This has turned into a six (!) part series. The individual parts (including this one) are at:

Adapting Nikon lenses to Sony Alpha: Monster LA-FE1 autofocus adapter

Monster Adapter LA-FE 1 (2): AF-C for moving subjects

Monster Adapter LA-FE 1 (3): Another go with the Nikon 70-200 f/2.8 E FL

Monster Adapter LA-FE1 (4): Revisiting birds in flight

Monster adapter LA-FE1 (5): firmware v04

Suppose that a photographer buys a Sony Alpha camera, but has kept a legacy collection of Nikon F-mount AF-S autofocus lenses: an autofocus adapter would give them the option of continuing to use prized lenses on the new camera. For the most part, older lenses can be more usefully replaced with Sony native mount lenses, but there may be some that represent useful options or that have no equivalent in the Sony system. This is my situation.

I bought a Sony A1 about 6 months ago, and have slowly — slowly — been accumulating E-mount lenses to go with it. It is a slow process because of the expense involved, and as I’ll explain in another blog, as amazing as the A1 is, it does not do everything I need, so I am keeping a bunch of Nikon gear to cover the rest — at least for the time being. The corollary to this is that it would help enormously to continue to use my favourite Nikon lenses on a Sony body. And this is where the Monster Adapter LA-FE1 comes in.

My primary concern for using such an adapter would be for still photos, not video. I should point out up-front that I am not going to examine video performance. The manufacturer’s product page states “For photo shooting mode only, autofocus in video mode is not available.”

If you just want to see some photos taken using this adapter, you can skip to the end of this article where I’ve put a selection of sample pictures. I have also put an album on Flickr.

Over the years, various F- to E-mount autofocus adapters have been released, which all work to one extent or another (for example see here for a comparison of three). More recently, a company called Monster Adapter have released the LA-FE1 adapter which claims to provide support for Nikon AF-S lenses on recent Sony Alpha bodies. Autofocus (including eye-AF), VR and auto-exposure are claimed to be supported.

When I tried the Nikon FTZ adapter (which adapts F-mount DSLR lenses to the mirrorless Z-mount) I thought it had significant limitations on the Z6, Z7 and Z7II, especially in the speed of pickup of a subject when autofocusing. In this sense, I don’t especially like relying on autofocus adapters, but if it means that it becomes an option to use my existing Nikon AF-S lenses on a Sony body — even in a limited range of use cases — then that is all to the good.

For example, I have Nikon F 20mm f/1.8 G and 50mm f/1.4 G lenses: I don't use these a lot, but there are occasions when I absolutely need them. Although alternative lenses exist within the Sony ecosystem, replacing them with the Sony equivalents would be expensive relative to the number of times I would use them. It makes sense to consider such existing lenses via an adapter.

The Nikon 70-200mm f/2.8 E FL is such a good lens that I am reluctant to part with it, even though Sony’s new FE 70-200mm f2.8 G Master OSS II Lens is undoubtedly excellent. Among other things, I use this a lot for multiple exposures in-camera, which the A1 won’t do, so I need to keep this, along with a Nikon DSLR body.

A different example is the Nikon 500mm f/5.6 PF lens. Numerous entries in this blog demonstrate how much I like this lens: for the last couple of years, it has been my most used lens. There is no direct equivalent of this in the Sony system, so the option of being able to use this on a Sony Alpha camera would be a real advantage.

Fundamental caveat: the adapter is expensive in its own right, and in general, it seems highly unlikely that a third party adaptor, produced with no help from the lens manufacturer can give a lens performance — the primary concern being autofocus performance — that can match that lens on a native mount. In other words, there is no reason to expect that a Nikon F lens adapted to the Sony E-mount can match the performance of that lens on a recent Nikon DSLR. If you can afford to replace a set of existing lenses with native mount Sony lenses, that is probably the best course.

Just to be clear. I bought this adaptor with my own money, and I have had no contact with Monster about these blog posts. I am not sponsored in any way for these posts about this adaptor.

How it works

***Monster Adapter LA-FE1, shown from the Nikon F mount side***

Sony Alpha cameras feature a much smaller flange distance (the distance between the sensor and the lens mounting flange) than the Nikon F system. Because the distance is shorter, it's possible to put an adapter between the Nikon lens and the Sony camera body. What this means is that it is possible to use a Nikon lens on a Sony Alpha camera, and if its autofocus mechanism is supported by the adapter, the Nikon lens can be auto-focused by the Sony camera.

I can’t see any sign of rubber weather-sealing gaskets on the LA-FE1. The Monster website gives no indication that there is any weather/dust sealing.

Compatability

There is an extensive compatibility list on the page for the LA-FE1 on the Monster website. If you have any interest in the adapter, the first thing is to check out those lists to ensure that your equipment is supported. In my case, the Sony Alpha-1 body is supported, as are most of my Nikon AF-S lenses, including the 20 mm f/1.8 G, 50 mm f/1.4 G, 70-200 mm f/2.8E FL and 500 mm f/5.6 PF lenses, which are the ones I’ve been most interested to try out.

As far as I can tell, firmware in the adapter acts to translate commands between Sony and Nikon languages, thus commands sent from the camera to the lens can be understood, and vice versa. As an outsider, it sounds like Monster has managed to reverse engineer the command languages of at least Nikon (Sony's mount is more open than the Nikon F mount). Although this is the only practical approach when a lens provider insists on maintaining its proprietary commands, it does have potential downsides/limitations. First of all, even if it works well, it may not be perfect: the commands may not translate comprehensively from one side of the adapter to another. The other question is about speed. Having to translate from one language to another is always going to be slower than just using one language, thus the lens may not achieve accurate focus as quickly or consistently as the native mount equivalent.

With this in mind, I wanted to try out my Nikon lenses adapted to the Sony Alpha-1 under my kind of normal shooting scenarios.

Baseline expectations

Given the caveats I’ve mentioned above, I think that using this camera adapter has to be approached with a fairly realistic set of expectations. You are using a third-party adapter to connect to completely different systems. However, on Monster’s Twitter feed they provide examples of Nikon AF-S lenses autofocusing using the adapter. The videos I've seen show them using Single-shot AF (confusingly, also known as AF-S) mode. In other words, this adapter should work fine with static subjects where the precise focus should be obtained. Suitable applications would therefore include landscape, still life and some types of portraiture.

As far as I know, Monster does not specifically demonstrate tracking of demanding subjects in motion in any of their videos: this requires continuous autofocus (AF-C). However, their website states that “LA-FE1 can make F-mount lenses achieve AF and AE continuously when shooting at a maximum of about 10 frames per second (camera support required) and the focusing accuracy will be highly improved at high-speed AFC mode.” This seems to imply it should work, at least to some extent on high-end Sony Alpha cameras featuring their latest AF systems. Nevertheless, it remains to be seen whether high-speed action, sports, small birds in flight, fast-moving aircraft, and so on would be suitable subjects with this adapter. There is a clear limitation as well on the frames per second that can be achieved: while the Alpha-1 can achieve 30fps, the adapter seems likely to limit this to 10fps. This would be a drawback certainly, but not necessarily a dealbreaker, depending on the use case.

In trying out this adapter I've been interested first of all to probe how well it works in AF-S mode, and subsequently whether it works at all for applications that require continuous servo.

Adapter firmware

The adapter was supplied with firmware version 02. Monster Adapter has indicated that they are continuing to update the firmware, and an update was expected around the New Year. This did not appear, so I contacted Monster over Twitter to ask about progress on this. They replied "it’s too hard to tell the release date now. Because there’re hundreds of F-mount lenses, tests needs more time than other adapters." This is an indication that they are still working on the firmware — so, fair enough — patience!

The version 02 firmware updater is for Windows computers only. Firmware updates are provided via the Monster Adapter website.

Tripod adapter and usage

The adapter itself is a plain ring with electrical contacts. It was supplied with a removable tripod adapter. I found this adapter got in the way more than being useful, so I have removed it. With smaller lenses, it should be OK with a tripod plate on the camera body. With larger lenses, I put the tripod plate on the foot of the lens, so the mount is not strained by the weight (the camera body is very light). When using the camera plus adapter on larger lenses, I always carry the combination by holding the lens.

In use for still photos in Single-shot AF (AF-S)

The adapter mounts very easily between the lens and the camera just using the normal bayonet fittings. It seems to lock in place nicely, without any undue looseness or stiffness.

One of the first test pictures I took using the LA-FE1 on the A1 with the Nikon 50mm f/1.4 G lens: old ivy on a wall on a very dull day. AF-S focus mode, 1/100sec, f/5.6, ISO 320, handheld. It is accurately focussed and sharp edge-to-edge.

The first lens I tried on the adapter was the 50mm f/1.4 G lens. 50mm is not my go-to focal length, but it has done me very well since I first bought it around 13-14 years ago (for an example picture – see here). It has never been a very fast focusing lens – by today’s standards, it is downright sluggish. It also has very low contrast wide open, and I generally prefer to use it stopped down a little in daylight when it can give beautiful, sharp well-rendered images.

Testing it using both AF-S and AF-C revealed that on the adapter it feels a little slower to focus than it does on my Nikon D810. This is not surprising, but it means it becomes (even) less suited to following fast action. Then again, that is not typically what I use it for. I got the impression that focus using AF-S is more reproducibly accurate than when using AF-C. I’ve not actively quantified this, but if I want to be sure of accurate focussing, I’ll switch the camera to AF-S. Having said that, in AF-S the focus is extremely accurate every time. The lens appears to render exactly as it does on my D810 - with one exception that I’ll come to below.

I’ve not yet done a proper portrait session with the A1-(LA-FE1)-Nikon 50mm f/1.4 combination, but eye AF seems to work well in the few pictures I’ve taken with it. I won’t add any pictures to this blog: hopefully, I’ll give it more of a workout at a later stage.

The other lenses I mentioned above all give nicely focussed, well-rendered, sharp images using AF-S focusing. The 70-200 and 500PF lenses all seem to focus quickly and pick up focus only slightly slower than on a Nikon DSLR. I’ve put a selection of images from these at the end of this article.

Image stabilization

One potential advantage of using older lenses on the A1 is that they should benefit from the in-body image stabilization (IBIS). The 50mm lens has no VR (Nikon's image stabilization in the lens), so I tried photographing multiple series of shots at different shutter speeds both on the Nikon D810 (native mount, but with no IBIS or VR) or on the A1-LF-AE1.

The data shown in the graph here represent % sharp images at different shutter speeds obtained from batches of 30-40 images, shot in AF-S mode in groups of 10. Sharpness was judged against reference pictures shot on a solid tripod. Raw images were examined at 100% view in Photomechanic without any image processing. I was very stringent in assigning an image as sharp: any hint of blur viewed at 100% did not count, even if, say, an A4 print made from the same image would look fine.

In general, I think the A1 provides 1.5-2 stops of IBIS in my hands. The slopes of the two data sets are different: note how the unstabilized D810 images show a gentle decline in sharpness, whereas the A1-LA-FE1 images seem to fall off a cliff below a threshold of around 1/15 sec.

Please note that the data shown here apply to my wobbly hands, and may not be reproducible directly by other photographers with different wobbliness and basic techniques. Incidentally, I was both surprised and disappointed to find that I don't get 100% perfectly sharp images at 1/60 sec. I've always considered that to be a reliable baseline with this lens. Maybe I'm just getting wobblier! But this test was more stringent than simply making a print or social media post, so perhaps it is not simply me.

Ghosting or veiling flare into the light

I haven’t noticed this very often, but occasionally, it knocks me right between the eyes.

While I was first trying the LA-FE1, I took pictures of a decaying old building, which I think makes an interesting test subject. It was against a bright grey sky, and it is an image full of little details. But what surprised me was a large area that looked a bit like fogging. I think this would be classified as veiling flare.

In all the years I’ve owned this lens, I’ve never seen that before. I didn’t notice it again for quite a while, but then at random, it showed up strongly in another picture, again photographed against a bright grey sky. As a result, I decided to try to reproduce this, and compare it to a similar picture taken on the D810, ie with the 50mm lens on a native mount, not with an adaptor.

In the comparison picture shown here of a bright (blown) sky, you can see that there is some haze over the upper portion of the picture taken with the 50mm lens on the A1-LA-FE1. This is not present in the D810 picture. This is a real drawback to using the 50mm lens via the LA-FE1 on the Sony.

I've not noticed any veiling flare with other lenses I've tried, but I've not given this a systematic work-out.

EXIF data

Dumb adaptors do not report lens EXIF data back to the camera, so things like the lens model and aperture cannot be automatically recorded. Since the LA-FE1 communicates between the lens and the camera, it should be possible to accurately record the EXIF data.

In practice this works very well, but with one exception. The lens model is not accurately recorded. So, for instance, a Nikon lens will simply be recorded as an E lens. This has one practical consequence. When the RAW (.ARW) file is read into Lightroom or ACR, lens profiles are not correctly applied. I have Lightroom set up to apply lens correction profiles on import, and this works perfectly with homologous pairs of lenses, i.e. Sony lens on a Sony body or Nikon on Nikon. However, with the heterologous pair of Nikon lens and Sony body, Lightroom does not automatically apply lens correction, because the software does not know which lens has been used. Occasionally the software applies a best guess, e.g. for my 50mm Nikon lens a profile for a Rokinon lens might be applied. This is not a particularly big deal because it is easy to set the correct profile by hand in Lightroom. It is still a nuisance. I hope this can be addressed in future firmware updates.

One further consequence is that when exporting JPGs for use on social media, the lens data is not correctly represented. The first time I loaded a picture from LA-FE1-adapted 500mm PF lens onto Flickr, it simply showed it was taken with an E 500mm lens. Not a big deal, but still.

A simple solution to this is to edit the EXIF data using Exiftool. The command that works for me is like this:

$ exiftool -lensmodel="Nikon Nikkor AF-S 500mm f/5.6E PF ED VR" _AJB9335.jpg

This command uses Exiftool to change the Lens Model field in the EXIF data to the description of the actual lens used. The name of the file to be edited is specified.

I prefer to edit the data in the output JPG, rather than the .ARW file: Exiftool writes a second file with the new data in it which is much larger than the original. When editing the JPG, the output file is the same size as the original, and the duplicate does not add much to storage space, plus the original JPG file can be removed without worry. You can see the result of this editing in the shooting data in this picture on Flickr.

Impact on battery life

I have read elsewhere that autofocus adaptors can result in extra battery drain. I have not noticed this so far; there is little enough (if any) that I have ignored it for practical purposes. (Nevertheless, the normal advice stands to take a spare battery with you in any case).

Summary

Overall, I have found the LA-FE1 to be a useful option to make it possible to use my Nikon lenses with the Sony A1. The advantage is that, at least for use in AF-S mode, it works generally satisfactorily for applications involving still or slow-moving subjects. I’ll return to its use with faster moving subjects in a future blog. Be aware that the adapter does not seem to have any weather sealing between itself and the lens or camera body. Significant downsides are that slow-focussing lenses focus even slower, although this is not necessarily an issue for lenses such as the 70-200 f/2.8 E FL or 500mm f/5.6 PF lenses which still focus very fast. Perhaps more significant is the veiling flare when shooting towards a bright sky. For the most part though, image quality is unaffected. What this means is that if you can’t afford to replace all your Nikon lenses overnight, the LA-FE1 gives you the option to carry on using them for certain applications, while your bank balance recovers sufficiently for you to buy replacements.

Update 2022-02-02: AF-C tracking for focus and recompose with still subjects

It is that time of the year when the bluebell flowers form purple-blue carpets in the woods here in southern England. Last week I took the opportunity to take the Alpha-1 up to our local woods to try out focus tracking for focus-and-recompose using the bluebells as a subject. I took two lenses: the Nikon 50mm f/1.4G and the Nikon 70-200mm f/2.8 E FL, together with a native Sony lens, the 35mm f/1.8, as a comparator.

In summary, the 70-200 worked like a charm, whether in AF-S or AF-C. In any of the tracking modes I tried, back button focus with AF-C set to the tracking mode of my choice worked quickly, responsively and accurately.

On the other hand, the 50mm f/1.4 does not work satisfactorily in this way. In my hands, my lens did not seem to be able to refocus quickly enough to allow the tracking box to follow the subject as I moved the frame. Nonetheless, the 50mm lens worked satisfactorily using conventional focus-and-recompose with AF-S and flexible spot. By comparison, the Sony 35mm lens was a joy to use with focus tracking - extremely smooth, responsive and accurate.

In the future, I'll be happy to use any of the tracking modes with AF-C and back-button focus with the Nikon 70-200mm E FL lens to help with composition on still subjects. I'll only use the 50mm lens with AF-S and single spot focus on static subjects.

I've put some bluebell pictures at the end of the sample pictures.