Pentax 77 | Wide-open | Soft?

jonnycreative · 08-25-2016, 04:58 PM

Hey, all -

Just received my 77 - tore open the package like a kid at Christmas.

Of course, the build, fit, and finish are all beyond superb.

However, after sorting through a few test shots, it seems that it is shooting very soft, wide open @ 1.8.

I know that all lenses are soft[er] at maximum aperture. But my 50 1.8 is significantly sharper wide open -- same camera body, same settings, etc.

Haven't been able to find my calibration chart. Maybe the focus is slightly off...

Things seem to change dramatically around 5.6 or so -- still not to the degree that one would expect.

Have any of you had a similar experience? I am trying to determine if it is simply a bad copy or how the lens performs wide open.

I will share a few comparative test shots, once I get them uploaded.

The rendering and bokeh are absolutely otherworldly, no doubt about it. I just feel a little disheartened by the lack of sharpness.

Any input or insight is greatly appreciated, as always.

Thanks, all.

Cheers,

-Jonny

**clackers** · 08-25-2016, 05:05 PM

Hi Jonny,

Of course, like all lenses, it's at its worst wide open.

You seem not to have done a decentreing or microadjustment check on your new purchase, yet ... the court wants to know why you are negligent, since it may have to be sent back! :-)

You should start by doing some shots with either Live View or manual focus, to see if adjustments are needed. :-)

jonnycreative · 08-25-2016, 05:12 PM

Originally posted by clackers

You seem not to have done a decentreing or microadjustment check on your new purchase, yet ... the court wants to know why you are negligent, since it may have to be sent back! :-)

Criminally negligent, even. Ha!

I know that the lens will be at its worse wide-open. I'm just shocked that wide-open it seems to be outclassed by my humble 50 1.8.

Seems like I can nail manual focus wide-open -- with relative ease -- for what it's worth.

**clackers** · 08-25-2016, 05:24 PM

Originally posted by jonnycreative

Seems like I can nail manual focus wide-open -- with relative ease -- for what it's worth.

So ... if there's a difference between that and using AF ... what are you waiting for? Do the adjustments!

Here is Photozone's analysis - centre sharpness peaks at f4, you want f5.6 or f8 for the edges to come up too. That sort of behaviour is similar to almost any 50 bar a macro lens.

http://www.photozone.de/pentax/128-pentax-smc-fa-77mm-f18-limited-review--test-report?start=1

Last edited by clackers; 08-25-2016 at 05:31 PM.

Sandy Hancock · 08-25-2016, 05:32 PM

Get the focus right and the FA77 is sharp enough:

As Clackers said, do some tests on a tripod with CDAF, and adjust accordingly if PDAF doesn't match it.

Belgarchi · 08-25-2016, 05:34 PM

I own the Pentax 77/1.8 FA-L for a long time.....
With my Pentax K10D (10 MP), and later my K30 (16 MP), I thought that it was an outstanding lens...
A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad.
It begins to be good at f/4.0, and is really good at f/5.6.
I think that it reached its limits with the 24 MP sensor even if it looks more like a contrast problem than a resolution problem.
Also, I wonder if there would be some sort of bad synergy between the 77/1.8 and the 24 MP sensor?

Sandy Hancock · 08-25-2016, 05:35 PM

Anyway, this is a portrait lens, and sometimes less than perfect sharpness is a good thing:

---------- Post added 26-08-16 at 10:08 AM ----------

It handles a 36 MP sensor quite adequately.
OK, I cheated; this is at f/2.0

howieb101 · 08-25-2016, 06:00 PM

Have you tried to check the AF accuracy? Your camera body may need -ve or +ve AF adjustment for your copy of the FA 77mm Limited. Try manually focusing the lens and if its sharper than using AF it may indicate you may need to do the AF adjustment. Its worth it.

I just bought a Sigma 85mm F1.4 and was initially very disappointed with it. After I dialed in the appropriate AF adjustment, it now focuses just fine.

If you have the K1 you'll be able to AF adjust the lens.

Howie Be

**clackers** · 08-25-2016, 06:04 PM

Originally posted by Belgarchi

I own the Pentax 77/1.8 FA-L for a long time.....
With my Pentax K10D (10 MP), and later my K30 (16 MP), I thought that it was an outstanding lens...
A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad.
It begins to be good at f/4.0, and is really good at f/5.6.
I think that it reached its limits with the 24 MP sensor even if it looks more like a contrast problem than a resolution problem.
Also, I wonder if there would be some sort of bad synergy between the 77/1.8 and the 24 MP sensor?

Something odd with what you're doing, Belgarchi ... it's fine for me on a Sony NEX-7 and A7 (both 24Mp) and K-1 (36Mp), and was fine for you in years past.

Belgarchi · 08-25-2016, 06:31 PM

'Less than perfect sharpness is a good thing'
You are joking? She is so beautiful that sharper is better...
(Joking..... I apologize if I offended someone, but I couldn't resist)

Also, I tested the 70/2.4... puzzling. It is as good (at same aperture) as the 77/1.8 (and I thought it was markedly inferior).

My testing and camera are fine, I checked and re-checked the parameters, and got outstanding results with the 50/1.8 DA and the 100/2.8M D-FA.

I wonder... there is one thing I didn't check... maybe the in-camera lens correction (I was in jpeg mode) is wrong for the 77/1.8?

Beautiful photos by the way, congratulations.

stevebrot · 08-25-2016, 06:55 PM

Originally posted by jonnycreative

Have any of you had a similar experience?

No, the FA 77/1.8 should not be particularly soft wide open; mine isn't. As noted above, you might want to test using manual focus in magnifiedlive view.

Originally posted by Belgarchi

A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad.

The key is probably the significant upgrade to 24 Mpx. When the K-3 first came out there was a flurry of soft lens complaints. With high resolution comes higher demands for technique, specifically focus and camera motion. If using PDAF with the FA 77 be sure to use the K-70s f/2.8 sensitive center focus point for highest precision. If focus is critical use live view CDAF or manual focus in magnified live view.

Steve

stevebrot · 08-25-2016, 07:06 PM

Originally posted by Belgarchi

'Less than perfect sharpness is a good thing'
You are joking?

No, what he said is conventional wisdom for portrait lenses. That being said, experience on this site has been that the FA 77/1.8 is not soft by most metrics.

Originally posted by Belgarchi

My testing and camera are fine, I checked and re-checked the parameters, and got outstanding results with the 50/1.8 DA and the 100/2.8M D-FA.

Well, I guess since you have outstanding technique and outstanding results from these other two lenses, your FA 77/1.8 is probably a dud. I won't offer any advice for comparative testing though I am curious as to how you do yours? Tripod? Distance(s)? Subject? PDAF? CDAF? MF? Best of 3, 5, 10?

As for the "markedly inferior" DA 70/2.4 Limited, I expect you may get a few heated comments from the fans of that lens. Are you saying that the FA 77/1.8 is better than the DA 70/2.4 on the K-30, but the relationship evens up on the K-70?

Steve

zestoi · 08-25-2016, 07:13 PM

Originally posted by clackers

So ... if there's a difference between that and using AF ... what are you waiting for? Do the adjustments!

this

---------- Post added 08-25-16 at 07:15 PM ----------

Originally posted by howieb101

Have you tried to check the AF accuracy? Your camera body may need -ve or +ve AF adjustment for your copy of the FA 77mm Limited. Try manually focusing the lens and if its sharper than using AF it may indicate you may need to do the AF adjustment. Its worth it.

I just bought a Sigma 85mm F1.4 and was initially very disappointed with it. After I dialed in the appropriate AF adjustment, it now focuses just fine.

had the same issue with the sigma 85/1.4 I bought yesterday too. it front focussed initially.

micromacro · 08-25-2016, 07:19 PM

Found my picture, K-5iis, 77mm wide open.
https://www.pentaxforums.com/forums/14-general-talk/99051-your-latest-acquisi...ml#post3565663

My copy is not soft wide open, and definitely not softer than 50mm f1.8
Also at f5.6 it's very sharp, far from "still not to the degree that one would expect".
Hope it helps.

robthebloke · 08-25-2016, 07:26 PM

I find the sweet spot in my copy to be f2.8 to f5 range, but wide open it is very sharp. The narrower dof at f1.8 can fool you into thinking its soft with a camera like the k70, simply due to critical focus falling in between those points. I'd probably whether at f2.2 it performs as well as the DA50 focus wise, and then test your copy on a k-3 (if you know anyone that has one). Those extra focus points do make a difference, on the k-1/k-3 for example I have very few issues wide open, but I used to have problems on my k-5/k-x.

08-25-2016, 04:58 PM	#1
jonnycreative Site Supporter Join Date: Aug 2016 Location: Denver Posts: 31	Pentax 77 \| Wide-open \| Soft? Hey, all - Just received my 77 - tore open the package like a kid at Christmas. Of course, the build, fit, and finish are all beyond superb. However, after sorting through a few test shots, it seems that it is shooting very soft, wide open @ 1.8. I know that all lenses are soft[er] at maximum aperture. But my 50 1.8 is significantly sharper wide open -- same camera body, same settings, etc. Haven't been able to find my calibration chart. Maybe the focus is slightly off... Things seem to change dramatically around 5.6 or so -- still not to the degree that one would expect. Have any of you had a similar experience? I am trying to determine if it is simply a bad copy or how the lens performs wide open. I will share a few comparative test shots, once I get them uploaded. The rendering and bokeh are absolutely otherworldly, no doubt about it. I just feel a little disheartened by the lack of sharpness. Any input or insight is greatly appreciated, as always. Thanks, all. Cheers, -Jonny

08-25-2016, 05:34 PM	#6
Belgarchi Junior Member Join Date: Jan 2013 Location: Texas Posts: 32	Amazing... Same problem here I own the Pentax 77/1.8 FA-L for a long time..... With my Pentax K10D (10 MP), and later my K30 (16 MP), I thought that it was an outstanding lens... A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad. It begins to be good at f/4.0, and is really good at f/5.6. I think that it reached its limits with the 24 MP sensor even if it looks more like a contrast problem than a resolution problem. Also, I wonder if there would be some sort of bad synergy between the 77/1.8 and the 24 MP sensor?

08-25-2016, 06:31 PM	#10
Belgarchi Junior Member Join Date: Jan 2013 Location: Texas Posts: 32	To Sandy Hancock 'Less than perfect sharpness is a good thing' You are joking? She is so beautiful that sharper is better... (Joking..... I apologize if I offended someone, but I couldn't resist) Also, I tested the 70/2.4... puzzling. It is as good (at same aperture) as the 77/1.8 (and I thought it was markedly inferior). My testing and camera are fine, I checked and re-checked the parameters, and got outstanding results with the 50/1.8 DA and the 100/2.8M D-FA. I wonder... there is one thing I didn't check... maybe the in-camera lens correction (I was in jpeg mode) is wrong for the 77/1.8? Beautiful photos by the way, congratulations.

08-25-2016, 07:06 PM	#12
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Belgarchi 'Less than perfect sharpness is a good thing' You are joking? No, what he said is conventional wisdom for portrait lenses. That being said, experience on this site has been that the FA 77/1.8 is not soft by most metrics. Originally posted by Belgarchi My testing and camera are fine, I checked and re-checked the parameters, and got outstanding results with the 50/1.8 DA and the 100/2.8M D-FA. Well, I guess since you have outstanding technique and outstanding results from these other two lenses, your FA 77/1.8 is probably a dud. I won't offer any advice for comparative testing though I am curious as to how you do yours? Tripod? Distance(s)? Subject? PDAF? CDAF? MF? Best of 3, 5, 10? As for the "markedly inferior" DA 70/2.4 Limited, I expect you may get a few heated comments from the fans of that lens. Are you saying that the FA 77/1.8 is better than the DA 70/2.4 on the K-30, but the relationship evens up on the K-70? Steve Last edited by stevebrot; 08-25-2016 at 07:14 PM.

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08-25-2016, 05:05 PM	#2
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	Hi Jonny, Of course, like all lenses, it's at its worst wide open. You seem not to have done a decentreing or microadjustment check on your new purchase, yet ... the court wants to know why you are negligent, since it may have to be sent back! :-) You should start by doing some shots with either Live View or manual focus, to see if adjustments are needed. :-)

08-25-2016, 05:12 PM	#3
jonnycreative Site Supporter Join Date: Aug 2016 Location: Denver Posts: 31 Original Poster	Originally posted by clackers You seem not to have done a decentreing or microadjustment check on your new purchase, yet ... the court wants to know why you are negligent, since it may have to be sent back! :-) Criminally negligent, even. Ha! I know that the lens will be at its worse wide-open. I'm just shocked that wide-open it seems to be outclassed by my humble 50 1.8. Seems like I can nail manual focus wide-open -- with relative ease -- for what it's worth.

08-25-2016, 05:24 PM	#4
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	Originally posted by jonnycreative Seems like I can nail manual focus wide-open -- with relative ease -- for what it's worth. So ... if there's a difference between that and using AF ... what are you waiting for? Do the adjustments! Here is Photozone's analysis - centre sharpness peaks at f4, you want f5.6 or f8 for the edges to come up too. That sort of behaviour is similar to almost any 50 bar a macro lens. http://www.photozone.de/pentax/128-pentax-smc-fa-77mm-f18-limited-review--test-report?start=1 Last edited by clackers; 08-25-2016 at 05:31 PM.

08-25-2016, 05:32 PM	#5
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,272	Get the focus right and the FA77 is sharp enough: As Clackers said, do some tests on a tripod with CDAF, and adjust accordingly if PDAF doesn't match it.

08-25-2016, 05:35 PM	#7
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,272	Anyway, this is a portrait lens, and sometimes less than perfect sharpness is a good thing: ---------- Post added 26-08-16 at 10:08 AM ---------- It handles a 36 MP sensor quite adequately. OK, I cheated; this is at f/2.0

08-25-2016, 06:00 PM	#8
howieb101 Veteran Member Join Date: Nov 2008 Location: Melbourne, Australia Photos: Gallery \| Albums Posts: 594	Have you tried to check the AF accuracy? Your camera body may need -ve or +ve AF adjustment for your copy of the FA 77mm Limited. Try manually focusing the lens and if its sharper than using AF it may indicate you may need to do the AF adjustment. Its worth it. I just bought a Sigma 85mm F1.4 and was initially very disappointed with it. After I dialed in the appropriate AF adjustment, it now focuses just fine. If you have the K1 you'll be able to AF adjust the lens. Howie Be

08-25-2016, 06:04 PM	#9
clackers Otis Memorial Pentaxian Join Date: Jul 2013 Location: Melbourne Photos: Albums Posts: 16,397	Originally posted by Belgarchi I own the Pentax 77/1.8 FA-L for a long time..... With my Pentax K10D (10 MP), and later my K30 (16 MP), I thought that it was an outstanding lens... A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad. It begins to be good at f/4.0, and is really good at f/5.6. I think that it reached its limits with the 24 MP sensor even if it looks more like a contrast problem than a resolution problem. Also, I wonder if there would be some sort of bad synergy between the 77/1.8 and the 24 MP sensor? Something odd with what you're doing, Belgarchi ... it's fine for me on a Sony NEX-7 and A7 (both 24Mp) and K-1 (36Mp), and was fine for you in years past.

08-25-2016, 06:55 PM	#11
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by jonnycreative Have any of you had a similar experience? No, the FA 77/1.8 should not be particularly soft wide open; mine isn't. As noted above, you might want to test using manual focus in magnifiedlive view. Originally posted by Belgarchi A few weeks ago I received the K70 (24 MP) and tested many lenses on a brick wall 60' away... very careful manual focus... and surprise, the 77/1.8 came off pretty bad. The key is probably the significant upgrade to 24 Mpx. When the K-3 first came out there was a flurry of soft lens complaints. With high resolution comes higher demands for technique, specifically focus and camera motion. If using PDAF with the FA 77 be sure to use the K-70s f/2.8 sensitive center focus point for highest precision. If focus is critical use live view CDAF or manual focus in magnified live view. Steve

08-25-2016, 07:13 PM	#13
zestoi Forum Member Join Date: Nov 2015 Location: British ExPat in Bucharest Posts: 86	Originally posted by clackers So ... if there's a difference between that and using AF ... what are you waiting for? Do the adjustments! this ---------- Post added 08-25-16 at 07:15 PM ---------- Originally posted by howieb101 Have you tried to check the AF accuracy? Your camera body may need -ve or +ve AF adjustment for your copy of the FA 77mm Limited. Try manually focusing the lens and if its sharper than using AF it may indicate you may need to do the AF adjustment. Its worth it. I just bought a Sigma 85mm F1.4 and was initially very disappointed with it. After I dialed in the appropriate AF adjustment, it now focuses just fine. had the same issue with the sigma 85/1.4 I bought yesterday too. it front focussed initially.

08-25-2016, 07:19 PM	#14
micromacro Pentaxian Join Date: Jan 2014 Location: Florida Photos: Gallery Posts: 3,722	Found my picture, K-5iis, 77mm wide open. https://www.pentaxforums.com/forums/14-general-talk/99051-your-latest-acquisi...ml#post3565663 My copy is not soft wide open, and definitely not softer than 50mm f1.8 Also at f5.6 it's very sharp, far from "still not to the degree that one would expect". Hope it helps.

08-25-2016, 07:26 PM	#15
robthebloke Veteran Member Join Date: Sep 2013 Location: Sydney Photos: Albums Posts: 844	I find the sweet spot in my copy to be f2.8 to f5 range, but wide open it is very sharp. The narrower dof at f1.8 can fool you into thinking its soft with a camera like the k70, simply due to critical focus falling in between those points. I'd probably whether at f2.2 it performs as well as the DA50 focus wise, and then test your copy on a k-3 (if you know anyone that has one). Those extra focus points do make a difference, on the k-1/k-3 for example I have very few issues wide open, but I used to have problems on my k-5/k-x.