[Neopifex]

Those of you who have a K 500mm, how do your images look straight out of the camera, in terms of sharpness?

I have a K 500m f4.5 and it is very much not sharp. I've tried shooting at all apertures and a variety of light conditions (cameras used: K-5, K10D, Q7), but I always end up having to apply a ton of sharpening to make even a small image look halfway presentable. I know a lot of old lenses don't do well on digital, but this seems too much for that excuse.

I'm trying to figure out if my lens is a bad copy, or needs some internal cleaning, or just performs as well as any other like it.

[aaacb]

I don't have that lens, but adding an example image could help as a point of reference.

[Ronald Oakes]

I have the lens and it does OK...….quite well actually.
My SMC-K 300m is a bit sharper and so is my 400mm 5.6.
By no means is my 500mm 4.5 really lacking in the sharpness department.
I really don't have any issues with sharpness as much as I do with purple fringing on all of these.
For best results try below....
Shoot with a hood.
Shoot on a tripod.
Use focus peaking and magnification for best results.
Try shooting when the lighting is best and not at all backlit.
Its a very easy lens to clean ......sounds like a thorough cleaning might be in order ?

[monochrome]

A well adjusted K500/4.5 is quite sharp for a 40 year old fairly simple telephoto design. Have you considered a CLA?

My problems are always motion blur (even when shooting from a tripod) and focus error. I do best using Live View at max zoom and a hand resting gently on the barrel. I’ve learned mastering long lenses is a sub-skill within the hobby.

[swip]

That lens is very heavy. So I presume you are shooting with a tripod.
What shutter speed are you shooting?
Motion blur due to camera shake is a possibility.
Did you perform fine focus adjustment?
Have you tried to shoot with Live View? This will minimize camera shake due to mirror motion.

[glasbak]

lens test I did long ago : Pentax, Sigma and Leitz 500mm..560mm optics - PentaxForums.com

[Just1MoreDave]

I don't have that lens, but have noticed that just the air can be a problem at 500mm. I'm 55 miles away from Long's Peak and it fits nicely into the frame at 500mm. I can take a shot from my deck very easily. But between me and the subject are so many sources of heat distortion, pollution, weather or whatever. Sharpness is more about that than the lens.

[luftfluss]

There are some sample photos - including heavy crops - here: SMC Pentax 500 f4.5 - PentaxForums.com

My own experience with the lens matches what Ronald and monochrome have stated. It's not an easy lens to use, but the challenge is part of the fun and when everything goes right the images are rewarding.

Posting a sample image with EXIF intact would help us diagnose the issue.

[Neopifex]

There are some sample photos - including heavy crops - here: SMC Pentax 500 f4.5 - PentaxForums.com

Holy cow, your photos are amazing! I suddenly feel very inspired to go out with mine and hunt the local wildlife. In fact, I may go do that this weekend.

Posting a sample image with EXIF intact would help us diagnose the issue.

You're right, I should have done that, and I meant to last night when I got home from work. Let me see if I can find a DNG that I can share.

[clickclick]

I have the earlier SMC Takumar version of this lens, and it can do well. Stop it down a few clicks. You'll probably find, like most lenses, it has a sweet spot in the midway settings e..g around f8-f11. It does fringe badly wide open, so shooting in RAW and cleaning up in post is often necessary.

[luftfluss]

Holy cow, your photos are amazing! I suddenly feel very inspired to go out with mine and hunt the local wildlife. In fact, I may go do that this weekend.

Glad to read this. There's nothing better than inspiring a person to go out and shoot.

[Neopifex]

So I've been digging through photos I've taken with this beast and I'm having a hard time finding any that aren't from air shows, where there would be a ton of smoke/exhaust in the air, or from the 2017 solar eclipse, where I was shooting through solar filter material and couldn't focus worth a damn. I'm going to take some test photos this weekend and see how it does, then report back here. Many thanks to all responders thus far, you've given me a pretty good idea of what to do next.

[Neopifex]

Alrighty, I've got some sample pics to share. First, I should note that I looked inside the lens and noticed the rear element was hella dirty, so I cleaned it first as best I could. I also cleaned the front element.

Here's an imgur album with one photo for each aperture ring click-stop. Shutter and ISO were adjusted to get consistent exposure, and I ran them all through Adobe Camera Raw with default sharpening and "Auto" exposure adjustments.

Pentax K 500mm f4.5 Test - Album on Imgur

The camera said it was focused on the palm fronds in the very center of the photos, but I think it was actually focused just behind. I don't think the K-5 has focus peaking, so I had to rely on the viewfinder confirmation lights and beep. Here are direct links to each photo, which make it easier to view full-size.

f/4.5 - https://i.imgur.com/9B3WEf4.jpg
f/5.6 - https://i.imgur.com/06oyS7t.jpg
f/6.3 - https://i.imgur.com/BA297kz.jpg
f/8 - https://i.imgur.com/EBBRq7A.jpg
f/9.5 - https://i.imgur.com/6A0s9U3.jpg
f/11 - https://i.imgur.com/MK9MUU6.jpg
f/13 - https://i.imgur.com/MwBD3l8.jpg
f/16 - https://i.imgur.com/IqAActb.jpg
f/19 - https://i.imgur.com/8CVFd9m.jpg
f/22 - https://i.imgur.com/aregmse.jpg
f/32 - https://i.imgur.com/uT4B42D.jpg
f/45 - https://i.imgur.com/ppN3zJh.jpg

I guess I'll just have to use it at f11 and up if I want to start with anything close to decent sharpness.

Incidentally, does anyone know of a cleaning guide for this lens? I'd like to see if I can get to the interior elements, if possible.

[luftfluss]

Alrighty, I've got some sample pics to share. First, I should note that I looked inside the lens and noticed the rear element was hella dirty, so I cleaned it first as best I could. I also cleaned the front element.

Here's an imgur album with one photo for each aperture ring click-stop. Shutter and ISO were adjusted to get consistent exposure, and I ran them all through Adobe Camera Raw with default sharpening and "Auto" exposure adjustments.

Pentax K 500mm f4.5 Test - Album on Imgur

The camera said it was focused on the palm fronds in the very center of the photos, but I think it was actually focused just behind. I don't think the K-5 has focus peaking, so I had to rely on the viewfinder confirmation lights and beep. Here are direct links to each photo, which make it easier to view full-size.

f/4.5 - https://i.imgur.com/9B3WEf4.jpg
f/5.6 - https://i.imgur.com/06oyS7t.jpg
f/6.3 - https://i.imgur.com/BA297kz.jpg
f/8 - https://i.imgur.com/EBBRq7A.jpg
f/9.5 - https://i.imgur.com/6A0s9U3.jpg
f/11 - https://i.imgur.com/MK9MUU6.jpg
f/13 - https://i.imgur.com/MwBD3l8.jpg
f/16 - https://i.imgur.com/IqAActb.jpg
f/19 - https://i.imgur.com/8CVFd9m.jpg
f/22 - https://i.imgur.com/aregmse.jpg
f/32 - https://i.imgur.com/uT4B42D.jpg
f/45 - https://i.imgur.com/ppN3zJh.jpg

I guess I'll just have to use it at f11 and up if I want to start with anything close to decent sharpness.

Incidentally, does anyone know of a cleaning guide for this lens? I'd like to see if I can get to the interior elements, if possible.

FWIW I've never had good luck with Pentax's focus confirmation when using long lenses. Just lots of practice.

I've never taken apart my 500/4.5, but this thread might be useful: Repair guide for Takumar 500mm 4.5 - PentaxForums.com

[barondla]

There are some sample photos - including heavy crops - here: SMC Pentax 500 f4.5 - PentaxForums.com

My own experience with the lens matches what Ronald and monochrome have stated. It's not an easy lens to use, but the challenge is part of the fun and when everything goes right the images are rewarding.

Posting a sample image with EXIF intact would help us diagnose the issue.

Amazing images luftfluss. Lens records impressive sharpness in your hands. See many mentions of this lens being difficult to shoot. Is it more difficult than other large 500mm lenses?

Bought one of these years ago. Don't remember it being anywhere near this quality. Will drag it out and try it on the K-1. Are there different versions of this lens? Mine has an interchangeable back piece that accepts m42 or K mount fittings. What do you feel is the sharpest aperture for this lens? Sorry for all the questions.
Thanks,
barondla