Question for Bugeye or Brian on Stop Down

[JayMorr]

Hey fellas I have a question. When you get some time maybe you can comment or share how you "Stop Down" on a camera in order to hone in on finding the ideal fstop for best possible clarity. This would be on any given lens before an image starts to soften on the outer edges... (I guess this is probably more important for me to understand since I am not rockin the best glass yet and I want to push my lens and get the best clarity without having to use Lightroom or CS3). Right now I find myself stopping down from f8 to f11 and most of the time I stay in between the two in fear of losing clarity. Maybe I am just not understanding it correctly.....

Any help is appreciated.

JayMorr

[mtbbrian]

Using the best glass possible helps Jay.
I am guessing you're using consumer grade glass, which are good lenes, but the pro ones are much better, because your comments sound more like an issue regarding lens sharpness rather than depth of field.
Remind me what system are you using again? Nikon or Canon?
I am sure Doug can add something a bit more relevant.
I see that the two of you are doing presnetaions at the Wasatch Expo in May.
Kudos to both of you!
Brian

[JayMorr]

Thanks Bri...

I am shooting Canon. My Tokina 80-400mm is considered pro grade but I know it still is not Canon L series. I guess I am mainly concerned with my fstop and going farther out on my mm. Most of my other lens's are Canon consumer grade, however I am trying to change that ;)

I am using http://www.whcamera.com/index.asp?PageAction=VIEWPROD&ProdID=4648

JayMorr

[mtbbrian]

however I am trying to change that ;)

JayMorr

You'll get to that point soon Jay!
Personally, and this is just "photography according to mtbbrian", a lens with that kind of range isn't a lens a pro would have in his or her bag.
And I also prefer to shoot with the same lens as the name on the camera, it's just my thing. I know Tamron, etc are good, I just prefer shooting Nikon glass with a Nikon body.

A lens with that kind of range probably has a pretty narrow depth of field, so I'd imagine you'd be OK at f8-11, especially with the kind of work you do.

I'm going to be at the Wasatch Expo, so I'll try to meet up with you.
Brian

[BugEye]

Hi JM. The simple answer is this: Most lenses are sharpest two or three stops down from maximum aperture. For example, if you shoot with a f/2.8 then that particular lens is sharpest @ f/5.6-f/8 (as a general rule). If you use an f/3.5 lens, best performance is achieved somewhere around f/8--f/11. That's one reason to get the fastest lenses possible as a two stop difference is huge. Stopping down to f/16 of f/22 (for example) will give you more depth of field but drain detail through lens refraction (in most cases) so avoid it.

One thing you might try is to set your camera up to automatically bracket your aperture while you shoot, then snap an extra few frames. So when you're shooting that cool shot and your settings are, say, 1/500 sec @ f/8, your camera will take two extra images: a 1/250 @ 16, and a 1/1000 @ f/5.6 frame. Open 'em up in whatever software (you are shooting RAW images right? Good!) and blow them up to 100%. Make sure to look at the corners and the best setting will shine.

Hope this helps.

BugEye

www.nowpicturethis.com

[mtbbrian]

Hi JM. The simple answer is this: Most lenses are sharpest two or three stops down from maximum aperture. For example, if you shoot with a f/2.8 then that particular lens is sharpest @ f/5.6-f/8 (as a general rule). If you use an f/3.5 lens, best performance is achieved somewhere around f/8--f/11. That's one reason to get the fastest lenses possible as a two stop difference is huge. Stopping down to f/16 of f/22 (for example) will give you more depth of field but drain detail through lens refraction (in most cases) so avoid it.



You could do a test like this, shooting a street sign, say a speed limit sign, that is black and white and has good hard lines.
I know magazines use some kind of chart, but a street sign would work in a pinch.
Brian

[JayMorr]

Doug and Brian....thank you very much! That is exactly what I was looking for, I appreciate it. Doug, I had not thought of bracketing. Awesome! (btw, yes everything is shot in RAW ;) I am heading out today to purchase a 1terabyte external. I know its another topic but I would love to see how you catalog your images! Maybe we can talk at the expo. I made a mistake early on and now I am re-indexing all of images with date tags. Seems to work better. Do you keep everything you shoot for reference? I am using lightroom now which has helped but I still have some issues with it and how it auto changes image settings. However, my files have been a mess with the RAW, coverting them multiple times to tif and jpeg etc... 1 image sometimes equals out to be 10. Space has always been an issue.



JayMorr