[pschlute]

One way to look at it is that the Fa 50 1.4 is a nice budget option

If I am carrying my camera around for the day, but not with a specific project in mind, these days I always slap the FA 50mm 1.4 on the K1. The combo is a lot easier on my shoulder than the 24-70 !

The quality of the FA 50mm 1.4 is still there nearly 30 years after it was born...............

[stevebrot]

It's not about the element count. I am referring to the 8 element takumar optical design. 7 element pentax still uses the 7elementvtak optical formula. But if they updated the 50 with the 8 element formula, and newer coatings. I am sure it would perform better

I am pretty sure that a re-release of the 1962 8-element design will not be to "modern standards" and perhaps not as good as the current 7-element design*. Comparisons between the 8-element Super Takumar and the 7-element Super Tak do show a difference in rendering, but no huge difference in performance metrics.** Both are Planar variants and share the general virtues and short falls of the design.


Steve

* The current 7-element 50/1.4 design debuted with the A-series lenses in 1984 and while still planar-derived differs from the earlier (1964) design in multiple ways. The K-mount page has diagrams for both (LINK)

** I am working from memory here and will do some additional research, though my recollection is that there is nothing earth shattering in regards to the 8-element, despite that lens' adherents.

[SunnyG.]

I'm late to the show, but here goes.

You cannot just "add" an element to a design. What you refer to is a new design. And having more glass elements in an optical design is not a sign of quality, there is no direct relation between IQ and the number of elements. In general, for cost, size, weight, you want the lowest number of elements possible. You add elements when you need to correct for optical flaws.

So saying "let's add an element" is simply not how optical design works.

I was talking about the 8 element takumar design

---------- Post added 11-04-20 at 12:23 PM ----------

I am pretty sure that a re-release of the 1962 8-element design will not be to "modern standards" and perhaps not as good as the current 7-element design*. Comparisons between the 8-element Super Takumar and the 7-element Super Tak do show a difference in rendering, but no huge difference in performance metrics.** Both are Planar variants and share the general virtues and short falls of the design.


Steve

* The current 7-element 50/1.4 design debuted with the A-series lenses in 1984 and while still planar-derived differs from the earlier (1964) design in multiple ways. The K-mount page has diagrams for both (LINK)

** I am working from memory here and will do some additional research, though my recollection is that there is nothing earth shattering in regards to the 8-element, despite that lens' adherents.

It's true! There isn't such a huge difference. I agree. But maybe perhaps we are using it on digital that's why. These lenses were made for film.


And besides the 8 element lens didn't have SMC nor HD. But there is a big possibility if it had hd coatings, and calibrated for digital (mostly stack thickness of the sensor). I have a feeling it could be a stellar sub 500$ performer.


Hasn't this thought ever crossed your mind?

[stevebrot]

It's true! There isn't such a huge difference. I agree. But maybe perhaps we are using it on digital that's why. These lenses were made for film.

Makes perfect sense to release the lens again for digital. I totally get it and am tiring of this thread.

Hasn't this thought ever crossed your mind?

Our interaction is over. On this side of the world, that phrase is considered abusive.


Steve

(...remember...don't feed the trolls...)

[clackers]

Why does modern FA 50mm still use the 7 element design? They could use 8 element design and upgrade it DFA.

Any thoughts on this?

It's not modern, it's a film era lens, affordable because its development was paid for long ago.

Sounds like you need the DA*55 or DFA*50 for your K-50, Sunny!

[leekil]

So saying "let's add an element" is simply not how optical design works.

He's not saying "add an element", he is assuming the FA50 uses the 7-element Takumar formula, and if they are using that, why would't they go with the 8-element Tak, since that lens is more highly regarded.

[Fogel70]

He's not saying "add an element", he is assuming the FA50 uses the 7-element Takumar formula, and if they are using that, why would't they go with the 8-element Tak, since that lens is more highly regarded.

It is most likely not possible to re-use an old lens design and expect it to perform exacly the same today. The type of glass used for the 8 element design are not allowed to be used in manufacturing today as it included toxic materials.

So the optical glass of today do not have the same optical performance as in the past. This is something that they most likely have to compensate for, and if they have to redesign the optical formula they may also want to optimize it for use on high resolution digital cameras. So they may end up with a large lens with Fi 15 lens elements.

It is said that Asahi lost money on every 8 lens element 50/1.4 Takumar they sold as it was expensive and difficult to manufacture. So if they tried to reproduce this design today it would most likely be very expensive. Possibly more expensive than DFA 50/1.4, as it most likely would only be manufactured in small quantities.

---

Last edited by Fogel70; 11-04-2020 at 10:28 PM.

[ChristianRock]

A lot of those older designs from the 50s and 60s use glass elements that can't be manufactured anymore.

According to this page, 3 8-element Takumars were tested and all were radioactive, though not at the same level of radioactivity of the 7-element design. I quote:

"Contrary to common belief, the early 8-element Super Takumar too is radioactive:

You Tube

You Tube

Besides the lens shown here, I have tested 2 others for beta & gamma particles, getting readings at the back of up to about 1.2-1.35 µSv/h and at the front of about 0.2 µSv/h (against a background radiation of about 0.14 µSv/h). All 3 lenses have been verified to be of the 8 elements type: besides having all external characteristics, I serviced them, so I could count the elements. The radiactive elements are those at the back, not at the front. The good news is that all radiation from the rear is effectively stopped by a digital camera back (e.g. Sony Alpha 7RII). This is unfortunately not the case for the much more radioactive 7-element lenses."

In which case, there's just no way to produce this same design today. It would have to be a new design.

[Wheatfield]

Why does modern FA 50mm still use the 7 element design? They could use 8 element design and upgrade it DFA.

Any thoughts on this?

The FA 50/1.4 is a 20 year old design, probably based on a 50 year old design. I had one. It required more of an upgrade than what one more element would give it (which would in all likelihood not be a results upgrade at all).

Pentax introduced the D FA* 50/1.4 as a very meaningful upgrade to the FA 50/1.4. If you want an upgrade to the FA 50/1.4, the D FA* lens would be a good place to start.

[SunnyG.]

It's not modern, it's a film era lens, affordable because its development was paid for long ago.

Sounds like you need the DA*55 or DFA*50 for your K-50, Sunny!

The DA 55 is APSC. The DFA is pro. I am talking about an improved FA 50. DFA 50. you understand my point? All those lenses exist. But I am not talking about those.

---------- Post added 11-05-20 at 03:37 PM ----------

He's not saying "add an element", he is assuming the FA50 uses the 7-element Takumar formula, and if they are using that, why would't they go with the 8-element Tak, since that lens is more highly regarded.

Finally someone gets it! Exactly! A modern version of 8 element takumar! With HD coatings and sdm!

---------- Post added 11-05-20 at 03:43 PM ----------

It is most likely not possible to re-use an old lens design and expect it to perform exacly the same today. The type of glass used for the 8 element design are not allowed to be used in manufacturing today as it included toxic materials.

So the optical glass of today do not have the same optical performance as in the past. This is something that they most likely have to compensate for, and if they have to redesign the optical formula they may also want to optimize it for use on high resolution digital cameras. So they may end up with a large lens with Fi 15 lens elements.

It is said that Asahi lost money on every 8 lens element 50/1.4 Takumar they sold as it was expensive and difficult to manufacture. So if they tried to reproduce this design today it would most likely be very expensive. Possibly more expensive than DFA 50/1.4, as it most likely would only be manufactured in small quantities.

As far as I have read, the procedure of cementing the lens elements, was partly responsible for the higher costs. I could be wrong.

But anyways now a days it's not a factor. Also aren't the DA* 200 and 300 based on film era FA series lenses? Their price is less than DFA* 50mm.

---------- Post added 11-05-20 at 03:47 PM ----------

The FA 50/1.4 is a 20 year old design, probably based on a 50 year old design. I had one. It required more of an upgrade than what one more element would give it (which would in all likelihood not be a results upgrade at all).

Pentax introduced the D FA* 50/1.4 as a very meaningful upgrade to the FA 50/1.4. If you want an upgrade to the FA 50/1.4, the D FA* lens would be a good place to start.

DFA* 50, doesn't really look like an upgrade. First of all the FA was never a star lens. Secondly, it's in its own category. A first for Pentax. You can call the DFA* 85 as an upgrade. Cuz an FA* version already exists.

[Wheatfield]

The DA 55 is APSC. The DFA is pro. I am talking about an improved FA 50. DFA 50. you understand my point? All those lenses exist. But I am not talking about those.

---------- Post added 11-05-20 at 03:37 PM ----------


Finally someone gets it! Exactly! A modern version of 8 element takumar! With HD coatings and sdm!

---------- Post added 11-05-20 at 03:43 PM ----------


As far as I have read, the procedure of cementing the lens elements, was partly responsible for the higher costs. I could be wrong.

But anyways now a days it's not a factor. Also aren't the DA* 200 and 300 based on film era FA series lenses? Their price is less than DFA* 50mm.

---------- Post added 11-05-20 at 03:47 PM ----------


DFA* 50, doesn't really look like an upgrade. First of all the FA was never a star lens. Secondly, it's in its own category. A first for Pentax. You can call the DFA* 85 as an upgrade. Cuz an FA* version already exists.

The point is, if you want a better lens, one is available, whether its nomenclature is absolutely correct or not.
Its definitely a performance upgrade over the FA 50/1.4 by every metric.
Also, what new lens introduction would you delay?

[ZombieArmy]

I do wonder why Pentax stuck with the cheaper 7 element designs on the 50s rather than the original 8 element Tak after they did away with the thorium elements. Probably was still prohibitive in cost I guess.

[clackers]

The DA 55 is APSC.

It definitely is a full frame lens, Sunny, I use it all the time.

I would recommend it over the FA50 for sure. It is a Star lens, I'm sure you know what that means.

[stevebrot]

I do wonder why Pentax stuck with the cheaper 7 element designs on the 50s rather than the original 8 element Tak after they did away with the thorium elements. Probably was still prohibitive in cost I guess.

The answer may be summed up in two words, "cemented triplet".


Steve

[Fogel70]

As far as I have read, the procedure of cementing the lens elements, was partly responsible for the higher costs. I could be wrong.

But anyways now a days it's not a factor. Also aren't the DA* 200 and 300 based on film era FA series lenses? Their price is less than DFA* 50mm.[COLOR="Silver"]

It is a big difference to release a new version of lenses that where manufactured a few years earlier, like it was with FA and DA* 200 and 300. FA version where in production until 2004, and DA* version where introduced in 2008.
Compared to release a new lens based on a lens that has not been manufactured for more than 50 years, to replace a lens still in production.

It is almost like asking for the K1 II replacement to be based on technology from Spotmatic.