[Craigbob]

And what about bokeh?. I have the sigma 50-500 OS and its bokeh is astonishing. How does it compare against pentax 150-450 bokeh?

I don't know to be honest. I'll shoot a few more comparisons and let you know.

[dagoban]

I don't know to be honest. I'll shoot a few more comparisons and let you know.

Ok, thank you very much.

[Pentax Syntax]

Nice comparison. The 150-450 photo is sharper and has much higher contrast wide open. The contrast issue is often more important for telephoto applications. Wide open is also a good choice since we are often forced to shoot wide open in real life situations. Thanks for posting:-)

[Paul the Sunman]

And what about bokeh?. I have the sigma 50-500 OS and its bokeh is astonishing. How does it compare against pentax 150-450 bokeh?

I've always thought that bokeh is a strong point of the DFA 150-450

[Craigbob]

B looks significantly better to me.

Are those two spots on the far right side about middle from the sensor? Sorry if it's a dumb question, I'm not well versed in this stuff.

Yeah, I need to clean the sensor.

Here are the unprocessed shots including crops of them.


150-450 Unprocessed


Crop of the above


Unprocessed Sigma 50-500


Crop of the 50-500 unprocessed.

[SteveinSLC]

Thanks for posting those unprocessed photos. I waffled on the choice between the Pentax and Sigma, and ended up spending the extra for the Pentax. This shows I definitely made the right choice. The Pentax is much sharper.

[dagoban]

At open wide the pentax is sharper than sigma, mainly on edges, it is better against chromatic aberrations and it is weather resistant.

The best aperture for sigma is F8-F9, mainly in large apertures when it starts to loose sharpnes. The sigma has better bokeh (I found that sometimes the pentax bokeh was nervous), it has pseudo-macro mode and it is more versatile because it offers 50-150mm and 450-500mm that pentax can't. The optical stabilizer of the sigma is another strong point because it is better than k1 stabilizer, mainly at larger apertures than 300 mm.

The final decision depends on the use you are going to do to the lens.

For fauna the pentax is better but in that cases the 450mm are not enough and I recomend the pentax 1,4x converter, it works ok with the 150-450 (with only a little vignetting). Ahhh, and the converter 1,4x is really 1,5x instead of 1,4x.

In my case, I needed a lens for sports mainly, and fauna in other cases, then my decision was the sigma because of its versatility and today I'm very happy with the decision.

[gaweidert]

I find the bokeh on my 150-450 is good to about 400mm. After that it seem to go downhill. Out of focus blades of grass and twigs double up to look like two fuzzy blades side by side. Not sure if it is my lens or what. The bokeh on close up shots is good. There is just this spot where the out of focus areas look like the shutter shock effect on he K1. I see it on my K3 shots too so it is not the camera.


All in all I am very happy with the lens, but it does have it's moments. Here is a heavy crop from an image I took in September 2017. Egret is in focus and sharp but look at the out of focus area behind the bird. 450 mm, f8 at 1/1000 sec. I have seen this effect on a few other shots on the forum using this lens too. I have had it for about 3 1/2 years now

[simple1]

Yeah, I need to clean the sensor.

Thanks for the reply. As long as I’ve had a DSLR I should know more than I do

[normhead]

In any comparison of lenses conclusions can be draw from very few, images and can be incorrect, because circumstances didn't match. I'd suspect with long lenses it isn't that hard to produce decent bokeh, and just as a general perspective doubts that Pentax engineers would ignore that in their design, in fact the last few years they have been ver concisous of it, adding size and weight to lenses.

I'd certainly be interested in some comparative images. IN almost every situation, more zoom range leads to higher CA values, loss of resolution and weak spots in the design, usually at the long end.

It's easier to create smoother bokeh with a longer lens, and much more difficult to create a lens that is sharp at both 50mm and 500mm. SO my expectation is that the 3:1 ratio of the 150-450 would make it the better lens optically.

If someone wants to post evidence that the 50-500 at 500 is sharper and has better bokeh, I'd be willing to have look. I'm just talking about my expectations here.
But on the other hand, if we don't have two equally framed images I'm not biting. There was a thread that wanted to know if the 150-450 provided more resolution at 450 than the Sigma did at 500. There was evidence that the 1504-50 was better. It would be nice if someone who owns both could provide some evidence to settle this once and for all.

[Craigbob]

In any comparison of lenses conclusions can be draw from very few, images and can be incorrect, because circumstances didn't match. I'd suspect with long lenses it isn't that hard to produce decent bokeh, and just as a general perspective doubts that Pentax engineers would ignore that in their design, in fact the last few years they have been ver concisous of it, adding size and weight to lenses.

I'd certainly be interested in some comparative images. IN almost every situation, more zoom range leads to higher CA values, loss of resolution and weak spots in the design, usually at the long end.

It's easier to create smoother bokeh with a longer lens, and much more difficult to create a lens that is sharp at both 50mm and 500mm. SO my expectation is that the 3:1 ratio of the 150-450 would make it the better lens optically.

If someone wants to post evidence that the 50-500 at 500 is sharper and has better bokeh, I'd be willing to have look. I'm just talking about my expectations here.
But on the other hand, if we don't have two equally framed images I'm not biting. There was a thread that wanted to know if the 150-450 provided more resolution at 450 than the Sigma did at 500. There was evidence that the 1504-50 was better. It would be nice if someone who owns both could provide some evidence to settle this once and for all.

The SOOC shots I posted above are framed the same, and were taken moments apart. That's as close as I could get to identical images from both lenses. To me it settles the question for me, the Pentax wins on IQ and the Sigma wins on Range/versatility. Now if only Pentax would make a 50-500 with the quality of the 150-450.

[normhead]

The SOOC shots I posted above are framed the same, and were taken moments apart. That's as close as I could get to identical images from both lenses. To me it settles the question for me, the Pentax wins on IQ and the Sigma wins on Range/versatility. Now if only Pentax would make a 50-500 with the quality of the 150-450.

One is a 3:1 zoom ratio, one is a 10:1 zoom ratio, that would be a "go to the moon" type marvel of technology.

My reference to comparisons above was to shots that displayed the quality of out of focus both, for both smoothness and transitions.. the demo images above show edge to edge for landscape.

[bassek]

Is it really fair to compare a 3x zoom against a 10x zoom? The big thing that is surprising is that the (both non OS and OS version) Sigma is that good.

Seb, who does not own either

[normhead]

Is it really fair to compare a 3x zoom against a 10x zoom? The big thing that is surprising is that the (both non OS and OS version) Sigma is that good.

Seb, who does not own either

And that's really the point, after all it's all Rupert ever used, and he used that lens as much as anyone uses any lens.
Got Squirrel Shots? (In memorial of Rupert) - Page 13 - PentaxForums.com

[dagoban]

Some examples with my Sigma 50-500 OS HSM and k1:

Sigma 50-500 is not weather sealed:



Pentax 150-450 is sharper on edges and better with chromatic aberrations, but sigma 50-500 is quite sharp closing to F8-F9, bokeh is softer,





It's more versatile:

50 mm:



500 mm:







It has a pseudo macro mode:



And the optical stabilizer is better than the k1 stabilizer:



The final decision on the lens depends on the user (more photos: Probando el Sigma 50-500 OS HSM | Flickr ).