[jatrax]

A tripod will help but it won't solve the problem if the subject is moving as in the shot I posted.

Yes, of course that makes sense. I was speaking of totally static images, no people, birds, whatever as that is generally what I shoot. But if there are moving objects then a slow shutter will not work.

And you are also correct that just walking around with a tripod in a city is unlikely to be a good experience. Which is why I avoid cities at almost any cost.

[pres589]

Ok, I did this quicky low light / f-stop comparison shot this evening using my Pentax M 50mm f1.4 and K-5 II. This was a classic low-light situation; 1/20th of a second exposure time, 1600 ISO, hand held in really low light. No post processing save for PEF to JPG conversion and resize in Adobe Photoshop Elements. One shot at f2.8 on the aperture ring, the other at f1.4, with the whole purpose to show off how much real world light is grabbed with one setting vs. the other. Your mileage may vary, normal caveats apply, et cetera. This is to show Bui what a lens that pulls in about as much light as his DA 40 wide open pulls vs. something rated for much better light grabbing ability;



In short, get something more like the Pentax 50 f1.4's and this will get a lot easier.

[GeneV]

I have observed the opposite. Long shutter speeds will give increased detail which can make the shot look sharper as long as the camera (and subject) is stationary.

Agreed, but that last part is the big if.

[GeneV]

Yes, of course that makes sense. I was speaking of totally static images, no people, birds, whatever as that is generally what I shoot. But if there are moving objects then a slow shutter will not work.

And you are also correct that just walking around with a tripod in a city is unlikely to be a good experience. Which is why I avoid cities at almost any cost.

For those kinds of images, absolutely. For those kinds of images, the Kx probably wouldn't be my first choice, either. If I have the time, tripod and a stable subject to shoot, I'd rather have one of the bodies with all the dials and WR.

I'm a little like Norm in my older years. Back 30 years ago, I'd carry tripods and bodies everywhere I traveled, and I also shot more landscapes than people. I got good at hiding the bag in the back and supporting it on a wall like I'm doing in this photo, but that Tenba around my neck weighed about 20 lbs, the pad on my shoulder is about 2" thick, and a child could sleep in that bag. Now, that's not so much my style for traveling. My profile photo is shooting a Kx about 7 years ago wearing a small bag about the size of my wife's purse.

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Last edited by GeneV; 01-22-2017 at 06:04 AM.

[Bui]

Ok, I did this quicky low light / f-stop comparison shot this evening using my Pentax M 50mm f1.4 and K-5 II. This was a classic low-light situation; 1/20th of a second exposure time, 1600 ISO, hand held in really low light. No post processing save for PEF to JPG conversion and resize in Adobe Photoshop Elements. One shot at f2.8 on the aperture ring, the other at f1.4, with the whole purpose to show off how much real world light is grabbed with one setting vs. the other. Your mileage may vary, normal caveats apply, et cetera. This is to show Bui what a lens that pulls in about as much light as his DA 40 wide open pulls vs. something rated for much better light grabbing ability;



In short, get something more like the Pentax 50 f1.4's and this will get a lot easier.

This is impressive. I wonder if there a good (and cheap) fast option a but wider? 50mm on my K-x is a bit too long

[pres589]

50's are going to be the easiest to find. If you don't mind manual focus, a used lens like the M 50 I have shouldn't cost too much. DA 50 1.8's aren't as good at pulling in light but it would still be a big step up from an f2.8 lens.

I've considered a Sigma 30 f1.4. The current Art series lens has autofocus issues, the previous EX doesn't seem to. You'll want to read reviews before buying one though. I think they go for about $250 or $300 used in EX, Art's are more as they're newer.

The Pentax FA 35 f2.0 might be worth consideration as well. It's not a bad focal length on APS-C. Obviously not as light grabbing as a 1.4.

[lesmore49]

I was checking out my Pentax 40mm Limited today on my old K10D. Sharp lens...at low light, even at F 2.8.

[Jonathan Mac]

50's are going to be the easiest to find. If you don't mind manual focus, a used lens like the M 50 I have shouldn't cost too much. DA 50 1.8's aren't as good at pulling in light but it would still be a big step up from an f2.8 lens.

I've considered a Sigma 30 f1.4. The current Art series lens has autofocus issues, the previous EX doesn't seem to. You'll want to read reviews before buying one though. I think they go for about $250 or $300 used in EX, Art's are more as they're newer.

The Pentax FA 35 f2.0 might be worth consideration as well. It's not a bad focal length on APS-C. Obviously not as light grabbing as a 1.4.

I can assure you that the older version also had AF issues too, and from what I've read the new one had inherited exactly the same ones. My copy wasn't sharp at all until stopped down to at least f/2.8, defeating the purpose of an f/1.4 lens.

[Na Horuk]

I can assure you that the older version also had AF issues too, and from what I've read the new one had inherited exactly the same ones. My copy wasn't sharp at all until stopped down to at least f/2.8, defeating the purpose of an f/1.4 lens.

This is often a problem with fast lenses; and this is the best argument for the DA 35mm f2.4 or the Pentax limited lenses like DA 40mm. Aperture is not the fastest, but they can be used wide open.
Now some manufacturers are trying to make lenses that are sharp at f1.4, but these cost a lot of money and they are BIG, like the Zeiss Otus or Sigma Art. Many of us simply will not lug around such massive lenses

[GeneV]

I can assure you that the older version also had AF issues too, and from what I've read the new one had inherited exactly the same ones. My copy wasn't sharp at all until stopped down to at least f/2.8, defeating the purpose of an f/1.4 lens.

It seemed like wide open sharpness was less of an issue in the old days, when just getting to focus at F/1.4 or F/1.2 was enough to make the fast lens worthwhile. It still helps the AF system, but today, folks want a lens that fast to take photos as that aperture.

However, in truth, I do not find too many occasions where the trade off in DOF works for me. Portraits work well with just the eyes in sharp focus, and a wall mural looks good at any sharp aperture, but the vast majority of subjects look better with some DOF past what F/1.4 provides on most lenses.

[pres589]

This is often a problem with fast lenses; and this is the best argument for the DA 35mm f2.4 or the Pentax limited lenses like DA 40mm. Aperture is not the fastest, but they can be used wide open.
Now some manufacturers are trying to make lenses that are sharp at f1.4, but these cost a lot of money and they are BIG, like the Zeiss Otus or Sigma Art. Many of us simply will not lug around such massive lenses

The OP already has the same basic optics as the 40 Ltd with his 40 XS so no help or improvement there. The DA 35 f2.4 isn't bad wide open but some folks really don't seem to like the out of focus rendering of that lens. I'm okay with it but I think my standards are kind of low. It's not much faster than the 40 XS he's already got. I've shot with that lens in a club setting and it's okay.

For low light work, I really like having a 50 1.4 at my disposal; if I can accept soft edges and the challenges created in focusing with such a shallow depth of field, that lens is fantastic. If the subject is far enough away that infinity focus is where I need to focus the thing that lens is like having a cheat code.

---------- Post added 01-24-17 at 11:35 AM ----------

I can assure you that the older version also had AF issues too, and from what I've read the new one had inherited exactly the same ones. My copy wasn't sharp at all until stopped down to at least f/2.8, defeating the purpose of an f/1.4 lens.

I didn't think the EX was as bad about AF issues as the Art 30 1.4. Unfortunate. I've kind of decided to eventually get a FA 35 f2.0 if I stick to crop, which I think I will for the foreseeable future. Thanks for the info on your experience with the 30 EX.

[Na Horuk]

For low light work, I really like having a 50 1.4 at my disposal; if I can accept soft edges and the challenges created in focusing with such a shallow depth of field, that lens is fantastic. If the subject is far enough away that infinity focus is where I need to focus the thing that lens is like having a cheat code.

Yes, but fast 50mm lenses are pretty good wide open, unlike fast lenses of other, non-normal focal lengths. Having a fast 50mm is a good idea in general

[pres589]

I think I would pin that down to design and decades of honing of optical engineering going into something like the FA 50 1.4. I doubt there's any reason why, say, a 37mm f1.5 couldn't be made decently sharp. Might be kind of large/heavy but as long as it's not Sigma building it...