[noelpolar]

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I preffer a lens that performs poorly.... so it's not me.....

[JohsonChou]

For the bokeh test:
A is AIV and B is MIJ.

[jpzk]

I have the AIV type ... no problem for me.
I don't think having the MIJ type would make much difference, to me.
Mind you, some people are dead centered on the MIF "because" it is all made in Japan ! ... Go figure.

And ... I don't see the point in people trying to sell the MIJ at a premium over the AIV.

[Digitalis]

I don't see the point in people trying to sell the MIJ at a premium over the AIV

Nor do I. They are optically identical.

[JohsonChou]

Nor do I. They are optically identical.

Maybe it is because terrible people like me likes it silver...

[yucatanPentax]

It appears you have put a fair amount of effort into this, IMO anyone who tries to compare lenses for "fun" isn't doing it properly or with the required scientific rigor that, what is for many is still considered a controversial topic. Testing lenses like the FA31 isn't easy, the only way you can make any distinction that is statistically significant between these lenses is by testing multiple copies and taking the variables introduced by the camera itself out of the equation entirely. Also the lighting has changed in the "pixie dust test" images - which can introduce bias towards an image, rather than emphasize the qualities of the lenses you are trying to differentiate between....in other words noise is overpowering the signal.

Take this into account: the FA43 one of the first of the FA limited lenses has had its coatings changed three times over its production history*. It is important to note that the optical design has remained consistent in all cases. The early silver versions** of the FA43 had different coatings from the later black versions. The LTM mount FA43 has different coatings and was produced in a limited number: 1000 made for sale in Japan. The differences between the K mount and the LTM version of the FA43 doesn't stop there: the LTM version also has 9 aperture blades compared to the K mount versions of the SMCP-FA43mm f/1.9 which have only 8 bladed apertures.

It isn't far fetched that the FA31 may have gone under some minor revisions over time, the FA77 most likely has too. The important thing is that the optical design has not been changed.

* That I'm aware of.
**the first hundred or so that were put into production.

Just curious what you think, or have heard, Digitalis, on the supposed lens composition of the early FA 43's vs later. Specifically, lead. Supposedly, earliest versions had lead in the glass, which was later reformulated.

I realize this is very likely an urban legend, or if true, has little bearing. I just thought I'd ask since you mentioned the coating variations. Thought you may know something about the glass composition. Do you think the lead (if true) has any effect on the image? TIA

[jpzk]

Maybe it is because terrible people like me likes it silver...

... Mine is AIV and ... silver !

[JohsonChou]

... Mine is AIV and ... silver !

Oh, lucky you! I don't think you can get new silver ones now.

[Digitalis]

on the supposed lens composition of the early FA 43's vs later. Specifically, lead. Supposedly, earliest versions had lead in the glass, which was later reformulated.

I have heard many things about the early FA43, there was even a rumor that the early batch of 100 lenses in production had aspherical elements in them. This has been thoroughly debunked.

Thought you may know something about the glass composition. Do you think the lead (if true) has any effect on the image?

This is much harder to prove, I have no proof but my instincts say: No. Leaded glass (over 5% lead by weight) is still in production (albeit in very small amounts). Hypothetically, to prove this non-destructively I could pull two lenses apart entirely and use an abbe refractometer* to calculate the abbe number of each lens element and compare each elements RI to early and modern examples of the lens, and see if there is any difference in the abbe number which would indicate a change of chemical composition (the geometry of the elements would be another, indirect way to tell) . However, an abbe refractometer is something I do not have - and they are expensive. An ICP-MS** would be quicker, and give a definitive answer to the chemical composition of the glass elements, but it would require both the elements from both lenses be subjected to chemical treatments that would in all probability, destroy them completely.

* you can get hand held versions of these for gemological use, but I doubt these would have the accuracy, or be designed for use in measuring optical glass. There are laboratory grade refractometers used for analyzing properties of glass, but they are big - and expensive.
**Inductively coupled plasma mass spectrometer, again: expensive, and something I do not own...hey,perhaps I should start a gofundme so I could get one.

[noelpolar]

I can confirm some stuff about the early FA43. I have one that is serial number 0000347.

When used, firstly with the K5II, then the K3 I began to suspect something but refused to be drawn on it. Now I have tried it on my K-1, and subsequently undertaken rigorous testing I am willing to take a public stance with my findings, that I believe are beyond repute.

Generally, my findings are: my shots still suck. Maybe there is a more special lens out there that will change all that........

[Digitalis]

Generally, my findings are: my shots still suck.

I have a question that might possibly be related to this: have you ever tasted saké?

[noelpolar]

I have a question that might possibly be related to this: have you ever tasted saké?

I have.... and after a bit of it.... if I squint.... some of my shots aren't so bad anymore.... anyway.... I've accepted that this life is about up-skilling..... and the next will be worthy of photographing and I'll be ready..... and be nice to me..... I can spot you in a full Adelaide Central Market remember....

[Digitalis]

I have.... and after a bit of it.... if I squint.... some of my shots aren't so bad anymore.

hmm, is this proportional to the amount of saké consumed?

[noelpolar]

hmm, is this proportional to the amount of saké consumed?

up to a point.... then everything looks good....for a short while.... then well.... I can't be sure anymore of anything really.... except feeling my age.

Anyway I recommend this stuff...... https://en.wikipedia.org/wiki/Maotai after a bit you won't care about any lenses....

[Unregistered User 8]

Oh, lucky you! I don't think you can get new silver ones now.

Australian dollars.
Pentax SMCP FA 31mm F/1.8 LIMTED LENS - SILVER & BONUS 16GB SD CARD 27075051133 | eBay