Konica Autorex – Shooting full and half frames on the same roll of film

By Stuart Jenkins

Here we have the Konica Autorex; the only 35mm SLR that can switch mid-roll between full-frame and half-frame. It’s quite rare (only a handful in the UK) and I was able to borrow it from a friend for a test.

It was launched in 1965, as the Autorex in Japan and the Auto-Reflex (with a hyphen) in the rest of the world. This was the first Konica SLR with a new version of their bayonet lens mount — the K/AR (Konica / Auto-Reflex) mount, which was used for the remainder of the Autoreflex (all one word) line of cameras.

The layout is quirky in places. The rewind lever sits right on the end of the camera, like some rangefinders. It’s geared, so the axis of rotation isn’t concentric with the film cassette. There’s no built-in flash shoe on top of the prism (which gives a clean ‘vintage’ look) but this one has the optional accessory shoe that attaches to the circular viewfinder, held in place with a threaded ring.

Another oddity of the Konica Autorex is the shutter speed selector dial, which is mounted on the front of the body.  It’s a design choice only used a handful of times over the history of 35mm SLRs.  Olympus chose it a couple of years earlier for the Pen F, as did Ricoh a couple of years later for the Singlex TLS.  Exakta chose it again in 1970 for the Twin TL, and Arsenal went for a front-mounted shutter dial another fifteen years later for the Kiev 19. If you don’t count the manual adapter for the Olympus OM-10, then I can’t think of any other SLRs with the speed selector on the front of the body.  If you can think of any, or if you think it’s a good or bad choice, please comment below.

Front-mounted shutter speed dial

This dial arrangement contributed to my missing an important feature, and mistakenly thinking the light meter wasn’t working. Testing the Konica on my TTL meter calibration rig showed no difference in the reading as the amount of light going through the lens was changed. A little alarmed, I contacted the owner who pointed out that it doesn’t have TTL metering, and the light sensor window is on the front of the shutter speed dial. A slightly egg-on-face moment…

Apart from that, the Konica Autorex handles like many of the other big heavy 35mm SLRs of the period. Except, that is, for its party trick — the little lever next to the prism that’s marked ‘HALF’ and ‘FULL’.

Lever for switching between full frame and half frame

Moving it to the Half position brings a couple of masks across the film gate, reducing the width of the opening. It doesn’t change anything in the viewfinder, but the focusing screen has two vertical engraved frame lines that define the limits of the smaller format. It also reduces the film advance distance from 8 perforations to 4, seemingly achieved by making the wind lever only engage with the mechanism for the second half of its travel.

Shutter mask for half-frame images

On the back of the Konica Autorex is a label showing the correct operating sequence when going from full-frame to half-frame or vice-versa. You have to ‘Wind’ first, then ‘Flip’ the lever when going from FF to HF, and ‘Flip’ then ‘Wind’ for HF to FF. Do it in the right order, and there will be a frame gap of 11mm for each transition. Get it wrong, and you’ll end up with overlapping images on the negative. Frustratingly, there isn’t any visual indication of whether the camera is already wound on (like on a 1970s L-series Praktica), which would be especially useful here. The frame counter always counts up to 36 by the end of the film, whichever format you’re using.

I look it to a garden open day at Holme Hale Hall, near Shipdham in Norfolk. The camera I borrowed came with the original Hexanon 50mm f1.8 lens, and I had no others with the K/AR mount. However, the dual format gives you another effective focal length of 70mm in half-frame mode, so there were plenty of creative opportunities. The built-in meter allows for shutter-priority automatic exposure, or you can use the needle reading against the aperture scale in the viewfinder as a suggestion and chose a manual aperture setting. Focusing is with a central microprism spot, which isn’t as easy as a split-image prism but is still usable.

Viewfinder with aperture scale and vertical lines to help with composition in half-frame mode.

In the course of shooting a roll of Kodak ColorPlus 200, I switched between FF and HF several times so I could see how it looked on the negative.

Neat trick huh? Switching in either direction leaves a frame gap of 11mm.

Here’s a few of the pictures, with the captions indicating whether they’re full-frame or half-frame.

Full frame
Full frame
Half frame
Half frame
Full-frame

 

Share this post:

Find more similar content on 35mmc

Use the tags below to search for more posts on related topics:

Donate to the upkeep, or contribute to 35mmc for an ad-free experience.

There are two ways to contribute to 35mmc and experience it without the adverts:

Paid Subscription – £2.99 per month and you’ll never see an advert again! (Free 3-day trial).
If you think £2.99 a month is too little, then please subscribe and I can manually edit the subscription value for you – thank you very much in advance if this is what you would like to do!

Subscribe here.

Content contributor – become a part of the world’s biggest film and alternative photography community blog. All our Contributors have an ad-free experience for life.

Sign up here.

Make a donation – If you would simply like to support Hamish Gill and 35mmc financially, you can also do so via ko-fi

Donate to 35mmc here.

About The Author

By Stuart Jenkins
Camera & lens collector, restorer, and tinkerer. As a photographer I'm trying to wean myself off digital and back onto film. IT Business Analyst by trade, and formerly a vintage aircraft engineer / restorer. Norfolk, UK.
View Profile

Comments

ReFreshed@66 on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

Hi. Thanks for the review of this truly "one-of-a-kind camera". As you mentioned, this pre-dates the more common Autoreflex T-series but like them has auto exposure (shutter priority). Additionally, as the first (and only) dual-format 35mm camera, it was also the first focal-plane shutter camera with auto-exposure.
As for your question about front-mounted shutter speed selectors, the Pentax AP and K series from the late 1950s had them too, albeit the front dial was for slow speeds, complemented by a top plate dial for faster ones.
Yes, beginning with the "F" (metal shutter; coupled meter), Konica was quite a formidable SLR innovator in the 1960s; it's a shame that history (and internet influencer reviews) have overlooked its valuable contributions. Your review is welcome for keeping memories of this lovely camera (and company), alive. Cheers!
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Thank you, yes I have a couple of later Konicas and they are very nice cameras.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Marcus Gunaratnam on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

If memory serves me right one of the Alpha model also had the facility to switch from half to full frame
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Marcus Gunaratnam replied:

Comment posted: 09/07/2025

It was one of the Alpha models made by the Swiss not Sony made in Japan.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Hi Marcus, assuming you mean the Swiss ALPA cameras, there were a few made as half-frame. I'm not aware of any of them being switchable mid-roll, but it's difficult to find technical information about them.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Nathan Leroy on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

Thank you for this great review, it's a very interesting concept for a camera system!

Do you have any clues as for why it was dropped for later cameras ?
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Thanks Nathan. I would imagine that cutting the cost of manufacture had something to do with it. Plus it maybe reflects the retail cost of film coming down, so there wasn't as much of a need for consumers to be frugal in how much they used.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Danilo Leonardi on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

Great article! There’s also the ‘divided’ option for speeds, where the slower speeds are on the dial at the front, as found on some Leica thread models and on various Leica copies such as Nicca, Reid, Leotax, and others.

My philosophy is that since there’s no single camera design that does everything perfectly every time (and there couldn't be such a thing), a bit like car design, and because I use a small arsenal, it’s really just about awareness that one design places the controls in one spot and another in a different one. That’s my take: it’s all a matter of getting used to whichever system you’re working with at the moment.

By the way, the Hasselblad XPan and the Fujifilm TX-2 offer dual frame sizes, both panoramic and full frame and you can switch mid-roll. So, in addition to their native panoramic mode (24×65 mm), they can also shoot standard full-frame format on 35mm (24×36 mm) by masking the film gate. Although who would truly use such an "electronified" camera in 2025 as a regular 35mm is another question, it's probably best used in panoramic mode while everything is working as it should, but I digress.

And of course, there’s the yellow tell-tale of thorium in the lens. The camera looks absolutely beautiful.
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Thanks Danilo! I hadn't thought about the X-Pan, but yes it's basically doing the same thing.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Bob Janes on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

Great article - I've shot the AR mount for years, but have never got my hands on an original Auto-Reflex.
I imagine the front mounted dial was to simplify the metering - with the ASA setting altering a mask in front of the CDs cell - that's what the Auto S3 does...
Does the red mask on the aperture scale in the viewfinder adjust as you put a lens on? with the later models it shows if the lens can open as far as the camera wants it to..
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Thanks Bob. The red range is fixed, and the red bump is the target for the battery check function. Later K/AR cameras and lenses transmitted the maximum aperture value via the mount, using a variable cutout in the aperture tab protection fence or a pin in the same position. This early model doesn't have that feature and the lens doesn't have the cutout. Lenses could be modified under warranty for use on later cameras, but this example was missed out.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Gary Smith on Konica Autorex – Shooting full and half frames on the same roll of film

Comment posted: 09/07/2025

Interesting critter.

Shooting both on one roll seems like an odd requirement, sort of like removing a roll mid-way and switching to another film. How often do you want/need to do so?

I have a hard time shooting 36 exposures and remembering what I have on the roll let alone shooting 72.

I suspect there are folks who loved the option!

Thanks for your review!
Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Stuart Jenkins replied:

Comment posted: 09/07/2025

Thanks Gary, Yes it's an interesting feature, but it's only useful if you want to keep changing your mind on-the-fly about the best tradeoff between image resolution / grain and the number of frames on a roll. Having said that, I wish there were more mainstream SLRs available as half-frame or even square format.

Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Leave a Comment

Leave a Reply

Your email address will not be published. Required fields are marked *