Any way to make a 5D always take a picture when I push the button?

[alan_bryant1]

In AF mode, it won't trip the shutter if it doesn't think the lens is in focus.

 

In MF mode it will.

 

I want a compromise: Keep AF, but *always* take a picture when I push the button, no matter whether it's in focus or

not.

 

Last night I photographed a Halloween party in a dimly lit space. I used my new 85/1.8 (love it!) for the whole night. In

the darker corners I was getting 1/4 sec f/1.8 at ISO 1250, which I translate to EV -0.9 at ISO 100 - just below the

official metering range of the 5D, and so dark that you can't expect much from AF.

 

But the fact of the matter was, AF was working surprisingly well. It just didn't realize it was working well, so it was

refusing to trip the shutter. Even when AF didn't work, I could generally fix the focus with the handy-dandy FTM focus

-- but that was useless unless I also switched the lens to MF mode, because the camera refused to take the picture.

And it is absolutely infuriating to have people posing at a fast-paced party and be standing there like an idiot

screwing with switches on the camera.

 

Is there any way to persuade the camera to ALWAYS TAKE A PICTURE when I push the button, because I DON'T

CARE whether it thinks it has good focus or not?

 

Thanks for any tips...

 

Alan

[rainer_t]

Focusmode servo (rather than one shot) might help.

[j_smith6]

You could use Al Servo but it won't be working great in such lighting.

 

You could also use "One Shot AF" but you have to turn on a cutom function which allows setting autofocus with (*). You set AF with (*) and then when you press shutter button camera will take a picture (unless you hold (*) and it can't lock the focus).

[buck_rogers1]

Custom Function 4

[bob_osullivan]

Buck, I don't think so, CF4 is AE/AF lock button assignment. It wont make the camera fire the shutter before focus is found.

 

Alan, why would you want to? Out of focus images are a waste and you'll get zero keepers anyway. Use MF.

[alan_bryant1]

Michael/Buck, that does appear to approximate what I had in mind. It adds a step (pressing the * to focus) but it otherwise appears to behave like MF while allowing AF. I'm going to leave the camera in this setting (CF 4 setting 1) for a while and see how I like it.

 

Bob,

 

(1) Who cares if they aren't all keepers? It's digital, the cost is nothing.

 

(2) As far as I know, not taking the picture is the only guarantee of zero keepers. And not taking the picture is what the camera is currently doing.

 

(3) I want to leave AF on because I'm shifting rapidly between different light levels. AF works in the good light, for the rest I want to use FTM. It's moronic to have to flip a switch on the lens every ten seconds. Why can't the camera just DO WHAT I TELL IT?

 

(4) ...And as I pointed out, AF often worked in the poor light too. It apparently just "wasn't sure" or something, so it focused right and THEN refused to take the picture. Absolutely infuriating.

 

(5) Not to belabor the point, but why can't the camera just DO WHAT I TELL IT? Am I the photographer or not? I don't want my camera trying to read my mind. I want my camera obeying my orders.

 

...Maybe it's just because I'm older, and spent many years with MF film cameras that never said no. I want an Ado Annie "I'm just a camera that cain't say no" mode.

[tommyinca]

Set CF4 = 1 will allow you to seperate AF (* button) and shutter release button. It will release shutter without AF

button being pressed. Note: Once you pressed the * button, you will have to release it first, if you want to fried the

shutter before focus is achived. With fast USM AF motor, you may have to train your reaction a bit :-

).

[j_smith6]

<i>(4) ...And as I pointed out, AF often worked in the poor light too. It apparently just "wasn't sure" or something, so

it focused right and THEN refused to take the picture. Absolutely infuriating.</i>

<br><br>

Exactly. Even though focus is perfect sometimes it won't lock it because camera is not sure. This is why I always

use 2-buttons option in such situations. Right now I use EOS 40D and there's additional button "AF on" just under (*)

so it's pretty useful.

[robert_tan1]

i have the same problem with my xti coupled with 75-300 tele..it keeps on focusing and even when it stops,it still

won't snap a shot..i have to use MF all the time..grrr..any suggestions?

[robert_tan1]

don't get me wrong guys since many of us prefer canon ..here goes..

i also have the sony a200k and it works much better than the xti..it snaps even at low light conditions,focusing is never a problem,is more sensitive to light..meaning it will take good shots when even the xti won't even snap at all and the resulting quality is impressive too..i wonder what is it has that the xti doesn't?

[robert_campbell8]

@ Robert as well as Alan

 

I have an XTi and I make great use of the Custom Functions on the camera.

 

Menu -> Tools -> Custom Functions (C.Fn) -> 04 Shutter/AE lock button -> Set to 1 (AE lock / AF)

 

This will set the camera up to use AF only when you press the * button on the camera. I've completely gotten used to this now... very fun to use the 1/2 shutter to lock the exposure as well.

 

This will solve your problem of not being able to take a shot even though the camera thinks it is not in focus.

[roger_smith4]

R Tan- Robert Campbell is right and it saved me a lot of frustration with my 20d.

[robert_tan1]

thanks to robert and roger..i will try this out tonight...btw,can i keep on snapping a few shots with the same

custom feature or should i press the * and snap again ..meaning it is a one off feature..?

[matt_needham]

"...why can't the camera just DO WHAT I TELL IT?"

 

No blaming the gear for operator error. ;) When you have the AF button coupled with the shutter release you are telling the camera to focus first, then release the shutter. It's doing exactly what you told it to do.

 

"...can i keep on snapping a few shots with the same custom feature or should i press the * and snap again..."

 

The focus distance of the lens will remain the same until you refocus.

[alan_myers]

Hi Alan (et al),

 

I use a pair of 30D, a 10D (as backup) and a pair of EOS3, which all have essentially the same AF setup as your 5D. I've also used Elan 7s and 1V in the past.

 

Granted, the AF systems vary from camera to camera in some other ways. The EOS3 share their AF system with the 1-series cameras, so it's more sophisticated. But I actually "dial it down" with another CFn to use far fewer AF points, so they operate more similarly to my 30D and your 5D. I also tried and no longer use Eye Control, which the EOS3 have and some people would like to see Canon offer on new models again. (I hope not!)

 

Regarding your concern about the extra step.... Once you get used to using the * button to focus, it quickly becomes second nature. You'll focus without even thinking about it after just a short while, I can assure you. I was frustrated at first with AF when I switched to the Canon system years ago. Using CFn 4 and the * button instead has solved that completely. The only "loss" is that the * button is no longer available for AE Lock.

 

So, one thing you need to know, CFn 4/1 locks exposure per the half press on the shutter release button (AE Lock enabled). CFn 4/3 is the same as far as focus is concerned, but allows metering to continue right up to the moment of exposure (AE-Lock not enabled ).

 

When using one of the auto exposure modes like Tv, Av or P, CFn 4/3 is the setting I use 99% of the time. Heck, I use it most of the time even when I set up exposure manually (which is about 75 or 80% of the time). So, you might want to try CFn 4/3 instead of 4/1.

 

Another thing that CFn 4/3 or 4/1 allows is more accurate use of the center focus point only, to focus and then recompose. When shooting fast (sports), I'll do this consistently. I only select one of the other focus points when shooting slow and deliberately. I never select all the focus points and leave it up to the camera to choose.

 

CFn 4/3 and 4/1 work equally well with either One Shot (non-moving subject) or AI Servo (moving subject). With the latter you need to keep the AF point on the subject and the button pressed to have AF keep tracking as the subject moves. With One Shot and a non-moving subject, you can simply press *, achieve focus (which is confirmed in this mode by the LED in the viewfinder and the "beep" if you have it enabled), then release the button and take the shot. With AI Servo and moving subjects, it's more a press and hold the * button process.

 

I never use AI Focus.... It's another automation mode, that's supposed to have the camera decide for you whether or not your subject is moving, then choose between One Shot and AI Servo. I tried it and think there is a slight delay to the process... Too many missed focus shots so I stopped using it.

 

I don't agree that there is no cost to missed shots. There's significant wear and tear on your camera, wasted storage space and battery consumption, wear and tear on all the removable parts of your system (CF pins in both the card and the camera, contacts on the batteries), etc. There's also lots of time spent downloading and then weeding out the missed shots. That puts wear and tear on your computer and leads to more frequent defragging and other storage issues.

 

Plus I make a living with my cameras so there's potential loss of income. My "keeper" rate averages around 60% or maybe a little higher most of the time, and pretty few of the garbage shots are due to missed focus (maybe a dozen or less out of roughly 500 shots I made at a shoot on Saturday, for example).

 

Another thing that can really help your focus accuracy when using large aperture lenses is to not believe everything you see in the viewfinder. Your 5D is better than my 30Ds in this respect. The larger viewfinder give you a more accurate idea of depth of field. Crop sensor cameras are not as good at this, because of the smaller image we see in the VF and that DOF is a bit exaggerated. So, when I'm shooting "wide open", if DOF looks adequate at f2.8, then I'll sometimes stop down to f4 just to be sure. This has saved me more than once, having just a little extra DOF to compensate for any slight focus error.

 

By the way, using USM lenses, you don't need to turn off AF at the switch to override it manually, in case you didn't know. That's only mandatory on non-USM lenses (manual override will break them, if AF is not turned off at the switch!)

 

One of my lenses, 70-200/2.8 IS, I found I often bumped the AF or IS switches and switched them off. It has a piece of gaffer tape over the switches now, to prevent that! It's not pretty, but it works.

 

In a way it's ironic... Today's camera's have tons of automation built into them. People buy them largely for the automation, in fact. "Wow! It's going to be easy to be a great photographer with this camera. It does all the hard stuff for me!" they think.

 

Truth is, all that automation pretty quickly gets in the way for many people, and the camera can only do so much. We have to take control back from the camera, it turns out. You've reached this point with AF. Next you'll be setting custom white balances, buying a handheld meter and setting manual exposures, I bet! ;-)

[alan_bryant1]

Am I the only one who's noticed the remarkable number of Alans who post in this forum? I meet very few in my day-to-day life. I guess they're all here.

 

Well. Definitely my keeper rate for the evening was abysmal. And mostly it was due to operator error (among other things, I apparently bumped the mode knob from Av to Tv partway through the evening, and it took some time to figure out why the camera had gone nuts). This was a gig for fun, not pay, so it doesn't matter much. Anyone seriously needing to take pics at EV -1 would use a flash with a focus assist beam. But flashes annoy people, and these are my friends, I didn't want to annoy them. So I accepted that I'd be doing well to get 10% keepers, and dove in with that expectation. I fact I didn't manage 10%, except in the brighter-lit portions, where I got some very good shots.

 

Having said all that, it was my first dimly-lit event with my first digital SLR, which I've only had a couple months, so I was mostly hoping for a learning experience. And it has been :-)

 

The debate on the cost of missed shots is interesting... and yes, I suppose there is some. Though not nearly as much as film has. The 5D is rated for 100,000 shots, so each individual missed shot has incredibly tiny impact. But I concede that, over a lifetime, they aggregate: For instance a careful and methodical photographer who only takes pictures after lots of preparation might get 50% keepers, whereas a more snap-everything-sort-em-out-later photographer might manage only 5% or less. The first photographer will get 50,000 good pictures in the lifetime of their 5D shutter, the second only 5,000.

 

So yes, wear and tear on equipment is an issue. Batteries is an issue mainly for flash -- in my experience anyway -- I can't hardly kill my 5D battery, I shot the entire event on one battery and it still says it's full. Likewise card space, I've got enough for a vacation, which is more than I need for an event. Hard disk space gets to be an issue, though with 1 TB drives at about $200, then even assuming you keep a main drive and two backup drives (as I do) the cost of storing a 5D RAW+L is about $0.013, which isn't much, and it will decline over time as drives get cheaper.

 

For me though, the most immediate cost is the time it takes to look at the bad pictures. I've got a system worked out so I can do it quite fast, but still it adds up.

 

So I guess my assignments are...

 

- Get used to using the * for AF so the shutter button will always be on, and

 

- Slow down my photography and work toward a higher keeper rate, and

 

- Look into the Ee-S focus screen, which is widely reported to make it easier to manual focus fast lenses

 

Thanks for all the thoughts... got to get back to work now...

 

Alan

[robert_tan1]

thanks to Matt Needham and others:

you guys here really know your stuff and for sharing with us.

[alan_bryant1]

<p>It's working out so far. I'm growing used to focusing with *. I must say, after tweaking the focus of a shot, it's sweet to be able release the shutter button and press it again without changing the focus.</p>

 

<p>A sample: Student drawing a sidewalk-chalk advertisement at night, 85mm f/1.8, 1/8 second at ISO 1600, hand held. I noticed in some shots I could see stars in the sky. Very nice.</p>

 

<p><img src=http://img.photobucket.com/albums/v490/alanpix/IMG_2960M.jpg></img></p>