[Class A]

Is there a way to get reach >= 300mm on a budget with decent IQ?

I currently use the Tamron 18-250mm and am really happy with the lens but wonder if there is some solution to get reach at least up to 300mm without breaking the bank. The Bigma seems to be a common choice but is too expensive for my current budget.

The Pentax 100-300mm is referred to as being one of Pentax' weaker efforts.

Are their other solutions from Pentax, Sigma, Tamron, Tokina, etc. which would give me a reasonably fast and long telephoto?

Are teleconverters the way to go? I'd probably need a pretty good and fast prime then to start with. A 2x teleconverter seems to be pretty extreme in terms of losing stops and downgrading IQ. Unfortunately it seems that 1,4 x teleconverters have vanished from all markets known to me.

I'd prefer aperture control by the camera (P/KA) and ideally AF, but would also consider fully manual lenses if they make up for the lack of automation by IQ and affordability.

Any insiders' tips?

[8540tomg]

Class A

Might I suggest the K 300mm f4. It is fuly mnually but the best bargain out there in the 300mm range. There is an extensive thread:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/29940-pentax-smc-300-4-a.html

and many reviews in the lens database. It is heavy and lacks a tripod mount but is a very good value for the money IMO.

Tom G

[Lowell Goudge]

I would have to agree with tom.

I put a link directly to some shots I took with the 300 F4 and 1.7x AF TC (making it a semi autofocus 510mm F6.7.

https://www.pentaxforums.com/forums/392996-post102.html

except the last one which was scanned from film, these were all taken over a 10 minute span, to simply show that this lens could produce keepers without much effort, as one of the posters was complaining he could not get the shot and his ratio of keepers was very low.


Best bang for the buck in my humble opinion

[philbaum]

Class A,
I also have the Tamron 18-250,

I bought a Tamron 1.4TC to go with the 18-250, but later on, i found out that Tamron doesn't recommend their own 1.4 with their own 18-250. Prob. is that MF focusing with those two products is possible but very stiff because of the additional AF linkage, i guess. Also the 1 stop of light loss due to the 1.4 makes a difference indoors as well as evening outdoors.

I've never had a SMC 300 M or K, but that might make a lot of sense. Especially now that a lot of stuff is changing hands. Also, if you liked the 300 M or K, getting one of the TC's, once they become available again, would provide additional flexibility some day.

[hinman]

I find great liking with noted caveat on Purple Fringe with my used Tamron 70-300 Di LD 1:2 Macro lens. And I have used both Tamron Pz-AF 1.4x TC and Promaster AF 1.7x TC to satisfactory results in reaching 420mm and 510mm.

The noted caveats on PF/CA is true but I avoid it with higher ISO, aperture smaller than f/8.0 when high contrast is noted in the scene as in tree branches.

Tamron 70-300 Di LD 1:2 Macro

#1
300mm


#2
Tamron Pz-AF 1.4x TC



#3
with Tamron 1.4x TC




#4
with Promaster AF 1.7x TC




#5

[Arpe]

You realise that's there's not much diff between 250 and 300?

The sigms 70-300 APO is supposed to be not bad. They also have a non-APO one which isn't as good. What are you doing this Sunday avo? I'll probably be at Elsdon Park photoing. I could bring my 80-320 for you to have a play so you can see for yourself. Not sure of the time yet.

[sharko]

You shouldn't use a TC of any sort with the 18-250 superzoom as it will not autofocus at all and the viewfinder becomes so dark its hard to see anything because of the loss of light.

[audiobomber]

You realise that's there's not much diff between 250 and 300?

But due to its design, the 18-250 doesn't have reach like a true 250mm lens. I did some comparisons with the 55-300mm vs the 18-250 and found that at 30 feet distance and 250 mm the 18-250 had the same FOV as the 55-300 set for 200 mm. At about a mile, the 18-250 looked like 230 mm.

[m8o]

get an old SMC 500/4.5. Very good copies from KEH are going for $749. (I've been told in the past they were under $500.)

[cwood]

One word

BIGMA

The best 500mm lens out there for less than $5000

[Class A]

Might I suggest the K 300mm f4.

Thanks a lot for the tip and the link to the other thread!
I'll go and do some reading.

I put a link directly to some shots I took with the 300 F4 and 1.7x AF TC (making it a semi autofocus 510mm F6.7.

Thanks much, I'll check them.

I bought a Tamron 1.4TC to go with the 18-250, but later on, i found out that Tamron doesn't recommend their own 1.4 with their own 18-250.

Will AF still work? Without putting on a high strain on the camera motor?

Also the 1 stop of light loss due to the 1.4 makes a difference indoors as well as evening outdoors.

And outdoors? I guess with "only" 1.4 magnification the IQ should still be OK, given sufficient light?

I find great liking with noted caveat on Purple Fringe with my used Tamron 70-300 Di LD 1:2 Macro lens.

Hinman, these images are awesome!
Not only do they demonstrate the sharpness of the lens, they are also really great shots. Chapeaux.

You realise that's there's not much diff between 250 and 300?

Hmmh, I theorised there wouldn't be much difference but I wasn't sure. The last 50mm on the 18-250 do not seem to make much of a difference. Extrapolating that, you're right, 300mm cannot be a world of a difference. But then the 18-250mm gets slow at 250mm and some say even "soft". I think one can still take decent pictures at 250mm but let's say a prime at 300mm should be faster and sharper and that's a useful difference even if the reach isn't terribly higher. It would allow for cropping with better results and this way give more reach nevertheless.

What are you doing this Sunday avo? I'll probably be at Elsdon Park photoing.

It'll be great to meet you there. I'll check my availability and will contact you.

You shouldn't use a TC of any sort with the 18-250 superzoom as it will not autofocus at all and the viewfinder becomes so dark its hard to see anything because of the loss of light.

Not even a 1.4 x TC?

But due to its design, the 18-250 doesn't have reach like a true 250mm lens.

Depends on where you are focusing at. The IF mechanism changes the effective focal length depending on the focus. In his Tamron 18-250mm F/3.5-6.3 AF Di-II LD Aspherical (IF) Macro Review Bob Atkins reckons that the effective focal length of the 18-250mm is ~125mm at its close focus distance of 45cm. But focused at infinity the focal length should be 250mm.

At about a mile, the 18-250 looked like 230 mm.

Interesting. I guess a mile should be practically infinity already, right? Not sure whether focusing any further away would help but it seems odd that Tamron would specify 230mm as 250mm.

[cpopham]

There's a shop up here which has the DA 55-300 at a price you might find hard to believe for an NZ new (and official) lens (about $1k). It's still a few hundred more expensive than importing yourself from B&H though

[Stratman]

For the money, the Tamrom 70-300 LD Di is tough to beat. I have had mine for almost 2 years, and have managed some nice shots with it, and the 1:2 macro comes in really handy too !!

Here are a few "macro" examples.





And some long range shots.

300mm

[ivoire]

Mirror lenses are another option. I have a 600mm sigma and a 500mm tokina and find them useful for bird pics. They have their limitations, but they are inexpensive.

See pics here if interested: Dons Creation

[Lowell Goudge]

But due to its design, the 18-250 doesn't have reach like a true 250mm lens. I did some comparisons with the 55-300mm vs the 18-250 and found that at 30 feet distance and 250 mm the 18-250 had the same FOV as the 55-300 set for 200 mm. At about a mile, the 18-250 looked like 230 mm.

there is an interesting article somewhere about this.

it is true of virtually all zooms but more so of super xooms. due to the internal focusing (almost a requirement for AF) the lens designs are such that focusing changes the focal length also and that true focal length is only at infinity. .

I looked at several lens reports and no one reports on the effective focal length as a function of distance. There must be a test somewhere yor all the measurebaters out there to report on this