2.5Q's - Manual focus, External flash.

Innocence · Nov 19, 2006

Another 2-ish questions

1/ When people say "focus on the eyes" am I supposed to:
(a) use manual focus? Or do I
(b) 'manually' choose an AF point and then point the chosen point at the eyes?

1.5/ What is manual focus for? (maybe I should be asking how do I use it?!! haha) Or am I missing the point? Becuase the eye hole isn't big enough for me to see if things are in focus!! I can generally make out what is "sort of" in focus, but I'm pretty sure my eyes through the eyehole can't match the AF mechanism - and I don't mean in terms of speed.

2/ When will I get a desire to buy an external flash? (might seem weird, but it's a serious question. I mean, I would want to buy a 500mm lens when I get into nature photography or something - haha, but I don't really get when I would want a flash unit.)

Thanks very much!
Have a nice day!

Tiberius · Nov 19, 2006

Whenever you're in a situation where you'd use flash a lot, you'll want an External. Bounce Flash is about a billion times better than the head-on variety your onboard flash uses, plus the external flashes are more powerful and recharge faster.

Don Simon · Nov 19, 2006

Innocence said:
What is manual focus for? (maybe I should be asking how do I use it?!! haha) Or am I missing the point? Becuase the eye hole isn't big enough for me to see if things are in focus!!

If we were talking about a film SLR or a full-frame dSLR with a decent viewfinder, I would say that manual focus can be a better way of focusing. Not only do you have full control over where you focus (no need for selecting anything) but focusing screens can have various textures and patterns which make it easy to see what's in focus. But as you pointed out, the viewfinders in lower-end crop-sensor digital SLRs suck (to use the technical term). Those with a pentaprism instead of a pentamirror may suck less, but they're still fairly sucky. On top of that, modern autofocus lenses may lack distance or DOF scales and may be fiddly to use in manual focus. However there are times when you might still need to use manual focus, and if so you might want to do the following... first play with the diopter adjustment on your camera to see if you can make the viewfinder any clearer... if that doesn't help, find out if your camera has interchangeable focus screens, if so you may want to consider one.

Innocence said:
When will I get a desire to buy an external flash? (might seem weird, but it's a serious question. I mean, I would want to buy a 500mm lens when I get into nature photography or something - haha, but I don't really get when I would want a flash unit.)

Maybe tomorrow, maybe never

If you don't have the desire to buy one yet then why worry? Having said that, an external flash can provide more light, more range and more control than the little one that pops out of most dSLRs. One of the main advantages is that an external flash can be bounced or diffused, and if used off the camera it can be fired in pretty much any direction from any angle - you control the light source, which completely changes the image.

xfloggingkylex · Nov 19, 2006

The problem with the viewfinder on most entry level dSLR's is they use pentamirror systems, whereas the higher end SLR's and I believe most film SLR's use penta prism. Pentaprism (from what I hear) is brighter and therefor easier to focus manually.

The only time I use manual focus is when I want the focus locked for multiple shots, or if the room is dimly lit, instead of waiting for the flash to strobe for AF assist, I just try to do it myself.

Big Mike · Nov 19, 2006

1/ When people say "focus on the eyes" am I supposed to:
(a) use manual focus? Or do I
(b) 'manually' choose an AF point and then point the chosen point at the eyes?

I almost alway use the centre AF point. I focus on the subject (eyes etc.) then recompose and shoot. It's that simple.

xfloggingkylex · Nov 19, 2006

Big Mike said:
I almost alway use the centre AF point. I focus on the subject (eyes etc.) then recompose and shoot. It's that simple.

This is a great technique. I was wondering though, does recomposing after focus lock cause the subject to be out of focus at all? it just seems that with shifting the plane it would cause a slight out of focus.

Innocence · Nov 20, 2006

ok thanks guys for the responses!!

benhasajeep · Nov 20, 2006

Focusing

Most cameras will lock focus if you compose with the acitive focus indicator on the area you want and hold the shutter button down half way. Some have a seperate button. Now you have to remember on alot of cameras this also locks exposure. Then you move the camera to compose the scene you want while still holding the button.

When to use manual focus. Well in the example above. Say you move the camera to focus on the spot you want and then lock the focus / exposure. Then recompose. But you may run into the fact that the metering may not be most correct for the newly composed shot (it is set for the scene composed for the focusing). It's time to go to manual focus or use exposure compensation. Manual focus will be the easiest if you do not know what setting to compensate exposure for. You also have a second choice. Meter the shot first. Focus the shot and lock focus. Then set the camera to the metering you remembered before focusing. This way if you have a hard time focusing (low light). You can still use the camera auto functions for metering and focusing. Or go ahead and bracket your exposures. Its digital so you not wasting any film.

A flash really deppends on if you really need it. Or the better responce is if you need a top of the line flash. Most cameras with onboard flash are really intended for snapshot / fill flash situations. Not much else good about them. If you take lots of people shots, or indoor shots then you need a flash. Now do you need a $400 dollar top of the line flash unit. Or a $100 dollar off brand flash unit?

I think most non proffesionals can do just fine with an off brand dedicated shoe flash. They have near the same features as the branded units but about half the cost. Do you need a flash with a 150' range? Probably not. A decent flash with a guide number (GN) of around 25 to 30 would probably suffice. Moveable head is worth the little extra $ (bounce).

I use a flash more for interior shots than anything else (building interiors not people). I actually use 2 flashes for this. Second main use is for fill flash. I have one branded dedicated unit, and one higher powered off brand dedicated unit.

As for the 500mm lens vs flash. The flash wins. Especially since a decent flash can be had for $100. Can get it and still get the 500mm in the future. You just may have to wait just a little longer. But while saving for the 500mm or 600mm

you have the option to use the flash. There are so many more uses for flash than to just take night shots of people.

Now if you have never used the onboard flash, and have no plans at all to use a flash then no need in getting one. It really deppends on what you want to do. But they do have more uses than just snap shots.