How are K1 owners finding their film-era lenses?

I'm just a curious bystander until the K1 drops in price - presumably when the K0.5 (or whatever the FF replacement is going to be called) is released, which is not going to be for a good while yet.

I do, however have a bit of a treasure trove of FF lenses from my film camera days, and keen to know how people are finding such lenses - IQ, speed, anything of interest - when used on the K1. These film-era lenses are currently sat on a shelf as the focal lengths aren't as useful for APS-C, and I'm casually interested in which might be worth resurrecting should I buy a FF body.

I recall the issue of perpendicularity of light onto sensor coming into play when I first got a DSLR, at least in terms of pixel-peeping discussions, but most of my current lens set are designed with digital in mind so I'm not sure if I ever really noticed this as a problem. Was this actually a 'thing' or just some theoretical issue (or, dare I say it, something cooked up by lens manufacturers looking to get sales for digital-specific lenses) that never really came to pass?

I've got an old Sigma 28-70 EX f/2.8 that I can't wait to use again, hopefully someone on here has tried this or its 24-70 cousin, I'd be interested in how it stacks up- especially against the Pentax 24-70, if anyone is lucky enough to own a copy of both such lenses!

Good question, will be interesting to hear the feedback.

I use a few film era lenses on the K-1, including the SMC Pentax-FA 50mm f/1.4, SMC Pentax-FA 43mm f/1.9 Limited, SMC Pentax-FA 20-35mm f/4 and SMC Pentax-FA J 75-300mm. All are fine.

The issue of the way the light falls on a sensor is real enough and modern lenses are designed appropriately. Having said that, it's more of an issue with wide angle lenses as the light at the edges of the images strikes the sensor at a much more oblique angle.

I have recently upgraded to a K-1 but at present do not have the funds to commit to any modern full-field lenses so have done a review of my lens collection to identify what I have in the way of full field lenses and have found 12 FF lenses over a range of focal lengths.

I am more of a close-up/Macro photographer so am really pleased with the performance of both my copies of the D-FA100 and D-FA50 macro lenses.

I have a Sigma 135-400 APO F4.5-5.6 which perhaps is a little soft at the long end but otherwise works quite well although is rather big & heavy.

I also have an old 2nd hand Sigma 15mm f2.8 ex 360 degree fish-eye which works very well and is a lot of fun to use on the K-1.

I do have a Sigma 28-70 F2.8 EX DG bought new back in 2005 and up to now has hardly ever been used. While I believe it is not as good as the 24-70 version, which I do not have, it does appear to work really well on the K-1 and I am now using it as my default K-1 walk-about lens.

I have not really used the rest of my old full-field lenses other than doing a quick focus test on all of them. This includes a Sigma 28mm F1.8 and old Pentax 28-200, 28-105, FA 50mm F1.7 (bought 2nd hand for £69 back in 2007!), 35-80 and a couple of 28-80s.

While I am sure I will eventually have to buy at least one modern HD full field lens I am happy that I can make good use of the full field capability of the K-1.

Glyn

Sorry that should have been 180 degrees . Its been a long night.

Glyn

I using on K-1 SMC F 28mm f2.8, FA 43 ltd and FA 77 ltd and can't complain about. Very sharp, good contrast, super bokeh, only little problem about chromatic aberration. Anyway, mostly on my camera is fitted dfa 24-70 , awesome lens .

When considering my K1 purchase I had mixed feelings of excitement and dread. The excitement was the opportunity to use some of my favourite lenses originally designed for full frame (albeit not digital) in the way they were meant to be used. The dread was the possibility that they wouldn't be good enough and I'd have to replace them with newer equivalents (when they become available).

Out of my K, A, F and FA selection I have yet to come across a lens that is disappointing, some are not as good as others and some are superb, all are enjoyable to use though. While I understand some of the reasons why "designed for digital" is better, the advantages are not enough to replace a legacy collection. I'm excited by the introduction of fast primes (50 and 85) but I'm unlikely to replace the K50/1.2, the DA*55/1.4, or the FA*85/1.4 anytime soon - they are all better on the K1 than I am capable

Just look at all the wonderful photos taken with a K-1and old film lenses on here and elsewhere. They speak for themselves.
Despite some thinking otherwise, full frame doesn't push the lens so much as APS-C so an old lens that seemed deficient on APS-C may be just fine on FF. Pixel peep, though, and the deficiencies may again become noticeable.

The only issue with the older lenses on FF compared to APS-C would be the corner performance. As the corners are further away from the centre on the larger sensor, a lot of these lenses might not be able to hold up as strongly as they did on the smaller sensor.

Same applies to new lenses too! Clearly a budget lens that cost £10-£20 brand new back in the 70's (eg the early zooms) isn't going to hold up as well as a good quality item, but it doesn#t mean it wouldn't be worth trying. I tend to find flare is the biggest problem with older lenses, especially where dust has got on the inside of the front element. Having recently dismantled and cleaned an old Tamron 28-200 recently, the improvement after cleaning was remarkable.
If the corners are naturally out of focus it doesn't really matter if the lens can't resolve them. In the end, you get what you pay for but the differences can be marginal.
As to the OP's query about the Sigma 24-70, can't comment on that one but the older Sigma 24-60 f2.8 isn't too bad at all and minute in comparison to the 24-70's.

And also just to add to John's points, the older lenses have a certain colour rendition and 'character' to their images (most often due to the inferior coatings and often due to the presence of light flaring). You might like the kind of images that these lenses produce.

For example, I used the S-M-C Takumar 50mm f/1.4 to take an image of my little one in bright sunshine and loved the way it rendered the skin tones and colours in the scene - it captured his joyful mood perfectly. If I had used a digital lens for the same image, I might have found the image too 'clinical' in appearance (either too sharp or not enough defects/CA), even though the subject of the image may have been exactly the same.

^ Take all of that with a pinch of salt too, this field is full of experiences and subjective opinions.

Its not difficult to experiment with old lenses. One can buy and try and if not happy move them on for more or less what one paid. It's possible to build a good collection of excellent primes such as many of the Pentax K & M lenses for comparatively little money.

Since getting my K1 last november it has had a few outings with the film-era lenses (K;M;and FA.

My experience so far is that they are well up to the task. The usual caveats of course are to use a hood and beware of high contrast scenes especially with K and M series (CA can intrude). I have been using the FA*85mm 1.4 a lot recently for my pet portrait photography, and cannot think any other lens could do better. For general photography, the M 120 and 200 lenses have performed superbly, and I will shortly be giving the M 20mm an outing.

The one very positive difference I notice with what I have used so far in the K and M series is that the progressive overexposure issue as one stopped down, which was apparent with my K10D and I believe other aps-c Pentax DSLR cameras (post *ist DS) is no longer an issue with the K1. Perhaps because the lens is now being used on a format (size-wise) for that which it was intended, makes all the difference.