That Time I Shot an 18-55mm APS-C Digital Lens on a 35mm Pentax Film Camera

Those of you who follow my ramblings will be aware that I’ve recently been through a little bit of a phase of shooting Pentax SLRs. The thing I’m beginning to love about them is how I can mount pretty much any Pentax PK lens on any of the Pentax cameras I own and get some level of functionality. It’s the understanding of that fact that had me dream up this slightly ill-conceived plan.

In fact, this plan is actually the marrying of two enjoyable photographic pursuits: the recently discovered and aforementioned pairing of lenses within the Pentax system, and the longer-standing joy I have for crop-panoramic 35mm shooting. Actually, the latter is usually all but entirely confined to shooting my Minolta Riva Panorama… that was until I spotted a little switch on the back of a recently acquired Pentax MZ-5.

I bought the MZ-5 through little more than passing intrigue. I’ve been talking myself in and out of the Pentax 43mm f/1.9, and have felt that if I’m going to make that leap I need to do so knowing that I can shoot it in AF with a camera I enjoy using. It is apparently a great manual focus lens too, but I didn’t want to miss out on the autofocus option if I was going to take the leap and spend that sort of cash. The problem is, I’ve not really found myself overly taken with many of the Pentax AF bodies. The MZ-5, MZ-3 and MZ-S being the only ones that look like they wouldn’t annoy me too much. The latter two are harder to find and in the case of the ‘S’ a lot more expensive. The MZ-5, on the other hand, is quite cheap… one also happened to arrive in my local camera shop literally one day after I asked Garath if he’d seen one recently. It was super-cheap too. He’s a camera-wizard that guy!

I figured that to begin with, I would just mount a Pentax-DA 40mm XS onto it and see how I got on. This particular 40mm was one I picked up a while back with the intention of finding an ‘*ist’ film body to shoot it on. That combination would be tiny and potentially a lot of fun. Unfortunately, an ‘*ist’ has yet to materialise in my life (they seem to be hard to come by – even the camera-wizard can’t find one of them) so the lens had just sat on my desk at work. Buying the MZ-5, as I said, gave it a bit of a home though. But, in mounting it, I had a sudden thought. If this DA 40mm (designed for crop-digital) lens had enough coverage to cover full-frame 35mm film, then what other lenses might do the job too?

I soon found myself back in London Camera Exchange with a little bit of a plan. I wasn’t expecting many digital lenses to provide full-frame coverage, but what if they provided enough coverage with the camera switched to panoramic crop mode? Most of the vignetting should, I thought, be limited to the corners of the frame, so by switching to pano-crop, I could potentially eliminate that issue.

The lens I had my eye on was the Pentax-DA 18-55 lens. On APS-C digital cameras these lenses provide an equivalent of 28-85mm ish. On full-frame, if my plan worked, I would, of course, have an 18-55mm zoom pano-crop camera/lens combo.

Sure enough, the camera-wizard was able to present me with one of these lenses with a Pentax K100D super attached to the back. I didn’t need the Pentax K100D Super, but the package came for the not too unattractive total of £60. I figured I was unlikely to lose too much on a digital SLR and lens for £60 so went for it. Actually, in the end, I’ve given the camera to Connie who has for the first time taken to the idea of actually taking photos for fun – but that’s a story for another day…

So anyway, I tried the 18-55 digital lens on the 35mm film camera, and it looked like it was going to be a successful pairing. It worked perfectly for a start – the AF worked and the camera was able to select an aperture. There’s no way to manually control the aperture with an MZ-5, but that’s ok – for what I wanted I was happy with program AE anyway. Of course, the all-important bit was the lens’s ability to cover the frame. Looking through the viewfinder all looked well too – or close enough. There was a lot of vignetting when in full-frame, but in pano-crop mode, the vignetting only seemed quite slight when at the widest angle. Zooming in even slightly and the vignette disappeared. Success – I had myself an 18-55 zoom-pano-crop camera. And the best of it, the MZ-5 has cost me £20, and if the lens was half the price I paid for the camera/lens combo it came on that was another £30. So, £50 total outlay!

Full-frame vs. crop

Feeling quite smug, I went out shooting with it. I actually took it out for a spin on a day that Duncan from SilverPan Film Lab popped up to see me. We just went for a slight detour on the way back to his car from lunch, but that was enough for me to give the camera a bit of a spin. I shot a few frames at the wide-angle, and a few frames zoomed in. In practice, I could definitely see the slight vignette more than I had done when I’d tried it in the shop, but it looked little more than slight shading still.

What I hadn’t taken into account, of course, was the viewfinder coverage. The Pentax MZ-5 isn’t a particularly high-end camera, and like many consumer cameras, the viewfinder has less-than-100% coverage. What this means in practice is that whilst I could only see a slight shading in the viewfinder, what the film was seeing was a lot more shading. In fact, as you’ll see in my images, the edges of the frame have actually vignetted to black.

A couple of zoomed-in images

Experiments with a Pentax MZ5 and Pentax Digital leneses

Experiments with a Pentax MZ5 and Pentax Digital leneses

At the wide end where the vignette doesn’t matter as much

Experiments with a Pentax MZ5 and Pentax Digital leneses

Experiments with a Pentax MZ5 and Pentax Digital leneses

Experiments with a Pentax MZ5 and Pentax Digital leneses

And a couple where it’s very obvious

Experiments with a Pentax MZ5 and Pentax Digital leneses

Experiments with a Pentax MZ5 and Pentax Digital leneses

I don’t suppose it’s a particularly big deal I could just crop to what I’d seen in the viewfinder, or even further to remove the vignette entirely. I could even just zoom in slightly… but, in reality, I can’t see me shooting this combination again. A fun experiment, and a testament to the compatibility of Pentax lenses between lots of different film and digital bodies. I also quite enjoyed the MZ-5, so you might well see more of that camera yet.

I’m still not convinced by the 43mm though – I really like the look of it, but it’s just quite a lot of cash to sink on a lens. This experiment, for however unsuccessful it arguably was, has cost me very little… and there’s something I’m really enjoying about shooting cheap gear at the moment. It’s just fitting very well with my post-photography-low-ebb mood!

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9 thoughts on “That Time I Shot an 18-55mm APS-C Digital Lens on a 35mm Pentax Film Camera”

  1. Hamish, and interesting exercise with results better than I would have expected. You’ve got a very inexpensive super wide lens there. Personally, re the vignetting I’m not too bothered by the amount shown here and except for purists, it doesn’t impact too much when we see images with it because, generally, we tend to compose images with the main interest centred in the frame where our eyes constantly scan the most.
    Just think, if a FF Pentax could crop to panorama mode and you shot video with this lens. What an interesting result we’d see!

  2. Pentax mount lenses are directly compatible with more different bodies, over a longer span of time, than any other, especially when you include M42 mount. This helps make up for the long Pentax flange-focal distance which makes Pentax bodies bad for adapting to other brands of 135 format cameras. But, your options for adapting lenses to Pentax open up considerably if you start looking at medium format. I have gotten fantastic results using an adapter to shoot with Mamiya 645 lenses on Pentax film bodies, especially the relatively small and cheap M645 80/2.8 and 55/2.8 lenses.

  3. I shot a sigma 10-20 on my canon rebel after confirming that the mirror did not hit the rear element. The all-black vignetting was entirely gone by about 14 mm iirc. Very wide on 135 format.

  4. Most APSC zooms (including the 18-55) fully work starting from a focal that is its widest multiplied by the crop factor, so the 18-55 should work as a 28-55 (the same is true for the 12-24 that can work as a 18-24). I also have the 40/2.8 HD, it covers the whole frame but unfortunately it’s not sharp at all on the corners, even stopping down quite a bit (at least on the digital k-1), but I don’t know if the same is true for its manual twin from the M series.

  5. I’ve done my fair share of using DA18-55 on P5 way back. I even used DA18-55 on my MZ-S a few times. The lens vignettes quite a lot on the wide end, becomes almost fully usable at 21mm and becomes vignette-free at 24mm. Basically 24-55mm lens, 21-55mm with some tolerance for darker corners. Not bad at all for such a cheap and common lens.


    There’s no shortage of K-mount lenses to try and the older 28-80mm or 35-80mm film kit lenses will provide similar results to the DA lens but without the vignette.

    Regarding cameras, anything MZ is too light and plasticity. I would recommend an older AF body for a better viewfinder and much better build quality. They’ll be heavier but definitely worth it – I recommend the SFXn or Z1.

    As for the 43mm, I just got a copy myself but haven’t had much time to try it out, especially with the CV lockdown. If you get a used copy you won’t lose much, if anything, from selling it on. Head over to the Pentax User forum too hunt down a used copy and for general Pentax advice.

  7. Thanks!
    I just tried the 12-24 on my old MZ-5, and in panoramic mode the hard vignette seemed gone by 14 or 15 mm! Newer have I seen such a wide angle view. From what I could see through the smallish viewfinder the 12-24 is really well corrected, and well suited for panoramas.

  8. Pingback: Pentax ZX5n & 40mm DA Limited - A Crop Pano for a Winter Coat Pocket - by Rob Jamieson - 35mmc

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