[bkpix]

Thanks for the info and insight. The DA 300 and tc might get me in the territory of my 400 lens, but analysis has shown that the Canon 300 f/4 IS and 1.4X tc doesn't quite touch it.

Do note that Pentax doesn't currently have a 1.4x AF converter in their lineup.

[str8talk83]

Do note that Pentax doesn't currently have a 1.4x AF converter in their lineup.

What tc's do they use?

Are they hard to find?

[bkpix]

People use a variety of off-brand TCs or look for the old Pentax 1.7 converter. I am not familiar with any of them.

In your position I'd probably look for a long lens from Sigma.

Or stick with Canon.

[str8talk83]

People use a variety of off-brand TCs or look for the old Pentax 1.7 converter. I am not familiar with any of them.

In your position I'd probably look for a long lens from Sigma.

Or stick with Canon.

That's where I'm leaning at this point too. The 50-500 seems to be slightly better than the 120-400/150-500, but quite a bit more expensive...

It's a tough call for sure. I think that no matter what I'd miss my 400.

[atomiccow]

The problem of off brand teleconverters and Pentax old teleconverter is they'll break the weather sealing on your system. Canon has WR teleconverters but Pentax hasn't released any replacements for its old era teleconverters. The DA * 300 is the furthest you'll get with a full WR system.

I don't see why you doubt the WR on your L lenses. They're made to be paired with Canon's highest end cameras which have much better WR. Clearly they're designed not to be the weak link.

[str8talk83]

The problem of off brand teleconverters and Pentax old teleconverter is they'll break the weather sealing on your system. Canon has WR teleconverters but Pentax hasn't released any replacements for its old era teleconverters. The DA * 300 is the furthest you'll get with a full WR system.

I don't see why you doubt the WR on your L lenses. They're made to be paired with Canon's highest end cameras which have much better WR. Clearly they're designed not to be the weak link.

believe it or not, the 400 is not technically a weather sealed lens. It doesn't have the rubber gasket at the mount and the switches do not have sealing like the weather sealed L's do. This is a misconception because almost all of the newer L's have weather sealing, but many of the older models do not, such as the 28-300L, 100-400L 300 f4L and 400 f5.6L. The 400L was actually designed in 1993.

That being said, I don't worry about it too much in general, but wouldn't shoot with it in heavy rain without some kind of cover. I have a lot more concern for my 40D in bad weather to be honest. I've shot it in rain before and even out of a canoe (I know I'm brave...) but it was always a risk.

[inferno10]

It doesn't look like anyone mentioned this, but that Sigma 150-500 isn't a weather-sealed lens. I just wanted to mention that because weather-sealing was one of your concerns in switching. But you probably already know that.

Tokina used to make the AT-X 400mm f/5.6 SD for the Pentax mount. I used to own one for photographing surfers in action, and it did an okay job - not the best, but workable (see photos here: Flickr: Search inferno10's photostream). It's a pretty rare lens to find now (the manual version of this lens is easier to find, though), but it's another option for you. Oh, and it's also a non-weather-sealed lens.

- Jason

[johnmflores]

Fwiw have you considered Olympus, maybe an older E-3 or new E-5 plus some sweet Zuukio zooms?

[robjmitchell]

Its a tough one, Have you considered split systems, swap one of your 40d's for K20+ lenses of choice?

[Boris]

Str8talk83, I'd like to recommend you this link. Likely some useful practical information will be found there.

I would suggest to proceed with caution as it may so happen the whatever Pentax has to offer, including their newest cameras and lenses, it may still be insufficient for your specific style/kind of shooting. It is not difficult to match any of your lenses except 400/5.6. As well you might want to keep one Canon body and that specific lens as your secondary kit and use Pentax for everything else.

Also Pentax has very interesting proposition of DA* 60-250/4 that sans the potential SDM issues seems like an interesting idea.

[rod_grant]

What ever you decide, don't do it in haste. Most decisions made in haste are regretted.
If you are determined to jump into the Pentax world, first assess what your current lit is worth on the market. Then assess what a suitable Pentax kit will cost. Check asking prices on the forum's marketplace and final prices paid on ebay etc.
Whatever you do, never look back - you can waste a lifetime living in regret.

[paperbag846]

I love my K20d, but I think you would miss the Canon with long-range performance (lost prime, AF speeds) for things like nature and sports photography.

I would wait, and see how affordable the K7 is in the near future after the K5 is released.

I am considering a switch from Canon to the Pentax system. I was originally going to go with Pentax but got impatient and bought some camera gear with a BB credit card deal with no financing and then payed it off with an army bonus I got later...long story short, I ended up going with Canon because they had it in the store.

My current kit is in my sig (plus a lot of accessory gear not mentioned...)

I would be going from:
40D (2)
Canon 17-55 IS
Sigma 70-200 f/2.8
Canon 400mm f/5.6L
Canon 50mm f/1.8

to
Pentax K20D (2)
DA 16-50 f/2.8
DA 50-135 f/2.8
Sigma 150-500 os (?)

My main reason for considering the switch, is weather sealing and portability. Being a wildlife and nature photographer, I often hike with my gear as well as a popup blind. I like the idea of the lighter weight lenses and bodies as well as the reasonably priced weather sealed optics. One of the most frustrating aspects of my camera is the lack of "real" sealing. Simply put, I can't trust it in bad weather. This goes for all my lenses as well.

My main concern is with autofocus and having to give up my 400 prime. From what I have heard on here, the autofocus is pretty bad on all of the Pentax bodies with the k-7 being only decent. It seems like none of them are on par with what my 40D is giving me, which is a bit disappointing because it's not even considered that great in the Canon camp. As far as the 400 is concerned, it's just a stellar lens in IQ and autofocus and I feel like I will really miss it if I go with one of the Sigma supertelephotos. I really wish Pentax had a sealed 400mm f/5.6 lens. Are there any long range pentax options even?

[bymy141]

There are 2 issues with your list I would say:

- The K20D is a *slow* AF performer and lacks AF in low light.
- The F 400 lens is much sharper, but less versatile, than the Sigma 150-500mm.

I have a K10D (same AF as the K20D) and a K-7, the K-7 AF runs circles around the K10D.
Cotineous AF of the K-7 is still not very good. The K-5 however is another class, see:

You Tube

You Tube

I've been shooting a lot of daylight, evening and night photo's in Zambia, with my K-7 and a DA*60-250mm (+1.7 TC) next to a German guy with a Canon 50D + Canon 28-300mm lens.
My K-7 worked better in low light, many more keepers, more pictures in focus, as good as the Canon in daylight, worse than the Canon in "bird in flight" situations.
I'm not in the position to compare Canon in the "wind full of dust" or "pooring rain" situations, because the Canon's stayed in their bags!

The 60-250mm x 1.7 = 102-425mm works very well, it is much, much sharper than my Tamron 18-250mm on 250mm.
If you have a look of Tcom's pictures taken with the DA*300mm with the 1.7TC, then you'll see that the results are much better than acceptable.
Much sharper (IMHO) than the pictures I've seen from the Sigma [50,120,170]-500mm lenses.

- Bert

Perhaps you should do some pixel peeping on images available on the Internet before deciding.

[Miguel]

I added a Canon 7D to my Pentax toolset about two months ago. It was specifically for shooting sports (in a corporate PR role and for personal ends) and birds (for personal use).

Many reasons: Canon offered a higher frame rate, the predicative AF was unmatched by Pentax totally, the lens choices with a Canon (or Nikon) system was significantly larger, and the support from the rest of the world was readily available.

It took me about 30 minutes of initial use to see significant improvements in shooting results in sports; about ten minutes for birds. While I'm usually in the "it's the photographer's skill that matters" camp, for birds and sports hardware does matter quite a lot.

While I'm sure that the new K-5 has great hardware performance upgrades, the long lens infrastructure is very thin. Sigma is the only maker that offers any current lenses >300mm, and the quality of many of the zooms I don't think matches Canon or Nikon.

While there are some excellent older Pentax long lenses (the 250-600 comes to mind), most of them are ancient in AF design and exponentially behind USM quiet and speed.

I've used other cropped Canon DSLRs and the 7D is so much better. The ergonomics are very good and in several ways approach Pentax quality. I'd say the viewfinder is superior to a Pentax K-7.

The smaller size of the Pentax body and the excellent DA Limited and DA* lenses are outstanding for hiking, landscapes, street shots, and typical product shots. I'm still using my Pentax tools for that.

Do realize that the Canon lens lineup is really oriented towards their 135-sized bodies. Most of the EF-S (cropped sensor) lenses are average at best. I prefer the 7D because of the perceived larger image with telephotos especially. The perfect world have Canon issue a 5DMKIII with the ability to switch between APS-C and 135 framing like Nikon does with the D3.

Hope this helps.

M

[rfortson]

Sounds like you'd want a K7. The price should drop once the K5 comes out. I have the K20D, which is larger than the K7/K5. I have problems with AF on my K20D with the 16-50, but I put that on the lens. On every other lens, my AF is better than my K10D. K7 is supposed to be better, and the video I've seen demonstrating AF on the K5 looks better still.

Pentax has a good line up through 300mm, but after that, you're going third party or used. Someone else mentioned Olympus, which has a nice weather-sealed body and great zooms, but the 4/3 sensor will be a step down from what you're used to. I have the Olympus E-P1 and while the IQ is very nice, I can tell a difference once the conditions get a little challenging (low light, high contrast, etc). Not bad by any means, but noticeable.

The Sigma telephotos are supposed to be nice, but not sure they equal your Canon 400. I have the Sigma 50-500 (the "Bigma") and it's a very handy lens, but it's not fast.

Perhaps you can sell off everything except your 40d and the 400, and buy a K7 and all the other nice primes that Pentax has. That might make the most sense for a dual system.