[Serkevan]

So here I am again, asking the good people of the forums on advice about how to wreck my finances .

The thing is, I'm slightly short (hah) on lens options - my longest lens reaches 210mm. However, I've been finding myself in situations where I want to have giant sun disks (or just take some photos of distant landscape) and I might start dabbling in astrophotography in the near future. So I'm in the market for a long telephoto. It's not something that I would consider a walkaround lens or even something that's going to get super frequent use, so I don't want to spend an arm and a leg*. I also have no real interest in wildlife so I'm pretty sure I can manage manual focus, it's hard to miss a mountain .

The only camera is the K-1 so FF-compatible lenses are preferred. Ideally in K-mount but I suppose I could work with M42.

Options I have considered so far:
-Super Cosina 100-500mm f/5.6-8 macro (I found a cheap one). Looks fairly competent but I haven't seen any into-the-sun samples and flare is typically a problem with such old designs...
-Pentax FA 80-320. I think it would mostly overlap with my Tokina 70-210/4.5 and the image quality seems to drop quite sharply at the long end which is where I'd like to use, but how bad would it be? Otherwise it's actually light and f/4.5 until 200mm, which is great in theory...
-Pentax DA 55-300 PLM. Might as well get a one-size-fits-all for hiking, but it's already about as much as I'm willing to spend right now because the 21 Limited won't be cheap.
-One of those generic 400mm f/5.6 or f/6.3 telescope types with 4 or 5 elements. The obvious pro is that they're dirt cheap but, well, I won't exactly get stellar IQ out of them. Flare is another big concern.

Any ideas? I'm of course open to any and all other suggestions, please go ahead

EDIT: for reference, expected viewing size is ~A4 print at maximum or, say, 24" computer screen.

*I know that the only correct options are the 150-450 or some of the FA* super teles, but it's what it is .

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Last edited by Serkevan; 06-30-2020 at 10:51 AM.

[pepperberry farm]

I'd suggest only an F* or FA* 300/4.5

you won't be happy with any zoom you list at that distance....

[Serkevan]

I'd suggest only an F* or FA* 300/4.5

you won't be happy with any zoom you list at that distance....

I know that if I get picky I'll have to go for one of the big guns, but the only examples I've seen run (deservedly) for 700-800€ at the lowest... and that's a bunch of money for something I won't be using too often. I'm willing to compromise a fair bit in IQ

[pepperberry farm]

I know that if I get picky I'll have to go for one of the big guns, but the only examples I've seen run (deservedly) for 700-800€ at the lowest... and that's a bunch of money for something I won't be using too often. I'm willing to compromise a fair bit in IQ

I was there once, also... manual film-era primes, manual zooms, teleconverters, looking to squeeze that last pixel outta those boat anchors...

and finally realized that I just would not be satisfied with any of them... so I sold them all off and saved for a serious prime...

[bertwert]

Well, you already know what I'm going to suggest

You could probably find an A 400/5.6 for cheaper than a 55-300 PLM if you spent some time looking.


Since you mention you're not interested in wildlife at all, here's a mountain sample:




Do insects count as wildlife, if not, here's another sample:



Here's a moon, since you mentioned astro stuff:




Now, I now you said you're not interested in wildlife at all, but after using the lens a bit, how could resist taking photos of these cuddly guys?

[jatrax]

Good, Cheap, Telephoto. Pick two.

Like @Pepperberry Farm I went through the whole progression: cheap mirror lens, bazooka 500mm, teleconverters, M42 primes, etc. And the net result was a lot of money spent and time wasted. I would have been ahead to just buy a good lens in the first place.

One of the Pentax 300mm primes would be good. If you cannot get the DA* 300mm then the FA* or F* are very good. A Pentax-A 300mm would be a good manual focus choice. Or the Pentax-A 400mm f/5.6. I had that lens and decided manual focus at 400mm was not for me but the image quality (when I got it right) was fine.

I now have the DA*300 and the DFA 150-450 and am delighted with both. Not cheap but I simply was not happy with the results of any of cheap long lenses I tried.

[Serkevan]

Good, Cheap, Telephoto. Pick two.

I'm painfully aware . I'm basically trying to maximize the goodness at a reasonable expense, I was hoping there could be some decent performers for not-huge-enlargements, although the more I research the more I see that aberrations and flare are going to be more of a problem than sheer resolution... and what a problem

---------- Post added 06-30-20 at 11:54 AM ----------

Well, you already know what I'm going to suggest

You could probably find an A 400/5.6 for cheaper than a 55-300 PLM if you spent some time looking.

Since you mention you're not interested in wildlife at all, here's a mountain sample:

Do insects count as wildlife, if not, here's another sample:

Here's a moon, since you mentioned astro stuff:

Now, I now you said you're not interested in wildlife at all, but after using the lens a bit, how could resist taking photos of these cuddly guys?

Unfortunately people around here insist on not getting rid of their copies . The only 400mm primes I've seen are cheapo terrible things... except for one quite decent Tokina that got away .

[jatrax]

The only 400mm primes I've seen are cheapo terrible things

There are two Pentax-A 400mm f/5.6 listed on fleabay. Both at under $500.

[aslyfox]

I've been lucky

living in the US, I have found good " experienced " equipment in the market place and other sources

my D FA 150-450 and * 70-200 were bought used as was my DA * 300mm

I did buy my DA 55-300mm PLM new but it was on sale

I have noticed that the forum's market place is not as " active " elsewhere

The Pentax Marketplace | Buy & Sell Pentax Cameras and Lenses (EU) - PentaxForums.com

unfortunately you get what you pay for and a " cheap " telephoto might, " in the long run " might prove money down the drain

[Austro-Diesel]

If money is tight and 300 mm are enough: The performance of the Sigma 70-300 DG OS works surprisingly well and you will surely find one for about 100 to 150 €. The built-in optical stabilizer works very satisfactorily.

Some pictures here: DigitalFotoNetz.de :: Thema anzeigen - Sigma 70-300/4-5,6 DG OS

Sure, there are better lenses, but not for these few bucks. Don't take an APO oder other Sigma or Tamron variants, only the "70-300 DG OS" is recommendable.

[C_Jones]

I would recommend Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE Lens, but from my experience, I was never satisfied with my telephoto needs until I got my Sigma 150-500 DG OS for Pentax. That was before the Pentax 150-450 was being made, or else I would have gotten that Pentax model. Having a super telephoto lens remedies the need for distance seeking. Of course, as you may not be in the position to make that step now, I can see your point, but for me it was either do it or not do it, and I will never regret it.

If you did decide to get something like the 55-300 that I mentioned, it would give you mid telephoto range, and that is the scope of performance that you would have to rely on until you decided to make the step to super telephoto. There is also the option of a teleconverter, but I myself have never used one, and really do not plan on it. A shortcut to that 55-300 is below, and a shortcut to a Pentax converter is below that. Good luck with your decision and happy shooting!

amazon.com : Pentax HD DA 55-300mm f/4.5-6.3 ED PLM WR RE Lens : Camera & Photo?tag=pentaxforums-20&

https://www.bhphotovideo.com/c/product/1029081-REG/ricoh_37962_1_4x_hd_da_af...SABEgJkMvD_BwE

[marcusBMG]

There are some slightly left field possibilities.

Of manual focus 400mm possibilities,a lens like the tokina made 400mm f6.3, which comes in various guises like soligor, vivitar as well as Tokina RMC, is really quite decently sharp stopped down to f8+. But I am something of a fan of the tamron 400mm f6.9 - a lens of this type doesn't deserve to perform this well (and the "nestar" is really rather cool). However perhaps the best price/performance of the MF era is the sigma apo 400mm f5.6, second version - a game changer on introduction with its compact design and sophisticated optics. But the game with that lens is to find one that is only minimally affected by hazing/spotting of a cemented group in the middle of the lens. The sigma apo 500mm f7.2 of the same era/series doesn't suffer from hazing usually, and IMO is the best price/performance 500mm option available.
If you would like to try something completely different, then browse around (seach listings in Germany) for a novoflex 400mm f5.6, specifically the later 3 element t-noflexar objective. For landscape and static shooting, find one fitted with bellows rack and pinion focus as well as the trigger stock.
Optically superior and photographically more interesting, but necessarily rather more pricy, would be a tamron adaptall 300mm f2.8 - the most readily available and best price 300-28. A plum to own and gratifying to use.

[Just1MoreDave]

I've had a Tokina SD 400mm f5.6 for maybe 14 years. The SD is manual focus with an A position on the aperture ring. The lens is internal focus so its length doesn't change - about 230mm. It's about a kilogram. Filter size is 72mm, six aperture blades. Minimum focus distance is 4m. It has a tripod mount and a slide out hood. Image quality is OK I think. Flare isn't ever a problem. It has some purple fringing but that is mostly wide open and not too bad. I shoot it between f8 and f11. Contrast and colors don't look great compared to shots I've seen from the Pentax-A 400. Sharpness is OK, again it looks behind the Pentax. It is pretty consistent across the frame on APS-C, no real vignetting. Long telephoto is demanding anyway because focus has to be right, atmosphere has to be right, you don't have a lot of exposure latitude. Generally I take the easy shots like the moon and avoid small birds. I like the size, weight, handling and features of the lens. I paid $175 which is somewhat irrelevant today but I feel like it was a decent value. The focal length is useful.

A few months ago I bought the Tokina AT-X SD 400mm f5.6, which is similar but with autofocus. The optical formula is different because it focuses closer, and there are two more aperture blades. The reviews suggest the AT-X is sharper. It is a bit sharper but on the order of comparing 100% crops of carefully taken test shots, not OMG look at that it's amazing. I guess the AF is useful. I haven't looked at fringing differences. The lenses are similar in features and the same size. I paid $250 on the marketplace. That seems good for 400mm and AF.

I was never willing to sort out which Sigma is awesome and which one decays to unusable junk. The Tokinas don't do that.

[gatorguy]

There are two Pentax-A 400mm f/5.6 listed on fleabay. Both at under $500.

There's also one A*400 2.8.

[jatrax]

There's also one A*400 2.8.

I'll bet its not under $500...................................