[Stavri]

Yesterday I got my hands on a Sigma Ex dg 50mm f1.4 HSM and decided to compare it to my old trusty -F 50mm f1.4(Dreadful i know). This is completely a subjective testing of bokeh at large apertures. Exposure is kept the same on both lenses. AF performance is about the same on the K-3, both lenses focus quickly, the -F 50mm hits focus marginally quicker with less hunting.


Pentax-F 50mm @ f1.8


Sigma Ex 50mm @f1.8


Pentax-F 50mm @f2.8


Sigma Ex 50mm @f2.8


Pentax-F 50mm @f4


Sigma Ex 50mm @f4

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Last edited by Stavri; 09-18-2014 at 07:42 AM.

[JinDesu]

I find the Sigma's bokeh to be smoother at F1.8 than the F50.

[Stavri]

I agree, The Sigma is slightly sharper then the -F 50 at larger apertures, past F4.0 they're indistinguishable. I wish the color palate on this pictures was a bit more expansive, I would have liked comparing the rendering of both lenses (next time perhaps) I also think the -F 50mm has better micro contrast (deeper blacks between the stalks).

[jrpower10]

I find the Sigma's bokeh to be smoother at F1.8 than the F50.

As do I, but I like both actually. Both work for me in different ways.

Oh yeah, I definitely perfer the size of the F 50.

[JinDesu]

I agree, The Sigma is slightly sharper then the -F 50 at larger apertures, past F4.0 they're indistinguishable. I wish the color palate on this pictures was a bit more expansive, I would have liked comparing the rendering of both lenses (next time perhaps)

I found the Sigma to be great, but it does have some LoCA on the out of focus areas when there's highlights. Also, it's HUUUUUGE (as your picture shows). Even my DA*55 is more compact!

The newer Sigma 50 1.4A is supposed to be even sharper and more impressive (larger too I think).

[Stavri]

I found the Sigma to be great, but it does have some LoCA on the out of focus areas when there's highlights. Also, it's HUUUUUGE (as your picture shows). Even my DA*55 is more compact!

The newer Sigma 50 1.4A is supposed to be even sharper and more impressive (larger too I think).

How does the Sigma Ex dg 50mm compare to the Da* 55 at large apertures (F1.4-2), I've seen some amazing pictures of the DA* 55 shot @f1.8

[JinDesu]

How does the Sigma Ex dg 50mm compare to the Da* 55 at large apertures (F1.4-2), I've seen some amazing pictures of the DA* 55 shot @f1.8

I did take some comparison samples.


Full size link for 100% crops: https://farm4.staticflickr.com/3708/11830257953_5b9247b07f_o.jpg


Full size link for 100% crops: https://farm6.staticflickr.com/5498/11830400844_d285a0a5ef_o.jpg

Album link: https://www.flickr.com/photos/jindesu/sets/72157647736916351/
I'll update the album so each photo has a link to the full size image.

[Stavri]

I did take some comparison samples.

Thank you JinDesu. This confirms my suspicion that Da*55mm f1.4 is very usable f1.8-f2. God I love the rendering of the Da*. The OOF on the Sigma look "dirty" like its germinating with micro-organisms, the Pentax has very clean circles. Any thoughts on the SDM vs HSM performance?

[Drake Avenue]

The DA* is usable down to f1.4. I'll post some examples later today.

[JinDesu]

Thank you JinDesu. This confirms my suspicion that Da*55mm f1.4 is very usable f1.8-f2. God I love the rendering of the Da*. The OOF on the Sigma look "dirty" like its germinating with micro-organisms, the Pentax has very clean circles. Any thoughts on the SDM vs HSM performance?

SDM is slower. My Sigma 50 1.4 was quick on my k-x, and was very quick on my k-3. The DA*55 is slower and I have trouble tracking people walking towards me. Also, the HSM was quieter.

The quickshift on the DA*55 is much more enjoyable to use than the Sigma 50 F1.4. It's smoother and lighter. The Sigma 50 1.4's quickshift had more friction to it.

The body material on the DA*55 is better than the Sigma 50 F1.4 in terms of feel. It's got a bit of a roughness to it that makes it feel less slippery. I don't know about how the new ART lens is though.

The hood on the DA*55 is very nice and deep, with nice velvety material on the inside. The downside is that when reversed, I can't access the focus ring. On the Sigma, the petal hood is not as deep (made for a FF camera). It allows me to access the focus ring while reversed. Also, while attached normally, I can easily reach the lens cap on the Sigma while the DA*55's hood is so deep, it's hard to reach the lens cap. This matters because on the Sigma I usually left the hood on normally (not reversed), while I have to reverse the DA*55's for storage because it's so long.

I didn't have any focus adjustment issues on either lenses. I've used the DA*55 in several rainstorms without issue, also.

https://farm8.staticflickr.com/7385/11429762316_4a7bddaed0_o.jpg
F1.4 full size image above. At medium to far range subjects, the lens is sharp corner to corner (disregard the upper right corner, that's because I'm not perpendicular to the wall). On closer subjects, F1.4 is a little weaker, but still very sharp.

[Stavri]

https://farm8.staticflickr.com/7385/11429762316_4a7bddaed0_o.jpg
F1.4 full size image above. At medium to far range subjects, the lens is sharp corner to corner (disregard the upper right corner, that's because I'm not perpendicular to the wall). On closer subjects, F1.4 is a little weaker, but still very sharp.

I appreciate the detailed explanation. Is the above picture shot @f1.4 from the Sigma or the DA*?

[JinDesu]

I appreciate the detailed explanation. Is the above picture shot @f1.4 from the Sigma or the DA*?

Sorry, that is the DA*55.

https://farm9.staticflickr.com/8315/8037491972_fa1e425e92_o.jpg
^this one is the Sigma 50 1.4. It's pretty sharp too in the medium range.

[Stavri]

Sorry, that is the DA*55.

https://farm9.staticflickr.com/8315/8037491972_fa1e425e92_o.jpg
^this one is the Sigma 50 1.4. It's pretty sharp too in the medium range.

There's something terribly wrong with my Sigma 50mm copy, I cannot get marginally close to the above image shot wide open.

I checked your comparison of the Da* 55mm f1.4 and the Sigma. You seem to have two excellent copies. (I wish I had bought your copy of the Sigma when you sold it)

[JinDesu]

There's something terribly wrong with my Sigma 50mm copy, I cannot get marginally close to the above image shot wide open.

I checked your comparison of the Da* 55mm f1.4 and the Sigma. You seem to have two excellent copies. (I wish I had bought your copy of the Sigma when you sold it)

Did you try checking it manually focusing? I'll double check my Lightroom when I get home to see how much sharpening I added. I don't usually add a lot of sharpening, but maybe that's the difference (for reference, base is 25/1.0/25 in Lightroom, and I make it 45/1.0/45).

[Stavri]

Did you try checking it manually focusing? I'll double check my Lightroom when I get home to see how much sharpening I added. I don't usually add a lot of sharpening, but maybe that's the difference (for reference, base is 25/1.0/25 in Lightroom, and I make it 45/1.0/45).

I did check for F/B focusing, I dialed different settings and found the optimal one (-4). I took another picture of the flower pot. I'm getting similar results, softness at f1.4. I don't have any lenses that are sharp wide open and though I was asking too much from my 50mm, after looking at the photos of your Sigma 50mm copy with its incredible sharpness at F1.4 I'm seriously wondering whether I got a bad one.

Ok K-3, AFA center spot focus. On the three flower row, focus placed on the middle flower.

crop: