Pentax SMC K 1.8 55mm vs. A 1.7 50mm?

paperbag846 · 08-27-2010, 07:41 AM

I am blown away at the quality of my SMC K 55mm 1.8. To my eyes it just makes people and objects look beautiful. I'll use the cliche "3D".

I have the opportunity to swap it for a SMC A 1.7.

Should I do it? Is the IQ Better with the SMC A? Some people would have me believe that...

The only thing I find frustrating with the 55mm is the inaccuracy of stop down metering.

So between them, which would you pick?

axl · 08-27-2010, 08:45 AM - **1 Like**

If you love K55 don't swap.
I used to have both but sold them. I wouldn't say IQ of A50 is better. It may be tad sharper wide open but stopped down the K is at least as sharp if not sharper. Those 5mm do make difference and I'd say K55 has nicer OOF wide open thanks to this. Stopped down both suffer from hexagonal (and sometimes jagged hexagonal) OOF highlights. I always preferred 50 for general use but 55 is terrific for portraits IMO. K55/1.8 is also warmer in tone than A50/1.7 and quite a bit so IMO. K is better built too but A is smaller and lighter. And of course there is the advantage of having A setting. If your budget permits have both IMO.

Hope this helps, regards Peter

paperbag846 · 08-27-2010, 09:02 AM

Originally posted by axl

If you love K55 don't swap.
I used to have both but sold them. I wouldn't say IQ of A50 is better. It may be tad sharper wide open but stopped down the K is at least as sharp if not sharper. Those 5mm do make difference and I'd say K55 has nicer OOF wide open thanks to this. Stopped down both suffer from hexagonal (and sometimes jagged hexagonal) OOF highlights. I always preferred 50 for general use but 55 is terrific for portraits IMO. K55/1.8 is also warmer in tone than A50/1.7 and quite a bit so IMO. K is better built too but A is smaller and lighter. And of course there is the advantage of having A setting. If your budget permits have both IMO.

Hope this helps, regards Peter

I love the handling of the K55. Compared to my A 28mm it feels like a "real" lens. I think the biggest difference isn't about IQ at all - the focusing ring is so beautiful on the 55 (and I'm sure most/all of the K/M lenses).

Do you find the difference between 50mm and 55mm is a big deal indoors? I've tried comparing the two with my kit lens, but since I almost always crop to a certain degree, I don't see much functional difference between them.

If sharpness is a wash and the k55 has nicer bokeh due to the focal length, i'll stick with the k55. It's mostly for portraits and landscapes. I'll save up and buy an FA 1.4 one day

.

Thanks for the advice!

séamuis · 08-27-2010, 09:16 AM

which camera body are you using for stop down metering with the K? personally, the K is the better lens overall, at least from my personal use and the K version of the 55mm 1.8 basically lives on my K7. you cant of course discount the ease of use of the ‘A’ setting in regards to both program exposure modes and use of strobes. if you are using these lenses mostly for portraits, I would say stick to the 55mm. (I am, and always will be biased towards the 55) but the difference in max aperture isn’t that much, so you are not gaining much in moving to the 1.7. I have owned and used both extensively, and I feel that the 55 is just a much better lens in everyday use. particularly for wide aperture portraits.

in regards to inaccuracy, I can honestly say that with the K7 that its not a problem. I have tested side by side with screwnount bodies using the 55mm takumars, kmount bodies with the K and a hand held sekonic light meter, and the metering the K7 gives is almost always dead on. the only camera that didn’t always agree with me was the MX.

paperbag846 · 08-27-2010, 09:57 AM

Originally posted by séamuis

in regards to inaccuracy, I can honestly say that with the K7 that its not a problem. I have tested side by side with screwnount bodies using the 55mm takumars, kmount bodies with the K and a hand held sekonic light meter, and the metering the K7 gives is almost always dead on. the only camera that didn’t always agree with me was the MX.

I'm using the k20d, and would rather spend 100 dollars on a new lens than a replacement viewfinder... but that's just me. After i figure out the light the metering problem is a non-issue.

bdery · 08-27-2010, 11:04 AM

Let's be honest about one thing : when comparing 50s, we are comparing the best lenses out there more often than not. So saying "lens x is better" means "both lenses have amazing IQ, but if we HAVE to compare, lens X is better on one specific aspect"...

I'd say it's a balance between the comfort of a lens you know vs the convenience of auto-exposure. Sure there might be small differences between the rendering of the two lenses, but it's really quite marginal.

paperbag846 · 08-27-2010, 12:54 PM

Yeah I noticed that almost immediately when comparing the 55 to my 28mm f2.8. The k55 is just a beautiful lens.

Thanks for the advice everyone. I think I'll hang onto the K55, if for no other reason, then it is a rarer lens than the A 50 or M 50, and is more of a unique focal length.

One day I'll own a FA 50 1.4.... excited for that day.

m42man · 08-27-2010, 10:56 PM

Have a look here (this is the third time I've posted this link in 2 days!):

Nifty 50 Shootout ERPhotoReview

This tests the F 50/1.7 and Tak SMC 55/1.8, which will no doubt be similar to the A50/1.7 and K 55/1.8.

I think the 50/1.4 is the one to have (but it's expensive!). I don't have any experience of the 55/1.8 (in any form), but I do have an M 50/1.7, and don't find it particularly special (in fact it has the worst colour rendition of all my 50s).

Oro · 08-28-2010, 01:26 AM - **1 Like**

When you say "blown away" what are you comparing it to? A kit lens? Or another 50mm? I don't have an apples-to-apples comparison for you, but I will in a week. I have a K 55mm/1.8 on the way, and I have two M 50/1.7s and an A 50/2. These I have had for almost two decades, though only know really using on DSLR and comparing critically. I also have a K 50/4 Macro on the way.

Originally posted by bdery:

Sure there might be small differences between the rendering of the two lenses, but it's really quite marginal.

This is what I am finding as I grow my 50(-ish, counting the 55) collection.

Between the two M50/1.7s I have no difference. Between the M 50/1.7 and the A 50/2, I see no difference, just like what m42man just said - I see nothing special in the M 50/1.7 and I have two copies I've tried. It's good, very good. But no different vs. a 2 except the f-stop. But based on "buzz" I am really excited to see what the 55/1.8 does and the 50/4. From what I can extrapolate the 55/1.8 should be much more interesting than the 50/1.7.

As to metering, I find my A 50/2 and M50/1.7s meter exactly the same in AV for the A and stop-down with the M. I have run some tests on that at every f-stop. Maybe there is something peculiar about the 55/1.8? Anyway, I am going to do some head-to-head comparisons in about a week.

I am betting what I will eventually do is get an A 50/1.4, and keep that and the K 50/4 macro, sell the others. I bet I will keep the 55/1.8 for novelty value. That is my bet now; we'll see how it plays out in a month's time and lots of tests.

Quote:

One day I'll own a FA 50 1.4.... excited for that day.

I feel that way, too. I bet in a year or two I will spring for one and be overjoyed.

Pentaxor · 08-28-2010, 02:07 AM - **1 Like**

I have a 50/1.7, 50/2 and 55/1.8. the differences between the 3 lenses would fall under bokeh rendering and quality in certain situations and color temperature. the 50/2 shows a warmer cast, the 50/1.7 a bit cool and the 55/1.8 a bit warm. as far as the bokeh quality goes, the 50/1.7 can be busy or destructive at times, the 50/2 quite the soft bokeh type which I find unpleasant, and the 55/1.8 has that smooth bokeh rendering that makes it the best portrait lens among the 3 lenses.

m42man · 08-28-2010, 02:32 AM

Originally posted by Pentaxor

I have a 50/1.7, 50/2 and 55/1.8. the differences between the 3 lenses would fall under bokeh rendering and quality in certain situations and color temperature. the 50/2 shows a warmer cast, the 50/1.7 a bit cool and the 55/1.8 a bit warm. as far as the bokeh quality goes, the 50/1.7 can be busy or destructive at times, the 50/2 quite the soft bokeh type which I find unpleasant, and the 55/1.8 has that smooth bokeh rendering that makes it the best portrait lens among the 3 lenses.

Haha! Confirmation of "cool" for the f1.7! Mine transforms my red car into a sort of cerise. On top of that, it has poorer contrast than my other (i.e. non-Pentax) 50s. And I fully agree about its bokeh.

I rather like "soft" bokeh, so I might try to get hold of a cheap f2.

As for the 55/1.8, I can see I'm going to have to get one! (Probably in Tak manifestation.)

paperbag846 · 08-28-2010, 05:56 AM

I would agree that the bokeh of the 55mm is far superior to anything i have tried:

kit lens (duh)
SMC A 28mm 2.8 (better bokeh than the kit... but not really)
Takupmar Bayonet 80-200 (this lens actually has a nicer bokeh than the kit or 28mm... maybe it;s the focal length?
Soligor C/D 70-200 (sold)
Vivitar RMC 70-210 (sold)

So I have NOT done an apples to apples comparison, but I LOVE the look of this lens over anything I have ever tried.

If the 55mm has a special look to it compared to the 50mm 1.7, then I think I'll keep the 55mm 1.8 for sure.

Thanks everyone!

paperbag846 · 08-28-2010, 06:00 AM

Originally posted by Oro

As to metering, I find my A 50/2 and M50/1.7s meter exactly the same in AV for the A and stop-down with the M. I have run some tests on that at every f-stop. Maybe there is something peculiar about the 55/1.8? Anyway, I am going to do some head-to-head comparisons in about a week.

What's your camera model? The k20d has a documented problem metering with manual glass as you move the fstop from f4.

Adam · 08-28-2010, 08:35 AM

Originally posted by m42man

Haha! Confirmation of "cool" for the f1.7! it has poorer contrast than my other (i.e. non-Pentax) 50s.

have you tried using a good hood inorder to improve contrast? it makes a world of difference.

Pentaxor · 08-28-2010, 08:39 AM

Originally posted by paperbag846

So I have NOT done an apples to apples comparison, but I LOVE the look of this lens over anything I have ever tried.

funny you mentioned an apple to apple comparison, since I did use an apple literally in doing some comparative test shots. that's when I knew then that the 55 is special.

08-27-2010, 07:41 AM	#1
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395	Pentax SMC K 1.8 55mm vs. A 1.7 50mm? I am blown away at the quality of my SMC K 55mm 1.8. To my eyes it just makes people and objects look beautiful. I'll use the cliche "3D". I have the opportunity to swap it for a SMC A 1.7. Should I do it? Is the IQ Better with the SMC A? Some people would have me believe that... The only thing I find frustrating with the 55mm is the inaccuracy of stop down metering. So between them, which would you pick?

08-28-2010, 08:35 AM	#14
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by m42man Haha! Confirmation of "cool" for the f1.7! it has poorer contrast than my other (i.e. non-Pentax) 50s. have you tried using a good hood inorder to improve contrast? it makes a world of difference. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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08-27-2010, 08:45 AM - 1 Like	#2
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	If you love K55 don't swap. I used to have both but sold them. I wouldn't say IQ of A50 is better. It may be tad sharper wide open but stopped down the K is at least as sharp if not sharper. Those 5mm do make difference and I'd say K55 has nicer OOF wide open thanks to this. Stopped down both suffer from hexagonal (and sometimes jagged hexagonal) OOF highlights. I always preferred 50 for general use but 55 is terrific for portraits IMO. K55/1.8 is also warmer in tone than A50/1.7 and quite a bit so IMO. K is better built too but A is smaller and lighter. And of course there is the advantage of having A setting. If your budget permits have both IMO. Hope this helps, regards Peter

08-27-2010, 09:02 AM	#3
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395 Original Poster	Originally posted by axl If you love K55 don't swap. I used to have both but sold them. I wouldn't say IQ of A50 is better. It may be tad sharper wide open but stopped down the K is at least as sharp if not sharper. Those 5mm do make difference and I'd say K55 has nicer OOF wide open thanks to this. Stopped down both suffer from hexagonal (and sometimes jagged hexagonal) OOF highlights. I always preferred 50 for general use but 55 is terrific for portraits IMO. K55/1.8 is also warmer in tone than A50/1.7 and quite a bit so IMO. K is better built too but A is smaller and lighter. And of course there is the advantage of having A setting. If your budget permits have both IMO. Hope this helps, regards Peter I love the handling of the K55. Compared to my A 28mm it feels like a "real" lens. I think the biggest difference isn't about IQ at all - the focusing ring is so beautiful on the 55 (and I'm sure most/all of the K/M lenses). Do you find the difference between 50mm and 55mm is a big deal indoors? I've tried comparing the two with my kit lens, but since I almost always crop to a certain degree, I don't see much functional difference between them. If sharpness is a wash and the k55 has nicer bokeh due to the focal length, i'll stick with the k55. It's mostly for portraits and landscapes. I'll save up and buy an FA 1.4 one day . Thanks for the advice!

08-27-2010, 09:16 AM	#4
séamuis Banned Join Date: Oct 2007 Location: Savannah, U.S./Baguio City, P.H. Posts: 5,979	which camera body are you using for stop down metering with the K? personally, the K is the better lens overall, at least from my personal use and the K version of the 55mm 1.8 basically lives on my K7. you cant of course discount the ease of use of the ‘A’ setting in regards to both program exposure modes and use of strobes. if you are using these lenses mostly for portraits, I would say stick to the 55mm. (I am, and always will be biased towards the 55) but the difference in max aperture isn’t that much, so you are not gaining much in moving to the 1.7. I have owned and used both extensively, and I feel that the 55 is just a much better lens in everyday use. particularly for wide aperture portraits. in regards to inaccuracy, I can honestly say that with the K7 that its not a problem. I have tested side by side with screwnount bodies using the 55mm takumars, kmount bodies with the K and a hand held sekonic light meter, and the metering the K7 gives is almost always dead on. the only camera that didn’t always agree with me was the MX.

08-27-2010, 09:57 AM	#5
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395 Original Poster	Originally posted by séamuis in regards to inaccuracy, I can honestly say that with the K7 that its not a problem. I have tested side by side with screwnount bodies using the 55mm takumars, kmount bodies with the K and a hand held sekonic light meter, and the metering the K7 gives is almost always dead on. the only camera that didn’t always agree with me was the MX. I'm using the k20d, and would rather spend 100 dollars on a new lens than a replacement viewfinder... but that's just me. After i figure out the light the metering problem is a non-issue.

08-27-2010, 11:04 AM	#6
bdery Pentaxian Join Date: Mar 2008 Location: Quebec city, Canada Photos: Gallery Posts: 9,357	Let's be honest about one thing : when comparing 50s, we are comparing the best lenses out there more often than not. So saying "lens x is better" means "both lenses have amazing IQ, but if we HAVE to compare, lens X is better on one specific aspect"... I'd say it's a balance between the comfort of a lens you know vs the convenience of auto-exposure. Sure there might be small differences between the rendering of the two lenses, but it's really quite marginal.

08-27-2010, 12:54 PM	#7
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395 Original Poster	Yeah I noticed that almost immediately when comparing the 55 to my 28mm f2.8. The k55 is just a beautiful lens. Thanks for the advice everyone. I think I'll hang onto the K55, if for no other reason, then it is a rarer lens than the A 50 or M 50, and is more of a unique focal length. One day I'll own a FA 50 1.4.... excited for that day.

08-27-2010, 10:56 PM	#8
m42man Veteran Member Join Date: Jan 2010 Location: Southern England Posts: 623	Have a look here (this is the third time I've posted this link in 2 days!): Nifty 50 Shootout ERPhotoReview This tests the F 50/1.7 and Tak SMC 55/1.8, which will no doubt be similar to the A50/1.7 and K 55/1.8. I think the 50/1.4 is the one to have (but it's expensive!). I don't have any experience of the 55/1.8 (in any form), but I do have an M 50/1.7, and don't find it particularly special (in fact it has the worst colour rendition of all my 50s).

08-28-2010, 01:26 AM - 1 Like	#9
Oro Junior Member Join Date: Aug 2010 Location: Seattle-ish, USA Photos: Gallery \| Albums Posts: 41	When you say "blown away" what are you comparing it to? A kit lens? Or another 50mm? I don't have an apples-to-apples comparison for you, but I will in a week. I have a K 55mm/1.8 on the way, and I have two M 50/1.7s and an A 50/2. These I have had for almost two decades, though only know really using on DSLR and comparing critically. I also have a K 50/4 Macro on the way. Originally posted by bdery: Sure there might be small differences between the rendering of the two lenses, but it's really quite marginal. This is what I am finding as I grow my 50(-ish, counting the 55) collection. Between the two M50/1.7s I have no difference. Between the M 50/1.7 and the A 50/2, I see no difference, just like what m42man just said - I see nothing special in the M 50/1.7 and I have two copies I've tried. It's good, very good. But no different vs. a 2 except the f-stop. But based on "buzz" I am really excited to see what the 55/1.8 does and the 50/4. From what I can extrapolate the 55/1.8 should be much more interesting than the 50/1.7. As to metering, I find my A 50/2 and M50/1.7s meter exactly the same in AV for the A and stop-down with the M. I have run some tests on that at every f-stop. Maybe there is something peculiar about the 55/1.8? Anyway, I am going to do some head-to-head comparisons in about a week. I am betting what I will eventually do is get an A 50/1.4, and keep that and the K 50/4 macro, sell the others. I bet I will keep the 55/1.8 for novelty value. That is my bet now; we'll see how it plays out in a month's time and lots of tests. Quote: One day I'll own a FA 50 1.4.... excited for that day. I feel that way, too. I bet in a year or two I will spring for one and be overjoyed.

08-28-2010, 02:07 AM - 1 Like	#10
Pentaxor Veteran Member Join Date: May 2009 Location: Vancouver, B.C. Photos: Gallery Posts: 6,513	I have a 50/1.7, 50/2 and 55/1.8. the differences between the 3 lenses would fall under bokeh rendering and quality in certain situations and color temperature. the 50/2 shows a warmer cast, the 50/1.7 a bit cool and the 55/1.8 a bit warm. as far as the bokeh quality goes, the 50/1.7 can be busy or destructive at times, the 50/2 quite the soft bokeh type which I find unpleasant, and the 55/1.8 has that smooth bokeh rendering that makes it the best portrait lens among the 3 lenses.

08-28-2010, 02:32 AM	#11
m42man Veteran Member Join Date: Jan 2010 Location: Southern England Posts: 623	Originally posted by Pentaxor I have a 50/1.7, 50/2 and 55/1.8. the differences between the 3 lenses would fall under bokeh rendering and quality in certain situations and color temperature. the 50/2 shows a warmer cast, the 50/1.7 a bit cool and the 55/1.8 a bit warm. as far as the bokeh quality goes, the 50/1.7 can be busy or destructive at times, the 50/2 quite the soft bokeh type which I find unpleasant, and the 55/1.8 has that smooth bokeh rendering that makes it the best portrait lens among the 3 lenses. Haha! Confirmation of "cool" for the f1.7! Mine transforms my red car into a sort of cerise. On top of that, it has poorer contrast than my other (i.e. non-Pentax) 50s. And I fully agree about its bokeh. I rather like "soft" bokeh, so I might try to get hold of a cheap f2. As for the 55/1.8, I can see I'm going to have to get one! (Probably in Tak manifestation.)

08-28-2010, 05:56 AM	#12
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395 Original Poster	I would agree that the bokeh of the 55mm is far superior to anything i have tried: kit lens (duh) SMC A 28mm 2.8 (better bokeh than the kit... but not really) Takupmar Bayonet 80-200 (this lens actually has a nicer bokeh than the kit or 28mm... maybe it;s the focal length? Soligor C/D 70-200 (sold) Vivitar RMC 70-210 (sold) So I have NOT done an apples to apples comparison, but I LOVE the look of this lens over anything I have ever tried. If the 55mm has a special look to it compared to the 50mm 1.7, then I think I'll keep the 55mm 1.8 for sure. Thanks everyone!

08-28-2010, 06:00 AM	#13
paperbag846 Veteran Member Join Date: Jul 2010 Photos: Gallery Posts: 2,395 Original Poster	Originally posted by Oro As to metering, I find my A 50/2 and M50/1.7s meter exactly the same in AV for the A and stop-down with the M. I have run some tests on that at every f-stop. Maybe there is something peculiar about the 55/1.8? Anyway, I am going to do some head-to-head comparisons in about a week. What's your camera model? The k20d has a documented problem metering with manual glass as you move the fstop from f4.

08-28-2010, 08:39 AM	#15
Pentaxor Veteran Member Join Date: May 2009 Location: Vancouver, B.C. Photos: Gallery Posts: 6,513	Originally posted by paperbag846 So I have NOT done an apples to apples comparison, but I LOVE the look of this lens over anything I have ever tried. funny you mentioned an apple to apple comparison, since I did use an apple literally in doing some comparative test shots. that's when I knew then that the 55 is special.