[Lowell Goudge]

I have kit lens Pentax 18-55 & Pentax 50-200, plus a Quartary lens 50 - 300 we purchased in Florida 2 yrs ago.

these are the lens I would be working with.

Sadly none of these lenses are really suited for a tc

you need to consider that the final aperture needs to be F6.7 or faster. When you consider 1 to2 stops light loss with a TC, you really need a lens f4.5 or faster with a 1.4 X or f3.5 or faster with a 2 X TC

[lesmore49]

I do not the sarcism,but I wanted advice.

Thanks this will be my last post (ever)

I believe he was joking.

But from a fellow Canadian, I have to say that this is a great website and I have received a lot of good advice. I hope you reconsider your decision, IMO...lot's of benefits here.

One option you may want to consider is getting the Pentax 55-300 mm. I have one, very clear, even at the far side...ie; 300 mm.

On your K20D and KX this lens would be the 35 mm equivalent of about 460 mm , if I recall correctly. This would give you pretty good reach.

A friend also has a 55-300 and the kit 50-200mm that you have. He finds that the 55-300mm in his opinion, is a better performer then the 50-200mm. I don't know as I've never had the 50-200mm kit lens.

The 55-300 mm is about $ 450-499 CAD new, I think, now.

A used lens would be a cheaper option.

[Perrumpo]

Sadly none of these lenses are really suited for a tc

you need to consider that the final aperture needs to be F6.7 or faster. When you consider 1 to2 stops light loss with a TC, you really need a lens f4.5 or faster with a 1.4 X or f3.5 or faster with a 2 X TC

Damn, I was wondering about a TC for my DA 50-200mm, but I guess I'd have to really lay down the dough for longer reach. Could I still get away with it if my final aperture only needs to be f/8?

Are there any affordable lenses out there that go to at least 400mm worth owning? Would I be better off buying one of those or a fast shorter zoom with a TC?

[bymy141]

Damn, I was wondering about a TC for my DA 50-200mm, but I guess I'd have to really lay down the dough for longer reach. Could I still get away with it if my final aperture only needs to be f/8?

Are there any affordable lenses out there that go to at least 400mm worth owning? Would I be better off buying one of those or a fast shorter zoom with a TC?

I would not go in that direction. The DA 50-200mm is a decent lens, however not a great lens. You'll loose one or two stops of light and a lot of image quality.
For double the price of a TC you can get a 55-300mm which is a much better lens.
I've got 3 different TC's, a 1.5 Kenko, 1.7 Pentax and a 2.0 Vivitar. I do not have the 50-200mm lens, but I do have a number of older budget primes. The results are not satisfying with any of these lenses, while a TC on my (expensive) DA* 60-250mm works good enough.

For 300+ mm you will need to look at second hand Pentax or go third party. Sigma is making some decent 400 / 500 mm lenses. However, they come at a price, it depends what your definition of afforable is....

- Bert

[Perrumpo]

I would not go in that direction. The DA 50-200mm is a decent lens, however not a great lens. You'll loose one or two stops of light and a lot of image quality.
For double the price of a TC you can get a 55-300mm which is a much better lens.
I've got 3 different TC's, a 1.5 Kenko, 1.7 Pentax and a 2.0 Vivitar. I do not have the 50-200mm lens, but I do have a number of older budget primes. The results are not satisfying with any of these lenses, while a TC on my (expensive) DA* 60-250mm works good enough.

For 300+ mm you will need to look at second hand Pentax or go third party. Sigma is making some decent 400 / 500 mm lenses. However, they come at a price, it depends what your definition of afforable is....

- Bert

Okay. Well, I just got the 50-200mm since the 55-300mm goes for over twice what I paid for the 50-200mm, so the 55-300mm was not economical for me. I could save up for a $400, maybe $500 solution, but there's no way I can buy a $1,000 lens. Is there any way to get to 400mm for that price?

[Marc Sabatella]

You could buy a 500mm mirror lens for $100-$200. They're not ideal solutions, either. Mostly, I'd just suggest taking images form the lenses you already have and cropping them to yierld the same basic effect as alonger lens. This works as long as you aren't needing to make very large prints, and results are better than a TC with the lenses being discussed here, and comparable to but less hassle than a mirror lens.

[SOldBear]

I could save up for a $400, maybe $500 solution, but there's no way I can buy a $1,000 lens. Is there any way to get to 400mm for that price?

Look for a copy of the Sigma AF 135-400mm f/4.5-5.6. The running price of a used copy in good condition is $400 - $500 the last time I check. It is decent. But for good IQ at the long end, you have to close down to f/8 or f/11. A nice thing is that it is relatively small and light.

Somewhat related: I posted some test photos of the DA* 60-250mm with and without teleconverters in this post. The IQ of the combo DA* 60-250mm + Pentax 1.7X AFA (about $1250 used) is better than that of the aforementioned Sigma AF 135-400mm f/4.5-5.6 (about $450 used).

[Perrumpo]

Look for a copy of the Sigma AF 135-400mm f/4.5-5.6. The running price of a used copy in good condition is $400 - $500 the last time I check. It is decent. But for good IQ at the long end, you have to close down to f/8 or f/11. A nice thing is that it is relatively small and light.

There is one Sigma 135-400mm f/4.5-5.6 APO that doesn't come with the tripod collar. Is this an issue since you say the lens is relatively small and light? Would I be okay just mounting the camera instead of the lens to the tripod?

EDIT: Nevermind, the guy found the collar.

[bymy141]

Okay. Well, I just got the 50-200mm since the 55-300mm goes for over twice what I paid for the 50-200mm, so the 55-300mm was not economical for me. I could save up for a $400, maybe $500 solution, but there's no way I can buy a $1,000 lens. Is there any way to get to 400mm for that price?

I guess the only "cheap" (what is cheap? Cost is always relative right?) solution is Marc S suggestion to crop.
The only other thing I can think of is spending enough time on garage sales, pawn shops, ebay and other second hand forums to find an afforable optical solution.
400mm fast lenses for APS-C camera's with a quality that matches the camera capabilities *are* expensive. Not just Pentax, all brands.

Perhaps you should consider selling the camera and lenses and buy a super zoom.
I personally like the Panasonic FZ35 a lot considering its sensor size. A very sharp set of optics that thing has. You'd have all the zoom you'd ever need.

- Bert

[Lowell Goudge]

Okay. Well, I just got the 50-200mm since the 55-300mm goes for over twice what I paid for the 50-200mm, so the 55-300mm was not economical for me. I could save up for a $400, maybe $500 solution, but there's no way I can buy a $1,000 lens. Is there any way to get to 400mm for that price?

in the $500 range, you will be restricted to manual focus, but SMC Pentax or SMC Takumar 500F4.5 may be in that range.

My 300mmF4 and 1.7x AF TC combo can be any where from about $600-$800 depending on what you pay

You might get a used Sigma APO 70-200F2.8 for $6-700 and add $200 for the TC.

unfirtunately $500 is kind of on the low side, 7-800 gets you to the range in the used market, but over $1000 for new, and this is 400F5.6 or 500 F6.3 but no faster.

[Perrumpo]

in the $500 range, you will be restricted to manual focus, but SMC Pentax or SMC Takumar 500F4.5 may be in that range.

My 300mmF4 and 1.7x AF TC combo can be any where from about $600-$800 depending on what you pay

You might get a used Sigma APO 70-200F2.8 for $6-700 and add $200 for the TC.

unfirtunately $500 is kind of on the low side, 7-800 gets you to the range in the used market, but over $1000 for new, and this is 400F5.6 or 500 F6.3 but no faster.

That's what I was afraid of. As far as I know, it looks like the Sigma 135-400mm f/4.5-5.6 APO is my best bet. It has AF and if I can get it for $350 or less, I'd say it's a good solution. It compliments my DA 50-200mm nicely, too. I do wonder, though, if it is really worth having both of those lenses or just the DA 55-300mm.

[Lowell Goudge]

That's what I was afraid of. As far as I know, it looks like the Sigma 135-400mm f/4.5-5.6 APO is my best bet. It has AF and if I can get it for $350 or less, I'd say it's a good solution. It compliments my DA 50-200mm nicely, too. I do wonder, though, if it is really worth having both of those lenses or just the DA 55-300mm.

I am not familiar with the IQ of the sigma, but you will appreciate the extra 100mm.

Perhaps someone can comment on whether you have better IQ with the extra 100mm or with a 30% crop on all your shots.

[Perrumpo]

I am not familiar with the IQ of the sigma, but you will appreciate the extra 100mm.

Perhaps someone can comment on whether you have better IQ with the extra 100mm or with a 30% crop on all your shots.

Thanks. I did find this thread on the Sigma, so I will ask in there, since I've now gotten off topic for this TC thread.

[Mike.P®]

Thanks. I did find this thread on the Sigma, so I will ask in there, since I've now gotten off topic for this TC thread.

Well as a contributer on that thread I have to say I was probably a little harsh at times on the 135-400mm. I sold it in the end and bought a 50-500mm which is better but the smaller Sigma was pretty good for the money I paid.

Saying that it sold for way over the $350 you are thinking of, I think it was roughly the equivilent of $500.