Canon 300D 50mm F/1.8 question

[93octane]

Don't know if this is the correct forum to post this
Today I was bord so I shot a couple of pics of my daugter with a
new hat she found at a store. Well as I was looking at the pictures
I noticed that I always focused on her face as seen on the pictures
below but the sides of the hat and top are always more sharp then
her face. In the last one if you look closely you see her right her
your left is really sharp and her face is soft like out of focus is
it the lens or the camera??? 300D and Canon 50mm f/1.8 lens. Is
this front focus/ Back focus issue, DOF??? the lager pictures have all the exif info in them. Shot Manual mode at F4.0 ISO 100

http://home.rgv.rr.com/gt281/pics/center1.jpg

http://home.rgv.rr.com/gt281/pics/center1%20pic.JPG

http://home.rgv.rr.com/gt281/pics/center3.jpg

http://home.rgv.rr.com/gt281/pics/Center3%20pic.JPG

[Nolz]

if the shots are wide open at 1.8 or anything less than about f4 ish you get a very shallow DOF hence a limited zone in which everything is in focus. have you tried shooting at about f5 or so? this should have most if not all of her head and hat in focus whilst having the background nice and blurred.

[Jackal]

Looks like the lense might be backfocusing. I hear that the 50mm 1.8's focusing isn't the best and at 1.8 the depth of field is EXTREMELY shallow so if the lense is off...then well you will notice. =)

Try this test if you want: http://md.co.za/d70/chart.html

[93octane]

All the shot were taken at F/4.0 and ISO 100 I figured F/4.0 was wide enough for a shot like this one. Might have to experiment again with a larger DOF.

[Nolz]

certainly worth a shot!...it may just answer your own question :)

[triangle]

I fought this same thing with that setup. It is a DOF problem, the 50/1.8 will produce great shots for you. I have upgraded to a 20D now, but still use the 50/1.8 often. As a matter of fact it is what I use for individual and team pics. you can view some here (http://www.trianglephotography.com/events/basbeball/little_league/allstars/9_yearolds/pnteam/page_01.php). When I have someone else use my DRebel during a shoot, I have them use the 50/1.8 and have them get candid shots.

You can see the detail in your photos, like the small scrape/scar on her arm. Once you get your DOF right you will be very pleased with the results. If you want more background blur when you open that apeture up, try moving your subject a little further away from the background. (Like at least 4 - 5 feet from the fence.) And try shooting at 5.6, I think you will like what you get.

[93octane]

Thanks for the tip Triangle I'll try that.

[ron chappel]

I dissagree.
It's a backfocus problem as you originally thought.
As you say-you can see that the hat is clearly in focus but her eyes are just in front of the focus zone.

You may or may not wish to stop the lens down to have more of her head in focus but that is a seperate thing

Here's a very good focus test chart so you can find out for sure.

http://md.co.za/d70/chart.html

[triangle]

I dissagree.
It's a backfocus problem as you originally thought.
As you say-you can see that the hat is clearly in focus but her eyes are just in front of the focus zone.

You may or may not wish to stop the lens down to have more of her head in focus but that is a seperate thing

Here's a very good focus test chart so you can find out for sure.

http://md.co.za/d70/chart.html

Ron, backfocus is when the front is out of focus and the rear or (back of the shot is in focus) isn't it? If that is true than why is the front of her arm in such crisp focus that you can see the hairs and wrinkles in her arm? - Correct me if I am wrong, but I still believe this is a DOF problem.

[ron chappel]

Oops sorry!
I didn't wait till all the pics loaded and was judging everything on the first pics.
I still think the first pic is back focussed but the second image .....looks abit front focussed!
Hmmmm

More DOF would certainly cure everything but the lens could still be missfocussing.Wether slightly inaccurate focus is normal for the 50/1.8 i don't know.
It's hard to judge image magnification while scrolling the page around so i better just shut up i think! lol

[griff2]

There's also a parallel thread here (http://photography-on-the.net/forum/showthread.php?t=79442) which is addressing this very same problem albeit with the 20D. I'm having the same problems with the 300D and the 50 f/1.8.

[tzalman]

Sorry, but I don't think there is any problem here at all. IMHO it's a case of an inherently low contrast subject - the girl's face - made even more low contrast by under-exposure, and positioned next to a high contrast subject, the hat; all of which adds up to an apparent lack of sharpness (as, Ron, you noted in another post today). Look at the reflected highlight in the girl's left eye in the second picture - it's reasonably sharp.

[buze]

In my experience with the 50 f1.8 or 1.4, or even the 85 f1.8, the DoF is so thin that the slightest movement of the subject head can create an out of focus shot; so if you, say, want to lock focus on the eye, reframe and shot, you have to be quick, or lucky in the case of moving subjects.

In this portrait from yesterday, he started reading something as I was shooting; so the shot went from sharp to soft, and the plane of focus is now on his shirt, where his eyes were a fraction of second before! Bugger! :lol:

http://oomz.net/IMG_3891.JPG

[93octane]

I'll will be trying some shots at 5.6 and see how that goes. My only dissapointment is why have a lens that is able to go down to 1.8 or 2.8 when the DOF is useless up close and you have to crank it up to 5.6 to make it work in that case I could easily just buy any other lens that is nice and sharp and use it from 3.5 and above. I could stand back farther so the persons face fits in the DOF window but now I'm not filling the frame with the persons face and its more I have to crop. I have only been doing this for a year and I know there is alot I have to learn. Is there a proper way to be able to use a lens at f/1.8 or 2.8 and still be able to use the advantage of a low ISO and no flash but still get a good usable DOF without problems???? At the same arpeture 4.0 that I used on those pictures I took some indoors with a flash 420ex standing 6-7ft from the subject and the pictures come out looking really good and sharp.

[buze]

Just use the tools you have, the paper thin DOF at <= 1.8 is a superb tool when you manage to use it in proper conditions; but it's not easy to use. Be patient, practice! Practice on your favourite plant for example; I did that to get a "feel" of what one can get away with. The leafs getting out/int/out of focus is a very good scale of the limits at any apperture/distance.

And if you subject moves, there is not a lot of options : shoot away until you feel you got a sharp one. No technic or strategy will help you *at all* in low available light on moving subjects, I think. What I learned by practice is that if for example you shoot with portrait orientation, trying to re-frame on a moving subjedt will probably mean a OoF shot. so just shoot straight and forget the proper framing you would do in other light...

I'm becoming more and more in love with available light shots and portraits, I think it's hard, but very very rewarding when it works!
This one I took this week at f1.8, ISO 800:
http://galleries.oomz.net/pub/stroks/S/IMG_3681.JPG

[DxHatchback]

pics are too big to really see anything

[93octane]

I left them at full resolution so it was easier to pick out the focus parts from the un-focus parts. buze your picture is really nice I just think it still looks soft and out of focus compared to other pictures I have seen taken with this lens. seems you have the same problem as I trying to get a good sharp picture with a fast enought shutter speed.

[willg]

try printing them out...i had some soft focused shots from this weekend and i printed them and they look great

[buze]

There was no light at all, what do you expect ? I have taken sharper picts with the same settings, of immobile subjects, but this last one was 1/25s, and that near the limit of what I can do handheld anyway in a reproducible manner, I deliberatly went ISO 800 to be at 1.8 to have a slightly bigger DoF, otherwise an immobile subject I would have done ISO 400 f1.4!

When the lens/camera (as in that shot) sees *better* than what I could actualy see with the naked eyes, I don't mind the softness! Beside, his eyes are sharp, that was the aim :D

[ron chappel]

Tha slight softness in that one workd very well i say :)