Pentax D FA★ 85mm f/1.4 Review – For Astro!

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Pentax 85mm lead photo
Pentax D FA★ 85mm f/1.4ED SDM AW

The Holy Grail for Pentaxians?

Shipping early July in 2020, to say the Pentax HD D FA* 85mm f/1.4 ED SDM AW was a highly anticipated lens among Pentax users, would be an understatement. After the release of the highly praised D FA* 50mm f/1.4, Pentaxians have been hopeful. The lens first appeared alongside the D FA* 50mm f/1.4 in a February 2017 update to the Pentax lens road map (see below), which included the current lineup, as well as lenses to come.

Pentax 2017 lens roadmap
The 2017 Pentax Lens Road Map. Image by Ricoh Imaging, 2017.

Since then, the world of Pentax users has been buzzing regularly about how good the lens is going to be, how much it is going to cost, and, most importantly, when it will be released. Pentaxians were teased with prototype photos, spec leaks, and near-perfect lens performance charts.

It’s Finally Here!

After 3 1/2 years of anticipation, pre-production models slowly made it into the hands of notorious Pentaxians, primarily in Europe and Asia. On July 3rd, 2020, a lens with a serial number ending with #305 was among the first very few lenses to reach its final destination in the United States. 

It happened to come to rest in the hands of a Pentaxian that has been lusting after an 85mm f/1.4 since the day they picked up a camera in 2014.

That Pentaxian is Me!

I am one of the first lucky few to own this highly-anticipated, beautiful piece of glass. I also know with 100% certainty that I am the only one that was crazy enough to buy it specifically for astro! Coupled with Pentax’s Astrotracer feature on the K-1 and K-1ii, I thought the lens has the potential to be the holy grail of astro lenses.

Spoiler alert, the lens isn’t perfect, but it has not disappointed.

DISCLAIMER: The item in this review was purchased with my own money and not gifted to me, nor lent to me by any third party. This article is not a paid review.

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Why I Bought the Pentax 85mm f/1.4

To explain my reasoning as simply as I can, I have always wanted an 85mm f/1.4.

With the announcement of the new 85mm from Pentax, and considering the price, I knew that if I didn’t bite the bullet and use it for astro, then no Pentaxian would. Or at least, no one would do it for a long while. The Pentax D FA* 50mm f/1.4 was on the market for over a year and a half before a single Pentaxian used and reviewed it for astrophotography. And, once again, that Pentaxian was me.

You can read my full review on the Pentax D FA* 50mm f/1.4.

I preordered the 85mm with the simple plan to make sure that its full potential is shown across all genres from day one. Plenty of Pentaxians are already using it for portrait photography, which is where this lens shines. I plan on using it for astrophotography, which is an incredibly demanding genre for lens optics.

About The Pentax 85mm

Before getting into my thoughts and observations, first some technical jargon and a breakdown of the name. The full name is the HD Pentax-D FA* 85mm f/1.4 ED SDM AW. Pentax likes long lens names, but they’re descriptive.

The “HD” refers to the lens using Pentax’s “High Definition Coating.” It gives better light transmission with less reflections than existing coatings. The coating also reduces flare and maintains good contrast in backlit situations.

With the D FA marking, “D” means the lens is optimized for digital, and “FA” means the lens is designed for a 35mm full-frame sensor.

“ED” refers to the “high-grade Super ED (Extra-low Dispersion) glass optical elements and an aspherical optical element to compensate various aberrations to a minimum. In particular, to effectively minimize axial chromatic aberration to prevent the generation of purple fringing in backlit situations. It also reduces distortion — a serious concern in portrait photography — to nearly zero at a focusing distance of four meters.” –Ricoh Imaging

The “SDM” refers to Pentax’s supersonic focusing motor that is both fast and quiet.

The “AW” stands for “all-weather.” The lens features Pentax’s notorious weather sealing to handle any extreme conditions.

Finally, the star on the lens means it is part of the Pentax star-series lens lineup. According to the Ricoh Imaging website, that denotes “excellence in three categories: exceptional image quality, large aperture, and a lens barrel design with excellent strength and outdoor protection performance.”

Handling

Pentax 85mm size demonstration
I don’t have huge hands, but I do not have tiny hands either. Here is a photo of the lens upon delivery mounted on my K-1 with my hand for scale.

My first impression of the lens is it is an absolute beast to hold.

The most important feature on the lens is the fast f/1.4 aperture, which should let in plenty of light for photographing the night sky. At the other end of the spectrum, the lens can stop down to f/16 using its nine rounded diaphragm blades.

The lens also features a massive 82mm front filter thread leading into 12 lens elements in 10 groups, encased in an all-metal housing. There is very little visible plastic on this beast besides the lens hood and lens cap.

At 2.99lbs (1355g), the lens has almost half a pound on the notorious Zeiss Otus 85mm f/1.4 (2.51lb / 1140g). Despite its size and weight, it actually balances reasonably well on the similarly heavy Pentax K-1, which weighs in at about 2.2lbs (about 1000g) with an L-bracket.

If weight is a concern, a camera and lens kit that weigh a total of about 5.2lbs (2355g), is far from being a featherweight. 

Still, the lens is built like a tank and has the weight to back up that claim. 

A lineup of various Pentax lenses
A Photo to demonstrate how the size of the new 85mm (Fourth from left) compares to other lenses available for Pentax K Mount. From left to right: D FA 100mm f/2.8 Macro, Sigma 35mm f/1.4 Art, D FA* 50mm f/1.4, D FA* 85mm f/1.4, D FA 15-30mm f/2.8, D FA 24-70mm f/2.8, D FA* 70-200 f/2.8, D FA 150-450mm f/4.5-5.6.

Other 85mm Options

As things currently stand in the Pentax world, it’s accurate to say your choices for 85mm lenses are very limited, no pun intended.

At the $250 or less budget level, there are the Rokinon/Samyang 85mm f/1.4 lenses and the Mitakon Zhongyi 85mm f/2.0, which are all entirely manual.

Another new option is the Mitakon Zhongyi 85mm f/1.2 for about $700, which is also a fully manual lens.

Your only other options for an 85mm lens for the Pentax K mount are mostly used K-mount lenses like the FA* 85mm f/1.4 and the Sigma 85mm f/1.4 EX DG HSM. Prices range between $600 and $1000 depending on the market or condition.

The new D FA* 85mm f/1.4 has a small amount of competition in the Pentax world.

Price

With the Pentax’s excellent image quality and premium build-quality comes a premium price. At $1,896.95USD (July 2020), the lens is almost ten times the price of the Mitakonn Zhongyi 85mm f/2, eight times the cost of the Samyang/Rokinon lenses, and nearly three times the price of the Mitakon Zhongyi 85mm f/1.2.

In this case, it is quite an extravagant price. The only lenses across both mirrorless and SLR platforms that eclipse the current price of the new Pentax 85mm are the Canon EF 85mm f/1.2 L II, the Canon RF 85mm f/1.2, and the almost legendary Zeiss Otus 85mm f/1.4.

This lens is not considered budget-friendly. But is it worth its price?

Image Quality

The lens is built to withstand any conditions you put it through, and it is priced like a used car. I’m concerned about its image quality in the most optically demanding genre in photography.

There are a few factors we look at in night photography – the primary factor being coma distortion in the corners, followed by lens vignetting and chromatic aberrations.

Coma Wide Open 

Below are several test images shot with the D FA★ 85mm f/1.4. In these photos, the focal length and exposure time remained constant. Aperture and ISO are adjusted in 1 stop increments.

Pentax 85mm corner at f/1.4
A heavy crop of the corner of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/1.4.

The above image shows very obvious winged stars, most notably at f/1.4. However, they are confined to the extreme corners of the image.

On the Pentax D FA* 50mm, the coma distortion affected image quality almost to the center of the frame.

Pentax 50mm corner at f/1.4
A heavy crop of the corner of a test image shot with the Pentax D FA* 50mm f/1.4.

For comparison sake, check out this corner of a shot taken with the Pentax D FA* 50mm f/1.4 at f/1.4.

The coma distortion in these two lenses is very similar, but considerably worse on the 50mm.

Stopped Down – f/2.0

Pentax 85mm corner at f/2.0
A heavy crop of the corner of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.0.

Stopped Down – f/2.4

Pentax 85mm corner at f/2.4
A heavy crop of the corner of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.4.

Stopped Down – f/2.8

Pentax 85mm corner at f/2.8
A heavy crop of the corner of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.8.

As the three images above show, at f/2.0 and beyond, the coma distortion lessened but is never eliminated. Even stopped down two stops to f/2.8.

Despite the presence of some coma, even at f/2.8, there is a minimal, small amount, and it is only in the very extreme corners. For an ultra-wide lens or a mid-length lens like a 35mm or 50mm, this type of coma could be problematic and annoying.

However, considering this focal length, you may be shooting more panoramas to capture a 50mm or 35mm field-of-view. That means image overlap will likely eliminate coma at all aperture values.

Lens Vignette

The lens performed well in regards to coma. Its weak point, in my opinion, is vignetting wide open.

Pentax 85mm vignette at f/1.4
A test image shot with the Pentax D FA* 85mm f/1.4 @ f/1.4.

As the above image shows, the vignette produced by this lens is drastic, to put it lightly. At f/1.4, I have to increase the exposure of the corners over one stop to get an evenly-exposed frame. Therefore, when shooting at ISO 6400, the corners of the frame will have noise levels comparable to ISO 12,800.

By no means are they unusable. Lens vignette is easily correctable in post, despite adding more work.

Pentax 85mm vignette at f/2.0
A test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.0.
Pentax 85mm vignette at f/2.4
A test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.4.
Pentax 85mm vignette at f/2.8
A test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.8.

The above three images show reduced vignetting once you stop down. By f/2.8, the vignette is almost eliminated. The sweet spot for this lens seems to be at about f/2.4-f/3.5. That is only if you do not mind the extra work in post-production to correct the vignette.

Chromatic Aberration

Chromatic aberrations are another bane of the night photographers’ existence because they can show up as bright blue dots on prints. Removing them in post-processing can be painstaking as the aberrations are often the same color as various nebulas in the frame. Automatic lens corrections can eliminate the blue halos around bright stars, but may also affect nebulosity in night sky images.

Users of the 85mm can rest easy knowing that chromatic aberrations are almost completely nonexistent, even at f/1.4.

Pentax 85mm heavy center crop at f/1.4
A heavy crop of the center of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/1.4.
Pentax 85mm heavy center crop at f/2.8
A heavy crop of the center of a test image shot with the Pentax D FA* 85mm f/1.4 @ f/2.8.

The above images are heavy crops of the center of two frames. Shot with the D FA★ 85mm at f/1.4 and f/2.8.

As you can see, at f/1.4 the chromatic aberration is only barely noticeable, even at 200% zoom.

The photo at f/2.8 shows that, by stopping down, chromatic aberrations are eliminated on the 85mm.

For reference, a crop of the same part of the Milky Way shot with the D FA* 50mm f/1.4 at f/1.4.

Pentax 50mm heavy center crop at f/1.4
A heavy crop of the center of a test image shot with the Pentax D FA* 50mm f/1.4 @ f/1.4.

Most lenses suffer from this type of chromatic aberration.

Chromatic aberrations usually render as bright blue or purple halos around the brightest stars. Thankfully, they’re nonexistent in images shot with the Pentax 85mm.

Image Quality Summary

To summarize the image quality in a few short sentences, it is nothing short of excellent in most scenarios, as long as you don’t mind the extra work to correct the vignette.

Even at f/2.8, there is also some very light coma, which may or may not bother you. However, in my experience, this lens is a godsend for Pentaxians wanting to shoot deepscapes or Milky Way panoramas with Astrotracer.

When shooting a panorama, even at f/1.4, image overlap eliminates almost all of the coma in the frame corners. That means you can shoot at a much lower ISO and produce massive, highly-detailed panoramas. With almost no imperfections!

Panorama shot with the Pentax 85mm f/1.4
A 97 Megapixel Panorama shot with the Pentax K-1 and Pentax D FA* 85mm f/1.4. Photo by Aaron Martinez
Crop in on a panorama shot with the Pentax 85mm f/1.4
A heavy crop in on the Lagoon Nebula area from the above Panorama. You can see some coma that wasn’t removed by image overlap in the top left corner.

In the world of deepscapes, using Astrotracer means that, after stacking, you end up with an image that is reduced in size. That is because, with Astrotracer, the object you are shooting is moving across the frame. So when it comes time to stack images, you lose some of the edges of the frame as well as some of the corners, which is where most of the coma and vignette reside.

The resulting images are absolutely incredible with almost no chromatic aberration, no coma, and no noticeable vignette at f/1.4!

Deepscape shot with the Pentax 85mm f/1.4
“Stargazing.” A deepscape of the Rho Ophiuchi Cloud Complex shot by Aaron Martinez in New Mexico.

My overall impression of the lens thus far is that it is going to be a permanent addition to my nightscape kit. It has already started to assist me in increasing the quality of my work.

Pentax 85mm f/1.4 – Final Thoughts

Now to give a final answer to the question everyone has been asking – Is it worth it?

I’m trying to be 100% honest with anyone reading this article. I do have an answer for you.

If your only reason for wanting this lens is to shoot the night sky, then it is completely and absolutely not worth the price. It is admittedly an incredible piece of glass, and Pentax has put in an unfathomable amount of work in to try and make it optically perfect. For shooting the Milky Way alone, it is seriously like buying a Ferrari only to drive to work and back, when a used Honda Civic will do the job just fine.

You can very likely get good results with any other 85mm lens available for the Pentax K-Mount. If you have a tracker, then almost any telephoto lens stopped down will give you comparable or better results.

That said, if you aren’t buying it just to shoot the night sky, I have good news. I own the Pentax 15-30mm f/2.8, the Pentax 24-70mm f/2.8, the Sigma 35mm f/1.4 Art, the Pentax D FA* 50mm f/1.4, the Pentax D FA 100mm f/2.8 Macro, the Pentax D FA* 70-200 f/2.8, and the Pentax D FA 150-450mm f/4.5-5.6. These are some of the best modern lenses that Pentax currently produces.

None of them can even begin to compare to the quality of the new D FA* 85mm f/1.4.

The Bottom Line

If you do even just portrait photography outside of your night photography, then there isn’t currently a Pentax lens in existence that can give you better results than this 85mm across all genres.

Current rumors are even the legendary Zeiss Otus is only marginally better in the image quality department, but it also lacks autofocus. Are you up for getting Zeiss Otus quality with autofocus at half the price?

To sum up everything I just said, if you only do night photography then this lens is an absolutely unnecessary luxury.

To everyone else, this is currently one of the best 85mm lenses that money can buy across all brands and absolutely the Holy Grail for Pentaxians.

That is just my opinion, of course.

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