[VictorDA]

As usual it all boils down to your personal needs and expectations, there is not one correct answer to your question. Both bodies are very powerful.
However, I can share my experience: I chose to replace my K-3 II (bought new in 2017) by a lightly used K-1 this year. I already had some FF-compatible lenses (mostly manual focus) so the transition was not too painful. Basically just had to replace the 18-135 by a 28-105; the rest will be incremental improvements over time.
You are not scared of the size and weight of the K-1, and you seem to consider it within your budget, so I would say go for the K-1, I don't see how you could regret it.
The image quality is noticeably better that K-3 II for landscapes; family images also have a better rendering; the camera operation also seems faster and more reliable (in my case at least), except maybe the wake-up time that seems looong
I still haven't found one situation where my K-3 II would have fared better than my K-1, except the weight on the shoulder on hikes...

PS. I'm a bit surprised by your comment on used prices, here in Europe it seems a K-1 is still quite more expensive than a K-3 II in the same use condition (not easy to find below €900, whereas K-3 II can be had around €500).

PPS in edit: and I'm 100% with you on the appreciation of an integrated GPS solution, I really hope they don't ditch it in all future bodies as in the K-3 III... Of course accessories exist (O-GPS, link to smartphone), but I value simplicity and hate clutter

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Last edited by VictorDA; 08-13-2021 at 12:57 AM.

[aslyfox]

It is a complicated question. First, what does your current Gear struggle with? Put another way, what limits you today that the new camera will lift or reduce?

As usual it all boils down to your personal needs and expectations, there is not one correct answer to your question. Both bodies are very powerful.. . .

put it more bluntly

what are the OP's photographic goals and which sensor works best for those - the full size sensor of the K 1 family or the ASP-C sensor of the other Pentax 35mm DSLR family ?

by reading the reviews of the K 1/K1 II, you will see where its sensor works best and where it does not

so which fits better

if neither, what is it that the photographer wants the most

then compare which lenses you have or want works best with the cameras

unless you are lucky enough to get one of each

. . . Date your cameras but marry your lenses! Good glass will be with you through several camera bodies

a nice phrase and very good thought to consider

[swanlefitte]

Date your cameras but marry your lenses! Good glass will be with you through several camera bodies

But does the aperture ring alone cost 2 months salary?😀

I would go with better glass before shrinking my pixels cramming the 24mp in an 18mm x 24mm. The airy disc needs to be smaller.

The K1 only crams 15mp in that area and has more all around it.

[sneeds]

I'm curious: why not keep your K-S2 and get a Pentax O-GPS1 for when you do astro?
Save the rest for new/better lenses?

I've shot astro successfully with my K-S2, O-GPS1, and regular kit lenses:

Great shots, thanks for sharing!

[ehrwien]

I started out with a K-S2 (which I still have and use, most of the time with the 55-300 PLM... but I'm longing for a K-3 III ), and added a K-1 last year. I don't have a 28-105 or 24-70, but some primes between 28 and 100 mm.

What I have noticed so far: the K-1 is more reliable in terms of metering, I like the colours more that it produces, the pictures look so much smoother because of the bigger resolution (almost twice as many as in the K-S2), and there is so much more latitude in the shadows to be pushed in post processing. Part of that may be because of 14 bit RAW in the K-1 vs. 12 bit in the K-S2, but I think the K-3 II also offers 14 bit RAW files. Another part may be because of the bigger sensor, more and bigger pixels of the K-1.

If you want to shoot "astro", you should get a bit more precise to figure out what focal lengths you want to cover and if you already have lenses that you could use with the K-1 to achieve the desired framing or what you would need to get in addition to the body. For deep sky objects the approach with dedicated mount and telescope might get better results than with astrotracer and photographic lenses? For milky way nightscapes the K-1 with a wide lens and astrotracer might get better results. (??? Just some wild guesses by myself)

There are three arguments FOR changing the K-S2 for the K-3 II (with astro in mind): 14 bit RAW of the K-3 II, built-in GPS for Astrotracer and the small possibility for the K-S2's aperture solenoid to fail.
There are also arguments for NOT changing the K-S2 for the K-3 II: the fully articulating screen of the K-S2 should come in handy with the camera on a tripod pointed at the sky. I find the screen to be very useful in other situations as well. And the tiny and lightweight camera (ok, just about 100g difference) invites itself to come along more often.
NEUTRAL: K-3 II offers more FPS, 2 card slots, 24 vs 20 mp, longer shutter life (at least we get a number with 200,000 actuations, none given for the K-S2), better AF, more reliable metering, pro body ergonomics, USB 3 vs 2, ultrasonic dust removal DR II vs. sensor shake DR; K-S2 offers built-in flash

Personally, I wouldn't change a K-S2 for a K-3 II if I were you. If you want to get the best files, get a K-1, and perhaps additional lens(es), but you should be prepared for the additional heft and also the need for more processing power for working with the files.

But perhaps just getting another lens for use with the K-S2 will satisfy your desires already? Or, try and get more out of the setup you are using right now? Why do you not use it as much? What do you not like about using it, about the images?

[sneeds]

It is a complicated question. First, what does your current Gear struggle with? Put another way, what limits you today that the new camera will lift or reduce?

Well, I suppose that the main struggle for astro is the equipment management - it's not a relaxing hobby anymore because of all the gear. I want to consolidate. And for the times that I want to take some astro pictures (which has been about 3-4 times this year, so not much), I still want that ability. The K-1 should have better low light performance.

---------- Post added 08-13-21 at 10:57 AM ----------

Hi
Welcome to the most helpful forum on the planet
Are you trading your K-s2 for the upgrade? If so there are pros and cons.
The K-S2 is a brilliant camera and you won't see much iq difference with an apsc upgrade
The K-S2 has an issue in a VERY SMALL percentage of bodies where the aperture block fails giving you black images
The K3ii build quality is solid (no aperture block to fail) with no real negatives and a built in astrotracer
The K1 has better image quality and has the astrotracer but it is noticeably larger. Also you would need new glass
The K1 is double the price (used) of a K3ii

I am 100% with @Fozzfoster . the astrotracer unit will cost you £100(?) That's all you need right away. The lenses you have are fine. I would calibrate all but especially the 50-200mm as I have found it makes a big difference.
Possibly replace the 100-300mm with a 55-300mm. The PLM is super fast focusing but the ordinary HD or SMC versions have a nicer feel to the focus ring and as you don't need fast AF for astro there is no need to pay the extra 50%. Moving up to an HD, WR 55-300mm from the 100-300 will probably cost you £75. You would also be gaining quick shift which is way smoother for mf
Look at manual lenses. There are fast-ish 50mm vintage lenses out there for peanuts (pentax-m 50mm f2 - £20, 50mm f1.4, £80, Tokina RMC 28mm f2.8, £20, etc etc). Why not, for astro you don't need AF. Also, vintage glass is full frame

Date your cameras but marry your lenses! Good glass will be with you through several camera bodies

Hi - yes, if I got a new body, the K-S2 would go.

And just to emphasize, the astro part is a very small part of what I want the camera for (I just don't want to lose that ability).

Vintage glass is fine with me too and like you said, you don't need AF under the stars.

I guess, though likely not possible, I'd like to get to the 1 body (including paraphernalia) and one lens, and go with that for a while. The equipment is starting to bug me.

---------- Post added 08-13-21 at 10:59 AM ----------

As usual it all boils down to your personal needs and expectations, there is not one correct answer to your question. Both bodies are very powerful.
However, I can share my experience: I chose to replace my K-3 II (bought new in 2017) by a lightly used K-1 this year. I already had some FF-compatible lenses (mostly manual focus) so the transition was not too painful. Basically just had to replace the 18-135 by a 28-105; the rest will be incremental improvements over time.
You are not scared of the size and weight of the K-1, and you seem to consider it within your budget, so I would say go for the K-1, I don't see how you could regret it.
The image quality is noticeably better that K-3 II for landscapes; family images also have a better rendering; the camera operation also seems faster and more reliable (in my case at least), except maybe the wake-up time that seems looong
I still haven't found one situation where my K-3 II would have fared better than my K-1, except the weight on the shoulder on hikes...

PS. I'm a bit surprised by your comment on used prices, here in Europe it seems a K-1 is still quite more expensive than a K-3 II in the same use condition (not easy to find below €900, whereas K-3 II can be had around €500).

PPS in edit: and I'm 100% with you on the appreciation of an integrated GPS solution, I really hope they don't ditch it in all future bodies as in the K-3 III... Of course accessories exist (O-GPS, link to smartphone), but I value simplicity and hate clutter

Sorry, my mistake, you are right - the K-1 is about 50-70% more on the used market.

It's not that I have all that cash sitting around and the more expensive purchase is easy - I just have some stored in equipment I'm not using!

And it is the clutter thing that is messing up both hobbies for me - photography and astro!

---------- Post added 08-13-21 at 11:19 AM ----------

I started out with a K-S2 (which I still have and use, most of the time with the 55-300 PLM... but I'm longing for a K-3 III ), and added a K-1 last year. I don't have a 28-105 or 24-70, but some primes between 28 and 100 mm.

What I have noticed so far: the K-1 is more reliable in terms of metering, I like the colours more that it produces, the pictures look so much smoother because of the bigger resolution (almost twice as many as in the K-S2), and there is so much more latitude in the shadows to be pushed in post processing. Part of that may be because of 14 bit RAW in the K-1 vs. 12 bit in the K-S2, but I think the K-3 II also offers 14 bit RAW files. Another part may be because of the bigger sensor, more and bigger pixels of the K-1.

If you want to shoot "astro", you should get a bit more precise to figure out what focal lengths you want to cover and if you already have lenses that you could use with the K-1 to achieve the desired framing or what you would need to get in addition to the body. For deep sky objects the approach with dedicated mount and telescope might get better results than with astrotracer and photographic lenses? For milky way nightscapes the K-1 with a wide lens and astrotracer might get better results. (??? Just some wild guesses by myself)

There are three arguments FOR changing the K-S2 for the K-3 II (with astro in mind): 14 bit RAW of the K-3 II, built-in GPS for Astrotracer and the small possibility for the K-S2's aperture solenoid to fail.
There are also arguments for NOT changing the K-S2 for the K-3 II: the fully articulating screen of the K-S2 should come in handy with the camera on a tripod pointed at the sky. I find the screen to be very useful in other situations as well. And the tiny and lightweight camera (ok, just about 100g difference) invites itself to come along more often.
NEUTRAL: K-3 II offers more FPS, 2 card slots, 24 vs 20 mp, longer shutter life (at least we get a number with 200,000 actuations, none given for the K-S2), better AF, more reliable metering, pro body ergonomics, USB 3 vs 2, ultrasonic dust removal DR II vs. sensor shake DR; K-S2 offers built-in flash

Personally, I wouldn't change a K-S2 for a K-3 II if I were you. If you want to get the best files, get a K-1, and perhaps additional lens(es), but you should be prepared for the additional heft and also the need for more processing power for working with the files.

But perhaps just getting another lens for use with the K-S2 will satisfy your desires already? Or, try and get more out of the setup you are using right now? Why do you not use it as much? What do you not like about using it, about the images?

Ok, so for more background, I've been a regular astrophotographer for 5-6 years - nothing 'pro' level, but some stuff that I am proud of. (See attached for an example of a 200 mm lens on a star tracker). I've found that I can have fun with all focal lengths - fisheyes to telephoto - there is always something interesting to frame. My original star tracker setup was pretty decent though frustrating to find objects, so I got the setup I have now with the telescope and computerized equatorial mount. And it's completely taken the fun out of astro shots.

From the research I have done on astrotracer, it should fit the bill nicely as it can do decent exposure lengths even up to 200 mm (on APSC). I've heard it can foul up on wide angle shots, but that's ok as you don't real need a star tracker for fisheye stuff.

Anyway, with that out of the way, I'm not going to be a regular astrophotographer anymore, I just want to keep the ability to track the stars but get rid of all the equipment. I could stick on the 100-300 that I have now and be just fine in that range as I am not going for perfection with perfect stars edge-to-edge. I just want zero clutter.

[UncleVanya]

I would suggest looking for some threads on the astrotracer. It does not seem like our most adroit astro enthusiasts think it is a good substitute for a tracking mount - but it can be useful for some shots. The problem is that the movement isn't going to fully cancel movement evenly across the frame on wider shots. HOWEVER - I still bought one and plan to play with it - I'm shooting a K-3 and KP these days.

As far as a one lens solution with one body... wow. That would be where I would say - why get a DSLR at all if you plan to only have one lens? But there are really two choices I see for the K-1 that make a lot of sense, the 28-105, and the 24-70. Of these the 28-105 seems to be the most consensus winner for just plain fun and walking about. But it's a slower lens - and may not fit your criteria for a single lens.

[sneeds]

Well, I think it comes down to the following options after selling my unused gear:

1. K-1 and use my FA 35-80 and FA 100-300

2. K-3 with DA* 50-135, or

3. Keep the K-S2, get the O-GPS1, and either the DA* 60-250 or a combo of the 50-135 and 10-17 (I like fisheyes)

[UncleVanya]

Well, I think it comes down to the following options after selling my unused gear:

1. K-1 and use my FA 35-80 and FA 100-300

2. K-3 with DA* 50-135, or

3. Keep the K-S2, get the O-GPS1, and either the DA* 60-250 or a combo of the 50-135 and 10-17 (I like fisheyes)

The 50-135 is a fantastic lens. But on apsc crop mode it is a telephoto only; the perspectives it offers are similar to a 70-200 on full frame. This isn’t very versatile and I would pair it with the DA 18-50 or 20-40 to make a nice two lens package. The 20-40 is my recommendation - and there’s a slightly dinged up one in the marketplace that you should look at seriously.

If one lens is the goal the 18-135, 18-250, 18-270, 18-300 lenses all offer wide range but compromise in some optical properties- but they offer extreme flexibility. I personally shoot an 18-135 and the 20-40/50-135 combo and use both options when the need arises.

[mikesbike]

Well, I think it comes down to the following options after selling my unused gear:

1. K-1 and use my FA 35-80 and FA 100-300

2. K-3 with DA* 50-135, or

3. Keep the K-S2, get the O-GPS1, and either the DA* 60-250 or a combo of the 50-135 and 10-17 (I like fisheyes)

I agree completely with UncleV. Of your 3 options, the FA lenses you indicate are mediocre with the K-1. You would be far better off putting your money for the upgraded glass mentioned on your K-S2. A caution regarding the DA* 60-250, as having AF problems arise with its SDM system, which unfortunately is not uncommon, that it cannot be converted to screw-driven AF operation, while the DA* 50-135mm can, and with it you get the f/2.8 advantage for low light and higher shutter speed needs.

[UncleVanya]

I like my da* lenses I own all three of the original zooms (16-50, 50-135, 60-250) and each has a role. The 50-135 plus an HD DA 1.4 is also useful as it makes that lens a bit longer (70-192) Which is useful when you think you don’t need length and leave the 60-250 at home. The HD DA 1.4x is light and easy to pack.

[aslyfox]

. . . if I got a new body, the K-S2 would go. . . .

why ??

there are times it is advantageous to have multiple cameras to choose from

would it contribute too much to the " clutter " you want to avoid ?

unless you think you can get good value for it, I would advise you reconsider

of course you know best

[jatrax]

In fact, it does very well from 35-50 mm, and can render beautifully.

I'm sure it does but personally I would not be carrying around a 35-50mm lens when there are so many other options. If it is all you have then sure that's great, but I stand by my comment that it doesn't work on FF for my definition of 'work' anyway.

[VictorDA]

Well, I think it comes down to the following options after selling my unused gear:

1. K-1 and use my FA 35-80 and FA 100-300

As others have mentioned, in this case the quality of the lenses would not be a great match for the ability of the camera... However, that can be a starting point if you plan to upgrade the lenses one by one in the medium/long run.
Still, even in a limted budget I would add to this setup at least a 50mm prime (e.g. Pentax-A 1:1.7 50mm) for the capacity to get higher quality images, and for low-light stuff. And for the fun of manual focusing!

2. K-3 with DA* 50-135, or

3. Keep the K-S2, get the O-GPS1, and either the DA* 60-250 or a combo of the 50-135 and 10-17 (I like fisheyes)

These options seem more balanced immediately (K-3 II not I); but, on the other hand, they do not offer a clear upgrade path if you were to change your mind and go FF in the future.
Good luck with your choice and decision

Whatever happens, have fun with the equipment you have!!!

[UncleVanya]

These options seem more balanced immediately (K-3 II not I); but, on the other hand, they do not offer a clear upgrade path if you were to change your mind and go FF in the future.
Good luck with your choice and decision

Something glitched your quote as I wasn’t the one writing the quoted text. I quoted that myself. However I did recommend some crop lenses with a crop body, because the cost of buying the 1-2 lenses would be cheap if used gear is purchased. The future isn’t mortgaged heavily and a change in direction later wouldn’t require a lot of investment if the number of lenses is kept small.