[interested_observer]

It has been around 2+ years now, that the Sigma 18-35 lens has been announced and available. I have read quite a few threads, along with the reviews here on the lens.

• https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/277499-sigm...-thread-4.html

I have my 31Ltd that is not going anywhere - and in many ways, it is the seed that is causing me to consider this lens. Shooting the Milky Way, the 31 is superb - it's the speed that does it, but I really need to go wider. Stitching is possible, but it brings in additional problems. Pentax does not seem to have anything on their road map that is as fast.

Yes, I am considering it. I have the funds squirreled away in my sock drawer - and they are not burning a hole in my pocket in the slightest. Sigma's continuing practice of discontinuing K mount lenses, is a mounting concern. A couple of years ago I decided to pickup the 8-16, and now I am glad I did - since they have discontinued that one.

The Milky Way is back in season, and there are a number of landscape shots I have laid out, that I want to capture. 18mm is more than wide enough for what I want to capture. I am not going to go full frame any time soon - if ever. I like the physical size of the cropped bodies and lenses. If by judging the new full frame lenses that Pentax is announcing, by way of the DA* 60-250/f4 - that thing is massive and heavy - as heavy as I ever want to go. I am going to have little interest in the full frame lenses.

So, as of late - those of you that are shooting with the 18-35, and especially those that have recently acquired this lens - how is it performing? Getting any better? I am considering getting the lens, testing it and possibly taking it over to CRIS - who is a Sigma Warranty repair site, and having them set it up and align it (they did a really excellent job with the 8-16 which was 45+ units out of calibration 2 days after I received it new from the dealer).

With this lens, I tend to shoot nearly exclusively with Liveview off a tripod - so I think that is CDAF as opposed to PDAF (which is apparently where most of the problems occur).

I have missed this month for the MW - so, I am thinking about next month and the lens.... What is the current consensus?

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Last edited by interested_observer; 04-18-2015 at 05:38 PM.

[panoguy]

With the uses you've outlined, I don't think you'll be disappointed. You luckily have a service center not too far away to calibrate/ fix it, should there be a need, which is what boils most folks who get a lens that is underperforming in some way or another. Sending anything back, or into Sigma Service, is a bother and can sour even the best experience.

I've had the 18-35 in Sigma SA mount for a while now (thanks to the prodding of a fellow forumer), and it happily lives on my SD1 Merrill. Not light, not small, but optically excellent, which is needed for that picky Foveon sensor! Certainly beats the pants off the 18-50mm f/2.8 zoom and the 10-20mm wideangle I had before it. Alas, I've never tried the 8-16mm, but I'm keen to.

[MadMathMind]

Mine has been calibrated (by myself) and is totally awesome. I took a ton of recent photos with it:

https://www.flickr.com/photos/madmathmind/sets/72157651766956372/

Anything that's blurry is my fault: I used the center point and recomposed. I don't know why I did this; it messed up a few shots. I also used slightly too low of shutter speeds, 1/60 or 1/80 indoors. You can see that's the culprit when the whole image is very slightly blurry; an out of focus issue would look different. When I wasn't screwing up, the results are ridiculous:

https://www.flickr.com/photos/madmathmind/16452675303/in/set-72157651766956372

Zoom in on that one. You can see her pores and the individual grains of makeup. I softened her skin in post because it was actually too sharp...

If you want to browse through what I've done with the lens, here's the collection:
https://www.flickr.com/photos/madmathmind/sets/72157649140156878/

[drypenn]

Subscribed.

I'm very interested with the lens but still worried about the AF issue.

[interested_observer]

Based on - in part, the responses here (and the other threads on the subject) - I took a deep breath and decided - what the heck, just go ahead. So, I ordered it - well kind of. The rest of the story is in posted via the link below....

• https://www.pentaxforums.com/forums/94-pentax-price-watch/293869-greentow-sig...-warranty.html

So, it should arrive via the Pony Express rider sometime next Thursday - as they go galloping through town (in a mighty cloud of dust and a hearty Hi Ho Silver - away).....

So, a couple of things are apparent right off the bat.

• I should get my can up off the chair and put some of the lenses that I am not using that have been replaced / made redundant and put them up on the marketplace. I have been meaning to do this for the last 6 months, now....
• I was 90% sure after the 60-250 arrived last Black Friday that I wasn't going full frame - this pretty much makes it a certainty.
• Even with the K3II announcement, it does not look like the sensor has any less noise, so my somewhat taking a chance with the K5IIs for slightly lower noise - was a reasonable way to go.
• And, since most of the work with this lens will be done in the dark, I have been thinking about a rotor index (to make panning a bit easier). I found a relatively inexpensive one the other day - I should just order it and be done with it.

[MadMathMind]

I had complained of issues again in my thread. I took it to a farewell party for my boss and shot a ton of photos with it. Inside the bar, I had tons of focus problems. Light was about as expected for a bar: I was shooting at 1/30s, f/2.2 or f/2.5 and still needing ISOs of 2000 or 2500 for most shots. I really fought with the focus on those shots. I probably got a 30-40% focus rate on those. I did nail a shot in every group I took, except for one, so that worked out ok. Trouble is in that poor light that I can't see what's in focus and what is not and the lens is far too quiet to be heard. I think I was hitting the limit of the AF system in that bad light and we can't blame the lens for not working perfectly at -2EV to -3EV.

When we did outdoor shots, it nailed the focus on every single one of them. Still shot around f/2.5 or f/2.8 for DoF control, but focus was unspeakably sharp. I need to quantify this better but I think it's having nor more issues than any of the other f/1.8 lenses I have. My FA77 doesn't hit every time either. From my limited experience with my new FA31, it seems to miss too.

In my previous issue set, I think it was a battery that had gone stale. It's a 3rd party (Wasabi) that is pushing 2 years old now. It was reasonably charged for much of a shooting session and then it just went kaput after about 375 shots, although I did a lot of review of my work in there, so that cost a number of shots. My FA77 was missing badly too during that time, so I highly suspect that the wonky battery was a major cause of issues. I've purchased some new batteries and removed that old one from my bag.

[Conqueror]

Is the Samyang 16mm f2 also a contender? Seems pretty decent for night/astro and you already have ~30mm covered with the 31mm

[interested_observer]

Is the Samyang 16mm f2 also a contender? Seems pretty decent for night/astro and you already have ~30mm covered with the 31mm

That is a very fair question. My reasoning - with its faults, went as follows: I have been transitioning away from manual lenses. I picked up a new K5IIs with the improved AF in low light, last Black Friday, along with a 60-250 replacing my M135, M150 and A*300/f4. Manual focusing lenses (at least for me) are easier on the wider angle lenses (when there is enough light). I figured that the sharpness and IQ were going to be pretty much equal, granted the Samyang is 2mm wider, along with being quite a bit smaller and lighter weight. I am going to be up on a tripod most of the time, and using LiveView, and CDAF works much better than PDA (rumor has it), so I will come out ahead by a smidgeon there. The Sigma warranty center was closer than the Samyang lens exchange (via the retailer). The bottom line is that in the dark, it's probably going to be MF anyway, so go with the faster lens. Also, with the zoom range, it provides some framing options.

Along the way to several of the locations, I usually stop to top off the gas tank, and drop a 6 pack of water in the cooler (if I forgot to pull some water out of the refrigerator at home). I can go down the street a bit and pull off, take the camera out and AF at the brightly lit gas station, and tape down the focus (putting it into MF). Then (hopefully) I should be somewhat good to go out in the desert.

I should probably pick up a 10K candle hand held spot light from the Freight Closeout place sometime, so that I can light something up as an alternative backup target to AF on.

The Samyang was certainly enticing at half the cost. What it boils down to is just - paying the money and taking the change. I could easily have taken the analysis the other way. So, when it arrives - I should have a week or two before the moon cooperates with some really dark nights.

It's raining pigs and chickens out right now....

[interested_observer]

The lens arrived today at dinner time. US warranty card, everything was fine. I took some images around the house with AF (PDAF) and it focused just fine - very quick. Took it outside at about 10.30 at night with LiveView AF (CDAF) and it AF on a light source and everything was fine. So far, I am happy with the lens.

Shot this one image ISO 1600, f1.8 at 1.3 seconds, with 90% full moon, no street lights - and it came out well. I even captured some stars in the night sky. Downtown Phoenix is on the other side of the hill....

[drypenn]

The lens arrived today at dinner time. US warranty card, everything was fine. I took some images around the house with AF (PDAF) and it focused just fine - very quick. Took it outside at about 10.30 at night with LiveView AF (CDAF) and it AF on a light source and everything was fine. So far, I am happy with the lens.

Shot this one image ISO 1600, f1.8 at 1.3 seconds, with 90% full moon, no street lights - and it came out well. I even captured some stars in the night sky. Downtown Phoenix is on the other side of the hill....

Good shot, I think that this lens' IQ has never been seriously questioned. It's the AF that gets the most flak. So, how's your AF?

I'm seriously looking at 18-35 or Pentax' 20-40, now that the latter's price has been more reasonable.

[interested_observer]

Good shot, I think that this lens' IQ has never been seriously questioned. It's the AF that gets the most flak. So, how's your AF?

I'm seriously looking at 18-35 or Pentax' 20-40, now that the latter's price has been more reasonable.

The AF inside the house was first time, every time, no hunting, just locked on. No problems - and that was with the viewfinder. Outside last night was with LiveView. When I AF on a light source, it AF immediately locked (it took a tad longer than inside) and took the shot - no problem. Then I tried to AF on just something black - in total darkness. As expected - that did not work, it tried - but that is not a problem. So, I then went back and AF on the lighted area, where it did achieve focus, then switched to manual focus, re-framed and took the picture.

So far - absolutely no problems that I can see. Very happy! I am going out tomorrow night with a long time friend (25 years) who shoots Canon (does short movies - 7D and 5D3) and this will be his first attempt at night shooting in the dark.

On this shot above - I went with ISO1600 because that is what I plan to shoot the Milky Way with, and just wanted to see how it would all turn out. It was just a simple quick test but was pretty happy with what I captured.