DOF and MY circle of confusion

[suzyjazz]

No wonder I blew all my flower pics yesterday. According to this calculator, my DOF was something like 0.01 ft.

Sheldon, I am going to "pick" on one of your lovely photos; I hope you don't mind. :-) The below is one of Sheldon's photos in his Houston Zoo gallery in pbase -- is it OK for me to link to it?

http://www.pbase.com/sheldon/image/39727615

First, it's a 200mm lens and the EXIF says it's at 250 -- is that from using an extender?

How did you get this in focus at f4? I guess you'd have to be at least 30 feet away from the subject. I'm terrible at judging distances, but it doesn't seem like at 30 feet away that would fill the image.... Is it cropped?

It's a wonderful photo, and it's at f4 so I picked on it to learn with. Thanks to anyone who can help me out. I've read a little bit about this online, and I sort of understand what is beng said, but then I see pics online and still wonder how they were done. I guess the main thing you can't tell from the typical EXIF is how far away the shooter was -- which is actually very important.

Well, I feel dumb! Tomorrow I am going to the dog park to take some more out of focus pics!

Suzy

[Hogleg 44]

Suzy. You may have been getting camera movement. Not out of focus. Depth of field is directly related to the f setting. The higher the f setting you can use the greater the depth of field. What you probably need to try to do is use a tripod and a shutter release, or a selftimer release if your camera has that option, and set the camera on aperture priority at about f5.6 and let the camera automatically choose a shutter speed. If you get too much DOF you can use a lower f setting, and experiment from there to get what you want. But unless you have abundant light you probably really need a tripod to hold the camera still.

I hope this answer applys properly to your question>

[suzyjazz]

Thanks Paul. Maybe a monopod will do? I was outside in lots of sunlight, but my shutter speeds ranged from 1/100 (with the 28-135 IS lens, I still should have upped the ISO a little on that) to 1/2000 (with the 70-200 f4). I really hope I wouldn't have to worry about camera movement at 1/2000! The 70-200 will take a lot of getting used to. I know in the big scheme of lenses it is not big and heavy, but for *me* it is. I hope to get better with practice, but I think a monopod will help me so I plan to get one soon. The flower shoot wasn't very important to me so it was a good time to learn these lessons. If the camera was moving too much and the depth of field was as shallow as that calculator tells me, that would explain it.

[bbailey]

If you had speeds that high camera shake should be minimal, but I guess that depends. The subject may have been moving as well. Also remember that the closer you are to the subject, that shallower the depth of field becomes at any given f-stop. You probably noticed already this using the DoF calculator.

[Bill Huber]

Suzy, post some of your shots and let us see if we can come up with an answer. Not seeing the shot is it is real hard to say if it is camera shake, or DOF problems.

[suzyjazz]

Here's a few: http://suzyandscott.com/content/bad.htm
Out of laziness I posted all the JPGs extracted from RAW, no processing.

I didn't realize how shallow the DOF would be in this setup (standing so close) With gentle air movement, that's all I needed to mess it up!

Thanks for everyone's feedback. If I make it out to the dog park today I'll try using larger f-stops. I will be farther from the subject, though,in most cases, so I will try a variety of things!

[Bill Huber]

Originally Posted by suzyjazz

Here's a few: http://suzyandscott.com/content/bad.htm
Out of laziness I posted all the JPGs extracted from RAW, no processing.

I didn't realize how shallow the DOF would be in this setup (standing so close) With gentle air movement, that's all I needed to mess it up!

Thanks for everyone's feedback. If I make it out to the dog park today I'll try using larger f-stops. I will be farther from the subject, though,in most cases, so I will try a variety of things!

I don't think it was a movement problem, I feel it was just a DOF issue.

I have a real hard time with DOF calculates, that is how much is .2 inches of how much is 1 inch.

Here is a site that I use for the DOF calculator, I like it because it shows all the f stops not just the one you have to enter.

http://www.digitaldiver.net/dof_x.php

When I get my camera I just started to play with the DOF to see what it really was. Here are to shots, one at f3.5 and one at F11.

What I would do if I were you is shot some shots, the same distance, of the same thing, the only difference is I would change the F stop and see just how much difference it makes. I would have the camera in aperture priority.

1/1000s f/3.5 at 54.0mm iso200

1/125s f/11.0 at 54.0mm iso200

[suzyjazz]

Thanks Bill! I like that this calculator shows you the whole range. Although, I have a hard time with meters. ;-) I guess the trick to shooting flowers with the 70-200mm is to use a larger fstop, and if that doesn't look how I want, I could step back a little and then crop the image.

Oh well, it was a practice shoot and now I know better. I need to perform some tests and see how fast my shutter needs to be for me to hand-hold this thing. I shoot in Av mode 90% of the time but I am usually aware of the shutter speed (sometimes I forget) and will up the ISO a little if I need to.

Nice flower, BTW -- the kinds of shots I was trying to take, which I am sure is why you picked that one :-)

[Bill Huber]

Originally Posted by suzyjazz

Thanks Bill! I like that this calculator shows you the whole range. Although, I have a hard time with meters.

On the distance, just pick feet in the drop down menu.

I really like using my 50mm macro lens for flowers.
I of the neatest things about digital is you can take all you want and it doesn't cost anymore, and then there is the EXIF data so you don't need a little note pad in your pocket to write everything down.

Good luck and show us what you learned and found out about the DOF on the 200mm lens.

[suzyjazz]

Oops, didn't see the dropdown. Thanks! :-)

Flowers aren't really my thing, but next time I will use my 50 1.8. Planning to go to the dog park in a little bit to use the 70-200, so if I get anything good I will post!

[suzyjazz]

I must be a slow learner. :-( I made a new thread in the Photo Tips section on shooting fast action. I increased the depth of field and I think my problem is focusing. Even in my best shots, everything is just barely out of sharp focus. Next time I will shoot f11 and ISO 400 and see what happens. It was too hard to review my images in the field (too bright), so I didn't really know how I was doing.

http://www.lifeatf8.com/phpBB/viewtopic.php?t=2136

I didn't spend 500+ on this lens to completely stink at using it. I already bought my ticket to DC for Memorial Day, so I have 2 months to get a LOT better! That's about 8 weekends.

[Hogleg 44]

Originally Posted by suzyjazz

Here's a few: http://suzyandscott.com/content/bad.htm
Out of laziness I posted all the JPGs extracted from RAW, no processing.

Suzy, could this be the problem? The sharpness really comes from the post processing. For sure in RAW. The camera deliberately produces soft images by default. Try post-processing and applying various unsharp mask settings and see what that does.

[suzyjazz]

That is one reason I posted these JPGs, so someone who really knows could tell me if they're out of focus or just soft. I thought the JPG extracted from a RAW was processed some, but I guess I am wrong? To me, these look worse than images that just need a little sharpening. I have actually taken images with a 50 1.8 lens that were sharper in their RAW format (CRW file) than these JPGs are. Thanks for the idea, though! I wish that were the case.

[LoungeLizard]

Originally Posted by suzyjazz

That is one reason I posted these JPGs, so someone who really knows could tell me if they're out of focus or just soft. I thought the JPG extracted from a RAW was processed some, but I guess I am wrong? To me, these look worse than images that just need a little sharpening. I have actually taken images with a 50 1.8 lens that were sharper in their RAW format (CRW file) than these JPGs are. Thanks for the idea, though! I wish that were the case.

The JPEGs that are extracted from the RAW are processed using the parameters on the camera settings at the time.