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05-11-2010, 05:13 PM   #16
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QuoteOriginally posted by ManuH Quote
There is an interesting article about VR here:
Nikon VR explained
Thanks for the reply !
It's for Nikon but I think it should apply to all SR systems: Do not use SR when not necessary, do not use it at all on very fast shutter speed (1/500s and above).
I tried it OFF at shutter speeds up to 1/1250s and the results were no better than going Av/AF-S with the SR ON. Go figure!


To say the truth, I have not a lot of BIF experience (more with moving humans) and yes AF-C on the K10D and K20D was frustrating. It's better on the K-7 but it's not a miracle either. I found multipoint too slow on the K20D, on the K-7 it seems to be better for keeping the target in focus though.
That is true, certainly not a miracle. As for the multipoint, I gave up on that.

But if the bird is very far, do you really need AF? Focusing to infinity may be good enough. Of course, if you're talking about birds in a cluttered environment, the multipoint may not be the best choice indeed. I had a BIF with a sky background in mind when I said multipoint was better.

See my previous response ... that sort of environment would give a migraine to anyone I suppose.

It would depend on the quality of light. But you can think about TAv also: set the shutter speed to a safe speed (let's say 1/500 or faster) and good enough aperture. When you stop down, you have more DOF and thus more margin for AF errors. A rule is that you need 2 stops to double the DOF. You may also use a slightly less long focal length and crop to again get more DOF.
I thought of that and my guess is that by the time I am all set, the hawk will be long gone. But that is probably because I haven't used that mode much at all.
And even better mode for AF speed would be manual. Once you know the light, it doesn't change a lot unless you shoot birds with much different reflectiveness or there's clouds masking/unmasking the sun. Again the camera will spend less processing power to guess the correct exposure. Manual WB can help too to reduce the CPU load.
Lots of practice on gulls and crows before I even consider going after hawks that way.

Even with the K-7? I think it's more sensitive to low-contrast targets. But there's not much solution I can see. The only thing is to try the best glass you can with good contrast wide open, do not use TC, etc. That way the AF can perform better. You can also help the AF a little if your lens supports Quick-Shift, you can manually focus by eye close enough then let the AF do the final adjustment.
Yes, the K7 is more sensitive to low contrast situations, but not that much more than my K20D.

I appreciate your time with this.

JP


05-11-2010, 05:19 PM   #17
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QuoteOriginally posted by ManuH Quote
This could start a long debate but it's obvious that it's better to nail with a hammer than with a screwdriver, although you can do it. IMHO for BIF shots, Pentax is handicapped by 2 things: lack of great AF and lack of long and fast glass. This is not to say that in its class, it not good, but Pentax doesn't offer anything above the K-7 class of camera.
I too agree that it is not the gear but the photographer behind the gear, such as me, making mistakes.
However, I also agree that "maybe" the AF is more accurate and locks on better with some other brands. I haven't tried the competition, so that is the extent of my comment on that.
But again, I do have some great BIF shots already with the K20D and some with the K7 .... Not ready for a brand switch yet!
I am just trying to find ways to improve my technique.
All of those replies sure make me think and reconsider my approach to BIF.

Cheers.
JP
05-11-2010, 05:22 PM   #18
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QuoteOriginally posted by hcc Quote
There have been already some solid, strong opinions. I wish simply to add my experience.

I use typically AF-C, Centre focus, and I add Hi continuous shooting. I found that I can improve my success rate, using a burst of 4-5 shots than a single shot.

I agree with an earlier post that AF becomes meaningless when the bird is in the far field. MF would work better: e.g, being set a infinity as default. Two years ago, I shit some buzzards circling over a field with a blue sky on the background. The MF worked great then.

Hope that the comment will assist...
Sure, I tried this AF-C, this time with the K7, previously with the K20D. So far, no luck at all. I also use continuous shooting/ Hi burst rate (RAW) in Av.
This AF-C/Tv combo doesn't seem to work well at all with me though.

JP
05-11-2010, 06:10 PM   #19
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QuoteOriginally posted by Lowell Goudge Quote
there area lot of interesting ideas here

full AF matrix , while I agree might be good when a bird is close and fills the view finder, generally when you are tracking a BIF it starts a long way away and in the view of only one sensor at a time, the others on something else usually the infinite bluy sky
Well, exactly what I was thinking: how can one use full matrix when the target is distant and moving? We are talking about BIF here, not a scenery. I agree that the bird must be close enough for that to work properly, hence my choice of always using "point" AF.

the use of the 1.7x AF Adaptor is also true it focuses quickly within the limited range of focus, but you need to continually move this range when tracking.

As for a bird coming right at you, I have to disagree about pentax's AF ability. See the shot below done with a PZ1, and the K300F4 plus 1.7x AFA adaptor. I think it works pretty well.


This almost makes me believe that the A-FA 1.7x adapter actually might make your BIF keeper rate higher, or is it just me thinking that way?When I acquired this adapter, I did test it on a few "slow moving" birds and, frankly, I had better luck than with the DA*300 on its own. Now, I confess that this test-day was sunny, very low humidity and the targets were ... close enough.
while SR does require increased shutter speed to eliminate camera shake, it does nothing to freeze motion, that always needs shutter speed. Panning helps, but as I said, it also leads to blurr when SR is on.
I am still under the impression that this "SR OFF" thing is not working for me. Anyway, it will be another "testing" day when I get out there sometimes this week.
I will again test with the SR Off, TV, etc ... as suggested by several people here.

MF for distant subjects is also a valid idea, but many many AF lenses have limited focus trhow in MF mode, my sigma 70-200F2.8 for example has only 90 degrees, against my SMC300F4 with over 300 degrees. using an MF lens with a gradual focus throw is good when subject is at a distance and moving in, it is easy to track and keep focus, the issue is speed of aquiring focus. AF is faster when starting from the opposite end of the focus throw,
I can't really comment on that ... I am lost.

Thanks a bunch for the reply.

05-11-2010, 06:18 PM   #20
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QuoteOriginally posted by Marc Sabatella Quote
Some confusion here: neither 'center weighted average" nor "matrix" have anything whatsoever to do with focus. They are *metering* methods. The method you use for selecting focus point has *nothing* to do with the method you use for metering - they are two totally independent settings. Do be sure you are actually controlling the one you want.
Yeah ... well. Sorry about that.

I should have used:

"Selecting the Focusing Area" (AF point), such as "Center", "SEL Select", and "Auto".

Metering Method(s): "Multi-segment", "Center-weighted" an "Spot" metering.

That should take care of the confusion.

JP
05-11-2010, 06:33 PM   #21
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QuoteOriginally posted by snostorm Quote
Hi Jacques,

That was an early post, pretty much just after I got the K-7.

Things I discovered after that:

The focus limiting of the 1.7x AFA is good for BIF distant enough that you can set the lens at infinity and leave it there -- the increased speed to acquire is helpful, but the extra magnification makes the acquisition in the viewfinder more difficult, and when the bird gets closer than the limited focusing range, it's hard to recover focus manually while tracking the bird. This is a technique thing, so with practice, it could get easier, but as I mentioned, I don't shoot a lot of BIF, so have not developed the technique. I've heard from the best BIF shooters I know that a 400 f5.6 lens on a 35mm camera is about the sweet spot for this purpose, for both acquisition and handling, and have had about the best results with my FA*300/4.5, so I'll agree (450mm f4.5 eq).
Lots of practice needed, by the look of it.
I've tried my Pentax and Sigma AF 300/2.8s, thinking that the increased speed would give the AF system more light to work with, but the shallow DOF wide open for focusing works against you -- as does the extra mass of the lens, even on a gimbal/tripod.

In AF C, it's very important to get an initial focus lock beep before you start a continuous string. If the first shot isn't in decent focus, the camera will have trouble gaining focus during the string.
I tried that this afternoon, and I did get this initial beep, to no avail though: most of the resulting shots were awful.
Since my technique is lacking, and I have trouble keeping a bird in the center of the VF, I've had the best success with multipoint. There's a downside though -- Continuous High slows down to @ 3FPS. Center or Select point focusing allows greater frame rate, but I've found that, for me, multipoint gets me better results. Use as few "Auto" functions as possible to give the AF system and continuous shutter as much processing power as possible. I use multipoint focusing, Av priority (because panning will give you varying light), and AF C as the only "Auto" features, but if you can track a bird consistently in any single part of the frame, Center or Select will give you close to the full 5+FPS.
Multi point doesn't work for me.
Choose a relatively high ISO and a reasonably small aperture to get shutter speeds that will at least have a chance to stop motion. Deeper DOF makes the AF system's job easier.
Got that. This afternoon, all pics were taken at f8 to f11 and with a shutter speed of 1/1000s to 1/1250s; since it was a bright day, ISO was good at 320.
I've never turned SR off for this, but can't argue that it wouldn't give better results, both in focusing speed and frame rate. With relatively high shutter speeds to freeze subject motion, I don't think SR adds much to the mix, and it might detract from some of the other performance parameters, but I've not experienced SR induced blur because of the panning -- YMMV.

I've gotten as many as 19 shot sequences of gulls and Caspian Terns in flight with the K-7. I believe my record with the K20 was more like 6. Most show very good focus, but all were very usable, and with generally better focus than the K20. The improved tracking ability from the shorter blackout times is very noticeable. For me, the K20 is considerably better than the K10, but the K-7 is much better -- especially since SAFOX has been pretty universally panned for AF C performance.
I take your word for it, but as far as I am concerned, the keeper rate of 10 successive shots in AF-C would be maybe one or two! (for me) anyway).
For strings of an approaching bird (the best ones, IMO) I always start with the lens focused to infinity -- there's a lot less focus ring throw at distance, so the AF has less work to do to get the initial focus. After each string, I point at the sky and let the AF take the lens to infinity before I even start to look for the next subject.

I'm in the process of adding an external gun sight to the hood of my FA*300 (no, not permanently!) -- cannibalizing a cheap Daisy Red Dot for the hood and front reticle. I've tried it just jury rigged to sight birds in trees with my left eye, while my right eye is at the VF. I think this might help me get faster VF acquisition, and may even be a better way to track moving birds since there would be no blackouts.

I'll repeat the caveat that I'm neither an experienced, nor even a good BIF shooter.
Hope these tips might help some. . .

Scott
. . .and sometimes you just get lucky. . .This one is with either the Tamron 70-300 or the Tokina 80-400 at 180mm, cropped a bit.
Thanks for all of the very relevant info ... I guess it is back to practice.
Cheers.
JP
05-11-2010, 07:07 PM   #22
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QuoteOriginally posted by imtheguy Quote
I can help clarify this for those not familiar with this TC. Shooting with the AF 1.7x and a da*300/4 for example at f/11 (displayed), I can set the limited focus range so that it begins and ends about where all the action will be. Yesterday for Ospreys, I adjusted for a minimum focus of about 40m and the maximum was almost to inifinity, 300m maybe. Certainly way beyond any shot I would take.

My point being that you can set up a single large focus range in the big outdoors. Now obviously for little birds on a feeder at 8m the focus range is only good for the depth of the feeder and requires a manual adjustment to focus on a branch at 10m. But I much prefer that over a TC (or bare lens) that may allow the lens to do a complete cycle if you lose the focus point for a second.
Lee,
I don't quite follow you, sorry.
What is this "set the limited focus range" when using the AF 1.7X with the DA*300/4?
Would be nice to know how this really goes.

Cheers.
JP
05-11-2010, 07:17 PM   #23
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QuoteOriginally posted by jpzk Quote
Lee,
I don't quite follow you, sorry.
What is this "set the limited focus range" when using the AF 1.7X with the DA*300/4?
Would be nice to know how this really goes.

Cheers.
JP
The 1.7x af tc has it's own focusing elements because it. Wasoriginally designed to convert mf lenses to af. When used on a long lens the adapter does not have sufficient range to cover from infinity to minimium focus. As a result your lens becomes a mf lens with af assist for fine tuning the focus

05-12-2010, 05:57 PM   #24
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QuoteOriginally posted by Lowell Goudge Quote
The 1.7x af tc has it's own focusing elements because it. Wasoriginally designed to convert mf lenses to af. When used on a long lens the adapter does not have sufficient range to cover from infinity to minimium focus. As a result your lens becomes a mf lens with af assist for fine tuning the focus
Ah! Thanks for the info.
So, when I use this 1.7x adapter on an AF lens (in my case, a DA*300), I switch the lens and camera to manual focusing?
By the way, I think I had started the previous post with "Lee".

JP
05-12-2010, 10:51 PM   #25
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QuoteOriginally posted by jpzk Quote
Ah! Thanks for the info.
So, when I use this 1.7x adapter on an AF lens (in my case, a DA*300), I switch the lens and camera to manual focusing?
By the way, I think I had started the previous post with "Lee".

JP
Hi Jacques,

You switch the lens to MF, but keep the camera in either AF S or AF C. The AFA focuses within the adapter as it has its own focusing elements and does not have the capability to pass any AF ability to the lens, (you might not even have to switch the lens to MF, but I can't remember. . .)

Scott
05-13-2010, 03:41 PM   #26
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QuoteOriginally posted by jpzk Quote
Ah! Thanks for the info.
So, when I use this 1.7x adapter on an AF lens (in my case, a DA*300), I switch the lens and camera to manual focusing?
By the way, I think I had started the previous post with "Lee".

JP
no set the camera to AF and th elens only to MF

the adap[tor has it's own elements that need to move by the screw drive in the camera body

re, responding to another's question, If I don't see a response, I will offer the answer, I don;t worry about answering only if a comment was addressed to me, if I see you are not getting an answer, I will offer it on behalf of the person you asked., We're all friendly here, Arn't we?
05-13-2010, 06:00 PM   #27
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QuoteOriginally posted by snostorm Quote
Hi Jacques,

You switch the lens to MF, but keep the camera in either AF S or AF C. The AFA focuses within the adapter as it has its own focusing elements and does not have the capability to pass any AF ability to the lens, (you might not even have to switch the lens to MF, but I can't remember. . .)

Scott
QuoteOriginally posted by Lowell Goudge Quote
no set the camera to AF and th elens only to MF

the adap[tor has it's own elements that need to move by the screw drive in the camera body

re, responding to another's question, If I don't see a response, I will offer the answer, I don;t worry about answering only if a comment was addressed to me, if I see you are not getting an answer, I will offer it on behalf of the person you asked., We're all friendly here, Arn't we?
Scott, Lowell: thanks for the reply.
So this is it: camera on AF (either AF-S or AF-C) and the lens only on MF?
This means that I had it all wrong! No wonder I was goofing quite a "few" pics!

I guess this also means that one should "approximate" the area to be focused on and then let the adapter do its work for fine focusing. Hope I have it all understood noew.
Again, thanks a bunch!

JP
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