Manual focusing

Thirdfox

May be a stupid question but...

How do you know (in these modern digital SLRs like the 350D) that you have the manual focus spot on? In the viewfinder is there an aid to help you focus or do you just have to use your eyes?

I have a really old Minolta that has a circle with two halves in the viewfinder that align properly when the focus is on - is that still being used in newer cameras?

Thanks

ChityWest

That system is not in use in newer eos digital cameras. With auto focus you have a number of square boxes which glow red when they are the selected point of focus, these are programable if you want (as far as I remember it's either 9 boxes of 16 in very expensive ones). With manual focus your on your own. I usually just pick a feature - like say somones hair and make that as clear as possible if doing it manually.

Thirdfox

Is that a step backwards for manual focusing then? Why do they leave out the feature? (Cost?)

ChityWest

I know what you mean - but af usually works. If you want a non-standard focussing point i.e. say an object not covered by one of the focussing points (boxes) I usually just point the camera the another point - hold the button half way down to remain focused on that other point - then move the camera back to point at the person/thing in question & click there.

That way you can auto-focus on an object which is not going to be the main object in the frame. Otherwise just use your eye to try get a specific point in focus and fix it later in photoshop if you have to

I have no idea why that feature is not present in modern dslr's probably a different way of manufacturing the lenses or cameras.

Roen

You can replace the screens on most modern slrs so that you can get the old way you are familiar with back if you so desire. You gotta buy these seperately though.

ChityWest

Do you mean replace the layout of what you see through the viewfinder ? If you dont like the red boxes you can pick a different schema ? Is that what you mean ?

Roen

Think he means the matte screen that comes with most modern slr. These don't have the old split line focusing bit in the middle.
Like this one that you can buy for some of the Canon range

Thirdfox

That's the one Roen. I suppose the convenience of chucking out your out of focus digital photos outweights the ease of use of the split line focusing aid on a film camera.

Are the aids horribly expensive to buy (and install)?

ChityWest

Roen wrote:

Think he means the matte screen that comes with most modern slr. These don't have the old split line focusing bit in the middle.
Like this one that you can buy for some of the Canon range

Ok.

ChityWest

Is this the one your refferring to ?

http://www.camerahacker.com/Tools/Installing_Haoda_Screen.shtml

Roen

Not sure about the installation, Chity West seems to have that covered but the screens seem to be about $33 on http://www.bhphoto.com You should be able to get them locally too.

ChityWest

Ok that one will change what you see through the viewfinder - but it looks a total pain to get it installed.

JMcL

You can make use of the autofocus points in manual mode, at least on Canon SLRs. Half press the shutter release as you would to auto focus, focus manually and the autofocus points will light up exactly as they do in AF mode, but allows more precise focussing avoiding the lens hunting like mad. It may not be as precise as those focus screens, but it's cheaper!

John

Thirdfox

Thanks for that tip - especialy important for me as I don't have the best of eyesight

elven

Not sure if I'm missing the point here, but I thought there was a green dot that lights up when you're in focus, if you hold down the button you usually use to focus (I use the metering button on my 350D, not the shutter halfway down thing) then you'll see a green dot under the frame in the viewfinder as you focus back and forward. I also only use the middle focus point because I prefer to use the single point to focus on my subject in the middle of the frame, then re-frame the shot keeping that focus. I'm not sure if that affects the green dot thing. Is that what JMcL means too?

JMcL

elven wrote:

Not sure if I'm missing the point here, but I thought there was a green dot that lights up when you're in focus, if you hold down the button you usually use to focus (I use the metering button on my 350D, not the shutter halfway down thing) then you'll see a green dot under the frame in the viewfinder as you focus back and forward. I also only use the middle focus point because I prefer to use the single point to focus on my subject in the middle of the frame, then re-frame the shot keeping that focus. I'm not sure if that affects the green dot thing. Is that what JMcL means too?

I'm not sure about the 350D, it may do it differently, but the 300D just makes use of the red focus points that are visible in the viewfinder. The operate exactly the same regardless of whether AF is driving the lens, or if it's being done manually. I doubt it though as if it were to rely on an indicater at the bottom of the viewfinder, then which part of the image is it indicating to be in focus? Actually, rereading your post, I think you're locking the exposure. Pressing the metering button should do just that, ie. engage the center weighted metering. Is the green dot you refer to an '*'? For focusing, you need to use the shutter button, I'm pretty sure it's the same on the 350D

John

elven

It isn't the exposure lock * sign, it's a green solid dot. It's not indicating that the focus is locked, because it only lights up when the point of focus is actually on the subject.

I actually set the option on the camera to use the exposure lock button to focus, it's in the extended options that are buried under a few menus. I just never liked using the shutter halfway down thing. That way I can use my thumb on that button to focus and my finger on the shutter to take a light reading... and now I've got so used to it I can't change back.

440Hz

ChityWest wrote:

Ok that one will change what you see through the viewfinder - but it looks a total pain to get it installed.

It is actaully not that bad. Very precise and time is required, but it is not as complicated as it looks on that web page. Having said that I have never tried it myself but I have seen it done loads of times.

Roen

I've changed screens heaps of times on my Mamiya 645, then again you have acres of space to play around with compared with a 35mm. I'd imagine it would be fairly intuitive once you get started, I mean most things only fit in one way....don't they. And if you have a few bits left over just consider them as free gifts from Canon.

ladgie353

One note though, only the "pro" slrs (1, 3 and 5 series, digital and film) have interchangeable focusing screens.
The other series haven't been designed to make changing the screen easy and may not be able to use the canon screens.

CoolBoardr

I think JMcL is right - the green dot is related to the exposure not the focus.

eg. If you set the shutter speed to 30 seconds during the day (on Shutter Priority), the green dot will flash because there is no corresponding aperture value to expose the picture properly. If you change it down to say 1/60th, the green dot will light up solid meaning there is an equivalent aperture value to properly expose the image.

Roen

Says it's a focus indicator in my 20D manual.
*EDIT* Yep just checked it's called a Focus Confirmation Light. It will blink in one or more of the following circumstances because auto focus has failed to work. Low contrast, Low light, Backlit, Extremely reflective, Overlapping near and far objects or Repetitive patterns.

peter1892

CoolBoardr wrote:

I think JMcL is right - the green dot is related to the exposure not the focus.

eg. If you set the shutter speed to 30 seconds during the day (on Shutter Priority), the green dot will flash because there is no corresponding aperture value to expose the picture properly. If you change it down to say 1/60th, the green dot will light up solid meaning there is an equivalent aperture value to properly expose the image.

I don't know about the dSLR's but on the EOS 300v if you set the shutter speed to 30 seconds & a suitable aperture isn't available then the aperture value will flash on & off (if you're using shutter priority mode).

The green dot flashes when focus can't be confirmed in AF mode, it's usually only a problem in poor light.

SOL

It is a focus spot, it is the same on nikons and on some (like my old F801) it has arrows either side telling you which way to turn the focusing ring... very convenient...

CoolBoardr

You're all right! I knew something flashed if the exposure was off...

My mistake.