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Monday, September 29, 2014

Sigma 18-35MM 1.8 Art lens • Big Boy for Pentax K

For many years I would never buy third party lenses for my cameras. I felt that it was better to use the manufacturer's glass for proper fit, higher quality construction and supposedly better optical quality. Nikon and Canon did nothing to dispel the impression that third party lenses were cheap substitutions and until the 21st century, except for expensive lenses like Zeiss, they pretty much were. Sigma pretty much put the lie to that perception in the past couple of years with the introduction of the Art line of lenses. The one continuing complaint I read about the Sigma lenses is a tendency on certain lenses to miss focus. I have not had that experience with my lenses. Sigma addresses this with a USB dock to update the lens with firmware and to customize it, which I believe is corporate vernacular for fix-the-focus issue. 

As you may have seen from an earlier post I recently purchased a Pentax K-3. I wanted a smaller, low profile camera for street shooting and travel. As I did my search for lenses I came across the Sigma 18-35MM 1.8 Art lens for the Pentax. I own two Sigma Art lenses for my Canon system, the 50 & 35MMs and they are great performers. Before plunking down another 8 Benjamins I did my due diligence and read a few reviews. All said what I am going to tell you here, great lens, but heavy. Still, optical performance is the most important factor so I ordered the lens. It is large and weighs the same as the camera,  a bit over 800 grams. Put the lens shade on this big boy and it is about 7 inches tall, the same size as a Zeiss 135. So much for being unobtrusive and taking the weight off my shoulder.

The fit and finish of these Art lenses is wonderful. They are also elegant in design. Wide ribbed rings for focus and zoom with a nice tactile feel. There is a semicircle of the ribbed material in the center of the barrel as well. A secure grip on a lens is always a good thing and this Sigma has it. The zoom and focusing rings have the perfect amount of drag on them.  It has a focusing scale in meters and feet behind a plastic window. Those of you under 38 years of age can see it easily, I need my reading glasses and to be candid, I don't remember the last time I looked at one. One of the things I tend to notice on all lenses is the little dot used to properly align the lens mount to the body. Canon puts their in a low position around the base of the lens. You have to rotate the lens to find it, no big deal.  Zeiss puts theirs on the mount itself. That means you have to turn the lens upside down to find it, I find this a bit awkward. Sigma puts their white mounting dot on the bevel above the lens mount. It is easier to see from all directions. It is a small thing, but I am a nut about ergonomics and I think this was brilliant. Sigma uses what they call a hypersonic motor for autofocus. I have no idea what it means, but it is smooth, silent and accurate. Manual override is available without flipping a switch for those times when you want to fine tune your focal point. I also like Sigma's petal hood, which reverses on the lens for storage. It mounts easily and locks in position with a reassuring click.  

I like to work in early morning light when I am shooting for myself. The K3 is often praised for its pentaprism and when combined with the 1.8 constant aperture on the Sigma 18-35 the view is wonderful, more so in dim early morning and evening light. I took these next few images on an overnight escape from Washington, D.C. to Rehoboth Beach, Delaware.

ISO 400 F3.5 @ 1 .5 sec, lens at 29mm

ISO 400 F5.5 @ 2 sec, white balance fluorescent, 18MM
I took this next shot in front of Fat Daddy's BBQ in Georgetown Delaware. Shot at 18MM handheld, the shot shows no barrel distortion on the edges of the frame, it has a near rectilinear quality. 

As the other two Sigma art lenses I have for my Canon, this lens exhibits smooth color rendering, strong micro-contrast and  excellent sharpness. If Sigma made an 18-35 version for full frame I would be all over it. Its weight and size is an issue on the K3 but the balance is good and it handles just fine.  The Sigma 18-35 f/1.8 DC HSM lens is a winner. 

Recommended 98 points

Sunday, September 28, 2014

Part II: Pentax K3 for architecture? Believe it.

In the first installment of my review of the K3 I mentioned composition adjustment feature of the image using the sensor.  As my assignment work is about 75% architectural, I started thinking of the K3 with the 15MM lens as an alternative to my Canons with TSE lenses. The T in TSE stands for tilt, which can enhance depth of field, the K3 sensor cannot emulate that function.

I need Canon's full frame larger sensor for my clients, who often need large display prints.    So a few thought balloons floated up the inside my skull. How much use could I get out of this idea?  Could I use it for architectural images when I travel? Would the range of shift be equal to the TS-E lens? Would there be image degradation, especially in the corners with the sensor shift? With all of that in mind, I set off to do a few shots during an actual architectural assignment. 

This first shot was with the sensor in neutral position, no correction.  You see the usual problems when working without a shift lens, too much ceiling. The image could be cropped of course but real estate would be lost resulting in a smaller file. I try to shoot for every millimeter of the sensor when I work and this is even more important with a smaller APS-C format.   

The second exposure was at full shift down with a slight adjustment to the left of the frame to center the video panel. 

Both exposures were shot in natural light with auto white balance. Normally I would bracket exposures to add layers that would bring it the burned out window to the left. As this was taken during an actual assignment I had to save that effort for the Canon Mk III with the TSE lens. 

The lens used for these shots was the Sigma 17-35MM 1.8, at full zoom with an angle of view of a 52MM on full frame format. Exposure was at a 1/4 second @ ISO 100. The exposure varied a 1/2 stop  (F 9.5 - 11)as the lighting changed so I equalized it in Photoshop for illustrative purposes. Other than using the profile in LR5 and a minor adjustment curve, no other post processing was done on these images. 

For comparison, here is the finished image, fully post processed, shot with the Canon 5D III with the 50MM Sigma Art lens. ISO 100 1/8 sec. @ F11.  I am confident that the Pentax K3 image, fully post processed would look about the same, with a slight resolution boost to the Canon for the FF sensor. 

Here is another shot for comparison. These were shot with the Pentax 15MM, roughly equivalent to 22MM perspective. 

Note that at full shift in both series there is no degradation of resolution in the corners of the image, very impressive. 

Pros and cons. This is a very useful tool for architecture and landscape photography - with limitations. The shift amount is not as great as a TS-E lens but I would guess it is useful for about 90% of the time I would use shift, that's a plus. There is no degradation of the image at full shift, another plus. The sequence of actions needed to affect shift is somewhat inconvenient. First, the feature has to be activated in custom menus. That is easy enough. After that is done every time live view is used, the adjustment screen pops up. An exposure cannot be made until the OK button is pressed. Any shift you have implemented holds for subsequent exposures and no further shift adjustments can be made until live view is off than on again, a minus, but pretty much the only one I could think of. 

For me, composition adjustment in live view, the method I use when shooting architecture with the TS-E lens, is simply terrific. Keep in mind that I do work slowly so the multiple on/off steps don't bother me. This feature on the Pentax K3 allows the use of any lens as a shift lens. Now, how cool is that? A big plus.  
I keep my high recommendation for the Pentax K3. Part III of the review will be upcoming in a few days. 

Monday, September 22, 2014

Ricoh's Pentax K-3, Part One

A reminder. I only review gear that I buy for myself. I offer reviews based on my experiences in the field or studio. I do not peep at pixels, I do not photograph charts and color bars. All that super photo-geek stuff is available on other forums.

Ricoh Pentax K3 with battery grip and DA 70MM 2.4 Limited lens

"All this crap weighs a ton." That's the recurring thought I have every time I go out on assignment. My work requires the use of full frame DSLR with perspective correcting lenses or my even heavier medium format camera for my aerial and studio work.  So, I shlep roller cases and wonder when camera builders are going to come up with light weight carbon fiber bodies and lens barrels. Sure, it would double the cost of the gear, but at that moment, I don't give a damn.

While I can't give up the heavy gear for my work, I could go lighter for my street shooting and travel. Last year I bought the Canon 6D, a lighter built, smaller full frame body to use with my existing arsenal of Canon glass. The weight savings was but a few ounces on the body, everything else was the same. It was a fine camera, but not a solution. A year earlier I bought the mirror less Fuji X Pro-1. The size was Leica rangefinder like, the glass was good but the ergonomics drove me crazy and I hated the EVF. I'm old school, I like my view to be real time and unaltered. 

A few weeks ago I decided to visit the idea of buying the Pentax K-3. I've owned a good bit of Pentax gear in the past. I've always found that it well built with well thought through ergonomics that eludes other manufacturers. Market penetration seems to be a problem for the brand. Some of it might be due to the multiple changes of ownership over the past few years. Pentax was bought by Hoya, then dumped. Ricoh picked it up and seems to be giving strong support to the line.

As Ricoh/Pentax has been dropping prices and running promotions lately I thought it a good time to take the plunge. I picked up the K-3 kit with the battery grip and a few lenses and it was off to the races.

The only issue with the Pentax K5 I owned a couple of years ago was the 16 megapixel sensor. I make large prints and I found it a bit limiting, now that is no longer the case. Pulling the K3 out of the box I was immediately struck with how familiar the layout of the controls appeared. Sure, there are a few important changes for additional features, but for the most part, I was able to start shooting without a glance at the manual.

Here are three strong reasons I found the K-3 a smart choice. It is small profile, but not lightweight body with great build. The 24 Megapixel sensor without an anti-alias filter allows for higher resolution, larger images and Pentax offers a line of lightweight lenses with great image quality. If you prefer prime lenses you can put together a kit with the body, a 15MM wide, the 31MM limited normal, and a 70MM short tele and come in with a carry weight well under 4 pounds. For me, weight was the main consideration, but even if it were not, the Pentax K-3 is worth consideration. 27 AF sensor points should make any photographer make happy. It has a great feature set, the images compare well with any most full frame DSLR and the price/performance ratio is unbeatable. 

I have large hands, not gorilla sized hands as my son insists, but I wear a large or extra large gloves. This causes problems with small cameras with lots of control buttons like the Sony X-100 or the Fuji X-1 Pro mentioned above. I find the K-3 the perfect size for the smaller profile DSLR. The grip is deep and easy to grasp and oh so comfortable. There are easy to access hard switches and buttons instead of a myriad of sub menus. Some people have complained about it, I think the hard switches are great and easy to identify. Sure, you have to get used to the K-3 as any other camera, but once you do controlling the camera is near intuitive. The front and rear wheel dials are properly positioned and the AF and AE-L are controlled by separate buttons with enough space between them to avoid mistakes. The 7-mode knob on the top and left of the body has a lock or can rotate freely. To the right of the lens mount (facing the camera) are 4 buttons and switches. An AF on-off switch, an AF mode select button, a raw/FX toggle button, a button to pop up the prism mounted flash and a flash sync port, something you rarely see on prosumer cameras. The optical pentaprism viewfinder gives 100% coverage and the amber readout has all the relevant data you need without being distracting as you shoot. The camera has all of the functions you would expect. 7 shooting modes, 3 user defined modes, exposure compensation for both metering and built in flash, etc. 

I don't shoot video with a DSLR, so I can't offer an opinion on this feature. Reviews on video function on the K-3 haven't been great, not even good. However as a camera for stills, it is the best of the APS-C DSLR offerings. Find another pro level APS-C camera that offers over 8 frames a second, a 3 1/4 inch LCD, shutter speeds to 1/8000 sec and ISO to 51,2000 with a robust magnesium alloy build and is weather sealed, all for around $1100.  That's enough for now about features and such, how about performance? 

I've shot high ISO with my Canon 1Dx on a couple of occasions, usually doing music or theater performances. I think the max I've used was 12,800. I did this simple test on the K-3 starting at 6400 going to 51,200 ISO. The following images are non retouched jpgs from the original RAW files. In camera noise reduction was set for maximum effect from 6400 ISO and above. The photos were taken in dim light late in the afternoon, all handheld using the in-camera shake reduction. Aperture was F4.5 for all frames, shutter speeds ranged from 1/4 sec at 6400 ISO to 1/30 sec at 51,200 ISO. The lens was a Pentax 70MM 2.4 ltd.

6400 ISO

12,800 ISO

25,800 ISO

51,200 ISO 
As you can see, the noise level at 6400 is quite acceptable and very good at 12,800. If you are old enough to remember film, at 25,800 the noise gets to Tri-X grain territory, at 51,200 things get a bit messier, but the image is still usable. 

I took the 51,200 frame and used Dfine for further noise reduction. Not bad, is it?

The K-3 has a unique live view function I have never seen before, a composition adjust function, think shift lens without the extra glass. The image can be raised, lowered or rotated a few degrees by repositioning the sensor. This can be particularly useful for making minor adjustments during architectural, product or macro photography as shown below. All shots taken on tripod at ISO 800, Tamron 105MM lens, F4.0 @ 1/20th second, which accounts for the shallow depth of field. 

Neutral position, no adjustment

Full adjustment up

Rotate adjustment to level

Shift adjustment to include more of the left side of the image

Another feature offered on the K3 is focus peaking during live view. It took me a bit of time to find the software switch to turn it on (old eyes) but when I did I found it to be of great option, I wish my Canon cameras offered this feature. It is particularly useful for macro shooting when nailing the exact spot with your eye, as in lower light situations is difficult. Yes, on the Canon I can magnify to 10X on my focus point but peaking shows up better. The following macro shot of the flower was shot in low light. 1600 ISO, 1/45th @ 6.7 with the Tamron 105 macro. The focus peaking area is marked in the photo below. You can see how sharp it is. I love this feature.

This ends the feature review part of the program, now I'd like to show you some actual shooting I did over the weekend at Rehoboth Beach, Delaware. 

Friday was Senior's day at the shore town and hundreds were bused in from retirement homes around the area. Here six of the ladies enjoy the afternoon sun and a soft breeze. 

,There are a lot of places to eat on the boardwalk, but get a bit out of town and you can find independent, owner run restaurants, like Fat Daddy's. Exquisite North Carolina style pulled pork. 

I did minor post work on these photos. The dynamic range of the sensor for these full sun exposures was terrific. I opened the shadows a bit under the eves of Fat Daddy's store front, and didn't do much at all on the shot of the ladies. 

Initial Impression: The Ricoh Pentax K-3 does not disappoint. I had a high opinion of Pentax going in from my prior experience with the brand and it was confirmed in every way possible so far. I'll do more extensive testing on the AF features, bracketing and long exposures as I get the time. For now, I give the K-3 - 

97 Points - Highly Recommended