Shootout! K50/1.4 vs K55/1.8

troika · 06-30-2013, 06:32 PM

I'm not quite sure where I'm going with this, but I find myself owning nice copies of both the K55/1.8 and the K50/1.4. I've been trying to settle in on how I feel them, so I've been comparing results for myself and thought I might as well offer them up here in case someone else was interested. As of this typing, I haven't come to strong conclusions yet, so feel free to weigh in and if you have both lenses and want to contribute your posts, feel free.

I seem to have nice copies of both of these lenses. I've had (and loved) the 55/1.8 for a while now and the 50/1.4 recently came to me in a package trade. I had thought that it wasn't as sharp, but I got a few really nice pictures from it Friday night at a local music venue and so I thought I would set up some controlled tests and compare. Maybe it turns out that I don't need both of these lenses, but I'd have to figure out where my preference was if I was going to part with one. Maybe I keep them both, but if so, I should have a really good understanding of when to use which. No hurry to figure it out and I may update this thread for a while.

So, first test. morning shade, my Manfrotto tripod, green button metering through each aperture. Not totally controlled environment because the light may have changed slightly, though I went through this pretty quickly. Also there was a little breeze and these leaves were blowing slightly, maybe enough at the larger apertures. Two things I'll comment on, one is that the green button doesn't seem perfectly consistent. You can see exposures going up and down a bit, rather than staying consistent. I was walking around with the 50 today and was occasionally metering and then overriding pretty regularly with it and getting good results. That said, based on the metering and the 6 weeks or so that I've had the 50, I'm surprised at how little of impact that 1.4 has vs the 1.8 of the K55. Often it meters it to the same shutter speed or one partial stop away IN EITHER DIRECTION. Maybe not the most accurate indicator, but on light gathering alone, there's some difference, but not as much as I expected. Feel free to look at them on Flickr in whatever size you like and read the EXIF.

For now, I'm just trying to learn as much about each of these lenses as I can and for that matter about taking a decent picture. Maybe it will interest someone else as well.

Without further ado - The K50 photo will always be first and the K55 second. Same aperture and ISO, except at 1.4/1.8
If you'd like to view larger images, feel free to go to my Flickr set http://www.flickr.com/photos/15287103@N03/sets/72157634414087969/

f1.4 / f1.8

f2

f2.8

f4

f5.6

f8

F11

f16

f22

Last edited by troika; 06-30-2013 at 07:16 PM.

troika · 06-30-2013, 06:57 PM

Now a quick bokah test.

I've always really liked the K55 bokah wide open and I'm not sure that I see any real improvements in bokah wide open with the 50/1.4. I've never been a fan of the hexagons that show up in the mid apertures and thought that 50/1.4 would be better in that regard, but this test doesn't really show that. Maybe a small improvement, but not much.

Again, K50 is always first, K55 second.
If you'd like to view larger images, feel free to go to my Flickr set http://www.flickr.com/photos/1528710...7634414087969/

f1.4 / 1.8

f2

f2.8

F4

f5.6

f8

**monochrome** · 06-30-2013, 07:35 PM

50,@ f/5.6 has that 3D magic. Most Pentax lenses do at 5.6 IMHO.

stevebrot · 06-30-2013, 07:56 PM

Hexagons on both sides? I thought the K 50/1.4 had an 8-bladed iris diaphragm.

Steve

**Digitalis** · 06-30-2013, 08:08 PM

Interesting - i did a comparison between the K55mm f/1.8 and my Pentax K 50mm f/1.2 - the 50mm f/1.2 lens was slightly sharper,especially at wider apertures. But in the end the differences between them were so small at f/5.6 they would have been insignificant at print sizes less than A2.

Erd§ · 06-30-2013, 09:33 PM

Originally posted by stevebrot

I thought the K 50/1.4 had an 8-bladed iris diaphragm.

It does.
In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55.

JohnBee · 06-30-2013, 09:45 PM

Originally posted by Erd§

It does.
In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55.

Arg, these tests are flawed!
I demand a refund

troika · 06-30-2013, 11:21 PM

Originally posted by Erd§

It does.
In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55.

I reloaded and relinked those 4 photos. I'm pretty sure that they are as they should be now. It's tough to be 100% sure because the lens isn't identified in the EXIF, but I keyworded them. When i took these pictures this morning, I went through each exposure with one lens, switched lenses and went through them with the other lens, wrote the exposures in a notebook and then checked it with my files when I loaded them. You can see that the shutter speed on the 5.6 photos are slightly different and it's clear at this point at least, they they are different photos.

I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure.

Erd§ · 06-30-2013, 11:39 PM

Originally posted by troika

I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure.

Nah...they look as expected now. I now see octagons in the first f5.6 and f8 pics.

JohnBee · 07-01-2013, 01:01 AM

Originally posted by troika

I reloaded and relinked those 4 photos. I'm pretty sure that they are as they should be now. It's tough to be 100% sure because the lens isn't identified in the EXIF, but I keyworded them. When i took these pictures this morning, I went through each exposure with one lens, switched lenses and went through them with the other lens, wrote the exposures in a notebook and then checked it with my files when I loaded them. You can see that the shutter speed on the 5.6 photos are slightly different and it's clear at this point at least, they they are different photos.

I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure.

Thanks for all your hard work with this

BTW I've found that the 50/1.4 performs very well on a FF sensor with seemingly smoother OOF highlights than on crop:

Jonathan Mac · 07-01-2013, 01:45 AM

Thanks for the comparison. I also have both of these lenses but have never really put either of them through their paces, or even used them much (I have alot of 50s...).

Both seem nice and sharp with good colours and contrast, though the 55, surprisingly, seems to have smoother bokeh at smaller apertures.

Class A · 07-01-2013, 01:54 AM

I like my K55/1.8 a lot.

I wouldn't buy the DA* 55/1.4, but if they did an AF version of the K55/1.8, I'd buy it immediately.

I also have the FA 50/1.4 but for a portrait where I'm after something special, I'd go for the K 55/1.8.

**jt_cph_dk** · 07-01-2013, 02:29 AM

Originally posted by troika

Two things I'll comment on, one is that the green button doesn't seem perfectly consistent. You can see exposures going up and down a bit, rather than staying consistent

If you have a split prism, then that is probably the cause of the inconsistent measurement. They fool the pentaprism. Use LV for consistent measurements.

The Super-Takumar 1.4/50 1. version from `64 has an extraordinary image quality, different from all later Pentax fifties, which I find yields very similar (and great) IQ 50s 55s alike.
Have a look here: Super-Takumar 1.4/50 - a set on Flickr

drypenn · 07-01-2013, 03:11 AM

Originally posted by Class A

I like my K55/1.8 a lot.

I wouldn't buy the DA* 55/1.4, but if they did an AF version of the K55/1.8, I'd buy it immediately.

I also have the FA 50/1.4 but for a portrait where I'm after something special, I'd go for the K 55/1.8.

I have exactly the same glasses (K55 and FA50), and exactly the same thought (apathetic to DA*55/1.4)

troika · 07-01-2013, 08:46 AM

Originally posted by Erd§

Nah...they look as expected now. I now see octagons in the first f5.6 and f8 pics.

You know, I didn't count the sides, you're right, hexagons vs octagons. Sorry for the false start on the post the first time, it's confusing all of these pictures. This is exactly one of the reasons I wanted to share this here, I learn a lot from hearing about what you guys see and know.

Thanks for the responses everyone.

06-30-2013, 06:32 PM	#1
troika Pentaxian Join Date: Dec 2012 Location: Seattle, WA USA Posts: 1,753	Shootout! K50/1.4 vs K55/1.8 I'm not quite sure where I'm going with this, but I find myself owning nice copies of both the K55/1.8 and the K50/1.4. I've been trying to settle in on how I feel them, so I've been comparing results for myself and thought I might as well offer them up here in case someone else was interested. As of this typing, I haven't come to strong conclusions yet, so feel free to weigh in and if you have both lenses and want to contribute your posts, feel free. I seem to have nice copies of both of these lenses. I've had (and loved) the 55/1.8 for a while now and the 50/1.4 recently came to me in a package trade. I had thought that it wasn't as sharp, but I got a few really nice pictures from it Friday night at a local music venue and so I thought I would set up some controlled tests and compare. Maybe it turns out that I don't need both of these lenses, but I'd have to figure out where my preference was if I was going to part with one. Maybe I keep them both, but if so, I should have a really good understanding of when to use which. No hurry to figure it out and I may update this thread for a while. So, first test. morning shade, my Manfrotto tripod, green button metering through each aperture. Not totally controlled environment because the light may have changed slightly, though I went through this pretty quickly. Also there was a little breeze and these leaves were blowing slightly, maybe enough at the larger apertures. Two things I'll comment on, one is that the green button doesn't seem perfectly consistent. You can see exposures going up and down a bit, rather than staying consistent. I was walking around with the 50 today and was occasionally metering and then overriding pretty regularly with it and getting good results. That said, based on the metering and the 6 weeks or so that I've had the 50, I'm surprised at how little of impact that 1.4 has vs the 1.8 of the K55. Often it meters it to the same shutter speed or one partial stop away IN EITHER DIRECTION. Maybe not the most accurate indicator, but on light gathering alone, there's some difference, but not as much as I expected. Feel free to look at them on Flickr in whatever size you like and read the EXIF. For now, I'm just trying to learn as much about each of these lenses as I can and for that matter about taking a decent picture. Maybe it will interest someone else as well. Without further ado - The K50 photo will always be first and the K55 second. Same aperture and ISO, except at 1.4/1.8 If you'd like to view larger images, feel free to go to my Flickr set http://www.flickr.com/photos/15287103@N03/sets/72157634414087969/ f1.4 / f1.8 f2 f2.8 f4 f5.6 f8 F11 f16 f22 Last edited by troika; 06-30-2013 at 07:16 PM.

06-30-2013, 06:57 PM	#2
troika Pentaxian Join Date: Dec 2012 Location: Seattle, WA USA Posts: 1,753 Original Poster	Now a quick bokah test. I've always really liked the K55 bokah wide open and I'm not sure that I see any real improvements in bokah wide open with the 50/1.4. I've never been a fan of the hexagons that show up in the mid apertures and thought that 50/1.4 would be better in that regard, but this test doesn't really show that. Maybe a small improvement, but not much. Again, K50 is always first, K55 second. If you'd like to view larger images, feel free to go to my Flickr set http://www.flickr.com/photos/1528710...7634414087969/ f1.4 / 1.8 f2 f2.8 F4 f5.6 f8 Last edited by troika; 06-30-2013 at 11:17 PM.

06-30-2013, 09:33 PM	#6
Erd§ Veteran Member Join Date: Aug 2010 Location: SEQ Posts: 323	Originally posted by stevebrot I thought the K 50/1.4 had an 8-bladed iris diaphragm. It does. In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55. Last edited by Erd§; 06-30-2013 at 09:34 PM. Reason: typo

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06-30-2013, 07:35 PM	#3
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	50,@ f/5.6 has that 3D magic. Most Pentax lenses do at 5.6 IMHO.

06-30-2013, 07:56 PM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Hexagons on both sides? I thought the K 50/1.4 had an 8-bladed iris diaphragm. Steve

06-30-2013, 08:08 PM	#5
Digitalis Site Supporter Join Date: Mar 2009 Location: Melbourne, Victoria Photos: Gallery Posts: 11,694	Interesting - i did a comparison between the K55mm f/1.8 and my Pentax K 50mm f/1.2 - the 50mm f/1.2 lens was slightly sharper,especially at wider apertures. But in the end the differences between them were so small at f/5.6 they would have been insignificant at print sizes less than A2.

06-30-2013, 09:45 PM	#7
JohnBee Veteran Member Join Date: Sep 2008 Location: Newrfoundland Photos: Albums Posts: 4,667	Originally posted by Erd§ It does. In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55. Arg, these tests are flawed! I demand a refund

06-30-2013, 11:21 PM	#8
troika Pentaxian Join Date: Dec 2012 Location: Seattle, WA USA Posts: 1,753 Original Poster	Originally posted by Erd§ It does. In the bokeh set, it appears the OP has mistakenly displayed the same pic twice at f5.6 and twice at f8 - each being from the 55. I reloaded and relinked those 4 photos. I'm pretty sure that they are as they should be now. It's tough to be 100% sure because the lens isn't identified in the EXIF, but I keyworded them. When i took these pictures this morning, I went through each exposure with one lens, switched lenses and went through them with the other lens, wrote the exposures in a notebook and then checked it with my files when I loaded them. You can see that the shutter speed on the 5.6 photos are slightly different and it's clear at this point at least, they they are different photos. I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure.

06-30-2013, 11:39 PM	#9
Erd§ Veteran Member Join Date: Aug 2010 Location: SEQ Posts: 323	Originally posted by troika I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure. Nah...they look as expected now. I now see octagons in the first f5.6 and f8 pics.

07-01-2013, 01:01 AM	#10
JohnBee Veteran Member Join Date: Sep 2008 Location: Newrfoundland Photos: Albums Posts: 4,667	Originally posted by troika I reloaded and relinked those 4 photos. I'm pretty sure that they are as they should be now. It's tough to be 100% sure because the lens isn't identified in the EXIF, but I keyworded them. When i took these pictures this morning, I went through each exposure with one lens, switched lenses and went through them with the other lens, wrote the exposures in a notebook and then checked it with my files when I loaded them. You can see that the shutter speed on the 5.6 photos are slightly different and it's clear at this point at least, they they are different photos. I'm still seeing hexagons. I can retest it some time this week to be certain...but I'm pretty sure. Thanks for all your hard work with this BTW I've found that the 50/1.4 performs very well on a FF sensor with seemingly smoother OOF highlights than on crop:

07-01-2013, 01:45 AM	#11
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,911	Thanks for the comparison. I also have both of these lenses but have never really put either of them through their paces, or even used them much (I have alot of 50s...). Both seem nice and sharp with good colours and contrast, though the 55, surprisingly, seems to have smoother bokeh at smaller apertures.

07-01-2013, 01:54 AM	#12
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	I like my K55/1.8 a lot. I wouldn't buy the DA* 55/1.4, but if they did an AF version of the K55/1.8, I'd buy it immediately. I also have the FA 50/1.4 but for a portrait where I'm after something special, I'd go for the K 55/1.8.

07-01-2013, 02:29 AM	#13
jt_cph_dk Site Supporter Join Date: Apr 2011 Location: Copenhagen Photos: Gallery \| Albums Posts: 510	Originally posted by troika Two things I'll comment on, one is that the green button doesn't seem perfectly consistent. You can see exposures going up and down a bit, rather than staying consistent If you have a split prism, then that is probably the cause of the inconsistent measurement. They fool the pentaprism. Use LV for consistent measurements. The Super-Takumar 1.4/50 1. version from `64 has an extraordinary image quality, different from all later Pentax fifties, which I find yields very similar (and great) IQ 50s 55s alike. Have a look here: Super-Takumar 1.4/50 - a set on Flickr

07-01-2013, 03:11 AM	#14
drypenn Veteran Member Join Date: Nov 2012 Photos: Albums Posts: 963	Originally posted by Class A I like my K55/1.8 a lot. I wouldn't buy the DA* 55/1.4, but if they did an AF version of the K55/1.8, I'd buy it immediately. I also have the FA 50/1.4 but for a portrait where I'm after something special, I'd go for the K 55/1.8. I have exactly the same glasses (K55 and FA50), and exactly the same thought (apathetic to DA*55/1.4)

07-01-2013, 08:46 AM	#15
troika Pentaxian Join Date: Dec 2012 Location: Seattle, WA USA Posts: 1,753 Original Poster	Originally posted by Erd§ Nah...they look as expected now. I now see octagons in the first f5.6 and f8 pics. You know, I didn't count the sides, you're right, hexagons vs octagons. Sorry for the false start on the post the first time, it's confusing all of these pictures. This is exactly one of the reasons I wanted to share this here, I learn a lot from hearing about what you guys see and know. Thanks for the responses everyone.