[biz-engineer]

Currently looking in the lens database at ratings/evaluations of the DFA150-450 and Sigma 50-500, overall the DFA150-450 rates slightly higher than the Sigma 50-500, but when I look at actual images, I don't find the DFA150-450 to render very well, I don't know why, bokeh? sharpness? CA? According to the tests, the Sigma 50-500 has a lot of CA around both 50mm and 500mm. But the images from the DFA150-450 look like something get fuzzy, maybe lack of contrast or something else, although it is supposed to be a better lens because it carries the Pentax brand on it. Anyone having used both lenses here and could explain the differences regarding image quality?

[redpit]

You're right about the difference in images from the 2 lenses. After many comparisons as I still have both lenses, I've ended up that the OOF rendering of the DFA 150-450 is what makes this difference. The bokeh of the Bigma is soft and creamy (actually the main and only advantage in IQ over the DFA) while the DFA creates quite nervous backgrounds especially when there is not much distance between the subject and the background (e.g a bird on a tree and backlight branches-leaves behing it). It kind of reminds me the OOF rendering of my mirror lens! (when no "donuts" are involved of course). To tell you the truth I don't always find this ugly! Maybe I just got used to it, but I like ti sometimes! If I had to describe it is like a hazy background, as haze has affected the borderlines, so still there is some sharpness in there mixed with fuziness...

Concerning lack of contrast-microcontrast, or sharpness, there is no way the Bigma is better than the DFA. DFA excells as it does in CA and backlight situations where I find it superb (no flaring and minimum to no CA). That's my opinion on these 2 lenses, I hope that I helped a bit.

[biz-engineer]

The bokeh of the Bigma is soft and creamy (actually the main and only advantage in IQ over the DFA) while the DFA creates quite nervous backgrounds

Thanks a lot. Now that you wrote it, I realize that's also what I noticed on image posted from both lenses on the web.

[biz-engineer]

Have you searched other photo sites for 150-450 examples ? Like Flickr... https://www.flickr.com/search/?text=Pentax%20150-450&safe_search=1 My 2 cents... M

Thanks, humm yeah, it's hard to judge , the perception of image quality depends a lot on shooting conditions and what's in the frame.

[VoiceOfReason]

I don't know about the 50-500, but I had the 150-500 HSM and the DFA 150-450 kills it in image quality.

[biz-engineer]

Help me understand (assuming you are struggling with a buying decision)... So, you feel one can get a better general sense of lens capabilities from a limited number of this forum's lens database image samples by photographers seemingly promoting the lens versus a larger offering of samples from a broader spectrum of photographers using an image database like Flickr? Just curious... M

Ok, the problem for the DFA150-450 and other recently released lenses is that they can't be found in MTF tests sites such as Photozone, DXO, or other sites. Looking at pictures at web size (1024x800 or so) can hardly make a difference between lenses, as even a lens that resolves 20lpmm would look good when reduced to 1M pixels. Of the DFA150-450, I've seen "good" and "bad" image quality from the web, so I can't conclude anything. That's why I was asking how the 50-500 and 150-450 differ from the persons who owned both of them.

P.S: for the DFA24-70, and DFA150-30, it no secret that they are the Tamron 24-70 VC and Tamron 15-30 VC so everyone can find image tests available from lens test websites. This is not the case for the DFA150-450 and won't be the case for a while for the DFA70-200 as well, I suppose.

[Nicolas06]

Ok, the problem for the DFA150-450 and other recently released lenses is that they can't be found in MTF tests sites such as Photozone, DXO, or other sites. Looking at pictures at web size (1024x800 or so) can hardly make a difference between lenses, as even a lens that resolves 20lpmm would look good when reduced to 1M pixels. Of the DFA150-450, I've seen "good" and "bad" image quality from the web, so I can't conclude anything. That's why I was asking how the 50-500 and 150-450 differ from the persons who owned both of them.

P.S: for the DFA24-70, and DFA150-30, it no secret that they are the Tamron 24-70 VC and Tamron 15-30 VC so everyone can find image tests available from lens test websites. This is not the case for the DFA150-450 and won't be the case for a while for the DFA70-200 as well, I suppose.

You have ephotozine , they gave it 4.5 stars and there a few samples available for download.
https://www.ephotozine.com/article/pentax-hd-pentax-d-fa-150-450mm-f-4-5-5-6...w-review-27359 testing it on a K3:

150mm


300mm


450mm


I have also seen I don't remember were that the 500mm of the sigma are a bit optimistic with a few captures to show. From what I understand you can really consider both to have the same long end reach.

I understand the 150-450 is a great lens, pictures I have seen with it tend to look great, if you buy it, for you'd make a great buy. I have now idea on how it compare to 50-500.

[darylk]

I used the DFA 150-450 extensively last week. It can take very nice photos. How it compares with the Sigma, I don't know. Most of these were taken using the DFA: https://darylkottwitzphoto.smugmug.com/Travel/Sandhill-Crane-Watch-2016/i-gRkF4Rt.
Daryl

[biz-engineer]

I used the DFA 150-450 extensively last week. It can take very nice photos. How it compares with the Sigma, I don't know. Most of these were taken using the DFA: https://darylkottwitzphoto.smugmug.com/Travel/Sandhill-Crane-Watch-2016/i-gRkF4Rt. Daryl

Thanks, good to see some examples.

[tduell]

Here's a recent example, DFA 150-450, K-3 II.

[noelpolar]

Looking at pictures at web size (1024x800 or so) can hardly make a difference between lenses,.

Most Flickr images are not limited to 1024x800

[Wild Mark]

Here's a recent example, DFA 150-450, K-3 II.

I cannot fault the subjects in that image. Very nice indeed.

The bokeh does look a little nervous/ distracting. That is the only criticism I have and that is aimed at the lens not the shooter

[tduell]

Another example, with better bokeh.

[Wild Mark]

yes that is much better - the background is clearly quite distant from the subject to allow this bokeh.

Perhaps better OoF with wider open aperture setting? But what will that do to sharpness?

[tduell]

yes that is much better - the background is clearly quite distant from the subject to allow this bokeh.

Perhaps better OoF with wider open aperture setting? But what will that do to sharpness?

Generally the bokeh is pretty good when the background is distant. With my original example the background was quite close.
This latest shot was wide open...f/5.6 @ 450mm.

Cheers,
Terry