Worth it to upgrade to FA 50mm f1.4?

Class A · 05-02-2012, 05:51 PM

Originally posted by ChopperCharles

Does that half stop make it worth upgrading to? Or am I better off just keeping my 1.7?

User monochrome hit the nail on the head.

The difference between f/1.7 and f/1.4 is rather inconsequential.

You'd get the f/1.4 version for its different bokeh. It has under-corrected spherical aberration which makes the background bokeh smoother than that of the 50/1.7 but it isn't as sharp as the 50/1.7 in the range of f/1.7-f/2.8.

The 50/1.4 also has more field curvature (the focus plane isn't as flat as that of the 50/1.7) which makes it a lesser choice for using it in combination with extension rings / bellows.

Summary, get the 50/1.4 for its different rendering ("look" of images), if it appeals to you. The 50/1.7 is technically the better lens in a number of disciplines, but its rendering isn't as smooth as that of the 50/1.4.

Laurentiu Cristofor · 05-02-2012, 08:00 PM

Originally posted by ChopperCharles

I have the SMC-FA 50mm f1.7 lens, and I love its low-light performance and quick auto-focus.... however, the 1.4 *is* faster. Does that half stop make it worth upgrading to? Or am I better off just keeping my 1.7?

If you just care about the difference in speed, it is not really worth an exchange. You may want to look for an f/1.2 instead

Or as others recommended already - consider the DA* 55/1.4.

DaveHolmes · 05-04-2012, 07:09 PM

If you really want an upgrade maybe look at the DA*55-1.4... You get the half-stop AND massively increased IQ...

HEEGZ · 05-04-2012, 07:59 PM

I'd keep the lens you already have and look for a different focal length for your next lens.

ChopperCharles · 05-07-2012, 09:03 AM

I shoot a lot of low light, at ballroom dance events, and I cannot always use (nor do I always want to use) flash. Same deal for ballet recitals and such. I don't care about macro work, just low light performance and sharpness. Well, and dead-accurate autofocus. I can't manual focus to save my life with my Kx. With my full frame manual camera I can easily, and that's what I have the vivitar mounted to. It's a different lens optically though, it's far, far lesser quality than the FA1.7.

Chales.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Is it worth trying to fix a kr or upgrade?	Kricket	Pentax K-r	13	07-15-2011 10:29 PM
Kx to K5 worth the upgrade?	tbirdas	Pentax DSLR Discussion	4	12-24-2010 10:11 PM
is it worth it to upgrade to the K-r?	raf02	Pentax K-r	6	11-03-2010 11:50 AM
Tamron 17-50mm f2.8 worth the upgrade over DA18-55mm WR?	secateurs	Pentax SLR Lens Discussion	35	11-02-2010 12:37 PM
Upgrade to Tamron 17-50mm from kit 18-55mm: worth the investment?	virgilr	Pentax SLR Lens Discussion	2	09-04-2009 07:33 AM

05-02-2012, 05:51 PM	#16
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by ChopperCharles Does that half stop make it worth upgrading to? Or am I better off just keeping my 1.7? User monochrome hit the nail on the head. The difference between f/1.7 and f/1.4 is rather inconsequential. You'd get the f/1.4 version for its different bokeh. It has under-corrected spherical aberration which makes the background bokeh smoother than that of the 50/1.7 but it isn't as sharp as the 50/1.7 in the range of f/1.7-f/2.8. The 50/1.4 also has more field curvature (the focus plane isn't as flat as that of the 50/1.7) which makes it a lesser choice for using it in combination with extension rings / bellows. Summary, get the 50/1.4 for its different rendering ("look" of images), if it appeals to you. The 50/1.7 is technically the better lens in a number of disciplines, but its rendering isn't as smooth as that of the 50/1.4.

05-02-2012, 08:00 PM	#17
Laurentiu Cristofor Banned Join Date: Nov 2009 Location: WA Photos: Albums Posts: 3,055	Originally posted by ChopperCharles I have the SMC-FA 50mm f1.7 lens, and I love its low-light performance and quick auto-focus.... however, the 1.4 is faster. Does that half stop make it worth upgrading to? Or am I better off just keeping my 1.7? If you just care about the difference in speed, it is not really worth an exchange. You may want to look for an f/1.2 instead Or as others recommended already - consider the DA* 55/1.4.

05-04-2012, 07:09 PM	#18
DaveHolmes Veteran Member Join Date: Jul 2010 Location: Yorkshire Posts: 1,501	If you really want an upgrade maybe look at the DA*55-1.4... You get the half-stop AND massively increased IQ...

05-04-2012, 07:59 PM	#19
HEEGZ Senior Member Join Date: Jun 2010 Location: Missouri Photos: Albums Posts: 258	I'd keep the lens you already have and look for a different focal length for your next lens.

05-07-2012, 09:03 AM	#20
ChopperCharles Veteran Member Join Date: Jan 2010 Location: Durham, nc Photos: Albums Posts: 953 Original Poster	I shoot a lot of low light, at ballroom dance events, and I cannot always use (nor do I always want to use) flash. Same deal for ballet recitals and such. I don't care about macro work, just low light performance and sharpness. Well, and dead-accurate autofocus. I can't manual focus to save my life with my Kx. With my full frame manual camera I can easily, and that's what I have the vivitar mounted to. It's a different lens optically though, it's far, far lesser quality than the FA1.7. Chales.