[donyjunk]

lovely bird pic luftfluss - is that w/ your tammy 70-300? funny i hadn't thought about turning off sr. is the pentax SR gyro based? i was thinking of SR being a digital logic thing based on the image sensor but i could see a gyro being more reliable without needing crazy fast processing power.
marc i set it on sports program thinking it would up the shutter enough, but i guess not, the in camera preview it's hard to tell how sharp it will be, only if you get total junk. would there be any advantage to forcing the shutter speed even if underexposed and just jacking up brightness post processing?
laurentiu, with a 55-200, should i jump straight to a mirror, or is the 55-300 enough longer and better to make it worthwhile?
overall i'm starting to get the feeling i should optimize the k200d for tele shots since they're more demanding, and use the p&s for wide shots if i want to be able to grab from the backpack and shoot on demand for a range of conditions and subjects. some of the p&s out there claim crazy long tele ends, 600-800mm equivalent but just guessing with tiny sensor and superzoom that would be even worse iq than a consumer zoom + tc on my k200d?

[luftfluss]

OOps - I looked at the osprey pic and it's @ 500mm, so that would be the Sigma 170-500.

The Pentax SR is based on a floating sensor.

As far as superzooms with long teles go... it's tough. There's a lot of compromised optics squeezing light into a tiny sensor, photos really suffer. It's not impossible to get a great shot with an 800mm superzoom, but you need to have really low ISO and a relatively stationary subject. AF will be slower, too.

I've actually thought of getting a high-quality P&S, like a Panasonic LX5, Samsung TL500, etc. and taking that with me when I'm out for wildlife shooting so I could easily grab scenic shots. That's a lotta cash, though,

Here's a seagull taken with K100D + Tamron 70-300.

[RioRico]

overall i'm starting to get the feeling i should optimize the k200d for tele shots since they're more demanding, and use the p&s for wide shots if i want to be able to grab from the backpack and shoot on demand for a range of conditions and subjects. some of the p&s out there claim crazy long tele ends, 600-800mm equivalent but just guessing with tiny sensor and superzoom that would be even worse iq than a consumer zoom + tc on my k200d?

Yes, a P&S is handy for grabbing shots quickly. Yes, the IQ of a P&S superzoom is worse than what you'll put on your K200D. How much this matters depends on how you will display the pictures. Almost anything looks good if it's small enough. Almost anything looks good if it's printed on glossy paper, matted, set behind matte glass, framed, and hung in the right light and at the right distance. Almost anything looks BAD if it's pixel-peeped on a large video screen.

[Marc Sabatella]

would there be any advantage to forcing the shutter speed even if underexposed and just jacking up brightness post processing?

It's exactly the same as turning up ISO. In fact, that's all the camera really does whenyou raise ISO. The sensor has only one ISO - sometimes called base ISO. All others are acheived by taking the data off the sensor and brightening it. The only difference is that in-camera, it might be an analog process, at least up to 800 or so.

[Marc Sabatella]

My experience with Tamron 70-300 lens is different than Marc's. Perhaps the Quantaray versions have lesser QC? I found 300mm on the Tammy to be as sharp as the Pentax 50-200 @ 200mm.

I didn't mean to imply the tamron was much worse. It's very close at best, and in some shots it is a draw, or perjaps even an extremely slight win for the Tamron.

But given the 50-200 is smaller and flighter and focuses faster, I still consider it a win overall for the 50-200. and since the OP already has the 50-200, i dont't see any advantage to "upgrading" to the Tamron. But by all accouts, the 55-300 is indeed better.

[Marc Sabatella]

My experience with Tamron 70-300 lens is different than Marc's. Perhaps the Quantaray versions have lesser QC? I found 300mm on the Tammy to be as sharp as the Pentax 50-200 @ 200mm.

I didn't mean to imply the Tamron was bad. It's very close at best, and in some shots it is a draw, or perjaps even an extremely slight win for the Tamron.

But given the 50-200 is smaller and lighter and focuses faster, I still consider a tie optically to be a win overall for the 50-200. and since the OP already has the 50-200, i dont't see any advantage to "upgrading" to the Tamron. But by all accouts, the 55-300 is indeed better.

[Laurentiu Cristofor]

I expect there is also some sample variation at work with these inexpensive lenses. I find it easier to get keepers from the Tamron than from the DA. AF on my DA is useless and I find it harder to MF the DA than the Tamron. I reviewed both of these lenses on my blog, btw. For me, the Tamron was a useful upgrade.

[Marc Sabatella]

Interesting, AF was one of the things I found most improved when moving from the 70-300 to the 50-200. Much faster, much quieter. Accuracy was never an issue with either, nor should it ever be, since it's the camera that controls the focusing, not the lens. Sounds like you might have had a defective 50-200.

[Laurentiu Cristofor]

I still have the DA 50-200. And I just got some shots last week with it to refresh my opinion of it - see last eight shots in here. And here are shots from the Tamron. And since this thread also asked about mirror lenses, here are some samples of that too.

Note that from the samples above, you cannot tell that I prefer the Tamron to the DA other than because I have more samples for it - otherwise, at web size, both lenses are capable of producing nice results.

I don't think my DA is defective - I think it's just the way it is. Our different opinions are probably mainly due to the fact that (1) I prefer manual focusing and (2) my copy of the lens probably requires an AF adjustment. If your copy's AF works well with your camera, then the shorter focusing throw probably makes it a faster AF lens, but that also works against it for me when I try to manually focus it.

I found that I get better results manually focusing my copy than if I use autofocus - I just don't get them very reliably. In fact, my overall feeling with using the DA is that it is a lens that requires work and luck to get results - so I don't enjoy using it. I find it much easier to get shots I like from the Tamron - it even surprises me sometimes. The DA usually surprises me by its failure to get the shot I wanted to take. At the long end, their sharpness is very close - they both seem to suffer from spherical aberrations, so neither is sharp - I think the Tamron is a tiny bit better, but not by much and that may fall within sample variation differences (i.e. I got an above average Tamron and a sub-average DA). On the other hand, the Tamron is very good at 180mm and has a closer focusing distance at that focal length, so I would say it is a better lens than the DA optically and it is worth calling it an upgrade.

PS: AF requires both camera and lens to be adjusted to each other, as mentioned in these lensrentals articles (original and followup). The lens matters because its AF mechanism follows body commands within a certain tolerance, so errors are always possible.

[luftfluss]

I don't recall any noticeable difference in AF between my DA 50-200 & the 2 Tammy 70-300's that I had. The Pentax 55-300's AF is slightly slower. My Sigma 170-500 focuses slightly faster.

[luftfluss]

I didn't mean to imply the tamron was much worse. It's very close at best, and in some shots it is a draw, or perjaps even an extremely slight win for the Tamron.

But given the 50-200 is smaller and flighter and focuses faster, I still consider it a win overall for the 50-200. and since the OP already has the 50-200, i dont't see any advantage to "upgrading" to the Tamron. But by all accouts, the 55-300 is indeed better.

I can get preferring the 50-200 to the Quantaray/Tamron, I am surprised though that you found instances where the 50-200 cropped had a better image than the 70-300. Could be sample variation at work.

I agree that going from 200mm to 300mm isn't as big as it sounds.

[Marc Sabatella]

I don't think my DA is defective - I think it's just the way it is. Our different opinions are probably mainly due to the fact that (1) I prefer manual focusing and (2) my copy of the lens probably requires an AF adjustment. If your copy's AF works well with your camera, then the shorter focusing throw probably makes it a faster AF lens, but that also works against it for me when I try to manually focus it.

As I said, I prefer manual focus for BIF shots too, and agree the Tamron is somewhat better in that department. But both are light years behind a good MF lens, so I didn't consider that difference significant. When I said your lens might be defective, I meant, if it didnt focus much, much faster than the Tamron. Since you specifically mentioned AF not being as good, I assumed hat was what you mant. Sounds like you are actually talking about AF accuracy, not speed, but I'll submit you,re probaby mistaken about that and have let some bad luck on some shots color your judgement. Again, lens don't control focus, cameras do (and of course, people control cameras). Yes, I'm sure in certain corner case applications, residual spherical aberrations or whatever they are called might cause a lens to misfocus at some apertures even when the cmaera has correctly focused the lens wide open. So if you dpecifially tested for that case and found a problem, then again, I'd say your lens is defective. Otherwise, though, if it's just a vaguely placed sense that focus is not as accurate, then it's practically a gien that impression is actually incorrect.

PS: AF requires both camera and lens to be adjusted to each other, as mentioned in these lensrentals articles (original and followup).

I'm familiar with those articles. I think they have no scientific basis. Other than the specifci effect I mentioned, there's just nothing that coukd logically cause a lens to play a role in misfocus, at least on the Pentax system, which includes a second check on the acuracy of the focus. True, if the camera did not perform this check, then mechanical issues in the gearing could cause problems in cases where the initial focus point was far removed from the final one. But then, a second focus operatio would always correct it. It would be possuble to test for this condition as well, but my impression is that no one ever does.

[Laurentiu Cristofor]

I found MF lenses to usually suffer from stronger aberrations than these AF lenses - that kind of compensates the extra sharpness they might have. Of course, there may be top of the line MF lenses that do well in the CA area too, but those would be in a different price range.

Since I mostly shoot static subjects, AF accuracy is more important than speed to me, so that's what I had in mind until your last message.

For AF, I simply did some tests using the central focusing point - I found that I could always get better sharpness by focusing manually. Nothing scientific, just stuff like putting the central focusing point on a petal and taking a shot then checking if the area under the focusing point was actually in focus.

As for the accuracy of the Pentax AF system, I wouldn't place so much trust in it. The AF points light up even when the image isn't in perfect focus, so if their double check is similarly accurate, it doesn't really count.

[Marc Sabatella]

Unless that petal was perfectly flat and perfectly perpendicular to the camera, and was large enough in the frame to cover the entire focus sensor area, then all this shows is that you and the camera disagreed about where exactly to focus. After all, it would have been presenting several mm of depth to the sensor just on the petal itself, and if the petal didn,t complete cover the snesor, then who knows how much ,ore in front of or in back. Also, if not conducted on a tripod, tests like that are suspect because there is no guarantee you aren't moving by an amount that is significant compared to the DOF.

Performing focus tests well is hard; believe me, I've messed up more than my share. So I speak from considerable experience here. But that's why I tend to skeptical. That plus having put some thought and analysis into the question of what physical causes can exist for different AF problems, and how to test for them individually to identify the specific reason for a problem.

Anyhow, while I actually don't find he M200/4 to be much if any of an improvement optically over the DA50-200, I don't find it worse, either, and the MF ring is amazingly good compared to any of the zooms. Really is a joy to use for BIF this reason alone.

[newarts]

donyjunk...... with a 55-200, should i jump straight to a mirror, or is the 55-300 enough longer and better to make it worthwhile?...

Depends on the mirror; I have a Samyang 500:6.3 mirror that's not as good as my 55-300mm @ 300mm enlarged to match the mirror.

I haven't yet found anything better than just enlarging my 55-300 (including a kenko 1.5x teleconverter), but I understand there are better mirrors and teleconverters available.