Flowers

[ajohnw]

Yesterday I saw a flower that would make a good photo, Sunlight angle just right but clouds moved wrecking that aspect. Thought try today but very heavy rain so flower has had it.

I wanted to try an idea to reduce DoF. Use a telephoto. So chose some others and took this at 150mm F5.6 from about 1m or so. I just framed it, M4/3. It's come out getting near twice life size shown at 100ppi. The flowers are about 4" wide and leaves about the same behind it.



The depth compression isn't that apparent compared with an eye view. Pixel peeking suggests that F8 or a shorter FL would have been better and personally I feel the leaves are too blurred.

Simple processing. Sharpening plus a soft light layer and reduction.

[DanK]

John,

Using a telephoto lens won't have much affect on DOF if the framing of the flower is the same, although it will shift the DOF back to front. Check out the DOF tutorial on this site, under "how your camera works."

However, using a longer focal length WILL increase background blur. DOF refers only to the size of the distance range within which the image is acceptably in focus. Background blur is something different: how quickly the image blurs as you move back from the area of crisp focus. That contributes to the nice blurring of the leaves here. This is one reason (working distance is the other) that macro photographers often prefer longer lenses.

However, to get more of the petals in focus is really a matter of DOF. There are only two solutions for getting more in focus: a smaller aperture (larger f-stop), or focus stacking.

Dan

[ajohnw]

There is another factor. Eg the serrations on the edge of the petals are very small. It's reproduced by a combination of pixels and circles of confusion, These circles of confusion increase in size as distance increase each side of the actual point of focus, So DoF also relate to the detail that needs to be reproduced.

Magnification in this case as posted is ~2x

The sites calculator comes up with 10mm dof for the settings but no mention of the actual size of the circle of confusion.

I've also seen comments about the hyperfocal distance on here. If some one want the true figures with that it starts of with the size of the circle of confusion and then 2 sums are done for the near and far distance and in some instances also for the distance to objects behind the subject but in a slightly different way - the actual size of the circle of confusion to see how much blur will be introduced,

Much of these comments relate to what is actually recorded on the sensor not final image size.

I have a longer focal length macro lens and an APS camera just to use with it. purely due to the extra working distance compared with my M 4/3 one which is rather short. Olympus have introduced another fairly recently. Curiously max mag is from memory 1.4x not 1 to 1.

[DanK]

The new Olympus 90mm macro has a maximum magnification of 2:1 (2 x), which is unusual. Apart from a few specialty lenses, most macro lenses have a maximum of 1:1 unless you add tubes, etc. If I had limitless money, I would use an OM Systems OM-1 and that 90mm lens for bug macros. I think it's the best combination available. However, the pair is about US $4,000.