[mikesbike]

The DA* 16-50 will see an update soon, maybe soon enough for you,

I'd say this ^^^. Chances are it will not be cheap, but will likely be a winner.

[clickclick]

I'd say hang in there for the new DA* 16-50 too. It should have the focus speed and sharpness you're looking for in a fast package for low light. I have the original DA* 16-50, and I don't think it will be quick enough focusing, and the SDM issues are sadly real.

[DWS1]

If you can, I'd hold out for the new DA* 16-50mm also.

[Mooncatt]

Sounds like waiting for that new 16-50mm is the way to go once I actually get around to budgeting, if for no other reason than to see if it lives up to expectations. Doubt I'll be able to get it in time to put it to use this racing season, but I'll look into it regardless for future consideration.

[DonV]

I'd buy the current version 16-50; try it- if you decide the range/speed work for you and the IQ is lacking- buy the new one whenever!
If it works, your way ahead in time and saved $$ too boot; you can likely get your money back on the current version if you shop wisely.

[Mooncatt]

I'd buy the current version 16-50; try it- if you decide the range/speed work for you and the IQ is lacking- buy the new one whenever!
If it works, your way ahead in time and saved $$ too boot; you can likely get your money back on the current version if you shop wisely.

I was thinking of renting it for the next race I go to, but things are pretty up in the air if I'll go due to some other stuff going on in life.

[Aaron28]

leaning towards the Sigma 18-35mm f/1.8 DC HSM Art

lean all the way!

[red5isalive]

@Red5isAlive does motorsports, and, in a review, says the 50-135 is too slow, but notes in his profile that the Sigma 17-50mm f2.8 is one of his "go-to" lenses. You're not specific in identifying the parameters of your subject matter that you want to optimize, though. I'm thinking the biggest problem you'd want to solve is how to photograph very fast moving objects in relatively low light. Looks to me like the f/2.8 Sigma would be good for that. No idea about how quickly it can find and lock focus, though, and there are no reviews for it in PF that I could find. DxOMark reports too much distortion at the wide end. I'm thinking, if it were me, I'd be looking seriously at the Tamron AF016P-700 SP AF17-50mm F/2.8 Di II LD Aspherical (IF) (Model A16P), currently selling for about $160.

I see my name, I came to comment.
I'm sorry i'm a bit lost on your subject guys But I can give you my idea why my 50-135mm doesn't keep pace. It doesn't keep pace compared to my Sigma 100-300mm f4 on my bodies (K3-I, K3 and K5) and I have not had the time to test it on a K3-III as I did with both Sigma lenses (100-300mm f4 and 17-50mm f2.8 for the convenience of the focal lenght).

The 50-135mm f2.8 I usually use it for portraiture but I have also used it trackside depending on the motorsport category and it produces decent results in terms of focusing but as commented before the Sigma 100-300mm is faster.

If the topic is about a fast short distance lens I have had the Pentax 16-45mm f4 and its a brilliant lens but it lacks some light (for example while shooting inside a car's cabin), and overall the Sigma is slightly better. Is not the Pentax is bad, is the Sigma has a bit more everywhere except for the focal lenght on the below side.

I hope it helps, or please let me know in case of doubt how can I be helpful in the conversation you are having here.

BR,

---------- Post added 06-28-21 at 02:36 AM ----------

Okay I've read the original post.
I see you don't need to picture the car's cabin so you might be able to photograph what you like with the Pentax 16-45 f4 (usually are budget friendly lenses) or Tamron 17-50mm f2.8 (i've never tried one but heard good things about it and it's cheaper than the Sigma), Sigma 17-50mm f2.8 and of course the Pentax 16-50mm. But remember it has the SDM motor on it. And it promes to fail. So, is it worthy? It wasn't to me. A part from those ones I am not able to think about anything else on this range. Then you have the 20-40mm lenses like the Pentax and Sigma but I don't know if this is too much milimeters on the lower side for you. You could also consider something like a Sigma 10-20mm but maybe this is too low range¿?

Anyways I'd say if you can find a cheap 50-135mm with the SDM broken its very easy to fix it to use the screw focusing. Some say is faster than the SDM. This lens creates great images specially about the drivers/riders before they get in position but will also bring you closer to the subject (don't know if this is something you desire to do).

[mattb123]

I agree the current 16-50 is pretty good, especially if it has been converted to screw drive. I have one that the SDM motor failed on and I converted it. On the K-3iii this makes the lens very responsive and it's the fastest I have ever seen it for AF. I just shot a running race with my screwdrive 16-50 over the weekend and I don't think my AF missed a single shot over several hundred shots. If budget is a concern then this is probably your best bet. It's a solid combo.

[mikesbike]

I also have the Sigma 17-50mm f/2.8 EX DC HSM and find it to be a very fine performer. Too bad Sigma has dropped making it in the Pentax mount. But finding a used one in great condition might be possible, then if not the K-3 III, perhaps you can find a KP still available, this would give you a couple of stops better ISO capability for low light shots.

[red5isalive]

I also have the Sigma 17-50mm f/2.8 EX DC HSM and find it to be a very fine performer. Too bad Sigma has dropped making it in the Pentax mount. But finding a used one in great condition might be possible, then if not the K-3 III, perhaps you can find a KP still available, this would give you a couple of stops better ISO capability for low light shots.

Yes agreed in everything.

[Mooncatt]

I also have the Sigma 17-50mm f/2.8 EX DC HSM and find it to be a very fine performer. Too bad Sigma has dropped making it in the Pentax mount. But finding a used one in great condition might be possible, then if not the K-3 III, perhaps you can find a KP still available, this would give you a couple of stops better ISO capability for low light shots.

I just looked at some reviews and sample photos (including action shots) on that lens, and it does look like it would work out well. Looks like it can be had fairly cheap as well, which makes a big difference to be. Not that I'm a cheapskate, but let's say the updated Pentax 16-50mm option comes in at $1,000. If I can get this lens for $250, would the Pentax deliver me an extra $750 in quality/performance? Highly unlikely.

I have no interest in replacing my body for now. The K3 III is just too expensive, and the KP ergonomics are just a hard no for me with the grip style and set back shutter button. And again, it's about getting the best bang for my bucks.

[red5isalive]

I just looked at some reviews and sample photos (including action shots) on that lens, and it does look like it would work out well. Looks like it can be had fairly cheap as well, which makes a big difference to be. Not that I'm a cheapskate, but let's say the updated Pentax 16-50mm option comes in at $1,000. If I can get this lens for $250, would the Pentax deliver me an extra $750 in quality/performance? Highly unlikely.

I have no interest in replacing my body for now. The K3 III is just too expensive, and the KP ergonomics are just a hard no for me with the grip style and set back shutter button. And again, it's about getting the best bang for my bucks.

If it will be me, I'd not look after anything else than this lens.
Of course you should compare it to others and I'd say buy the cheapest one of the trio (including the Tamron 17-50mm f2.8) because I think any of those will work really well for your purpose.

And about weight it seems both the Pentax and Sigma weight 565 grams.

[Mooncatt]

If it will be me, I'd not look after anything else than this lens.
Of course you should compare it to others and I'd say buy the cheapest one of the trio (including the Tamron 17-50mm f2.8) because I think any of those will work really well for your purpose.

And about weight it seems both the Pentax and Sigma weight 565 grams.

Sorry I didn't see you mention the Sigma 17-50mm earlier as well. When I started looking at info on it, I found a lot of heads up reviews on the trio. The Pentax version is out due to the SDM concerns. Between the Sigma and Tamron, it looks like the Sigma beats it in sharpness, especially wide open, and also focuses much faster. So I think that'll be the top of my list for the time being.

Weight doesn't really bother me.

[red5isalive]

Sorry I didn't see you mention the Sigma 17-50mm earlier as well. When I started looking at info on it, I found a lot of heads up reviews on the trio. The Pentax version is out due to the SDM concerns. Between the Sigma and Tamron, it looks like the Sigma beats it in sharpness, especially wide open, and also focuses much faster. So I think that'll be the top of my list for the time being.

Weight doesn't really bother me.

No worries