Post Your Best Nature Shots!

[Stephen Probert]

Yeah, I think the vignetting is too much. It almost looks like a night shot and you were using a spot light or something. What were you going for? Also were you shooting through glass or was there something on your lens? The first image looks like it has a smear that goes through the mama Terns left foot.

[Sinh Nhut Nguyen]

thanks for the comments


The least terns are endangered so their nesting site is fenced off from the public, I had to shoot through a fence. The ground where they nest isn't that attractive so I try to use the vignette to isolate the subject, perhaps I over did it it. Thanks for the comments.

[Jon Ruyle]

I think you are right. Those are great, and I think the vignetting does help detract attention from the uninspiring background. If you tune the vignetting down a bit it might be perfect.


Your pics always look so sharp. I'm not sure what it is, because even a chepo lens should be sharp enough that it doesn't matter for small pics like the ones you've posted. I don't think it is the lens. I think it is something you do- lighting, exposure, or processing. Dunno. Maybe you just choose to photograph sharp birds []

[George Slusher]

Some backyard nature. I put a bird bath outside my office window. (No feeder, yet--I have to figure out how to thwart the neighborhood "rats-with-fluffy-tails," plus am a bit concerned about dropped seeds germinating.) So far, I've only seen jays using the bath. It may be too deep for smaller birds--I'm just learning about this. I'll keep the water lower and will add a smaller, shallower bath, as well.


I keep my Canon S3 IS near my desk to grab shots. These were with the S3 IS in aperture-priority mode at 1/100, f/3.5, ISO 80, FL = 44mm. The S3 IS has a 6x Field of View Crop Factor (FOVCF), so that's equivalent to 264mm for 35mm full-frame or 165mm on a Canon 1.6x camera, though see below.

















When one puts "equivalent to xxxmm full-frame," one should understand that this applies to framing--what is in the image. Other factors may not be equivalent. One very obvious one in the photos above is depth of field. Using the online calculator at DOFMaster, I made a comparison that shows the difference. The actual numbers for the photos above don't show up in the pop-up menus, so I used something close that did:

• Canon PowerShot S3 IS (6x FOVCF) @ 40mm, f/4, 15 ft: 14.2-15.9 ft, total 1.7 ft
• Canon xxD or most Digital Rebels (1.6x FOVCF) @ 150mm, f/4, 15 ft: 14.8-15.2 ft, total 0.45 ft
• Canon 5D or 1Ds or 35mm full-frame @ 240mm, f/4, 15 ft: 14.9-15.1 ft, total 0.27 ft

(Note that the DOFs are in ABOUT the same ratio as the Field of View Crop Factors, though not exactly.)


To get roughly the same total DOF at the same distance, the longer lenses would have to use smaller apertures.

• 1.6x camera @150mm, f/16, 15 ft: 14.2-16 ft, total 1.8 ft (it should be f/15, but that's not in the menu)
• 1x camera @ 240mm, f/25, 15ft: 14.2-15.9 ft, total 1.72 ft (should be f/24, but that's not in the menu)

Note that the aperture multiplies by the inverse of the ratio of FOVCFs. (IOW, multiply the aperture of the 6x camera by 6/1 for the full frame camera, 6/1.6 for the 1.6x camera.)


That shows why point-and-shoot camera have such long DOFs--and why it's difficult to get significant blurring/bokeh from them. The good aspect is that focus is less critical, so most people tend to get "better" shots. This is also why I use the S3 IS (6x FOVCF) for this, rather than my 30D (1.6x FOVCF) or even G9 (4.73x FOVCF).


Another way to get the same DOF with longer lenses on cameras with larger sensors is to back off. Again, the FOVCF comes into play.

• 1.6x camera @ 150mm, f/4, 29 ft: 28.2-29.9 ft, total 1.7 ft
  
• 1x camera @ 240mm, f/4, 37 ft: 36.2-37.9 ft, total 1.7 ft

Note that the distance is multiplied by the square root of the inverse of the ratio of FOVCFs.


That would, of course, change the perspective quite a bit. (Perspective depends upon the relative location of the "viewer"--camera--and subject, not upon the focal length, FOVCF, etc.)


Another note: DOF depends upon one's definition of "in focus." That's contained in the "circle of confusion" criterion, which is selected considering the magnification of the image at the sensor/film to get to a particular size for viewing on a screen or a print, as well as the viewing distance of the screen/print. What looks "in focus" in a smaller image or when a print is viewed from further away may not look as good in a blown-up (or 100%) image or the print viewed up close. One could choose a different set of circles of confusion and get different DOFs in the calculations, but, if the circles of confusion are chosen consistently for all cameras, the relative results will be the same.