NO Focus lock, any other way?

Mark Marshall · Jan 28, 2004

Sure - anything in focus that remains in the DOF should remain in focus. Obviously, if your stopped down a little it's less of an issue if something shifts a bit. If you have good vision you can always tweak the lens if needed. ~ m²

graph (g3) said:
so by switching to Manual focus after a desired focus on auto, it
maintains its current focus? what about soft lock or when the
subject moves on manual (i know its a lame question but i just need
all the right info and not assume the simple answers)

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

Mark Marshall · Jan 28, 2004

I'm sure it is. I don't do a lot of focus & recompose anymore, because unless you AEL ( ) you're metering off your focus point anyway. If you have a person standing at the edge of your picture, it's worth it to spin the wheel and put a side focus point on them, imho...the more you do it the less of a hassle it seems. Plus with > 6Mpx you can almost always perfect the composition in post. ~ m²

graph (g3) said:
when you recompose while holding the shutter halfpressed, is it
annoying when it still refocuses?

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

Chris Wyles · Jan 28, 2004

Mark Marshall said:
unless you AEL ( ) you're metering off your focus point anyway.

Are you sure that's correct Mark. I wasn't aware the ETTL metered off the focus point. For sure with AEL it meters off the centre 9% and with manual it uses centre-weighted but I believe it uses all 35 points in any other mode.

I'm willing to be corrected but I can't find anything in the manual.

Chris

noisebeam · Jan 28, 2004

In my experience it has kicked in the least with the kit lens.

But with the 100mm macro (at normal distances, not macro) it has kicked it quite a bit on static objects when doing the focus, recompose method.

Interestingly while photographing runners with 100mm macro it never kicked in and I have photos where the lead runner (unders the center focus point) is out of focus and the one right behind them is.

And also with 15mm fisheye, only when doing close ups, focus on closest point with center point and then when recomposing it always seems to kick in.

Al

lasm said:
Chris Wyles said:

Presumably the camera can't tell the difference between the
subject's moving across the view and our moving the camera to
recompose the shot.

So is servo-focus an issue if you move the camera too fast while
recomposing?

Click to expand...

The problem is more evident with longer zoom ranges, such as 200mm
and above...

Anything below that, it is generally quite safe and predictable
when using the focus-recompose technique..

--
http://gallery29564.fotopic.net/

Fender182522 · Jan 28, 2004

Michael Kilpatrick said:
I have no problem with the genuine cost saving features of the 300D
(plastic body, 4 shot buffer etc), but AI focus simply doesn't work
for me and I think it is mean spirited of Canon to inflict it on
people who, in many cases, have just bought the most expensive
camera they have ever owned (A$2000 - hardly a budget camera).
It still takes sensational photographs though.

Do people not understand that they've bought an EOS Rebel? The AI focus works the same as in the RebelTi. The DRebel doesn't have any less features than the film Rebels that it is based on, so Canon didn't keep any features "out" of the camera.

--
~~mike~~

lasm · Jan 28, 2004

Fender said:
Do people not understand that they've bought an EOS Rebel? The AI
focus works the same as in the RebelTi. The DRebel doesn't have
any less features than the film Rebels that it is based on, so
Canon didn't keep any features "out" of the camera.

I don't recall haviing this problem with an early model film Rebel, maybe it's something they added to all newer models of Rebel..?

With the 10d, this problem is alleviated by the custom function setting.. You can use AF to achieve focus, then press the -star button to switch to MF, thereby preserving a "hard" focus lock, and you don't even have to touch any MF switch on the lens barrel, nor do you need to drop the camera from the eye level to fiddle around..

The D70 preliminary specs however, does not seem to offer the kind of sophistication of the 10d.. so the problem could be the same as what the 300d user faces.

--
http://gallery29564.fotopic.net/

MRK83 · Jan 28, 2004

Odd response.

Of course I understand what I bought.

I researched as thoroughly as I could - are you seriously suggesting I should have bought a film EOS 300 first?

As I said, I knew there were some cost saving measures. However, short of taking the 300D home with a tele lens, which assumes I could have predicted what problems there would be with AI focus, I had to accept Canon's claim that the camera would know when the subject was moving and when it was not.

It doesn't. That is the nub of my annoyance with this feature, which should be user selectable in a camera of this price.

Not such a difficult concept, I would have thought.

Mark Marshall · Jan 29, 2004

Your right, it is evaluative. I'm not sure if it's weighted at all (behind the scenes), but it sure seems to be in usage sometimes. Thanks for catching that - I don't want to misinform anyone. ~ m²

Chris Wyles said:
Are you sure that's correct Mark. I wasn't aware the ETTL metered
off the focus point. For sure with AEL it meters off the centre 9%
and with manual it uses centre-weighted but I believe it uses all
35 points in any other mode.

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

Sam Bennett · Jan 29, 2004

graph (g3) said:
I would probably use it for still lifes (product shots for catalog)
and will be in a tripod so it would be really difficult for me to
more the thing just to focus.

usually i take a dozen shot of a single setup with different cam
settings and it would be really hard to refocus/recompose on each
shot.

I personally find the mandatory AI-servo in creative modes annoying, and it's one of the reasons I'll probably grba the 10D's replacement if/when it comes out (although I'll keep my Rebel since it's a great camera, and much lighter). With that said, you can definitely work around the AI-servo "problem".

In your case, if the camera is on the tripod simply use one of the seven focus points to get the subject in focus, then switch the LENS to manual. You can then tweak the shot a bit as long as you don't move closer or further away, and you avoid any AF problems.

I do this a lot when doing dog sports photography. Sometimes things are moving so fast that it would be impossible for any AF system to keep up, so I choose a focus point, switch to manual, tweak a bit and then fire off shots quickly as the dogs come by.

--

Sam Bennett - Photo Guy, Audio Engineer and Web-Apper - http://www.swiftbennett.com

Mark Marshall · Jan 29, 2004

Hi Sam - that sounds like a lot of fun. We have a dog track about 40 mi. away and I'll have to give it a go this summer. What lens are you using? ~ m²

Sam Bennett said:
I do this a lot when doing dog sports photography. Sometimes things
are moving so fast that it would be impossible for any AF system to
keep up, so I choose a focus point, switch to manual, tweak a bit
and then fire off shots quickly as the dogs come by.

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

Mark Marshall · Jan 29, 2004

That's the way the Rebel works too. Hit the "cross" button and spin the main dial. After a few times your finger will find it quickly w/o taking your eye from the vf. Unless I'm misunderstanding (I came from Coolpix, not G). ~ m²

graph (g3) said:
focus points meaning the 7 points aligned in a form of a cross?
its just weird that my g3 can scroll to any space in the image for
focusing (but then focusing is a weak point of my g3)

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

PaulyOly · Jan 29, 2004

warrick said:
lasm said:

graph (g3) said:

my understanding of a focus lock is that you point to something
then it focuses, you press the lock button and the focus stays at
that distance even if you let go of the shutter which was pressed
halfway. then you can recompose and take dozens of shot with the
same focus distance as long as the lock is still in place. am i
correct? and the 300d doesnt have this lock button?

Click to expand...

Pressing the half shutter will lock the focus and allow you to
recompose, AS LONG AS AiServo does not kick in when it detects
movement of the object. When AiServo kicks in, the focus lock is
lost, therefore the focus lock in 300D can be described as a "soft"
lock...

The bad news is there is no way to dsiable AiServo, so a "hard"
focus lock is one of the missing/crippled features in 300d

--
http://gallery29564.fotopic.net/

Click to expand...

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------------------------
http://www.absolv.com

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I tried a camera at bestbuy that had the same problem and also a ladies camera whom i work with, same problem, people that say it has focus lock just don't see this as a problem, it's a problem for me, hopefully the next 300d won't be so crippled.

DogsPlayingPoker · Jan 29, 2004

If you want to focus lock for more shots, just focus where you want and then put the lens in MF.

graph (g3) said:
I read somewhere that the 300d cannot focus on a specific part of
an image you want it to focus. I understand that the RB has 7
points on where you can assign it to focus but what if it is on the
part of the shot where it doesnt land on the 7 points?

is manual focus the only way to do this? how will i know if its as
sharp as it can get?

my understanding of a focus lock is that you point to something
then it focuses, you press the lock button and the focus stays at
that distance even if you let go of the shutter which was pressed
halfway. then you can recompose and take dozens of shot with the
same focus distance as long as the lock is still in place. am i
correct? and the 300d doesnt have this lock button?

this is something i can probably live without since if im doing
this im most likely to use a tripod, but i need to know if i can
rely on the manul focus.

PaulyOly · Jan 29, 2004

Mark Marshall said:
Max Fun said:

after you'd achieved the desired focal distance, and your focus
will be 'locked' all the way till you swtich back or adjust the
focus yourself.
Simple.

Click to expand...

--
'Brothers and sisters, we've learned that there's some bad bokeh
going around out there. So like, just be careful man, alright?'
(If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

--
http://www.pbase.com/paulyoly/root

If your subject is a bowl of fruit, not so great a solution if your subject can move or your subject doesn't like it when you move your hand. I wish there were a manual focus switch on the back of the camera then my problem would be solved.

JThomasLambert · Jan 29, 2004

Canon, in a support e-mail to me, admits that it wasn't evaluated well enough because this feature makes any FTM lens mess up. There's no way to use the FTM features of these lenses because the AI Servo kicks in and tries to refocus back to the focus point.

Michael Kilpatrick said:
Odd response.

Of course I understand what I bought.

I researched as thoroughly as I could - are you seriously
suggesting I should have bought a film EOS 300 first?

As I said, I knew there were some cost saving measures. However,
short of taking the 300D home with a tele lens, which assumes I
could have predicted what problems there would be with AI focus, I
had to accept Canon's claim that the camera would know when the
subject was moving and when it was not.

It doesn't. That is the nub of my annoyance with this feature,
which should be user selectable in a camera of this price.

Not such a difficult concept, I would have thought.

--

http://www.pbase.com/jthomaslambert

Sam Bennett · Jan 29, 2004

Mark Marshall said:
Hi Sam - that sounds like a lot of fun. We have a dog track about
40 mi. away and I'll have to give it a go this summer. What lens
are you using? ~ m²

Hey Mark! My dogs Sydney and Saucer compete in FlyBall, which is a team relay sport - here's a shot of one of our team mates, Bailey, using the technique I was referring to:

Most of the "action" shots I've done have been at practices, where I'm allowed to be pretty close - so my 50MM f/1.4 does fine. But for competitions, I'm going to grab either the 85MM f/1.8 (possibly the f/1.2 - I do a lot of low-light photography, so if I can find one used...) or the 100MM f/2.

Here's photos from a tournament, but almost none are "action" shots:
http://www.swiftbennett.com/photowerx/index.cfm?cid=29

Various shots from practice:
http://www.swiftbennett.com/photowerx/index.cfm?cid=3

--

Sam Bennett - Photo Guy, Audio Engineer and Web-Apper - http://www.swiftbennett.com

wilfredmrand · Jan 29, 2004

Also, half-press will hold focus for a few seconds while you recompose. I prefer the Manual Focus method though. 'ts easy.

Mark Marshall · Jan 29, 2004

Hi Paul - I'll check it again with my other lenses, but the way I hold the camera my thumb almost naturally falls on the focus switch. I was checking to make sure it wasn't the IS switch on the 28-135, but it wasn't. I realize not everyones hands are the same size (I'm 6'3"), and I see from Natalia's sig that holding styles vary widely as well, but I have the BG on, so that should equalize things for those that do cradle the lens without one. I see from JTLs post that FTM is messed up by AI Focus, so even ring USM lenses need to go to MF on the Rebel. I understand your frustration and haven't dissed your complaints, but you and Daniella are both bird shooters, and she sent hers in to have AI Focus sensitivity turned up - so shooting style probably does come into play. Is your camera back yet? If not did you ask to have your sensitivity turned down? ~ m²

PaulyOly said:
If your subject is a bowl of fruit, not so great a solution if your
subject can move or your subject doesn't like it when you move your
hand. I wish there were a manual focus switch on the back of the
camera then my problem would be solved.

--

'Brothers and sisters, we've learned that there's some bad bokeh going around out there. So like, just be careful man, alright?' (If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

PaulyOly · Jan 29, 2004

Mark Marshall said:
PaulyOly said:

If your subject is a bowl of fruit, not so great a solution if your
subject can move or your subject doesn't like it when you move your
hand. I wish there were a manual focus switch on the back of the
camera then my problem would be solved.

Click to expand...

--
'Brothers and sisters, we've learned that there's some bad bokeh
going around out there. So like, just be careful man, alright?'
(If Wavy Gravy emceed PMA) http://rhodeymark.instantlogic.com

--
http://www.pbase.com/paulyoly/root

I can switch the auto/manual switch on the 400mm f5.6L if it's on a tripod, but not hand holding the lens/camera, if i ever get my camera back i will try it next time i'm shooting in my backyard, the only problem in doing this is the switch is so tiny and seems fragile even on the L lens.

NO Focus lock, any other way?

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