[normhead]

I too am frustrated. I treated myself to a sigma 150-500mm as a retirement present to myself.
I’ve never been happy with the results. The staff at my go to store matched it to my K 50 as I wanted to take pictures of birds. Reading your email I think the K50 just doesn’t support the K50. In the last year I have struggled with dark exposures when starting up the camera. It’s a common fault and yet Pentax hasn’t recalled the cameras. I’m totally disillusioned with Pentax. Apparently they used cheap components for my K50 and several others in that range.

Many of our 150-500 shooters have moved on to the DA 150-450, which would appear to be a much superior lens, but a lot more money as well. The recommended introductory birding set up tends to be the DA*300 with the 1.4 TC.

"It’s a common fault and yet Pentax hasn’t recalled the cameras."

My goodness, who told you that?
An aperture block failure happens, when the Aperture block stops working. If you are still getting exposures, it's not that, and the problem isn't common.If serious, send it in for repair. Of the 10 or so Penax DSLR's I've used, I haven't experienced anything like that, but, I also don't own a K-50. At this point that's a pretty old camera. A second had K-5ii could be a huge improvement. Same age, but better components.

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Last edited by normhead; 07-19-2021 at 11:57 AM.

[cameranorm]

I agree. I bought a new Sigma 150-500...on my K5 ASPC the 35mm equivalent is somewhere around 775 mm. I have a K1, but I use my smaller ASPC sensor K5...for the extra reach...some 275mm.

I take pix of Owls, Pelicans, etc...large birds like that...BIF, stationary and I've never felt the need for a longer reach than my Sigma provides...on the K5.

"on my K5 ASPC the 35mm equivalent is somewhere around 775 mm. I have a K1, but I use my smaller ASPC sensor K5...for the extra reach...some 275mm.
I take pix of Owls, Pelicans, etc...large birds like that...BIF, stationary and I've never felt the need for a longer reach than my Sigma provides...on the K5."

Whoa! What a misstatement on a technical forum.
You are under the common amateur misunderstanding of what "crop factor" on APS-C bodies means.

Putting a lens on a crop-sensor body DOES NOT GIVE MORE REACH!!!. It does not become a "longer" lens. A lens's focal length does not (cannot) change.
What you describe as "more reach" is very simply the small sensor not capturing a lot of what the lens sees. The portion of the scene captured by the crop sensor is what a longer-length lens would on a full-frame body would capture.

The crop-factor of a sensor (1.5, 1.6, 2, whatever depending on its size) just gives an approximation of what a lens does on a full-frame camera.

[mikesbike]

PLM has limits to the weight of the lens focusing group. The 55–300 PLM is likely the longest PLM lens we’re likely to see, and it’s quite dark at the long end. The two DFA lenses you cite have DC focusing motors that are modern and fast. There’s no hope of making a lens of that size that uses PLM. I haven’t tried the DFA* 70–200 on the K-3 iii, but I rented a DFA 150–450 and it was snappy focusing on wildlife both with and without the HD DA 1.4x teleconverter. Let’s see what comes with the 70-ish to 300-ish DFA lens on the roadmap. The impending release of the DA* 16–50mm f/2.8 (You must have missed all the hubbub about it this week…the ambassadors have been released from their embargo.) means that they should be able to add another in development lens to the roadmap, which I imagine might be the DA* 50–135mm.

Hmmm- I wasn't aware of the PLM weakness in dealing with heavier lenses. So far I don't have any PLM lenses. The DC motors have worked fine for me, but I don't do much burst shooting, AF-C tracking, etc. Glad to hear DC lenses are very fast for AF on the K-3 III, as this is good news for true advancement of the Pentax brand.

---------- Post added 07-19-21 at 02:26 PM ----------

DFA *24 f1.4

That sounds very interesting- I hope it is for real, and will provide fine edge-to-edge performance!

[lesmore49]

"on my K5 ASPC the 35mm equivalent is somewhere around 775 mm. I have a K1, but I use my smaller ASPC sensor K5...for the extra reach...some 275mm.
I take pix of Owls, Pelicans, etc...large birds like that...BIF, stationary and I've never felt the need for a longer reach than my Sigma provides...on the K5."

Whoa! What a misstatement on a technical forum.
You are under the common amateur misunderstanding of what "crop factor" on APS-C bodies means.

Putting a lens on a crop-sensor body DOES NOT GIVE MORE REACH!!!. It does not become a "longer" lens. A lens's focal length does not (cannot) change.
What you describe as "more reach" is very simply the small sensor not capturing a lot of what the lens sees. The portion of the scene captured by the crop sensor is what a longer-length lens would on a full-frame body would capture.

The crop-factor of a sensor (1.5, 1.6, 2, whatever depending on its size) just gives an approximation of what a lens does on a full-frame camera.

I see.

[mikesbike]

Putting a lens on a crop-sensor body DOES NOT GIVE MORE REACH!!!. It does not become a "longer" lens. A lens's focal length does not (cannot) change.
What you describe as "more reach" is very simply the small sensor not capturing a lot of what the lens sees. The portion of the scene captured by the crop sensor is what a longer-length lens would on a full-frame body would capture.

While technically this is true- one could take the same size lens and crop the resultant image to match that of the APS-C result (losing a lot of pixels), or as you say use a longer, heavier lens to get the same image, and depending on the camera specs with possibly more resolution, in practical terms APS-C can provide a larger representation of the subject with the same size lens, so it DOES in this case, in real-life usage provide more reach.

I have both, with my K-1 II plus my KP and other APS-C bodies. To get similar results as my K-1 II with the DFA* 70-200mm f/2.8 (which I have not purchased), I would rather instead shoot with my still excellent DA* 50-135mm f/2.8 on my KP, a far, far lighter carrying and handling combo. Of course there are those who would prefer the K-1 II combo, for what ever improvement that brings, which is up to each as they see fit for their needs. But, still, if you put that same 70-200mm lens on the KP, you will get imaging similar to a 100-300mm f/2.8 lens on the K-1 II- a pretty neat idea! If I got such a lens, the KP is where I would likely use it. Others might say, yeah but one can still just add a 1.4x TC with the K-1 II. But then would the TC presence still produce a better image quality than on the KP without the TC? And it would no longer be f/2.8 aperture, as well as not quite a 300mm image. There is no 100-300mm f/2.8 lens for the K-1 II (it would be huge!). When you go to the FF DFA 150-450mm lens, but use it on the KP, there is no alternative for the K-1 II.

[normhead]

You are under the common amateur misunderstanding of what "crop factor" on APS-C bodies means.

Putting a lens on a crop-sensor body DOES NOT GIVE MORE REACH!!!.

The only thing in question here isn't "reach" a colloquial term with almost no defined meaning. Two terms that do have meaning and can be considered components of reach are field of view, and magnification. 150mm FF is the same field of view as 100mm APS-c. So that's part of what is meant by "reach" and APS-c gives you the same field of view with a shorter lens. IN that sense APS-c gives you more reach.

In the second part, magnification... how many pixels across is the subject of the image, APS-c 24 MP, gives you more subject magnification than anything short of 51mm FF with the same lens. So again, more magnification, the second component of reach.

Given the same lens and similar MP say a 24 MP FF and a 24 mm APS--c the APS-c will give you both narrower field of view similar to a longer lens on FF, and more magnification of the subject. Unless you can come up with another relevant metric that neutralizes the above two components, I'm going to have to dismiss that as a practically inaccurate statement

So I have to ask, in what metric does APS-c not get you more reach? In what possible definition of "reach" does APS-c not give you more?

Maybe before you start calling people amateurs, you might want to spend some time understanding what you're talking about. Implying others who think differently than you are amateurs doesn't make you right. No one who owns a K-3 and K-1 is going to make that mistake. You'd know from looking at your images.

[cameranorm]

Your lengthy rebuttals and quoting specific lenses endlessly does nothing to help the uninformed to understand the subject of crop factors.

Too bad.

I'm done here.

[Mark Ransom]

The problem with Pentax is their limited resources, so releasing a brand new products may take 3-5 years.
And the max capacity they have is working on 1-2 cameras and maybe 2-4 lenses at the same time, which means a camera released every second year and 1-2 lenses a year.

Which is why they often refresh old lenses. It take a lot less resources and can be done in a couple of month.

Definitely Pentax has a problem with limited resources compared to the rest of the camera industry.

But a "refresh" of something like the 16-50 involves a whole new optical formula. It's not something you can crank out in a couple of months.

[Mark Ransom]

... The lenses make a different story. The best ones are "forever" , aren't they? ...

Lenses used to be "forever", but I think that's changing. The newer ones have a lot more electronics and motors than the old ones, so expect them to wear out like anything else.

[Fogel70]

Definitely Pentax has a problem with limited resources compared to the rest of the camera industry.

But a "refresh" of something like the 16-50 involves a whole new optical formula. It's not something you can crank out in a couple of months.

I was thinking of the refresh they have done on older screw drive lenses over the years. Like DA & FA limited, FA 35, DA 10-17 , DFA 100 macro...
Where they made smaller updates and kept the optical formula.

[Serkevan]

Your lengthy rebuttals and quoting specific lenses endlessly does nothing to help the uninformed to understand the subject of crop factors.

Neither does your angry ranting, to be honest.

Focal length is focal length irrespective of sensor size, but smaller sensors tend to have a higher pixel density, which is what you want (as Norm wrote). At equal MP, with a given lens, the smaller sensor will have more reach, period.

In the specific case you were quoting, no, a K-5 wouldn't have more reach than a K-1 because it's a 16 MP body.

[normhead]

Your lengthy rebuttals and quoting specific lenses endlessly does nothing to help the uninformed to understand the subject of crop factors.

Too bad.

I'm done here.

This is a terrible place to bring in half baked ideas about topics you don't actually understand unless you're asking for information. Attacking those who add information and context, is even worse. It's good you're letting this go. Now maybe try and understand the explanations people have graciously provided you with.

[biz-engineer]

I just don't understand Pentax

It's easy to understand:

Pentax spells ペンタックス in Japanese,

ペ ___ Pe
ン ___ N
タ ___ Ta
ッ ___ Tsu
ク ___ Ku
ス ___ Su

which means Pentakkusu (courtesy google translate).


---------- Post added 20-07-21 at 13:46 ----------

The name "Pentax" was originally a registered trademark of the East German VEB Zeiss Ikon (from "Pentaprism" and "Contax") and acquired by the Asahi Optical company in 1957.

So in reality, you think you are shooting a Pentax, but it's a re-incarnation of a Zeiss Ikon.

[Kiparisas]

They do have, however, quite a collection of fixes!

[mtkeller]

I was thinking of the refresh they have done on older screw drive lenses over the years. Like DA & FA limited, FA 35, DA 10-17 , DFA 100 macro...
Where they made smaller updates and kept the optical formula.

Screwdrive AF was reliable, unlike the DA* 16–50’s SDM. They have also clearly demonstrated that corner sharpness wide open was able to be significantly improved.