[Rondec]

It is no big deal to switch brands if one offers something that what your are shooting now doesn't offer. As Falk and others have said, you need to evaluate what you want and what you are willing to spend. A 300mm f4 will probably be about your cheapest option in any system (maybe with a TC), but even these lenses aren't cheap. The Sigma 50-500/150-500 lenses give a little more range, but your aperture will be slower (although Kengoh does a lot of bird photography with one of these -- but not much bird in flight). https://www.pentaxforums.com/forums/post-your-photos/224520-nature-my-1st-k5i...ing-shots.html

[Class A]

I am considering it now, rather than later when I will have more Pentax lenses and therefore higher cost of switching.

Good thinking.

The D7100 will definitely will give you better continuous AF, but a K-5 II, for instance, should be fine with birds that don't come directly at you.

The Sigma 100-300/4 is indeed a fantastic lens. I just got a copy. It is not easy to find in Pentax mount, but sometimes a copy becomes available. There is one in the marketplace for $1250 right now.

Things I don't like about the D7100:

• No in-body image stabilisation.
• ISO button is in the wrong place.
• No user pixelmapping.
• Build quality not as high as the K-5 (II).
• Gets better scores from DPReview than the K-5 II even though the latter beats it in many disciplines.

P.S.: Scoot over to the Kiwi Pentaxians thread sometime.

[RonHendriks1966]

I switched to Nikon for wildlife and birds (Nikon D7100 and Nikon 500mm f/4 vr). I'm sticking with Pentax for medium and wide. The D7100 is superior to the K-5 for continuous/predictive autofocus, and the extra pixels allow for more aggressive cropping. So, more keepers on birds in flight. I expect Pentax will achieve parity on these features whenever it releases the successor to the K-5, but that leaves Pentax still way behind on long glass. Nikon has the 80-400mm 4.5/5.6, the 300mm 2.8, the 400mm 2.8, the 200-400mm f/4, the 500mm f/4, the 600mm f/4, and the 800 mm f/5.6. Each is optically superb and the in-lens stablization is superior at these longer lengths to the Pentax in body IS. Nikon also offers excellent TCs that mate well to all of these lenses except the 80-400. Against this Pentax offers a 300mm f/4, the 560 5.6 (not a great lens) and no TCs. Pentax isn't really in the game for long exotic glass. That's a shame because I would much rather hold and operate a Pentax camera than a Nikon. But switching to Nikon makes perfect sense to me given the type of photography you do.

Russ

Well the combo with 500mm/f4 is a perfect match I think, but a pricey one.


I haven't seen a good test on the Pentax 560mm to conclude that the lens isn't good. Up til now I Always think the one doing the test isn't good enough.

[reeftool]

One of my daughters shoots with a Nikon D200 and I can vouch for Nikons AF being pretty good. I've shot with it numerous times. I'm sure the new D7100 has some pretty good AF specs also. She has all Nikon glass and her results are pretty impressive. That Nikon glass does not come cheap however. I'm curious about Sigma AF performance on Nikons and how it compares to the Pentax version of the same lens on a current Pentax body. We all know that each lens is different. My own experience has been that the Sigma's I have used tend to hunt a lot, much more than my Pentax glass. It's adequate for my needs but for birds in flight, I do better with manual focus and f/11. I think the OP's time researching some reviews of whatever third party lenses he want to buy from Nikon sources would be well spent.

[Mallee Boy]

I am a little frustrated with Pentax at the moment in so far as they are not giving us a lot of info on the top end of their range and any planned upgrades or new products.

So much so that I am seriously considering a D600 or D800. Has anyone any experience with using adapters to put DA or FA lenses on the full frame Nikons.....what functions are lost for example ?

I am not looking forward to doing this, particularly given the learning curve involved (had to recently help someone with their new Nikon 5100 and found the menu system puzzling in the extreme...no doubt one will get used to it) and the cost of their lenses doesn't exactly thrill me either.

Look forward to the feed back.

Cheers
Grant

[bossa]

Placing adapters on K-Mount lenses for Nikon is a step down due to the need for an optical element in the adapter. You can get ones without the glass but they are more close-up lenses after that.

Re' the OP's idea for a Sigma 50-500 on a D7100: My thoughts here are that the lens will get nowhere near the sensor capabilities and whilst you may get a sensor full of image the effective resolution won't be anywhere near 16MP let alone 24MP. My advice would be to buy a DA*300 F4 for now and wait for Pentax' Teleconverter due out this year. I did use a Tamron TC1.4x on my FA*300 and that was fine but I sold all of that and bought a D800E and the Nikon AF-S 300/4 - whilst it's a nice lens I feel it doesn't handle flare as well as a DA*300, is possibly slower focusing and is substantially heavier. I find myself doing a lot of cropping to get in close and so I feel it would have been a better idea to have bought the DA*300 (stabilized via the body) or the Sigma 500 F4.5 for my K-5 than the Nikon lens.

PS: Actually, I would have been better off sticking with my FA*300 and my Tamron TC on my K-5.

[Mallee Boy]

Thanks for that Bossa.
I can see from your sig that you have dropped some serious cash on your Nikon set up.....are you getting a result for the investment?
Believe me when I say the lure of a DA* 300 is very attractive when compared to a Nikon outlay....so I guess I am saying I would be easily convinced to stay with Pentax.

[falconeye]

a D800E and the Nikon AF-S 300/4 - whilst it's a nice lens I feel it doesn't handle flare as well as a DA*300, is possibly slower focusing and is substantially heavier.
...
PS: Actually, I would have been better off sticking with my FA*300 and my Tamron TC on my K-5.

you have dropped some serious cash on your Nikon set up.....are you getting a result for the investment?

I am not as heavily invested as bossa (he seems to have two D800E ), but I do have e.g., a D800E and 70-200/2.8G VRII.

I do agree with bossa that 300mm currently is a weak spot in the Nikon lineup (old lens, no VR, not as sharp as the newer ones). I also have K-5 + FA300/4.5 + TC and like the combo.

OTOH, my 70-200 gave me some brilliant 200mm results which I wasn't able to fetch with my K-5 so far (certainly my fault though). Partly due to its fast and accurate focus and good tracking abilities. Nevertheless, the K-5 + 60-250/4 is close and a more agile setup.

If think the new 80-400 Nikon lens does make a difference for anybody needing full resolution at 400mm. Expensive, but not as expensive as the faster alternatives.

The real difference my D800E makes for me though is that I stopped to care about gear (oh yeah ). I say to myself, if this camera can't do it then it must be the photographer. I know, I know, we always tell so, but never to ourself

[Mallee Boy]

Thankyou falconeye......very helpful.
Cheers.

[bossa]

Thanks for that Bossa.
I can see from your sig that you have dropped some serious cash on your Nikon set up.....are you getting a result for the investment?
Believe me when I say the lure of a DA* 300 is very attractive when compared to a Nikon outlay....so I guess I am saying I would be easily convinced to stay with Pentax.

It depends on your use of course but if you're going to crop heavily (birds etc) then you may as well just stick with the K-5 and buy a DA*300. The fact that it's WR and stabilized is an advantage for one thing and it IS much lighter than the non-stabilized AF-S 300/4. And the shutter won't scare the birds away like Nikons do.

I wish I had not sold my DA*60-250 (FF= 90-375) as that was my main Pentax lens in the end. The 'equivalent" (not really but yes) Nikon lens would be the Nikkor 200-400 F4 and that lens costs 9 grand in OZ. That lens has appalling OOF highlights the likes of which I only ever saw when holding a scratched pair of spectacles up to the moon.

I wish Pentax would release a 24MP APS-C camera so I can sell my AF-S 300 and buy a DA*300. I am still toying around with the idea of another 60-250 but I'd have to sell a few things to justify that.

As far as getting my money's worth: I have back issues these days and don't really get around all that well with the heavy Nikon gear so I'm not sure if I really have or not.

PS: Re' the DA*60-250 = 90-375 on FF. The new Nikkor 80-400 VR F4.5-5.6 costs 3 grand in OZ so maybe a few Pentaxians should consider that when whining about lens prices.

[Class A]

PS: Re' the DA*60-250 = 90-375 on FF. The new Nikkor 80-400 VR F4.5-5.6 costs 3 grand in OZ so maybe a few Pentaxians should consider that when whining about lens prices.

One can typically point to something that is even worse.

Consider this comparison:
Sigma 18-35/1.8, fastest zoom in the world, 17 elements in 12 groups, 5 of which are special low dispersion elements and four of which are glassmold aspherical lenses. Reliable HSM. Price: $799.

Pentax 70/2.4, 6 elements in 5 groups, no special elements. Screw drive. Price: $696.95.

The Pentax lens is much cheaper to build and almost a stop slower, yet costs almost as much as the superb Sigma.
Something isn't right here.

[interested_observer]

PS: Re' the DA*60-250 = 90-375 on FF. The new Nikkor 80-400 VR F4.5-5.6 costs 3 grand in OZ so maybe a few Pentaxians should consider that when whining about lens prices.

Morning Bossa. On the focal length crop conversion, would not crop factor from ASP-C to FF be a reduction, so that the DA*60-250 would actually be a 40-166mm for a FF angle of view equivalent?

Also a 300mm on an ASP-C would be a 200mm FF angle of view equivalent, so for a FF equivalent you would need to bump up to around a 500mm lens.

So, on the telephoto end of things, an ASP-C provides a bit more reach at a somewhat reduced cost due to the necking down provided by the angle of view cropping.

[bossa]

Morning Bossa. On the focal length crop conversion, would not crop factor from ASP-C to FF be a reduction, so that the DA*60-250 would actually be a 40-166mm for a FF angle of view equivalent?

Also a 300mm on an ASP-C would be a 200mm FF angle of view equivalent, so for a FF equivalent you would need to bump up to around a 500mm lens.

So, on the telephoto end of things, an ASP-C provides a bit more reach at a somewhat reduced cost due to the necking down provided by the angle of view cropping.

APS-C to FF is a 1.5x magnification of the APS-C focal length so the 60-250 is a 90-375 on FF but the Pentax Australia website lists it as 92-383 I believe.

[falconeye]

Re' the DA*60-250 = 90-375 on FF. The new Nikkor 80-400 VR F4.5-5.6 costs 3 grand in OZ so maybe a few Pentaxians should consider that when whining about lens prices.

I like that comparison as it is relatively fair.

The APSC DA* 60-250/4 is a unique offer in the Pentax world and delivers very sharp images (I actually have the impression that it is sharper at 250mm than the DA* 300 at 300mm, at least with a body making full use of lens resolution).

The 4x 60-250/4 is 35mm-equivalent to 90-380/6 (numbers rounded).

The 5x Nikkor 80-400/4.5-5.6 is therefore roughly equivalent (*). It is a unique offer in the Nikon world as it is very sharp too, probably on par with the 60-250 when expressed in lp/mm.

Both lenses are similiar and the Nikkor shouldn't be twice as expensive. I agree. But OTOH, the Nikkor can probably deliver twice the MP resolution or in other words, has more cropping potential, assuming a high MP sensor.

So in summary, I would say that both lenses are a unique proposition and a gem in their respective systems.

__
(*) 400/5.6=71.4; 250/4=62.5; tele lens prices can depend heavily on lens diameter, like ^3.26 (source: my blog); the price factor then is 1.5. So, half of the Nikkor's higher price may in fact be due to both lenses not being exactly equivalent. But F5.6 is a requirement for the Nikkor to be usable as a 560/8 AF lens with TC.

[interested_observer]

APS-C to FF is a 1.5x magnification of the APS-C focal length so the 60-250 is a 90-375 on FF but the Pentax Australia website lists it as 92-383 I believe.

Morning Bossa and Falk,

Perhaps my thinking is flawed, backwards and all wet (it would not be the first time according to my wife). In comparing APS-C to FF, the APS-C with the smaller sensor, on the telephoto end of the spectrum has the smaller angle of view, when discussing a single specific focal length. In the nominal conversation, the 1.5 crop factor came into being when folks who were use to using a FF film body, wound up using a cropped APS-C digital sensor. "Suddenly", their FF film lenses had a "new" angle of view, that was 1.5x of the focal length they exhibited on film. A film photographer using their 100mm film lens on their "new" APS-C digital sensor, saw their lens exhibit an angle of view of a 150mm lens, courtesy of the smaller sensor's crop factor (1.5 * focal length = cropped apparent focal length).

Now we find ourselves here in Pentaxland, with the possibility / potential of a full frame digital sensor out on the horizon. With Canon, Nikon and Sony already having theirs on the market, Pentax shooters have either migrated or are using dual system to shoot both APS-C and FF bodies. With this in mind, folks who have been shooting with the APS-C cropped sensor focal length of say 100mm, in order to maintain the same angle of view, should see the reverse. If I mount a 100mm on my APS-C body, what focal length would I need to mount on my FF body to maintain the equivalent angle of view. I would think that it would be 100mm / 1.5 = ~66mm (rounded).

Using that approach, if I am use to using my trusty DA 60-250/f4 on my K5, and I go out and acquire a brand spanking new Nikon D800, and I want to maintain a similar focal length range (read angle of view) for it, what do I look for. Again, 60/1.5 = 40mm and 250/1.5=166mm (rounded). Stepping back and trying to look at this objectively, I am going from a smaller sensor (APS-C) to a larger FF sensor. Essentially I am loosing the "cropped" angle of view extension (factor), that the APS-C sensor afforded me. Bottom line, the FF sensor is going to be shooting "shorter" than the same lens on the APS-C sensor.

That is my thought process....

Bottom line is that I think that Pentax Australia's website is incorrect. They are just adding another 1.5x crop factor on to the APS-C, when in fact they should be dividing it out. Hence, moving from FF to APS-C multiply by 1.5 then moving from APS-C to FF divide by 1.5.

Then again, I am here in Arizona and today its going to be 110 out in Tumbleweed country.