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07-10-2011, 02:41 PM
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Quote:
Originally Posted by Otis226
But I'm liking the specs of the Cannon Powershot G11 and a few of the Nikons as well.
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The Cannon Powershots are good Cameras. That's what my last one was and I loved it. When I first got it I found it so much better than my previous camera. But I kept trying to do more and more and more with it and in the end after a few years found that I had outgrown it. I just hope I don't outgrow the new one too quickly, but I've got a lot to learn before that happens
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07-10-2011, 02:43 PM
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Quote:
Originally Posted by ronaldhanko
Congratulations, Rosie!!!!!!! I am so pleased that you've gotten a camera and a good one. Can't wait to see some pictures.
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Thanks Ron. Not up to the spec you work with, but not bad for a beginner like me and I've got a lot to learn I think before I can make the best of it.
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07-10-2011, 02:51 PM
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Quote:
Originally Posted by silken
If you don't have a tripod-that will be next for those macro shots.
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I have a smallish one (not one of those bendy ones, but one that ranges from about 1' to 3'). It will do for now but I will be looking for something more soon.
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07-11-2011, 12:27 AM
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Quote:
Originally Posted by Val
The good news is that macro lenses are designed especially for being used at the smallest apertures (up to 32 and even 45), thus achieving a maximum depth of field without loosing sharpness.
You could achieve better depth of field with a DSLR by using a special technique: focus stacking (see: Focus stacking - Wikipedia, the free encyclopedia and ).
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Generally there was good info, but unfortunately the macrolens-diffraction part is wrong. Diffraction is only dependent on f/stop and magnification. The difference between a macro lens and a regular lens (even of same focal length) is optimization of errors (e.g., chromatic aberration) at closer distance. Most regular lenses are optimized for close to infinity focus (possibly at hyperfocal distance wide open), whereas macrolenses are optimized for anywhere between 1:10 to 1:2. Depends on precise model of lens.
Yes, you get clearer images with a macrolens than with a regular lens set to close-focus (or with extension rings), but it has nothing to do with diffraction, but with optimization of lens design. If you look at long-sections of lenses, normal lenses are more asymmetrically built, while macro-lenses are more symmetrical. The old OM 80 mm bellows head lens was perfectly symmetrical as it was designed for 1:2 to 2:1.
Second issue is the difference between f-stop set on lens, and effective f-stop at the sensor plane. In close-up/macro, effective f-stop increases according to f(eff)= f(lens) x m+1. So if you set f/16 on lens, you focus to 1:1 (= close-up limit of the Canon Macro), then effective f-stop is 16 x 1:1+1=16x 1+1 = 16 x 2 = 32.
A few macro-lenses correct for that (e.g., the old MicroNikkor series, but not the Canon 65mm MPE). Not sure about the Canon 100 L.
Why bother about the above? It has to do with the question at which f-stop diffraction becomes objectionable depends on the final magnification of the image (size on screen, size of print). The usual rule is f/32 of 8x10 print held at viewing distance of 2-3 feet for 35 mm film = full size sensor (~8x magnification). The larger the magnification the more the diffraction blur (= Airy discs) gets magnified. The larger the format, the higher the f-stop you can shoot. So if you shoot 8x10 largeformat film and make a contact print, you can easily get away with f/64 (hence the name of the Adams photo group).
What that boils down to is, that with your APC format camera, if you want to print 8x10 you should stay well below f/32, possibly at effective f-stop of 16 for tack sharp images. Occasionally you may go beyond the threshold, but then you do it knowingly.
Focus-stacking, z-stacking is a lot of fun, as was pointed out.
If you (or your husband) like to learn more about optics, I can highly recommend Sidney Ray's Applied Photographic Optics from Focal Press.
Despite all this techy mumbo-jumbo, please have fun with your new camera. Glad you already turned off the AF, the most useless feature on modern cameras, particularly in close-up/macro.
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07-11-2011, 05:30 AM
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Thanks for that info.
Now you would have thought that the fact that I have a Masters Degree in Physics would mean that I understand optics very well (still have my optics textbook on the shelf) but the fact is I don't remember this any better than the rest of the physics stuff
I really will be reading a lot more about it though. Really finding it all quite interesting now it's for fun not pure study
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07-11-2011, 12:03 PM
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There may be a *slight* difference between theoretical physics and real life application, including optics ;-) We all remember those falling objects in pure vacuum.
Ray's book has some of the mathematical derivations in there, so if you are inclined, you may follow along. For me it was hard at times, and have forgotten most of it. Some of the more practical applications, however, have clearly sunken in. I think you can skip the math no problem, and the book is still terrific.
Completely agree that once you see the point, study is fun. And knowledge is power. For me it happened with statistics in the most prominent fashion. I leaned photography in the dept. phys. chem. back in school, so have a bit of a more techy take on photography.
If you like reading, I can highly recommend Hunter Biver & Fuqua Light: Science and Magic.
I don't know what your goal is with photography (view on monitor, post to websites, print); there's a significant amount of information on digital processing as well. The eye-openers for me were books on Lab color space and on sharpening. Color management for print is necessary but not terribly exciting.
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07-11-2011, 12:07 PM
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Quote:
Originally Posted by RosieC
Thanks for that info.
Now you would have thought that the fact that I have a Masters Degree in Physics would mean that I understand optics very well (still have my optics textbook on the shelf) but the fact is I don't remember this any better than the rest of the physics stuff
I really will be reading a lot more about it though. Really finding it all quite interesting now it's for fun not pure study
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And the great thing about digital, is that you can learn by taking pictures. Since you don't have to pay for film and developing, you can snap away at any setting you want, and find what works best. Photo stacking AND HDR (High dynamic Range) techniques are both fun and added bonuses.
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07-12-2011, 05:44 AM
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Quote:
Originally Posted by silken
And the great thing about digital, is that you can learn by taking pictures. Since you don't have to pay for film and developing, you can snap away at any setting you want, and find what works best.
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I know. That is the only reason I think I could get hubby on board with the idea. Years ago when we had a 35mm compact he never took photos. I had to really push him to take anything when we were on holiday and I wanted to have a couple of snaps with me in.
When we got our first Digital compact he was suddenly taking photos all the time. I asked why the sudden change and he said that it was because he knew he wasn't going to 'waste' the film/processing by taking a bad shot.
Now with this new one... well he's loving it as much as me and is planning to go out with a friend who has an SLR and likes to go out in the countryside snapping whatever he can. And is planning to go to a photography show with him as well.
I really wouldn't have experimented as much with film. First off I can see the result and if it is under or over exposed or if the depth of field is too shallow straight away and snap another shot with different settings straight away. Second (but not least) there is no cost involved with doing so.
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07-12-2011, 05:15 PM
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Some of the first taken on Saturday. These aren't the best, especially in respect of the focus was just auto focus on these. But what I particularly like here is that the colour is almost true. My old camera could not get a true colour for this orchid (always looked too red, or too dull purple).
The first pic was hand-held and one of our very quick snaps testing the new camera within the first hours of getting home. The second was on a tripod with a wider depth of field than the first and a half second exposure to force the ISO down (the first having auto picked 1600 ISO).
At the moment Hubby is taking pics of a different orchid that's just flowered. He's spotted a spiderweb on the flower that we couldn't see until looking at the pic
Last edited by RosieC; 07-12-2011 at 05:24 PM..
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07-12-2011, 05:20 PM
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And he's just done one with a 25sec exposure to force a low ISO on a picture. That is where a tripod is essential! I hardly dared breath even though I'm the other side of the room, but it came out sharp
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