front. My memory is that the rash of "digital optimized" glass in the mid-to-late 2000s was mostly makers caught with their pants down for their consumer-grade zooms where the rear elements were creating havoc with CCD sensors of the time.

As for adequacy of the SMC coatings on FA-series lenses, the proof of the pudding is in the eating and I have never seen evidence that the late-generation SMC coatings on my FA 77/1.8 and FA 35/2 were a cause for concern other than my usual practice of shooting with a hood. HD would be nice, but to be honest, if I were to replace the FA 35/2 with the HD FA 35/2, it would be to get the nicer focus grip.


Steve

[biz-engineer]

1) To avoid ghosting from multiple reflexions between sensor shiny surface and rear lens element, Digital (D-A or D-FA) have additional coating.
2) Isn't coating supposed to reduce things like purple fringing when shooting back lit subjectS? (which is the argument for the Pentax branded Tamron glass not being the same as the Tamron glass).

---------- Post added 26-02-20 at 19:38 ----------

s I understand it, SMC coatings are no longer produced, so the choices would be to switch to HD or replace the lenses with entirely new models...

I'd not even consider HD coating for $1000 prime lenses, I'd want the coating that's used for the Pentax star glass (DA*55, D-FA*50 1.4, D-FA*70-200): aerobright (Super Aerobright Coating II) http://www.ricoh-imaging.co.jp/english/products/lens/technology/hd_coating/index.html

If Ricoh would make the limited with Aerobright Coating II and sell them the same price, that would upset a number of owners of legacy limited primes, because the newer versions would be better. That'd be a bit like throwing a stone in the Pentax pond.

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Last edited by biz-engineer; 02-26-2020 at 11:43 AM.

[fehknt]

digital designed lenses also take into account the optical path differences caused by the hot-mirror and cover glass on the sensor (and I would assume maybe also some issues due to microlens array and color filter array etc). This causes minor differences in performance on digital versus film, particularly for light rays coming from the periphery and entering the sensor at a significant angle (so most relevant for large-aperture primes). But that would require at least a minor redesign of the optics, not just a recoating.

I also seem to remember reading that the FA limiteds (at least the 31?) were using ground aspherics -- modern lenses are using much cheaper construction techniques and I don't think it's reasonable to expect a new run of a modern lens to use a ground aspheric, it would just be too costly.

[c.a.m]

Coating [...] greatly improves CA and flare resistance.

I thought that chromatic aberrations occur because the refractive index of glass varies with light wavelength. Coatings cannot control the refractive index. However, the new HD coating does seem to improve flare control, which might also increase contrast.

It is surprising that Ricoh Imaging, given limited resources, haven't immediately after the launch of the Pentax K1 re-coated the FA Limited

Perhaps Ricoh had decided that the FA Limiteds are fine the way they are, or they determined that those lenses are not the most important things to work on. Or, they might have decided that new coatings would not necessarily spark new sales, given the relatively high price of the Limiteds.

What are they doing actually since 2016 ?

Are you referring to the application of their HD coating, or to the general activities of Ricoh Imaging? We know of the products that they have released since 2016, but we don't have insight into their 'behind the scenes' work.

- Craig

[nocturnal]

FAO BigMackCam

I too have read that HD coatings reduces CA in several different places can't remember where exactly, maybe a HD vs SMC DA 21mm review or something like that.

All I know is my HD DA15 and 20-40 Limited give the most accurate, contrasty and saturated colours out of every lens I have owned and that is reason alone to just love 'em :-)

Oh and the sun flare resistance too...
.
So very critical to a landscape photographer

[stevebrot]

2) Isn't coating supposed to reduce things like purple fringing when shooting back lit subjectS?

No, I don't think so. PF is a strange beast and is a sensor artifact apparently triggered by longitudinal chromatic aberration.* Address the CA with lens design and you've addressed PF. FWIW, there are several DA-series lenses that have significant PF.

If Ricoh would make the limited with Aerobright Coating II and sell them the same price, that would upset a number of owners of legacy limited primes, because the newer versions would be better. That'd be a bit like throwing a stone in the Pentax pond.

Considering the admitted fragility of Aerobright, I think not.


Steve

* I have actually done a fair amount of testing with film, CCD, and CMOS sensors in regards to "forcing" PF. Primes having floating elements as well as most zoom are the most common culprits, though not at all focal lengths/distances.

[BigMackCam]

1) To avoid ghosting from multiple reflexions between sensor shiny surface and rear lens element, Digital (D-A or D-FA) have additional coating.

See the comment from @stevebrot above. Better late-film-era multi-coated lenses were fairly well prepared for digital anyway, since the rear elements were already coated. I'm not aware of the FA Limited primes demonstrating problems with reflection between the sensor and rear element. I don't doubt the possibility that new DA and D FA lenses have an additional coating at the rear, but if you could provide the source for that too, along with the source for the "HD reduces CA" claims, I'd appreciate it. Something to read with my evening glass or two of wine

2) Isn't coating supposed to reduce things like purple fringing when shooting back lit subjectS? (which is the argument for the Pentax branded Tamron glass not being the same as the Tamron glass).

I've not seen any claim that HD coating reduces CA, hence why I'm keen to obtain your source. Nor have I read of this claim being used by Ricoh to differentiate between the Pentax and Tamron versions of the 70-210/4. Again, is there a source for this?

I'd not even consider HD coating for $1000 prime lenses, I'd want the coating that's used for the Pentax star glass (DA*55, D-FA*50 1.4, D-FA*70-200): aerobright (Super Aerobright Coating II)

Is there something you don't like about the HD coating? Something you feel would make it ineffective, inappropriate or sub-standard on a $1,000 prime lens? How much difference do you think Aerobright coatings would make in your photos, and could you actually distinguish it from HD glass? I respectfully suggest you could not.

If Ricoh would make the limited with Aerobright Coating II and sell them the same price, that would upset a number of owners of legacy limited primes, because the newer versions would be better. That'd be a bit like throwing a stone in the Pentax pond.

We're not even close to being in this position yet, so it's pure conjecture. Ricoh clearly has stocks of either FA Limited lenses, or SMC coated elements to make them, hence why all three lenses are still widely available. Since the lenses are so well loved, my guess is that when the time comes, they'll be re-released with HD coated glass, but this really is just speculation...

[aslyfox]

FAO BigMackCam

I too have read that HD coatings reduces CA in several different places can't remember where exactly, maybe a HD vs SMC DA 21mm review or something like that.
. . .

I linked to the " In Depth Review " comparing all of the HD and SMC DA primes in Response no. 4

here is the link once again

HD vs. SMC Pentax Limited Primes Review - Introduction | PentaxForums.com Reviews

[biz-engineer]

How much difference do you think Aerobright coatings would make in your photos, and could you actually distinguish it from HD glass?

The star Pentax glass that is aerobright coated definitely render differenlty from HD glass. Not saying that HD is not good, but HD does not render like aerobright IMO.

---------- Post added 26-02-20 at 20:18 ----------

Ricoh clearly has stocks of either FA Limited lenses

If so after so many years of having the FA ltd for sale, sales rate must be very low.

---------- Post added 26-02-20 at 20:20 ----------

here is the link once againHD vs. SMC Pentax Limited Primes Review - Introduction | PentaxForums.com Reviews

Yes, thanks for the link, but... I'd expect much less difference between DA ltd and HD DA due to DA lenses already being coated for use on digital cameras. My initial post is with regards to FA ltd re-coating for full frame digital.

[stevebrot]

This causes minor differences in performance on digital versus film, particularly for light rays coming from the periphery and entering the sensor at a significant angle (so most relevant for large-aperture primes).

This is a huge issue with mirrorless (e.g. classic Leitz M-mount glass on Sony A7-series), but much less with SLR lenses where the incident angle is usually quite mild due to greater flange distance.

But that would require at least a minor redesign of the optics, not just a recoating.

Yep...I could not have said it better. If changes have been required, they have been issues of optical design, not coatings.


Steve