[Rondec]

Some lenses are better than others at auto focus. To me, the DA 55-300 is my slowest auto focus lens, a lot slower even than my DA * 50-135, which is pretty slow. Not only is it slow, but it often struggles to grab focus at all and cycles back and forth. I just think it is a lens issue and not a camera issue. What I generally do is manually focus to close to where I think it should be and then let the camera tweak the fine focus from there. That seems to work better...

[UnknownVT]

Some lenses are better than others at auto focus. To me, the DA 55-300 is my slowest auto focus lens, a lot slower even than my DA * 50-135, which is pretty slow. Not only is it slow, but it often struggles to grab focus at all and cycles back and forth. I just think it is a lens issue and not a camera issue. What I generally do is manually focus to close to where I think it should be and then let the camera tweak the fine focus from there. That seems to work better...

That's a very good point.

Some lenses are slower and seem to have more difficulties.

BUT normally not in good bright light - such as the ones described -
most of the difficulties occur in low to moderate light -
when the camera's focusing sensitivity become more of an issue -
and this is Pentax's weaker point -
however this is not normally an issue in good light -
if anything, Pentax is stronger than most of its competitors -
everything else being equal.

When a lens hunts in good light - it does mean it cannot find anything to focus on - which normally means there probably isn't anything of enough contrast to focus on - in lower light it is the same thing - but what may seem good enough contrast to our eyes, may not be so in lower light.

But focusing the lens on a distance close to the desired, and letting the camera/lens do the final fine focusing is a very good technique that mostly will mitigate any tendency to hunt.

Good post, thank you.

[yoshizuki]

I'd prefer a nikon...
But my DA40 focuses really fast.

[planedriver]

I'd prefer a nikon...

which Nikon?

[rawr]

Some bad AF reports may be related to photographers keeping UV 1 and UV 0 or similar 'protection' filters on their lenses day and night.

Not only do the worst of these knock 5-10% off the light gathering ability of a lens, thereby dimming the view for AF to work with, but their optical properties (including the elements of spectrum they filter and things like the image softening and removal of contrast they may cause) may also sometimes make the AF less effective.

Pic related. This makes it easy to imagine how a bad UV filter might play havoc with AF:

From the LensTip.com UV filters review.

[FullertonImages]

Oh yeah, and I forgot to mention something that another post about kit size reminded me of. If you look are our lenses, we have almost an identical setup, when you consider the FF equivelent of my setup. Fo course he has the roughly 1 stop DOF advantage of FF, but aside from that, same equivelent FOV's and same apertures. But my kit was less than half the size of his, and waaay less than half the weight. I was ableto carry everything I listed, but another body and 10-17 fisheye, all in my LowePro Computrekker AW backpack, and it wasn't that bad to carry. He could only fit one body, 24-70, 70-200 and either the 300 or 500 in his backpack that was slightly bigger than mine. So I was able to carry 2 more bodies and 3 more lenses than him for still slightly less size and weight. That being said, do I want a 1d and 300/2.8? Yes, I would love one...

One more thing that this assignment pointed out about why I love Pentax so much. While shooting the first day of Whitewater kayaking, I was getting my K-7 and DA* 16-50 inches off the water, and at times less than two feet from the paddlers, to get some pretty interesting angles. Needles to say, tha camera was geting all sorts of wet, ranging from the constant mist of the frothy whitewater, to the frequent wave crashing against the rock I was laying on that would send droplets all over the body, lens and front element, to the occasional splash from a kayakers paddle that would douse the camera. You can see what I mean in these two photos.




But at no time was I worried, nor did I ever have any problems, aside from havingto wipe of the front element from time to time when it got too covered in water drops to take any decent photos. But after the event was over I was talking to some other photographers, and end up talking to a Nikon shooter who was having problems with his D3. Now a D3 is an awesome camera, and should theoretically put a K-7 to bed early without it's dinner, except in his words, his D3 "got mildly splashed one time, and then stopped working". Advantage... Pentax.

[rparmar]

Fun shoot!

[Blue]

I guess the news service should consider handing out Pentax to cover the water sports for the next Olympics and that way they may actually get complete coverage of the events instead of the putz reporters that were hanging around in Atlanta to find out what happened on the Ocoee and Hiwassee Rivers rather than shooting ON the rivers for the kayaking events etc. The can pass out the Canon gear for the soccer matches and gymnastics.

[chefpete1]

And whatever you do...DON'T even THINK about the T2i. 18 BIG MP of soft-focus gobbledegook in an attractive and exhorbitantly overpriced package. I was talked into one! After three weeks I am back. All the reviews and PR I read on this piece of user-enemy plastic and I thought "it must be ME." Thankfully it wasn't and the camera is on eBay NOW. Closes tomorrow 1/2. The Kx takes much sharper pictures across the board. Can anyone explain this to me?

[normhead]

If the next Pentax body doesn't significantly improve AF, I'm getting a Canon.
That doesn't mean I'll drop Pentax, but I'll choose the horse for the course.

Cute, how old are you?

[kxr4trids]

And whatever you do...DON'T even THINK about the T2i. 18 BIG MP of soft-focus gobbledegook in an attractive and exhorbitantly overpriced package. I was talked into one! After three weeks I am back. All the reviews and PR I read on this piece of user-enemy plastic and I thought "it must be ME." Thankfully it wasn't and the camera is on eBay NOW. Closes tomorrow 1/2. The Kx takes much sharper pictures across the board. Can anyone explain this to me?

From the images I have looked at, the two cameras are comparable in terms of image resolution and detail. However, since the image from the canon is 25% larger, it appears less sharp than the k-x when viewed side by side at 100%. That difference would disappear on any print. It's like like comparing a powerful v6 with a weak v8 in two cars that have identical 0-60 times. It's not that the v6 is better as much as it is a surprise that the v8 isn't.

Other than that, the k-x kit lens is supposed to be superior to the canon lens, so unless you were trying out other glass, I'm not sure the comparison was valid.

[GrinMode]

First of all thank you all for the positive comments about my pictures! I don't think it makes sense to go into any arguement about how fast a specific bird is but I have to tell you that seagulls are very agile and fly low and they are very difficult to track. So the only reason I'm telling you this is simple-my keeper rate is very low too!!! But until I get even ONE good one I don't care! (this is digital photography and we are talking about entry level body and kit lens or semi kit lens in the case of the 55-300) so I don't think a d700 and a pro lens would make me happier in the long run because if my keeper rate increases significantly I think I would lose interest in bird photography quickly. So the fun factor would go away. Now this is a challenge which can result in pleasent results-which requires skill and technique and some effort and luck of course..a good receipt for a rewarding hobby.

This just makes me wonder about those who do fishing for a hobby. I mean could they not just drop a stick of dynamite over and get a lot of keepers faster?

Sorry if my analogy is a bit 'overboard', but maybe for some, the means is as thrilling as the end .

[Ken T]

That doesn't mean I'll drop Pentax, but I'll choose the horse for the course.

Having young children, the horse will often be the Canon for the forseeable future tho...

Gosh, I don't want to be a sheep...

Hmm.

Hmph.

This is from 55 -300 & K-20D (not K7 or K5)

[chefpete1]

I think it's just motion blur. He's probably moving a lot slower, plus is farther away, so the motion isn't as exagerated.

Ditto that comment, PLUS the focal point seems incorrect with the signage and people in background looking as tight or tighter than the foreground. Depth of field just isn't that great at 5.6...he must be focused BEHIND the action.
Add to that, iso3200 on most Canons I've seen...including my T2i...look like they were done by MONET

[jlaubza]

Insults aside, Pentx focusing systems have lagged behind the Canikon competition, until recently. I have a K-X, which is chalk and cheese better than the K10d and the K5 is reported to be on a par, at last, with the competitors - it uses a colour based focusing system a la Nikon.

On the K10d, I have started to rely on manual focusing when I am not in a hurry as I get consistently sharp shots. But if we focus on the latest crop of Pentaxs', the focusing systems are 'up to speed'.