DSLRs v Bridge (compacts) - again

[Jack Harrison]

I readily concede that for ultimate quality, the DSLR reigns supreme. But a major disadvantage of a compact is not so much the direct result of each pixel being smaller, but the dynamic range that is not as great.

Now some technical matters.
A typical computer monitor has a dynamic range [of brightness] of 256:1 (Think of the RGB values). 256 is 2 to the power 8 (2*2*2*2*2*2*2*2). This equates in terms of camera F stops of 8. In other words, provided the subject being photographed has a dynamic range of less than 8 stops, then it should be possible to avoid over-blowing the highlights and losing detail in the dark areas as seen on a screen.

It just happens that most compacts can deal with a dynamic range of precisely that, ie 8 stops. So with perfect exposure, a compact can just about cope. On the other hand, DSLRs have a dynamic range of around 11 stops so perfect exposure is not quite as critical; moreover, DSLRs can photograph a subject with a much bigger dynamic range than is possible with a compact.

I really struggled today with this Red Admiral on Hawthorn blossom. I took many photos. Some had totally washed out highlights (the blossom) but the butterfly was exposed reasonably well. If I got the highlights OK, then the butterfly was too dark. There were many failures but at least, unlike the old days with film, it didn’t cost.
Auto-bracketing helped get it right.
Only one of these pictures hit it reasonably adequately but even this needed the PhotoShop “Enhance-Adjust-Shadows/Highlights”. I just about got there in the end but this really showed up a major disadvantage of the compact.



Photo taken with Panasonic Lumix FZ38, F/8, exposure bias -2 stops, minimal fill-in flash.

Jack

[Padfield]

That was a helpful analysis, Jack. I hadn't thought in terms of dynamic range, but it makes good sense.

With whites and yellows, I've increasingly adopted the habit of photographing them into the light so as to bring out upperside details, and this of course brings the additional benefit of reducing the dynamic range (by removing the bright extreme of light reflected off a white or yellow surface).

This wood white is taken into the light - hence the silhouetted body and the clear apical mark. With my compact I find it very hard to get that amount of detail on a white using purely reflected light.



Like you (I think), I value the lightness and convenience of a compact and am quite content to leave the heavy, expensive equipment to the serious photographers!

Guy

[David M]

That's interesting. I've noticed recently that Brimstones taken into the light seem to show up far better than those taken with the sun to the rear.

Wish I'd read this before photographing Wood Whites last Saturday and getting frustrated at the lack of detail coming through.

[Zonda]

LOL!!! Have a word with Gruditch.

[NickB]

Interesting analysis, Jack. It is all about getting used to your own equipment and the results you can achieve, as Guy often demonstrates.
I carry a wide-angle, zoom two macros and a tele-converter to achieve the same range of focal lengths as the FZ38.
But the compact can not match a good A3 print from a DSLR, however good it looks on the web, where the resolution is 800 pixels for all.
It all depends what you want and how much you think you can afford.
The rest is practice, practice and more practice

Luckily, when you love butterflies, that is easy

[Jack Harrison]

Nick:

It all depends what you want and how much you think you can afford.

Didn't I tell you Nick? Money is no object. I'm a millionaire (in pence).

I have often wondered how many millionaires Italy lost when it ditched the lira for the euro. If I'd been an Italian in 2002, I would have been highly ****** off to lose my status overnight.

Of course: "I don't give a **** about the Lira," was one of President Richard Nixon's more memorable foreign policy pronouncements.

Jack

[A_T]

I've often found with a compact because of the shutter-lag by the time the picture is taken the butterfly has gone!

[NickB]

I've often found with a compact because of the shutter-lag by the time the picture is taken the butterfly has gone!

One of the frustrations of a compact or bridge camera - remembering to stay still long-enough for the shutter to drop and missing shots as well.
The newer generations have less delay and do deliver outstanding close-up shots.
But I'm committed (or perhaps should be ) to carrying around a bag of glass with my DSLR and mono-pod (and sometimes tripod).
Obsession is a terrible thing....

[Jack Harrison]

Seeing Zonda and Chris in action yesterday with their big DSLRs, there is obviously another huge advantage over even the best of Bridge cameras. They were operating from a far great range than I had to use so they missed fewer shots.

So at what sort of distances from a butterfly can you DSLR people operate?

Jack

[Rogerdodge]

Jack
With my favoured (but sadly obsolete) Sigma 180mm Macro, I use it in the range-
Closest focus at 1:1, front of lens 9" (22.5cm) from the subject, and we have an image 13/16" (2cm) across the frame, which is too close for even an "in your face" Small
Bblue.
to
at (approx) 1:10, front of lens 6' (180cm) from the subject, image 8 1/8" (20cm) across the frame, which would give plenty of arty space around a Swallowtail.

[NickB]

My beloved f4 200mm Nikkor macro has the following characteristics:
"Close Focus: 1-5/8 feet (0.5m).
Working Distance: 10.2" (260mm), the distance between the subject and the front of the lens at 1:1.
Maximum Reproduction Ratio: 1:1, life size on-film or on-sensor"

In reality, my working distance with the 200mm is about 70ccm to 100cm generally; I can go closer in to 50cms, but for smaller butterflies only as the d-o-f is generally minute at that distance, unless you have very good light to push the aperture, or, as I recently experimented with, use higher ISO settings.
For larger butterflies and when I want a record shot, I can (and do) shoot from anything up to 4 or 5 metres; as Roger says, sometimes you have to content yourself with a more distant shot and concentrate on the composition or ID confirmation, rather than that scale-perfect one you were hoping from that species
....there will be another time......

[Zonda]

Hya Jack:
My current butterfly lens is a secondhand Nikon 300mm f4 prime, fitted to a Nikon D300s. It lets me stand off, (four feet) and i get less flyaways. It has no optical stabilisation, but it does have monopod stabilisation. It is not a macro lens, but the lens quality lets me crop quite a lot. I am about to experiment with extension tubes, i'll let you know.

[Jack Harrison]

Closest focus at 1:1

I do understand what that means if you have a 35 mm size film or sensor and used the term myself in the old days of film.
eg, at 1:1 a 1 centimetre object would be exactly 1 centimetre on the film.

But what does that term mean with a smaller sensor, for example an APS sensor of around 25 x 17 mms?

And Roger why all these funny terms such as 13/16" ? It's along the lines of a "youth" (actually just four few months younger than me) I was chatting with in a pub the other night. We were reminiscing about the price we paid for our first pints of beer. We both recalled paying "one and three" a pint and he would buy a round of three pints for "three and nine". We reckoned that such jargon would be incomprehensible to today's drinkers.

So Roger. I don't think you are quite as old as me so why all this feet and inches business?

Jack

[dilettante]

Closest focus at 1:1

I do understand what that means if you have a 35 mm size film or sensor and used the term myself in the old days of film.
eg, at 1:1 a 1 centimetre object would be exactly 1 centimetre on the film.

But what does that term mean with a smaller sensor, for example an APS sensor of around 25 x 17 mms?

1:1 always means 1:1, regardless of film/sensor size. At 1:1, that 1cm object is still 1cm on your APS sensor. You'll just get less in the frame at 1:1 than if you're using a 'full frame' camera or 35mm film. It's essentially cropping the middle of the 35mm image.

A smaller sensor allows you to fill the frame with less magnification than is required for 35mm, and hence greater working distance and depth of field for the same focal length, which can be an advantage. But it's essentially still just cropping.

[Rogerdodge]

And Roger why all these funny terms such as 13/16" ?

Because that is what it was....................
It wasn't 3/4, and it wasn't 7/8ths
Why on earth is it funny?

[Jack Harrison]

I just find the use of such old fashioned terms as 13/16 of an inch surprising. Quaint. And yes, funny.

The scientific world (and cameras are surely up to a point scientific pieces of equipment, certainly as far as things like sensor sizes are concerned) has been metric for years (except in America). Remember the space probe that crashed on Mars due to mix up of units, or the airliner that ran out of fuel in flight had been refuelled in pounds instead of kilograms.

That reminds me. I got some petrol the other day. It cost £6 5s 3¼d per gallon.

Jack

[JohnR]

That reminds me. I got some petrol the other day. It cost £6 5s 3¼d per gallon.
Jack

More than my first weekly salary when I started work full time, but when I was a teenager I got the agricultural rate of 10 3/4d an hour for filling 2 cwt sacks on the combine.

And yes I much prefer my DSLR to my Bridge if only for the manual focusing.