Hi there - Mike bought the Opteka 85/1.4 from me. I agree with you about the hood and front cap - but at least the Hama cap on it now (with centre pinch) can be used when the hood is fitted. The original one supplied by Opteka was even more basic!

The lens is very sharp from wide open, and was great all the way to f8 which is as closed as I bothered to go. I never had any metering problems: it seemed to work fine on the K-7, but that body seems to meter better with older and legacy lenses than some of my earlier Pentaxes.

Hope this helps,

Jon

Just been out taking pics of the moon myself, but I don't think any of mine will be as good as the ones you've just posted! From your intro, I assume you were shooting through some kind of telescope?

I think the 28-80 is supposed to be quite a good lens. Don't know about the 28mm f2.8. I assume the zoom is an Adaptall 2 lens? If you are interested in a mount, let me know as I have one more PKA than I need.

Cheers,

Jon

Must admit that I think the biggest hole in the Pentax lens line-up is a longer telezoom and if Pentax had sufficient market share, I reckon something like a 135-400 f4 DA* would be a good addition to the line-up. But I don't think they could currently justify the development of such a lens.

Therefore, I think the option you have suggested of reworking a decent starting point from Tokina, producing a compact and WR lens with some tweaks (aimed at improving the performance at 400mm) would appear to be a more sensible proposition.

Even then, I think this will only be a reality if Pentax market share increases - and actually I believe that is achievable - not at the expense of Canon or Nikon, but more likely through attracting current Sony and (especially) Olympus users.

The 4/3 dSLR system seems to have stalled recently, and I think Olympus will need soon to demonstrate some commitment to its future beyond the consumer end of the market. The E30 and (especially) E3 are looking somewhat tired now. I don't get the sense that Sony are doing particularly well in the dSLR arena either, despite the plethora of almost identical models they have launched.

Hi Simon,

Thanks - and yes, I've been looking for one of these on and off for over a year now, and was surprised when it came up on EBay!

I thought you/others might be interested in some further thoughts on comparison with the 55-300 after some obsessive pixel peeping this evening! I haven't posted all the shots here as frankly it's pretty dull stuff, but suffice to say that I used a tripod, SR off, remote control to trip the shutter, to try and keep the comparisons as fair as possible.

First thing is that colours between the two lenses are actually remarkably close. Tokina seems to have a similar and slightly warmer response that I am used to from Pentax lenses, rather than the cooler tones of some Sigmas and Tamrons that I've used. The Pentax looks marginally more contrasty.

Second is that the 55-300 undoubtedly does better at dealing with fringing and aberrations, as I mentioned above, although the Tokina is not awful in this regard.

My thoughts on sharpness at different focal lengths:

80mm

Centre - the Pentax lens is sharper wide open, and the Tokina does not catch up until around f8.

Borders - the Tokina is better around the borders - signficantly so - even at the widest aperture.

135mm

Centre - again the Pentax is better wide open in the centre, but the Tokina matches it by around f6.3, and if anything is marginally sharper if you stop down further although barely noticeable.

Borders - the story is similar to above - the Tokina performs better at every aperture.

200mm

Centre - the tables begin to turn. The Tokina is faster than the Pentax at this point, and the Tokina shot at f4.5 is as sharp as the Pentax at f5.6. There is very little difference in sharpness between the two from f8 onwards, although the Tokina may just about have the edge as you stop down further. These differences are barely worth talking about.

Borders - again, the Tokina holds things together better around the edges.

300mm

Centre - the Tokina outperforms my copy of the Pentax at every aperture, although the difference is small. Neither of them are especially good wide open.

Borders - no surprise here - the Tokina performs better. At the longest lengths, the Pentax controls fringing notably better than the Tokina, and in the shots I was comparing this was particularly notable around the borders (but the Tokina fringes everywhere).

Finally, from comparing the Tokina at 300mm and at 400mm, it would seem to me that below f8, you'd be better sticking to 300mm and cropping. Only beyond f8 does there appear to be an advantage in going to full telephoto. As mentioned in my post above, now I need to see where the image quality begins to drop - I've read elsewhere that you can get to around 360/380mm and get better results than 400 - so that's a job for next weekend!

Hope this lot was interesting to someone other than me!

Jon

As per another recent thread, I've recently bought a Tokina ATXii 80-400 lens, which I've had fun trying out during dog-walks with Harry my patient assistant over the last day or so!

First of all the musings:

Build quality is excellent. Decent metal construction and feels like it is going to last. Only the zoom lock feels a bit insubstantial but not a huge issue.

Despite the tank-like build, it's also remarkably compact and reasonably light given the range it covers. I've never been tempted by Bigmas and the like because they're so big I'd never use them. I'm sure they would outperform the Tokina, but of no interest to me if they are left behind at home.

Image quality is better than I expected it to be. This might sound like damning the lens with faint praise, but it's difficult to track down a proper professional review of the thing, and I was working on the assumption that as it's a relatively old design, and compact as noted above, then it must mean compromise.

I spent some time this afternoon comparing it with the Pentax 55-300, which to be honest I had assumed would outperform the Tokina without too much trouble. I think I may have to eat my words.

The Pentax definitely handles lens aberrations and fringing better (although the Tokina is no Tamron 70-300 purple monster). The Pentax also has nice extras like quick shift focus, and a lens hood that enables use of polarisers etc while still fitted.

However, if you compare the images side by side, there's precious little to choose between them. I doubt you could spot the difference at most focal lengths and apertures unless you were pixel-peeping. And the big surprise for me was that where there is a difference, I think it's in favour of the Tokina: especially at 300mm.

Both lenses benefit significantly by stopping down a bit especially at longer lengths.

One other thing that I've noticed is that image quality at 400mm deteriorates markedly - to the point where I think it may even be better to take a shot at 300m and then crop accordingly! So the next phase of compulsive testing will be to see if I can identify the point beyond which it is not worth zooming.

In the meantime, the link below will take you to a few early images for those who are interested:

link

Jon

Thanks for posting those links Richard- looks like you had a good day in Yeovilton!

Have spent a few dog walks over the weekend taking the Tokina with me, and am impressed with its portability given the range it covers. It's about as bulky a lens as I'm prepared to use. Early reflections are:

IQ is pretty good (I've mainly been using it at the long end where it will not be at its best) but I suspect may not quite rival the Pentax 55-300 (will compare them later to see). However the latter has a shorter range and is a little slower too.

Things seem a little soft at 400mm/f5.6 but what can you expect? Slightly more irritating are chromatic aberrations at the longer end - some green and purple. Not hard to process out and nowhere near as bad as I experienced with Tamron 70-300, but not as good as the 55-300.

Focussing may be marginally faster than the 55-300 but you miss out on quick shift, which is quite handy with long slow lenses....

F5.6 at 400mm quickly heads you towards high ISOs even with shake reduction. I agree that a lens that went to 400mm at f4 would be fantastic, but I think I'll be taking pictures of flying pigs before that happens!

All in all, my views so far are that this lens is a keeper because I don't tend to use telephoto all that often but, when I do, 300mm isn't always enough. My other option is my Tamron 500mm SP, which is great when you use it properly, but not much use for moving objects. It's fun on a nice day but not always practical - sort of the "Morgan" of my lens collection.

Will post a few more samples later.

Cheers,

Jon

Or wa it the other way round?

No - definitely a Tamron rebadged as a Pentax. And also rebadged for Sony, whose version is supposed to be the best of the three.

Sigma make an 18-250 in PK mount, if buying new is essential.

Can you get a secondhand Tamron/Pentax from a reputable dealer who will still offer a guarantee? That's how I got mine (Tamron version) and it's worked out fine. If possible aim to get a boxed one (implies the owner is helpfully compulsive if you are in the lens-buying game). To be honest, some people trade lenses and cameras so frequently, that it is quite easy to pick up excellent stuff secondhand - and these lenses are far too new for anything to have gone wrong unless they have been badly handled.

Sent you a PM!