[gofour3]

Now I'm searching a prime wide angle. I have the opportunity to take the FA*24/2 or A 20/2.8. Price is the same: 350 euros. Both in excellent condition. My thoughts are:

I have the FA*24/2 and A 20/2.8.

Both lenses are wonderful, so I would suggest also getting both the FA*24/2 and A 20/2.8. They are different enough focal lengths to justify having both and you can also never have too many lenses...

However if you go for the A 20/2.8 (or FA version) make sure you get a copy with the metal MH-RB67 OEM hood, this hood is almost impossible to find on its own.

Phil.

[johnha]

I don't have either, but I struggled to make my mind up between the FA20 & FA*24 (both were hard to find and expensive in the UK), I ended up buying the FA20-35/4 which has hardly been off my K-1 since buying it (or my LX before that). More recently I've been comparing the S-M-C-Tak versions of the 20/4.5 & 24/3.5, I find the 20/4.5 a much more interesting focal length, 24 feels similar to 28 after using the 20 for a while (note: I've not tried portraits with it).

[normhead]

Wonderfull pictures Sandy and Derek!



So, as has been suggested base your decision mainly on your personal stile (for me 24 mm is wide enough) but keep in mind, that in terms of sharpness the A or FA 20 has the better perfomance on the whole frame. While the 24 mm has a excellent center sharpness you need to stop it down the usual two stops to get it decent sharp at the edges and down to f 8.0 to get it good over the whole frame.


The dancers from Sandy will be a wonderfull subject with the 24/2.0 while it might struggle with the landscapes.

I stop down to ƒ8 for landscapes because I need it for the depth of field. You seem to be suggesting ƒ4 or ƒ2.8 landscapes are a thing. ON APS_c and FF both ƒ5.6 is the sharpest for all but premium glass. SO, if you want excellent sharpness, you need to be shooting at ƒ5.6 already. But neither lens has good edges at a ny focal length.

FA 20


FA* 24


Compare those to the DA*55


My point being if edge sharpness is concern, you won' t be using either of the lenses.

If edge sharpness is a concern then the FA 20-35 might be the better option.


As Sandy's photos demonstrate, these are "lenses for the way people take pictures lenses, not for the test charts." The exhibit pleasing characteristics that go beyond test chart analysis.

If you're looking for edge to edge sharpness, you're going to be looking at heavier, more expensive, more modern glass.

The chart for a EF 24mm f/1.4 USM L II

$1500 and a lot more size and weight for a lens that would seem to be only marginally better in terms of it's curve being consistent across the chart.

Canon EF 24mm f/2.8 USM IS fo $549.


Not really a lot better than the Pentaxes, if better at all.

Talking edge sharpness in wide angle lenses, my question is who's done it and what does it cost? You might want to look at Sandy's images and decide if you like the rendering. That's what's going to distinguish these lenses, not the assumption you're going to find one that's sharp edge to edge.

As far as I know no FF lens has excellent edges in the 20-24 range, but as always, I'd be happy to be proved wrong.

However on APS-c my 18-135 has excellent edges at 24mm, as do many other APS-c lenses.
https://www.opticallimits.com/pentax/597-pentax_18135_3556?start=1

Before you start asking for something, you really should establish it's practically possible.

---------- Post added 09-12-19 at 02:02 PM ----------

Just on whim I decided to check out the Sony ZA (Zeiss) 24mm ƒ2 S SM


IN terms of the quality for consistent edge and centre sharpness it might be the best, for a mere $1400. (But still not as good as my DA* 55 1.4). Go for it.

[leekil]

There's also the DFA 24-70 -- more flexible, but even bigger and heavier.

[Sandy Hancock]

There's also the DFA 24-70 -- more flexible, but even bigger and heavier.

And the DFA 15-30, which is even better at 24mm, and also gives you 20mm.

But I'm pretty sure we're WAY outside the OP's budget

[gofour3]

And the DFA 15-30, which is even better at 24mm, and also gives you 20mm.

But I'm pretty sure we're WAY outside the OP's budget

Yeah the OP though they would get away with only spending 350 EUR!

Phil.

[mikesbike]

One cannot compare a very wide angle lens with a 50 or 55mm lens. it has long been shown that a lens in the 50mm range can be made to have a faster aperture with very good to excellent performance at a lower cost, than is true of either a tele lens or a very wide angle lens.

Apparently, designing a fast 24mm lens having very good to excellent performance, especially on a FF body, including edge performance and vignetting, is a difficult proposition. Canon does a decent job- at considerable expense, but Nikon also at considerable expense is not so good. I wonder how well some of those MF lens brands do, like Samyang, etc.

When you need the aperture speed, you need it. I've long had the Sigma 24mm f/1.8 EX DG and find it satisfying for this purpose. It was tested by OpticalLimits in the Nikon FF section. It would do better for edge performance as well as vignetting if it were tested with APS-C, because a significant amount of the edges and corners are eliminated from the picture, which explains my finding it to be ok. I think better than the Pentax FA* 24mm f/2 above, which was tested with APS-C. This is aside from the subjective colors, rendering, etc. pixie dust. The FA 20mm f/4 lens looks better than the FA* 24mm, but then this is 2 stops slower.

If not needing the speed, might as well get a WA zoom lens. The FA 20-35mm f/4 AL looks quite good per the test above. Maybe the best bet for performance/cost/weight. Distortion at the mid-zoom of 24mm would probably be quite low. I have two Tokina such lenses- a metal-bodied 20-35mm f/3.5-4.5 II with a 77mm filter thread which I've liked on my film bodies, as well as the less expensive 19-35mm f/3.5-4.5 having a well-made plastic body and also a 77mm filter thread. In their test of this lens, Pop Photo had a lot of praise for it, even commenting on its good edge performance. Great for the price.

[normhead]

One cannot compare a very wide angle lens with a 50 or 55mm lens.

Exactly my point.... if you want edge to edge sharpness, it's available in a 50, in a 20, not so much.

DFA 50 macro. Consistent to the point where only diffraction, not the lens design limits the resolution and consistent right across the chart.


Then look at the 35 macro... same company, same design team, completely different story,


Hoping for 50 macro type results on a 24 isn't a real thing.

[mikesbike]

Yes, the FA 35mm f/2 does extremely well also, and on FF, which it was designed for, it provides a FOV like a 24mm on APS-C. The latest incarnation also has HD coatings. Both are still available. This is one reason for the appeal of a FF body for me- my FA 35mm f/2 will easily outperform any 24mm f/2 or f/1.8 on my APS-C body!

[billcarson_82]

Thanks to everyone for your suggestions. I realized that for my purpose FA* 24mm is quite wide. I can use it for street, people and landscape. Sharpness edge to edge can be obtained by stopping down to F8 (I hope), this is not a problem as I use always a tripod for landscape

I love colors and bokeh given by FA* 24, thanks for your samples! So this lens for me is more flexible and when I want more FOV I can use my old Zenith 16mm F2.8.
I could use also my Sigma 10-20 cropped, but I think I will sell it as love with this did not fire...

[pinholecam]

I had the FA*24 and I have tried the FA20/2.8 (my brother's copy actually).

I found the FA*24 to be a "sharper central and fast lens" that is better (very good in fact) for environmental type portraits that still had some isolation between subject and bkgnd.
It did ok for stopped down landscapes, but it you want edge sharpness at the pixel peeping level, then its not the best lens.
A K24/2.8 would be far smaller and do the same job (ie. landscapes ) a bit better.

FA20/2.8 (said to be optically same as the A20) is pretty nice as a landscape lens OF its vintage and size.
Its not going to beat more modern wides or physically larger ultra wides on the edge performance (and the trade offs for these will usually be cost and size).
So overall, its a good UWA especially if you also consider size/ weight/ portability.

[johnha]

This thread appeared just when I'd bought a S-M-C-Tak 24/3.5 and a hood for my S-M-C-Tak 20/4.5, it prompted me to try out these, a K24/2.8 and A28/2.8 lenses. I left my FA20-35 at home in an attempt to decide on 20, 24 or 28 primes. In short, I started to appreciate 20 more than I had in the past (previously mostly for landscape), 24 feels a bit too wide for 'normal' and 28 seems about right. I did confirm that my initial choice of the FA20-35 was the better option than one of these primes (it may not have the same character of the taks but it's a lot more convenient to use). I'd shoot any of them on the K-1 without any concerns about their rendering, balancing their character with the right subjects. I'd be interested to see how the FA*24/2 performs and the character that it might display, although it looks to be a fairly hefty lump compared to the others.