[limestonecowboy]

I recently bought a Samyang 14mm f2.8 for Astro/Landscape photos on my K-1 and K-3 II. I'd already had one for my Nikons which I sold to fund the K-1 so I knew what I was getting.

I'm now in a quandry, do I buy a used Samyang 24mm f1.4 (about £300) or save my pennies for a bit longer and get the Pentax 24-70mm f2.8 (about £700 used)?

The lens would primarily be used for landscapes and some astro shots and therefore autofocus isn't a big deal but the flexibility of the 24-70mm might outweigh the faster Samyang.

Or - should I get an old Sigma 24-70mm f2.8 to play with while I make up my mind about the Pentax

[Adam]

I recently bought a Samyang 14mm f2.8 for Astro/Landscape photos on my K-1 and K-3 II. I'd already had one for my Nikons which I sold to fund the K-1 so I knew what I was getting.

I'm now in a quandry, do I buy a used Samyang 24mm f1.4 (about £300) or save my pennies for a bit longer and get the Pentax 24-70mm f2.8 (about £700 used)?

The lens would primarily be used for landscapes and some astro shots and therefore autofocus isn't a big deal but the flexibility of the 24-70mm might outweigh the faster Samyang.

Or - should I get an old Sigma 24-70mm f2.8 to play with while I make up my mind about the Pentax

The 24-70mm would be quite a bit for versatile if you plan to use it as a walkaround lens.

However, if you will mainly be shooting astro, I would go with the prime.

IMO two completely different lenses- perhaps get one and then add the other later on?

[limestonecowboy]

I appreciate that they are different, but I can't afford both at present so although the Pentax is more money it might give me more opportunities for shots. I'll still have the samyang 14mm.

[angerdan]

Only the D FA offers all the features you're able to use with the K-1 - autofocus, QS, WR, lens correction...
Used copies are available for ~ $1,000.

Or if you prefer an prime lens, the FA* 24mm 2.0 offers a great image quality for half the price of an used D FA 24-70mm

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Last edited by angerdan; 04-30-2018 at 03:03 PM.

[jatrax]

The Samyang is very well regarded for astro, as I'm sure you know. One of the best for dedicated astro. But the DFA 24-70 is far more versatile and is OK for astro especially with the ISO capability of the K-1.

The 2 stop difference will make a difference for astro, but not for anything else, especially landscape. I would go with the 24-70 and then if it proves not up to your standards for astro look at a Samyang 24mm later.

[limestonecowboy]

Only the D FA offers all the features you're able to use with the K-1 - autofocus, QS, WR, lens correction...
Used copies are available for ~ $1,000.

Or if you prefer an prime lens, the FA* 24mm 2.0 offers a great image quality for half the price of an used D FA 24-70mm

Hadn't seen the FA* 24mm, hmm

[MJKoski]

Penron 24-70 is mediocre lens when it comes to IQ. It is double-priced (Finnish price) compared to the Tamron cousin and few rubber rings should not cost 100% more. But if you feel you need a zoom then you do need a zoom. That 24mm Samyang, if you get a decent copy (not very likely at first try), beats the 24-70 @ 24mm when stopped down to f/5.6 - f/8 range. The zoom will not reach superb IQ towards the corners ever. Also note that Tamron 24-70 design has nasty focus shift issue (check lenstip review for more information) which means that at short-to-medium range the photo will be focused in wrong place when stopped down to shooting aperture (slight error) compared to wide open setting.

Penron 24-70 WR function is not very impressive to say. I used mine in slight rain many times and everytime it fogged up (front element and focusing window). Also, it will not handle two stacked super-slim filters without mechanical vignette (well it does if you file away the threads from the 2nd filter).

[DeadJohn]

Samyang/Rokinon/Bower 24mm f1.4 for astro.

Pentax 24-70 for just about everything else.

[WorksAsIntended]

I am not the biggest fan of the 24-70. It is sharp and all that, but I dislike the concentric structure inside the bokeh. I would say go with the prime.

[DeadJohn]

I commented earlier on the lenses you asked about. I have a new thought:

Consider the Samyang 24mm *plus* the Pentax 28-105. The 28-105 is a great landscape lens if you don't need f2.8. Cost of the combo might be near the cost of Pentax 24-70.

[clackers]

Penron 24-70 is mediocre lens when it comes to IQ.

Well, that's the sort of statement you make that has people shaking their heads about your opinions, MJK.

I don't know why you're attempting the lens' character assassination, you and ePhotozine just don't agree.

They tested and showed it's off the charts at f5.6, for instance:

"At maximum aperture and 24mm, sharpness in the centre is already approaching excellent levels and the clarity towards the edges of the frame is good. Stopping down improves performance across the frame and peak clarity is achieved between f/5.6 and f/8 where resolution across the frame is outstanding.

Zooming to 35mm results in very similar performance at maximum aperture, which centre sharpness approaching excellent levels and good clarity towards the edges. Sharpness towards the edges doesn't improve as quickly when stopped down at 35mm, with peak sharpness being achieved at f/8.

Finally, at 70mm, overall sharpness is reduced a little, but clarity in the centre at maximum aperture is still very good. Towards the edges resolution drops down to fair levels at maximum aperture, improving as the lens is stopped down. Again peak quality across the frame is achieved at f/8, where resolution is excellent across the frame."

[clackers]

Here's ePhotozine's measurements of the Samyang 24mm, BTW, although not on the same camera.

I have the lens, and do like it. I tend to use zooms or the Sigma 24mm f1.8 at events for autofocus, but for astro the Sammy would be better.

[MJKoski]

Well, that Photozone test is practically worthless. It is based on flat test target at ~close distance. No one really shoots like that IRL. When you focus at infinity this happens:



That is edge crop of 24-70 @ 40mm & f/8 focused at infinity. Focused stopped down in live view to make sure it is as sharp as could be. 24mm setting is the same story, it just does not reach IQ worth the price. However the Samyang *does*.

Here is full-res PS sample @ 24mm & f/11 focused to the very edges:
https://mjkoski.1g.fi/kuvat/Miscellaneous/trash/_IMG0438.jpg/_full.jpg

At f/11 it is on the borderline to be acceptable by the corners, still astigmatic though.

[WorksAsIntended]

I agree that resolution depends on focus lenght. Therefore those testcharts give very limited information about general behaviour.
Edit: focus distance, not length is what I wanted to talk about.

[limestonecowboy]

Penron 24-70 is mediocre lens when it comes to IQ. It is double-priced (Finnish price) compared to the Tamron cousin and few rubber rings should not cost 100% more. But if you feel you need a zoom then you do need a zoom. That 24mm Samyang, if you get a decent copy (not very likely at first try), beats the 24-70 @ 24mm when stopped down to f/5.6 - f/8 range. The zoom will not reach superb IQ towards the corners ever. Also note that Tamron 24-70 design has nasty focus shift issue (check lenstip review for more information) which means that at short-to-medium range the photo will be focused in wrong place when stopped down to shooting aperture (slight error) compared to wide open setting.

Penron 24-70 WR function is not very impressive to say. I used mine in slight rain many times and everytime it fogged up (front element and focusing window). Also, it will not handle two stacked super-slim filters without mechanical vignette (well it does if you file away the threads from the 2nd filter).

Should the watermark say "Pixel-Shift Test" ;-)