[Craigbob]

So I currently have a manual focus sigma 50 2.8 macro that gives pretty good images. But I am looking for a faster lens.

Would I really be able to tell the difference between a 50mm1.4, 1.7,1.8 or my current 2.8 (which I am looking to replace with a Pentax AF version.).

I would like to stay below $200.00 on the lens, so the DA* 55 1.4 while desired, is out of the question.

What is the opinion of the DA 50 vs the FA 50 vs the 50 2.8 macro?

[robgski]

What do you want to use the lens for?
I bought a used f1.8 SMC-A lens for about $25, but if you need autofocus, you would pay more.

[Craigbob]

What do you want to use the lens for?
I bought a used f1.8 SMC-A lens for about $25, but if you need autofocus, you would pay more.

I definitely want AF, so I know the price will be in the $100-$200 range.

As for the use, I want something fast for low light, shallow DOF (I have a 10 month old granddaughter).

I've got the Sigma 50.2.8 macro and it's a well built lens great IQ, but a bit slower than I'd prefer and only MF. So I'm planning on getting a Pentax 50mm 2.8 Macro to replace the Sigma. But I'm also wanting something a bit faster. so While I hate having two lenses in the same FL, In this case I'll do it.

[TwoUptons]

I’d keep the Sigma as macro is a different beast from the work of a ‘normal’ 50mm.

I have the F50mm f1.7, so it’s ~30 years old at this point, but it’s sharp and focuses fairly quickly. Mine was really cheap but broken when I got it, so less of a bargain once fixed... But I really like it. It also is fairly adept at chasing kids.

The FA50mm f1.4 is available new a little out of your price range, but it’s also available used fairly often. I’ve skipped it since I have an optically similar manual focus version.

I think you’ve got good choices, though we may all change our minds once the new DFA50mm finally ships 🙂

-Eric

[Wheatfield]

So I currently have a manual focus sigma 50 2.8 macro that gives pretty good images. But I am looking for a faster lens.

Would I really be able to tell the difference between a 50mm1.4, 1.7,1.8 or my current 2.8 (which I am looking to replace with a Pentax AF version.).

I would like to stay below $200.00 on the lens, so the DA* 55 1.4 while desired, is out of the question.

What is the opinion of the DA 50 vs the FA 50 vs the 50 2.8 macro?

The fa50/1.4 is ok stopped down a bit. It can probably be found used in your price range. There is also the discontinued f50/1.7 that is likely the better lens, and not all that much slower.

[clickclick]

Did you see the "shoot out" between the Pentax 50mm macro, the DA 50 and FA 50 here on PF?

Pentax 50mm Prime Lens Shootout Review - Introduction | PentaxForums.com Reviews

I'd take a look at the DA 50. I think it will give you some nice wide open capabilities you lack now for thinner DOF and pleasing portrait work from there to where your macro starts. It often comes on good sales. Easy to over look, but a nice little lens. Do check out some sample photos though - you can search on camera and lens combos here: https://www.pentaxforums.com/forums/samplesearch.php It can vignette a little on full frame depending on the aperture, but many seem to use it on the K1 happily.

[ramseybuckeye]

You may be able tp find an Pentax-F 50/1.7 for bargain prices. I have one and it focuses fast, sharp, and renders nice colors. I've saw a few on shopgoodwill sold with cameras that go pretty well below $100.

[Craigbob]

I’d keep the Sigma as macro is a different beast from the work of a ‘normal’ 50mm.

I have the F50mm f1.7, so it’s ~30 years old at this point, but it’s sharp and focuses fairly quickly. Mine was really cheap but broken when I got it, so less of a bargain once fixed... But I really like it. It also is fairly adept at chasing kids.

The FA50mm f1.4 is available new a little out of your price range, but it’s also available used fairly often. I’ve skipped it since I have an optically similar manual focus version.

I think you’ve got good choices, though we may all change our minds once the new DFA50mm finally ships 🙂

-Eric

I like the Sigma, but want AF, so I'm planning on swapping it for a Pentax 50 2.8 macro.

[Adam]

AF with macro lenses can be hit and miss, especially if they have no limiter (the Pentax 50mms don't). I'd therefore keep the Sigma if you're limited by that budget.

I would recommend any F or FA 50mm F1.4 or F1.7. The FA 50mm F1.4 has the added bonus of in-camera corrections, which can of course be very useful. It's $271 new, which isn't too bad, but you could get much closer to $200 used.

Then there's the DA 50mm F1.8. Currently under $100, so it's definitely a bargain given the great image quality. Do note though, that it does exhibit more than average vignetting at the wider aperture settings (on FF), and that there are no correction profiles unless you use it in crop mode.

[Bob 256]

This Forum member just recently posted and has a 50mm f1.2 he wants to sell. Maybe PM him and see what he's asking (assuming that lens fits your needs as fast lens)?

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/360471-hello-alberta.html

[clickclick]

If you don't need auto focus, I like my A50/1.4 and think you can find a nice one for $100 or less. Think I paid around $80 for a mint copy.

[awscreo]

I have da 50 1.8 and a manual Pentax-A 50 1.4

Out of those two i prefer my manual 1.4, it sharpens up quite well by f2, and has a nice bokeh imo. The da 50 is quite good though, and has af. Price was roughly the same for those two, I got the 1.4 second hand. Build is way better for the 1.4

[Craigbob]

The fa50/1.4 is ok stopped down a bit. It can probably be found used in your price range. There is also the discontinued fa50/1.7 that is likely the better lens, and not all that much slower.

The DA 1.8 vs the F 1.7 which do you think is better? I have seen the 1.7 in my price range on e-bay.

[Roadboat24]

I have the 50mm 1.8. Use it on a k3 so i can not atest to vignetting on full frame. On the k3 I find it to be excellent. I seriously doubt I could tell the difference between 1.4,1.7,1.8. 2.8 maybe but i doubt it. If it covers the full frame sensor I'd go for it. They don't call it a plastic fantastic for nothing.

[Alex645]

Would I really be able to tell the difference between a 50mm1.4, 1.7,1.8 or my current 2.8 (which I am looking to replace with a Pentax AF version.).
I would like to stay below $200.00.
What is the opinion of the DA 50 vs the FA 50 vs the 50 2.8 macro?

In side by side comparisons with optimal bokeh conditions, you can see a difference between the 1.4 and the 1.7 or 1.8, but the better value is going to be with the 1.7/1.8. And yes, big difference from your 2.8. The 1.4 will be a bit faster, or perhaps efficiency in terms of AF because of the half EV more light.

Currently keh.com has a Pentax 50mm F/1.7 SMC F K in excellent condition for $139. 180 day warranty....just pick up a 49mm lens cap and probably a lens hood and youʻre set.
Pentax 50mm F/1.7 SMC F K Mount Autofocus Lens {49} at KEH Camera Store

They also have the FA version, for $199, but with your K-1, I think the F is better:
Pentax 50mm F/1.7 SMC FA K Mount Autofocus Lens {49} at KEH Camera Store

Personally, because the K-1 is not exactly the AF king and you want speed, Iʻd go for the f/1.4 for $218-$228:
Pentax 50mm F/1.4 SMC FA K Mount Autofocus Lens {49} at KEH Camera Store

...but the 1.7 is already over 2 EV faster than the 2.8, so the best budget choice.

The DA 50mm is excellent and affordable IF you can live with vignetting shooting the first couple stops wide open.