New 50mm f/1.8 and 430EX practice!

[yunaiseng]

Just picked up a nifty fifty and also a 430EX. Since it was my first dedicated flash unit, I wanted to go out and test out this new combo. Specifically I was trying to practice:
- focus with such small DOF
- high speed sync in order to take advantage of large apertures
- ETTL for the fill flash

I notice that I had some problems with focusing. When shooting at like f/1.8, what technique do you guys use for focusing? What happens if your object of interest (such as the eye) doesn't fall right on one of the focus points? Focus-recompose definitely gave me some off focus shots.

Anyhow, here are my first try pictures (my fiance, my patient model)! Most shots were between f/1.8 to f/2.2, and one f/2.8. Overall, I'm pretty happy with adding this combo to my gear!

http://www.yufamilyonline.net/nel/50mm430ex/01.jpg

http://www.yufamilyonline.net/nel/50mm430ex/02.jpg

http://www.yufamilyonline.net/nel/50mm430ex/03.jpg

http://www.yufamilyonline.net/nel/50mm430ex/04.jpg

http://www.yufamilyonline.net/nel/50mm430ex/05.jpg

http://www.yufamilyonline.net/nel/50mm430ex/06.jpg

http://www.yufamilyonline.net/nel/50mm430ex/07.jpg

[elysium]

Very nice work. I tend to stick to the centre focus point only for portraits. Focus and then recompose. You have nailed it very well in all photos.

Last photo seems to let the sign stand out and your fiance seem to be a bit dim

[yunaiseng]

Very nice work. I tend to stick to the centre focus point only for portraits. Focus and then recompose. You have nailed it very well in all photos.

Last photo seems to let the sign stand out and your fiance seem to be a bit dim

Oh yeah! You should have seen it before I fixed it up a little bit in Photoshop :o I think the combination of the fact that I tilted the camera, plus maybe that she's in the lower part of the frame (?), and maybe also the sign being reflective? I have to be careful about those things!

So even at f/1.8, focus and recompose works for you?

[elysium]

Oh yeah! You should have seen it before I fixed it up a little bit in Photoshop :o I think the combination of the fact that I tilted the camera, plus maybe that she's in the lower part of the frame (?), and maybe also the sign being reflective? I have to be careful about those things!

So even at f/1.8, focus and recompose works for you?
Yeah, f/1.8 works fine for me as long as I use the centre focus point. It is the sharpest part of the lens so easy to recompose. I should use my 50 1.8 more often. I tend to use it more for still life.

I need a model for portraits. :( I would like to compare it to my Sigma 24-70 2.8.

[tdodd]

Oh yeah! You should have seen it before I fixed it up a little bit in Photoshop :o I think the combination of the fact that I tilted the camera, plus maybe that she's in the lower part of the frame (?), and maybe also the sign being reflective? I have to be careful about those things!

So even at f/1.8, focus and recompose works for you?
At 50mm and f/1.8 a distance to subject of 5' would give you a DOF of 2.4" total. So that's about 1.2" in front of 1.2" and behind the sharpest point. It's easy to see that focus/recompose *could* throw the focus off simply due to the inevitable movement of the photographer in handling the camera.

Plus the fact that if you recompose you are changing the distance from camera to subject means that your focus could easily be thrown off at fairly close distances. There are diagrams and words in these links which explain the problem....

http://visual-vacations.com/Photography/focus-recompose_sucks.htm

http://www.bobatkins.com/photography/technical/focus_recompose.html

Explore DOF values further here - http://www.dofmaster.com/dofjs.html. I've attached an example of the calculations for a 50mm lens at f/1.8 on a Canon 1.6X crop body at 5' (60"). At a subject distance of 10' you get a lot more room for small focus errors to not be a problem. If you were to stop down a little, to f/2.8 instead of f/1.8 you would increase your DOF a little further (see second attachment) and the lens itself would also sharpen up - wide open is not its strong suit for sharpness - but you would still throw your background nicely out of focus.

If you select the most suitable focus point, rather than always using the centre point, you will reduce focus errors caused by recomposing, and maybe eliminate them completely. Remember as well that as the subject distance increases you gain DOF and also the change in distance to subject through recomposing becomes reduced. In other words, it may not always be necessary to stop down for reasons of sharpness.

By the way, nice pictures :)

[keegsmeister]

Wow my friend! Great shots with your EQ there. I just ordered in my new 430EX and 50mm f/1.8 with a BG-E3 coming my way too...as I have a model shoot coming up. I can sure learn a few tips from these shots. Great work.

[yunaiseng]

Thanks for the comments! I definitely need to keep practicing. It seems for now, a good way to ensure getting the focus right is simply stopping down a little bit for more DOF. But one day, I'll work my way up to a f/1.2 lens and hopefully by then, my focus technique will be refined enough to take advantage of shooting wide open! :D

[loony33]

At 50mm and f/1.8 a distance to subject of 5' would give you a DOF of 2.4" total. So that's about 1.2" in front of 1.2" and behind the sharpest point. It's easy to see that focus/recompose *could* throw the focus off simply due to the inevitable movement of the photographer in handling the camera.

Plus the fact that if you recompose you are changing the distance from camera to subject means that your focus could easily be thrown off at fairly close distances. There are diagrams and words in these links which explain the problem....

http://visual-vacations.com/Photography/focus-recompose_sucks.htm

http://www.bobatkins.com/photography/technical/focus_recompose.html

Explore DOF values further here - http://www.dofmaster.com/dofjs.html. I've attached an example of the calculations for a 50mm lens at f/1.8 on a Canon 1.6X crop boy at 5' (60"). At a subject distance of 10' you get a lot more room for small focus errors to not be a problem. If you were to stop down a little, to f/2.8 instead of f/1.8 you would increase your DOF a little further (see second attachment) and the lens itself would also sharpen up - wide open is not its strong suit for sharpness - but you would still throw your background nicely out of focus.

If you select the most suitabe focus point, rather than always using the centre point, you will reduce focus errors caused by recomposing, and maybe eliminate them completely. Remember as well that as the subject distance increases you gain DOF and also the change in distance to subject through recomposing becomes reduced. In other words, it may not always be necessary to stop down for reasons of sharpness.

By the way, nice pictures :)

Very informative. Thank you. Great links.

[MikeRichards]

Question, what body are you using? I see some vignette on the images and think it might be a 5D but I guess you could have done that in post too.