[PenPusher]

If I have the wrong section appologies.

As you know an F1.2 lenses surfaces once in a blue moon.

Today on European Union e-bay there are three, 55mm Porst, 55mm Cosina and 55mm Revuenon, if memory serves me correctly they all came out of the same factory with different labels but I could be wrong, they have about 3 hours to run from the time of this posting.

I have been informed by the real boss that I do not need one.

Good Luck

CD

[oxidized]

The Porst is a very different optical design and also not as sharp as the Cosina/Revuenon/Vivitar etc. Cosina, Revuenon and Vivitar differ slightly cosmetically but optically they are identical.

[Na Horuk]

The Porst should be cheaper than the others. Its different. If these are auctions, you can decide on a bid that you are willing to go; and then simply not go higher. Or if they are sales, sometimes they allow you to recommend a price, so you can make them an offer and maybe they accept it.
You can do it that way, so that your "f1.2 need" does not get into too much conflict with real boss

And to be honest, f1.2 lenses are really not that useful. Even f1.4 lenses are rarely used at f1.4. F1.2 is really difficult to focus, super shallow DoF, expensive and usually not as sharp.. If you already have a lens around 40-58mm faster than f2, I don't think you would really need that f1.2 - except as a personal treasure (and trust me, I know that itch! I think everyone on this forum understands)

[Alex645]

I once owned a Rokkor 58mm f/1.2 for my Minolta FSLR cameras. It was a beautiful thing to behold, but like others have posted, I was never satisfied with its lack of sharpness, size, weight, and of course cost. For the value, f/1.8 really makes the most sense, and if you really want the best bokeh and shallow depth-of-field, then f/1.4 is my recommendation.

If you're a collector, then I understand. But if it is for photography, short of getting a $10K Noctilux because you've got suitcases of cash weighing down your Tesla, I think there'd be regrets.

[Just1MoreDave]

The DA* 55mm f1.4 is really good and certainly better than my Cosina 55/1.2 at the wide apertures you're paying for. Plus you get AF, auto aperture, weather sealing, SDM and a warranty.

[bwDraco]

Yeah. There really isn't a good reason to do f/1.2 unless you have special requirements that demand that last half-stop of light.

For perspective, the Canon EF 50mm f/1.2L is big and heavy with relatively slow AF (even with Canon's high-performance ring-type USM), and the weight of the lens elements necessitates focus-by-wire where turning the focus ring runs the AF motor; it is not mechanically coupled to the focusing group.

f/1.8 is adequate for most uses with excellent value for money, and f/1.4 provides better performance and more light while remaining reasonably priced.

---

Off-topic: Note that there are valid reasons for focus by wire. For example, all of Canon's newer STM lenses, including the latest version of the EF-S 18-55mm kit lens, are focus-by-wire simply because dropping the mechanical coupling minimizes noise—these are designed to be totally silent for movie recording. The Pentax DA 18-50mm RE is also focus-by-wire, which is necessary to achieve the extremely compact retractable design.

[Jonathan Mac]

Only digital-age lenses of f/1.4 or faster are sharp enough to be used wide open on digital cameras and produce sharp results. Older designed-for-film lenses of that speed are soft at those apertures.

For digital I'd stick to f/1.7 for older lenses, there's no point in going faster. Modern, designed-for-digital lenses should be much better. I've tried a DA* 55/1.4 and wide open it was just within what I'd consider acceptably sharp, much better than the Pentax M, K or Takumar 50/1.4s.

[PenPusher]

The DA* 55mm f1.4 is really good and certainly better than my Cosina 55/1.2 at the wide apertures you're paying for. Plus you get AF, auto aperture, weather sealing, SDM and a warranty.

All of which add a lot of unnecessary size and weight, which you will notice after lugging it around for a day, not to mention the cost. You are far better off with the FA 1.4, small light and relatively inexpensive.

CD

[noelpolar]

mmmm.... my 1.2 makes old wrinkled people just ok...... sometimes softness is worth paying for.

[Just1MoreDave]

All of which add a lot of unnecessary size and weight, which you will notice after lugging it around for a day, not to mention the cost. You are far better off with the FA 1.4, small light and relatively inexpensive.

CD

I don't like big lenses at all but I'm willing to make an exception for the DA* 55/1.4. Well, maybe I cheat sometimes with an F50/1.7.

Cost is my main objection to the f1.2 lenses (that work on Pentaxes). In the marketplace yesterday, you could get a DA* 55/1.4 for slightly less than a Pentax-A 50/1.2 (typically $500). The DA* is only 30g heavier, a lot bulkier. Other f1.2s are all manual and often $300. Used prices vary somewhat of course. Depth of field is nearly identical between a 50mm at f1.2 and a 55mm at f1.4, only slightly different if both lenses are 55mm. A recent sensor probably can make up for the difference in light gathered, until light levels are extremely low.

It's just an alternative suggestion. There are certainly enough lenses in this range so everyone can find the exact ten or twelve they need.

[Kerrowdown]

informed by the real boss that I do not need one

Aye but you tell the boss you get bragging rights with "Special Lady” (SMC Pentax-A 50mm F1.2).

And for when only F1.2 will do.

[bwDraco]

Aye but you tell the boss you get bragging rights with "Special Lady” (SMC Pentax-A 50mm F1.2).

And for when only F1.2 will do.

In days where film topped out at ISO 400 or 800 and push processing came at a significant cost to resolution and dynamic range, lens speed really did matter. Today, things are different, and modern f/1.8 and f/1.4 lenses can deliver excellent optical performance. The focus these days has been on delivering the sharpness today's high-megapixel sensors demand, and that is often more important than speed given what modern sensor technology is capable of in less-than-optimal light. There's a reason Tamron's new SP primes are f/1.8 and not f/1.4.

Of course, though, there are a few situations where that last bit of speed really counts. Modern camera technology, however, has made the need for f/1.2 lenses much less acute than it once was.

[noelpolar]

The whole point of older 50/1.2s is simple. They're special......

Generally, the special things in life defy rationalisation............to try takes away from the experience as you move from heart to head.....

[Pioneer]

Fast 50s really are special lenses. I own several and use them frequently, even with digital.

I have carefully worked with my A 50/1.2 to make sure that it is focused right on the money for my K5iiS, at f/1.2.

Everyone here is absolutely right. No one probably "needs" this fast of a lens. But life would really be boring if all we bought and used were only the lenses we "needed."

As for the lenses you are looking at, I own the Tomioka, which is the company the built the Revuenon/Vivitar series. I use it on my Spottie and it is absolutely wonderful. I have never used the Porst 50/1.2 so cannot comment on whether or not it is any good. Remember, for these really fast lenses, being soft wide open is not necessarily a bad thing. In fact, for many portrait situations, it is a great thing. Most women, as well as a lot of men, are not interested in seeing every wrinkle, blemish and crowsfoot coming out in minute detail in their portraits.

[Digitalis]

Fast 50s really are special lenses.

Some of the f/2.8~f/4 50mm lenses are quite interesting too.

I have carefully worked with my A 50/1.2 to make sure that it is focused right on the money for my K5iiS, at f/1.2.

When you nail the focus the results are impressive:

Pentax K5IIs - Pentax SMC-K 50mm f/1.2 @ f/1.2 - right 100% crop un-sharpened