Focusing problem w/ 50mm 1.4 on Drebel (DOF misunderstanding?)

[markubig]

Hi all -

Well, I used my Drebel for the first time today. Had a family gathering, so I decided to slap on the 50 f/1.4 and take some quality candids and portraits. There was adequate tungsten lighting (i was even able to get a great custom white balance), so I was set on not breaking out my flash and i wanted to take all the pics w/ ambient lighting.

I was in Av mode all day, and I used the lens pretty open (most of the time between 1.8 -2.8 because I wanted to get good bokeh. I used ISO anywhere between 100-800, depending on the quality of the lighting.

Here's my problem: I GOT A LOT OF SUBJECT BLUR TODAY!!! I got full subject blur, partial subject blur (Two subjects standing together . . . same distance from camera, yet one is focused and one is blurred). I also have people standing offset (one slightly further from the camera) and one is focused and one is still blurred.

I used Auto Focus for all the photos. I had my review set so that I could check the histogram for exposure. All of the blurred pics looked fine on the LCD, and I didn't notice all the blur, until I loaded them on my PC. Trust me, I'm not blaming the camera . . . i know it's totally my fault (since i'm still VERY new to photography), so now I'm wondering what I am doing wrong, and if I am correctly understanding DOF:

Was I wrong to not want to use flash with the lens pretty wide open?
With the lens that wide open, do I only have a very thin plane to keep subjects in focus?
If I stopped down to say f8 in Av mode, wouldn't that slow the shutter speed, thus still producing the unwanted subject blur because of my hand/subject movement?
How are you supposed to properly use the 7-PT focusing system, especially when you have multiple subjects
Should I have used Tv mode instead? (i don't think i'm knowledgeable enough for M mode)
I was so excited when I was taking the photos, and I couldn't wait to get home to look at them on the computer. I just finished and I was so disappointed, Don't get me wrong . . . this 50mm f1.4 was sharp as a knife when I properly focused. I mean it was really sharp!!! Problem was that it wasn't too often I focused properly. Advice anybody???

Thanks, in advance, for your help!!!

[Wildman]

Try center focus and the subject's eyes as the focal point. If you want to get two people in the same picture, focus on one and hold the shutter half way down and re-compose the shot. The focal distance is very short (at large apature), so if the two subjects aren't in the same plane, one will be in focus and the other won't. You'll have more depth of field if you stop down a little more, but will sacrifice some background blurr (bokeh).

[aznkid.com]

it also depends on how close you are to your subjects..to get one in focus and one blurry, it sounds like you're quite close.. why not back it up to ensure a good DOF? ever try using your flash in Av ot Tv mode? it uses ambient lighting and fills flash for the shadows on their faces as opposed to using it in P where it uses the flash as the main source of light..

how about you post some samples?

[DocFrankenstein]

1.8 will give you about 5-20 mm of in focus in you're photographing from a meter or two.

What were the shutter speeds?

[tim]

Have a play with this (http://www.dofmaster.com/dofjs.html). At F1.8 and 2m you have a 10cm depth of field. At F2.8 it's 17cm. That's why :) Play with the calculator, it's interesting :)

[markubig]

Hey Guys -

Here are a couple of examples of my frustration from yesterday. Both were taken with a DRebel and EF 50mm f/1.4 USM. Flash was not fired. Could you tell me where I should have lined up my focus points in each picture?


1/6s, f/2.2, ISO400: In this one, both subjects are out of focus (actually everything is out of focus)
http://gallery.photo.net/photo/2972918-lg.jpg


1/40s, f/1.8, ISO400: In this one, the woman on the left is in focus, but the woman on the right is not (i know . . . her eyes are closed . . . i'm just using this pic as an example)
http://gallery.photo.net/photo/2972907-lg.jpg

Should I just use flash? I guess the fill flash would get rid of the shadows, but I just love how ambient light looks so natural . . . am I expecting too much considering the level that I am at?

Thanks!

[Scottes]

At 1/6 second I would expect everything to be blurred because of camera shake. Not out of focus, but blurred since the camera is going to move a bit. And in the second f/1.8 is just too shallow of a depth of field.

[markubig]

At 1/6 second I would expect everything to be blurred because of camera shake. Not out of focus, but blurred since the camera is going to move a bit. And in the second f/1.8 is just too shallow of a depth of field.Thanks Scotte. I was in Av mode, and I guess I took it for granted that the camera would give me a good shutter speed . . . thanks for pointing that out. I guess I need to pay closer attention to the exposure parameters before I take the shot

so for the one that was too shallow, if i stopped down to say f/4-5.6, would bumping up the ISO to 800 have been sufficient enough to keep the shot properly exposed? Do any of you with a DRebel shoot 800 or 1600 often when indoors?

[Hellashot]

From the sounds of it, you would need a 20D using ISO 800-3200 (from what I've heard) to do what you wanted to do.

On Saturday I did the same thing you did - use my 50mm f1.4 in a dark room without a flash and my Drebel to take images of a 3 month old. But he was laying down next to the Christmas tree and also hardly moving. I used ISO200 and f1.4 all the time and got some very good results.

[Scottes]

Yeah, f/3.5-f/4 would get them both in focus. You're already at 1/40, which is twice the recommended shutter for a 50mm on a DRebel. So you'd be looking at ISO 1600 to make this shot.

I'd be looking at picking and choosing the shots. One person and f/1.4 is fine - just get the eyes in focus. But with two people it gets to be much tougher unless their eyes are all in the same plane, so I'd take less shots with 2 people or take a LOT more and hope that some come out. :-)

Find a good spot where you can rest your elbows or lean against a doorway or some other way of adding some support to the camera to allow slower speeds. (But remember that a person standing perfectly still will probably still blur a little at 1/10s, so don't go too slow.) Bump the ISO and get NoiseWare or Neat Image to remove the noise.

Last resort, go flash if you can do the above, or when shooting multiple people. Alas, I love the natural light, too, but sometimes you just can't do it.

[snibbetsj]

The DRebel shows little noise up to ISO 800 and even 1600 is quite useable with noise reduction software. That gives a lot of latitude for shutter and aperture control in those low-light situations.
:-D

[markubig]

Thanks all . . . looks like I got a LOT more practicing to do!!! Good thing I'm on vacation until after the New Year . . . ;)

[mr.photoguy]

Hey Guys -

Here are a couple of examples of my frustration from yesterday. Both were taken with a DRebel and EF 50mm f/1.4 USM. Flash was not fired. Could you tell me where I should have lined up my focus points in each picture?


1/6s, f/2.2, ISO400: In this one, both subjects are out of focus (actually everything is out of focus)
http://gallery.photo.net/photo/2972918-lg.jpg


1/40s, f/1.8, ISO400: In this one, the woman on the left is in focus, but the woman on the right is not (i know . . . her eyes are closed . . . i'm just using this pic as an example)
http://gallery.photo.net/photo/2972907-lg.jpg

Should I just use flash? I guess the fill flash would get rid of the shadows, but I just love how ambient light looks so natural . . . am I expecting too much considering the level that I am at?

Thanks!

bro, your photo's are blurry because of your shutter speeds. You see the 1/6th of a second. You would need a tripod or table or lean on a wall for that. You want to have a shutter speed of at least 1/50th and above. (steady hand people can go a bit lower).

It may have been better to shot in TV mode and then try to get the Aperature to co-operate. Also it's sometimes better to just put the camera in P mode. Let it do the work and you just watch your shutter speed and iso.

I learned with my 50mm 1.8 to keep the shutter above 1/50th and this is when my nerves are not acting up. You can take your shots at iso 800 or so, you will just have to run the image through a noise reduction program afterwards, unless there is some way to reduce noise in photoshop...(I don't know how to do it in CS).

(I usually use my 50mm at f2 and above. 1.8 is nice, but a little shallow for me sometimes.

[scottbergerphoto]

Here is a series of shots I did to show the DOF of the 50/1.4 at various f stops:

http://www.pbase.com/scottbergerphoto/50mm_f_14__focus_test
Happy Holidays,
Scott

[markubig]

It may have been better to shot in TV mode and then try to get the Aperature to co-operate. Also it's sometimes better to just put the camera in P mode. Let it do the work and you just watch your shutter speed and iso.
So when is it ideal to use Av or Tv mode? I was of the understanding that Av would be good for portraits and Tv was good for action/sports shots.

Any of you use A-DEP mode? What's the difference between this and P mode, since the shutter speed and aperture are set automatically?

[robertwgross]

The easiest solution for shooting at 1/6 second is to use a tripod.

Also, and this is less important, mirror slap is a factor at this speed, so Mirror Lockup is smart, if your camera can do it.

---Bob Gross---

[RichardtheSane]

The other problem with lower shutter speeds is if your subject moves it will blur.

[F1_Fan]

Thanks all . . . looks like I got a LOT more practicing to do!!! Good thing I'm on vacation until after the New Year . . . ;)
I didn't realize how shallow the DOF is at large apertures and close distances until I worked with the lens for a while. For example, I used my 50mm at f1.8 for pictures of my cat from 0.5-0.75 m. It's pretty common for the eyes to be in focus and the nose out of focus. The DOF can be just that shallow.

[mr.photoguy]

So when is it ideal to use Av or Tv mode? I was of the understanding that Av would be good for portraits and Tv was good for action/sports shots.

Any of you use A-DEP mode? What's the difference between this and P mode, since the shutter speed and aperture are set automatically?

Well you have to remember. When you are shooting in Av mode you have to keep your eye on the shutter speeds, you have to remember that if you are indoors and you are shooting with a 50mm lens then you want your shutter speeds to safley be atleast 1/60th of a second. Even though you can shoot at 1/50th, lets just give that extra 10th.

So if you set your camera to P mode, the camera will automatically set the shutter and the aperature for you. However, you can adjust this by turning the dial next to the shutter, when you do this you can use different A-values and the shutter speed will adjust by itself accordingly. (please excuse my spelling)

If you use Av mode, then you have to keep a close eye on your shutter speed. You will have to adjust the Aperature so that you get the DOF that you want and yet have the right shutter speed to effectivly reduce camera blur.

If you use Tv Then you can set the camera to any shutter speed you want. Then the camera will choose the proper Aperature to go along with it. If the shutter speed is not feasible, then you will see the numbers start to blink. Then you have to either turn the shutter speed down or up accordingly.

I learned this the expensive way, with my film EOS.. But after paying for the prints/learning, I never forgot it.

Remember in P mode the camera calculates this for you.

At family gatherings, I usually just leave my camera in P mode. No time to sit there and fidel with Tv and Av mode. Expressions from kids move way to quickly for me to be switching knobs. Grown ups is a little better though, but even still, they get ansy after a while.

Also remember that when you review a image on the lcd screen, zoom in on it and pay close attention to the eye's and the eyebrows. Doing this has saved so many of my images, because I would stop everyone in their tracks and say "Hey we need to take that one again". Way to save the day huh.. lol...

[mr.photoguy]

So when is it ideal to use Av or Tv mode? I was of the understanding that Av would be good for portraits and Tv was good for action/sports shots.

Any of you use A-DEP mode? What's the difference between this and P mode, since the shutter speed and aperture are set automatically?
Oh yeah, I forgot to say,

I usually use Av for landscapes and car photo's and things of the sort. You can use it for portraits to also... among other things.

I usually use Tv for sports, and anything moving. I also use it occasionally for night shots if for unforsaken reason I can't get the aperature to close up to f22 or so. You can also use it to get to Bulb.

I have never used ADEP yet, I know it is supposed to give you the best reasonable DOF. Which would bring everything into focus.

I read the manual every chance I get.
We are responsible for knowing everything we can about our camera's. There are a lot of good explanations in that manual for the basic settings, and their usage.

Later
MP

[robertwgross]

When you are shooting in Av mode you have to keep your eye on the shutter speeds, you have to remember that if you are indoors and you are shooting with a 50mm lens then you want your shutter speeds to safley be atleast 1/60th of a second. Even though you can shoot at 1/50th, lets just give that extra 10th.

The difference between 1/50th and 1/60th is not an extra tenth.

---Bob Gross---

[gmen]

Just to throw that cat amongst the pigeons - why not consider using the Manual mode on the camera - a quick zap of a grey card, a reading with a handheld meter or even just taking a peek at the histogram and you can set the aperture/shutter speed combination you need for a given situation, without relying on the camera's (possibly unreliable) metering.

Just a thought.

[mr.photoguy]

The difference between 1/50th and 1/60th is not an extra tenth.

---Bob Gross---
What is it .10 th of a second? If I used the wrong measurment, just correct me.

[markubig]

What is it .10 th of a second? If I used the wrong measurment, just correct me.Oh man . . . that goes back a few years for me . . . I believe the difference is 1/30 or .03 s.

Anyhow, I understand what you meant . . . thanks for the help, Mr. Photodude!!!

[markubig]

You know what's killing me? The photos looked great on the camera LCD when I was taking the pictures, but it's not until I got home and looked at them on the computer that I realized all the blur. I could tell the bad ones immediately on the LCD, but the ones that had very slight blur looked fine on the LCD.

I guess I need to pay more attention to my exposure paramters before releasing the shutter

[Jon]

Oh man . . . that goes back a few years for me . . . I believe the difference is 1/30 or .03 s.

Anyhow, I understand what you meant . . . thanks for the help, Mr. Photodude!!!
Nit, nit. 1/300th, or .00333... sec. 1/60=5/300, 1/50=6/300.

[mr.photoguy]

You know what's killing me? The photos looked great on the camera LCD when I was taking the pictures, but it's not until I got home and looked at them on the computer that I realized all the blur. I could tell the bad ones immediately on the LCD, but the ones that had very slight blur looked fine on the LCD.

I guess I need to pay more attention to my exposure paramters before releasing the shutter


Did you zoom in on the LCD on their eye or wherever you initially focused?

I usually focus on one of the eye's and then take the photo and then review and zoom in to make sure the eye came out sharp. If it didn't I will take the photo over again with adjustments. I realized (learned) this from watching people on this and other forum take photo's of their cats, and they keep saying, "Put the Focus dot on the eye".

Here is an example of me...
http://www.pbase.com/brucescott/image/37547510
(focus was on my left eye)
(huge pic)
Another
http://www.pbase.com/brucescott/image/37424244
that's Fat Cat..
(focus was on her eye)

[mr.photoguy]

Nit, nit. 1/300th, or .00333... sec. 1/60=5/300, 1/50=6/300.
Thanks for clearing that up for me.

btw: Turn your pm's on.
Do you have a site that goes into detail about this.

[Jon]

About which?

[markubig]

Nit, nit. 1/300th, or .00333... sec. 1/60=5/300, 1/50=6/300.
oops . . . told u it's been a while for me . . .

[rkoshy]

I know it's a BIT off topic here.. but I did a "portrait" shoot of my girls with a 200 f/2.8 lens set at about 100mm from about 12 feet away... and the DOF was too darn short! The funny thing is that the props in front of them were in focus... while their faces were out of focus... oh well.. you learn. But the DOF calculator link in this thread did wonders in terms of my understanding of how small the dof on a long lens can get :-)

[eosster]

Thanks for heads up, nice information to know.

Cheers,

Charles,

[Scottes]

But the DOF calculator link in this thread did wonders in terms of my understanding of how small the dof on a long lens can get
Try this: http://www.liquidsculpture.com/dof.htm

It'll knock your socks off.

[PacAce]

Just to throw that cat amongst the pigeons - why not consider using the Manual mode on the camera - a quick zap of a grey card, a reading with a handheld meter or even just taking a peek at the histogram and you can set the aperture/shutter speed combination you need for a given situation, without relying on the camera's (possibly unreliable) metering.

Just a thought.

If there's not enough ambient light to begin with, setting the camera to manual is not goint to magically produce more light. No matter how much you fiddle with the camera in manual mode, it's not going to make the lighting situation any better. Take a look at the shutter speeds and apertures used in the example pictures.

[rkoshy]

If there's not enough ambient light to begin with, setting the camera to manual is not goint to magically produce more light. No matter how much you fiddle with the camera in manual mode, it's not going to make the lighting situation any better. Take a look at the shutter speeds and apertures used in the example pictures.

When I'm taking candid shots at family gathering I tend to use my 70-200 f/2.8 , or my 24-60 f/2.8 quite often... ALWAYS in Manual mode... generally leave it on exposure of 1/40-1/60 or so, and play around with aperture (f stop) as requried for DOF/lighting. Generally speaking, I'll use the nearest stable objet -- tables, chairs, bookshelves, etc to stabilize my elbow. THEN... if the target area is too dimly lit.. I'll use my 550EX to bounce some light off in that direction, mostly using a wall or ceiling. Walls are interesting in that they produce a slight off WB color rendition, BUT, it can be appealing if the tones are right... Most people that I know have white (or mostly white) ceilings... and just a small amount of light tends to lighten it up enough for me to get my shots.

[PacAce]

When I'm taking candid shots at family gathering I tend to use my 70-200 f/2.8 , or my 24-60 f/2.8 quite often... ALWAYS in Manual mode... generally leave it on exposure of 1/40-1/60 or so, and play around with aperture (f stop) as requried for DOF/lighting. Generally speaking, I'll use the nearest stable objet -- tables, chairs, bookshelves, etc to stabilize my elbow. THEN... if the target area is too dimly lit.. I'll use my 550EX to bounce some light off in that direction, mostly using a wall or ceiling. Walls are interesting in that they produce a slight off WB color rendition, BUT, it can be appealing if the tones are right... Most people that I know have white (or mostly white) ceilings... and just a small amount of light tends to lighten it up enough for me to get my shots.

There's nothing wrong with shooting in Manual mode. I use manual myself, too, when the circumstances call for it. My comment regrading the manual mode was not that you shouldn't use it but that it's not the answer to the problem at hand as the poster that I quoted was suggesting. Whether a shot is taken in Manual, Av or Tv, you will still have the same problem that needs to be overcome and that is the low lighting situation.