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SMC M Pentax 50/1,4 is fast as 1.2 lens, @ wide open
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PostPosted: Wed Dec 08, 2010 6:43 am    Post subject: SMC M Pentax 50/1,4 is fast as 1.2 lens, @ wide open Reply with quote
I made a comparation on how fast is the lens. It because on my test before,The Pentax is faster on wide open than HFT Planar.

I made it with Nikkor 55/1.2
I use Canon EOS 1000D, Speed is same @1/750 both wide open.
Pentax


Nikkor 55/1.2


Comparation with FD 55/1,2 SSC has a same result. Same speed, but I delete the image. Itsn't a good one Very Happy

Well... It looks like nikkor is slightly brighter. but If I increase the speed, it will be too dark.I think I have fast lens with cheap price Very Happy
Anybody has same test?


PostPosted: Wed Dec 08, 2010 7:32 am    Post subject: Reply with quote
how can you be sure the ambience light didn't change?


PostPosted: Wed Dec 08, 2010 8:17 am    Post subject: Reply with quote
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!


PostPosted: Wed Dec 08, 2010 8:19 am    Post subject: Reply with quote
Well for the picture above, I took picture & changed lens in short time. Changing lens isn't more than a minute right?
I'll make comparison with my FD 55/1.2 to make it clear. That nikon lens belong to my friend.


PostPosted: Wed Dec 08, 2010 11:30 am    Post subject: Reply with quote
But are you sure that these lenses are really f/1.2 ? It seems more logical (marketing point of view) to say a lens is f/1.2 with f/1.4 transmission than not saying an f/1.4 lens is as fast as f/1.2 Wink


PostPosted: Wed Dec 08, 2010 12:51 pm    Post subject: Reply with quote
keyser1884 wrote:
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!


the fuss is that you can use 1.2 lens for indoor shots without flash.


PostPosted: Wed Dec 08, 2010 1:24 pm    Post subject: Reply with quote
WolverineX wrote:
keyser1884 wrote:
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!


the fuss is that you can use 1.2 lens for indoor shots without flash.


There is much more to it than that. An f/1.2 lens usually has much better bokeh at f/1.8 than an f/1.8 f/1.8 lens wide open. Examples: http://www.fredmiranda.com/forum/topic/924270/16#9034350
(also scroll down to the next message for more examples)


PostPosted: Wed Dec 08, 2010 2:46 pm    Post subject: Reply with quote
keyser1884 wrote:
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!

Nor me, and they're harder to focus too. But you can't expect to convince people who don't mind paying 4x or 5x what they need to, just because they want to keep up with their friends (who know they've wasted their money but can't admit it!) It's like buying a £100,000 car that goes 2mph faster. Smile


PostPosted: Wed Dec 08, 2010 3:56 pm    Post subject: Reply with quote
This thread should be titled "1.2 lens as fast as 1.4", not the other way around Smile

The angle is different in the OP shots, so I'm not sure if whatever blur difference I see is due to that or to the aperture, but the differences are really small indeed.

WolverineX wrote:

the fuss is that you can use 1.2 lens for indoor shots without flash.


The fuss is usually around bokeh, not necessarily speed. There was a thread in PentaxForums about someone reaching the same conclusion about a 1.2 lens having the same light transmission as a 1.4 - he was supposed to look next into the blur difference, but I missed the follow up, if it happened at all.

keyser1884 wrote:
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!


I have a Cosina 55/1.2 - I got it significantly cheaper than the FA50/1.4 sells these days and it is sharp wide open - at least as sharp as the FA. And it gets very sharp when stopped down to f/2 or further. Very nice portrait lens. I heard that the Pentax 1.2s are supposed to be sharp also.

As for the fuss, I agree there is more fuss made than needed. People would have a hard time distinguishing between 1.4 and 1.2 shots.


PostPosted: Wed Dec 08, 2010 7:05 pm    Post subject: Reply with quote
Laurentiu Cristofor wrote:

As for the fuss, I agree there is more fuss made than needed. People would have a hard time distinguishing between 1.4 and 1.2 shots.

I think this is greatly depends on the lenses. Minolta 58/1.2 is quite different from Minolta 58/1.4, Canon EF 50/1.2L is quite different from Canon EF 50/1.4. And I mention only those I interested in. See here some examples http://gallery.me.com/om1er#gallery

Whether the difference in IQ justifies the difference in price is another question.


PostPosted: Wed Dec 08, 2010 7:17 pm    Post subject: Reply with quote
AhamB wrote:
WolverineX wrote:
keyser1884 wrote:
Well F/1.2 is less than half a stop of light quicker than F/1.4. These f/1.2 lenses often tend to be expensive, soft and 'glowy'... I personally don't get what the fuss is about!


the fuss is that you can use 1.2 lens for indoor shots without flash.


There is much more to it than that. An f/1.2 lens usually has much better bokeh at f/1.8 than an f/1.8 f/1.8 lens wide open. Examples: http://www.fredmiranda.com/forum/topic/924270/16#9034350
(also scroll down to the next message for more examples)


Hmmmm, that's interesting! Maybe I'll put some of my own lenses to the test!

Still, I think an f/1.2 lens has too little advantages over an f/1.4 lens to justify the price difference. In fact, about a year of two ago I owned both a Revuenon 50/1.2 and a Takumar 50/1.4. When I was using the Takumar, I rarely felt the need of switching to the f/1.2. In terms of optical quality, both lenses were pretty similar. I decided to sell the Revuenon however, because I preferred the mechanic feel of the Takumar.


PostPosted: Wed Dec 08, 2010 8:36 pm    Post subject: Reply with quote
dimitrygo wrote:

I think this is greatly depends on the lenses. Minolta 58/1.2 is quite different from Minolta 58/1.4, Canon EF 50/1.2L is quite different from Canon EF 50/1.4. And I mention only those I interested in.


Yes, but what is the cause of the difference? I assume it stems from different optical design, not necessarily from the ability to open up to f/1.2.


PostPosted: Wed Dec 08, 2010 10:03 pm    Post subject: Reply with quote
Laurentiu Cristofor wrote:
dimitrygo wrote:

I think this is greatly depends on the lenses. Minolta 58/1.2 is quite different from Minolta 58/1.4, Canon EF 50/1.2L is quite different from Canon EF 50/1.4. And I mention only those I interested in.


Yes, but what is the cause of the difference? I assume it stems from different optical design, not necessarily from the ability to open up to f/1.2.


Different designes and the fact that usually f1.2 lenses are top of the line and flagships of the manufacturers.


PostPosted: Thu Dec 09, 2010 12:02 am    Post subject: Reply with quote
dimitrygo wrote:

Different designes and the fact that usually f1.2 lenses are top of the line and flagships of the manufacturers.


In other words, you'd probably want the lens even if it's f/1.4 for those special optical characteristics. That's all I meant when I said too much fuss is made about f/1.2: most conversations focus on the aperture as being somewhat magical, but in fact the magic, if it's there at all, comes from other sources.


PostPosted: Thu Dec 09, 2010 3:04 pm    Post subject: Reply with quote
caspert79 wrote:
Still, I think an f/1.2 lens has too little advantages over an f/1.4 lens to justify the price difference. In fact, about a year of two ago I owned both a Revuenon 50/1.2 and a Takumar 50/1.4. When I was using the Takumar, I rarely felt the need of switching to the f/1.2. In terms of optical quality, both lenses were pretty similar. I decided to sell the Revuenon however, because I preferred the mechanic feel of the Takumar.


The perceived advantage is very subjective and depends a lot on the lenses that you compare. In the page that I linked to you can see very clearly that the Rokkor 58/1.2 can give a very different look than the 58/1.4. For many people the it's worth the price premium, and the f/1.2 speed is not the only reason for that.


PostPosted: Thu Dec 09, 2010 7:22 pm    Post subject: Reply with quote
I can say that my 150.00 FL 55mm f/1.2 is dramaticaly brighter than any of the 50 f/1.4s i have lying around.

those are pentax-m , summuilux, and nikon.

I was really surprised at how much so.

I'd say test indoors at night.


PostPosted: Thu Dec 09, 2010 7:52 pm    Post subject: Reply with quote
Laurentiu Cristofor wrote:
This thread should be titled "1.2 lens as fast as 1.4", not the other way around Smile

The angle is different in the OP shots, so I'm not sure if whatever blur difference I see is due to that or to the aperture, but the differences are really small indeed.

WolverineX wrote:

the fuss is that you can use 1.2 lens for indoor shots without flash.


The fuss is usually around bokeh, not necessarily speed. There was a thread in PentaxForums about someone reaching the same conclusion about a 1.2 lens having the same light transmission as a 1.4 - he was supposed to look next into the blur difference, but I missed the follow up, if it happened at all.!




But you cant tell if a lens is one lens brighter than another through a viewfinder as f1.4 will always look identical in brightness to f1.2 when viewed through a viewfinder...There are physical limits on how much light a viewfinder can pass. The proof of the pudding in the resulting pics.
If the background in the f1.2 shot looks noticably softer than the one in the f1.4 shot, when both lenses have the same focal length and both are taken from the same position, then the f1.2 lens is certainly faster. If the background has identical softness then both may indeed be passing the same amount of light.


PostPosted: Thu Dec 09, 2010 8:00 pm    Post subject: Comparing lenses Reply with quote
Maybe it's very untechnical, saying so...but is there really any visible difference or do we have to reach a conclusion like "the cheapest lens can't win"?

Let's make some fine pics out there...


PostPosted: Fri Dec 10, 2010 12:24 am    Post subject: Re: SMC M Pentax 50/1,4 is fast as 1.2 lens, @ wide open Reply with quote
IAZA wrote:

Anybody has same test?


no the same, but curiously a Nikkor-S 1.4/50 was a bit faster than a S-M-C 1.4/50 ( which should be indentical to your Pentax M 1.4/50 )


PostPosted: Fri Dec 10, 2010 12:28 am    Post subject: Reply with quote
DSG wrote:

But you cant tell if a lens is one lens brighter than another through a viewfinder as f1.4 will always look identical in brightness to f1.2 when viewed through a viewfinder...


Of course not - you need to take a shot with same exposure settings and see which image comes out as darker.

DSG wrote:

If the background in the f1.2 shot looks noticably softer than the one in the f1.4 shot, when both lenses have the same focal length and both are taken from the same position, then the f1.2 lens is certainly faster


Not sure what you mean by softer - do you mean brighter? The background may look different due to the aperture difference - however, that is a different point than light transmission.


PostPosted: Fri Dec 10, 2010 1:29 am    Post subject: Reply with quote
AhamB wrote:
caspert79 wrote:
Still, I think an f/1.2 lens has too little advantages over an f/1.4 lens to justify the price difference. In fact, about a year of two ago I owned both a Revuenon 50/1.2 and a Takumar 50/1.4. When I was using the Takumar, I rarely felt the need of switching to the f/1.2. In terms of optical quality, both lenses were pretty similar. I decided to sell the Revuenon however, because I preferred the mechanic feel of the Takumar.


The perceived advantage is very subjective and depends a lot on the lenses that you compare. In the page that I linked to you can see very clearly that the Rokkor 58/1.2 can give a very different look than the 58/1.4. For many people the it's worth the price premium, and the f/1.2 speed is not the only reason for that.

I made this test only the speed. Not other aspect. I agree with Ahamb. My FD 55/1.2 SSC is very different than FD 50/1.4 SSC. The color produce, built in optic, and handle light is better.
@kuuan... wow I should search for Nikkor-S 1.4/50 Very Happy
I have 3 50/1.4 lenses, hft planar. this pentax and Fujinon ebc. Pentax M is fastest. This is background why I compare it to 1.2 lens
I think if its juts look for fast lens and cheap, go for 1.4 lens. But if you want to find better optic, color etc. and of course pride Very Happy go for 1.2 lens
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