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Telephoto Reach and Digital Cameras - lens comparison
A comparison of fixed focal length lenses & consumer zooms on DSLRs when
photographing distant objects: http://www.clarkvision.com/articles/telephoto_reach/ including a comparison with a super-zoom P&S. http://www.clarkvision.com/articles/...are.moon.a.jpg A longer zoom may not be better than a shorter fixed focal length lens. |
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Telephoto Reach and Digital Cameras - lens comparison
On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor"
wrote: A comparison of fixed focal length lenses & consumer zooms on DSLRs when photographing distant objects: http://www.clarkvision.com/articles/telephoto_reach/ including a comparison with a super-zoom P&S. http://www.clarkvision.com/articles/...are.moon.a.jpg A longer zoom may not be better than a shorter fixed focal length lens. Yes, anyone intent on taking amateur photographs of the moon from their backyard should pay heed to this study. All six of them. -- Tony Cooper - Orlando, Florida |
#3
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Telephoto Reach and Digital Cameras - lens comparison
On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor"
wrote: A comparison of fixed focal length lenses & consumer zooms on DSLRs when photographing distant objects: http://www.clarkvision.com/articles/telephoto_reach/ including a comparison with a super-zoom P&S. http://www.clarkvision.com/articles/...are.moon.a.jpg A longer zoom may not be better than a shorter fixed focal length lens. Just more of Clark's garbage in, garbage out results. No wonder he was fired from so many jobs. His glaringly biased attempts to try to justify why he has spent all that money, like every other test he's ever done. You'll note that he should have used ISO100 and larger apertures on the superzoom, where the images would then have been nearly identical, because the superzoom lens improves on resolution at larger apertures, unlike on DSLR glass where the figure isn't good enough to hold to diffraction-limited resolutions at larger apertures. Instead he made sure to use the superzoom on settings where noise and diffraction limitations start to set in just to try to make his expensive gear look better to him. If you look at both images at pixel level you'll note too that he took a higher-resolution image from the DSLR then applied much higher JPG compression to the superzoom image. He just loves fudging his own tests to get the results he wants, always leaving out these important bits of details in his biased explanations. And all you fools fall for it, every time, guaranteed. |
#4
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Telephoto Reach and Digital Cameras - lens comparison
I was alerted to this thread by another.
Superzooms Still Win wrote: On Mon, 6 Dec 2010 16:20:48 -0000, "David J Taylor" wrote: A comparison of fixed focal length lenses& consumer zooms on DSLRs when photographing distant objects: http://www.clarkvision.com/articles/telephoto_reach/ including a comparison with a super-zoom P&S. http://www.clarkvision.com/articles/...are.moon.a.jpg A longer zoom may not be better than a shorter fixed focal length lens. Just more of Clark's garbage in, garbage out results. No wonder he was fired from so many jobs. His glaringly biased attempts to try to justify why he has spent all that money, like every other test he's ever done. The above statement is outright libel! I have never been fired from any job in my life. This is absolutely outrageous, and a complete lie. I have been with my present employer for 27 years and I was promoted this year. You'll note that he should have used ISO100 and larger apertures on the superzoom, where the images would then have been nearly identical, because the superzoom lens improves on resolution at larger apertures, unlike on DSLR glass where the figure isn't good enough to hold to diffraction-limited resolutions at larger apertures. Instead he made sure to use the superzoom on settings where noise and diffraction limitations start to set in just to try to make his expensive gear look better to him. Any astronomer knows that resolution is limited by aperture. It is a simple computation. The lens apertures found in superzoom cameras are quite small. Changing ISO does not change resolution, except in changing post image acquisition in camera noise reduction. The high zoom ratio of super zoom cameras are impressive in that they deliver OK image quality over a large range, but are soft compared to fixed focal length lenses. Stopping down a stop or so improves image quality on every zoom lens I have tested. So opening up the super zoom lens would have reduced diffraction up to 40%, but other aberrations would have reduced the image quality more. Figure 1 on the web page illustrates that effect using another zoom lens. If you look at both images at pixel level you'll note too that he took a higher-resolution image from the DSLR then applied much higher JPG compression to the superzoom image. They were the highest resolution jpeg each camera produces. And since the web image is one image with both the DSLR and P&S image embedded in it, the jpeg compression of the web image is identical. Of course the DSLR raw data could be used to produce and even better image. He just loves fudging his own tests to get the results he wants, always leaving out these important bits of details in his biased explanations. And all you fools fall for it, every time, guaranteed. BS. If you can match or better the DSLR+300mm+1.4xTC moon image shown with a P&S super zoom camera, the show us. You can't because simple physics proves you can't. The Dawes limit, is 4.56/D where D is the clear aperture diameter in inches: Thus: 300 mm f/2.8 lens, Dawes limit = 4.56/4.22 = 1.08 arc seconds. 300 mm f/4 lens, Dawes limit - 4.56/2.95 = 1.54 arc-seconds. FZ35 super zoom at max focal length of 86.4 mm fastest f/ratio, f/4.4, aperture =19.6 mm: Dawes limit = 4.56/0.77= 5.9 arc-seconds (and it only achieves that if other aberrations are smaller, and they are not at f/4.4). All superzoom P&S cameras have small clear apertures which limits resolution on a subject, regardless of focal length. It is simple physics, no bias. You have stated on rec.photo.digital that superzoom cameras are diffraction limited. Fine, but the diffraction is so large from the small aperture that it limits detail on a subject. DSLRs using telephoto lenses with larger clear apertures do not need to be diffraction limited to better the resolution on a subject over a P&S camera. Simple physics. Regarding Rich's comment: Anyone trying to take good moon shots by using a telephoto lens instead of a telescope is making a mistake. The point was not to compete with telescopes, but to show the relative performance of each camera and lens. The Moon is a natural target that anyone anywhere in the world can image, so they can test their own lenses and techniques and compare to others. At short focal lengths like 300 mm, atmospheric distortions are minimal. The Moon has effectively infinite detail and is not a bar chart, so more natural in terms of complexity of imaging in the real world. These results extend to wildlife, sports, people and other photography. Good telephoto lenses can take great images of the Moon. For example, check this out (be sure to click on the link to the full resolution image): http://www.clarkvision.com/galleries...0mm_e-900.html Let's see a P&S superzoom camera with its "super" telephoto lens beat that, or for that matter, even come close. It can't due to the simple physics of diffraction. No bias, just simple physics. Roger |
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Telephoto Reach and Digital Cameras - lens comparison
On Mon, 13 Dec 2010 23:20:21 -0700, "Roger N. Clark (change username to
rnclark)" wrote: Any astronomer knows that resolution is limited by aperture. It is a simple computation. The lens apertures found in superzoom cameras are quite small. Changing ISO does not change resolution Of course not, you ****ing moron, it changes the amount of sensor noise. The VERY thing that you are complaining about that's robbing the images of detail. You might want to learn how to use a camera properly to get proper exposures too, that too was used in your "tests" to bias your crap results to what you wanted them to be. lens I have tested. So opening up the super zoom lens would have reduced diffraction up to 40%, but other aberrations would have reduced the image quality more. Wrong, you ****ing MORON. Because the smaller glass for superzoom cameras allows the makers the ability to figure them to diffraction limited quality at an affordable price, whereby opening up the aperture DOES increase resolution. Unlike your piece of **** DSLR glass that ALWAYS degrades the images at larger apertures, because *NO* DSLR glass can ever be figured to diffraction-limited quality without putting their cost outside the reach of everyone. They were the highest resolution jpeg each camera produces. And since the web image is one image with both the DSLR and P&S image embedded in it, the jpeg compression of the web image is identical. So because they were the highest resolution available from each camera, you thought nobody would notice that if you didn't crop 1:1, pixel for pixel, representations from each camera, that NOBODY would see you trying to bias your test results with this blatantly obvious and simple TROLL'S BULL**** of yours again. As for JPG compression, I'm talking about SOURCE images you ****ing MORON. Care to trip over your side-stepping bull**** some more? So far your dance in your field of bull**** isn't going very well, is it. The rest of your BULL**** is just more of the same BULL****. No sense even replying to more than this. A waste of everyone's time. BTW: Someone already proved that they can get images of the moon with more detail and clarity using a handheld superzoom camera compared to $5000 worth of your DSLR crap gear. Even when your waste of money is mounted on sturdy tripods with mirror lock-up engaged too. Don't you remember that test? About 2 years ago. The last time you were laughed out of these newsgroups. Of course you do. That's why you've now spent two years of your useless life in fudging tests of images of the moon while trying to climb out of that pit you dug for yourself, and still you fail. Have some more omelet on your face. You're nothing but a ****ing joke. |
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Telephoto Reach and Digital Cameras - lens comparison
Superzooms Still Win wrote:
On Mon, 13 Dec 2010 23:20:21 -0700, "Roger N. Clark (change username to wrote: Any astronomer knows that resolution is limited by aperture. It is a simple computation. The lens apertures found in superzoom cameras are quite small. Changing ISO does not change resolution Of course not, you ****ing moron, it changes the amount of sensor noise. The VERY thing that you are complaining about that's robbing the images of detail. You might want to learn how to use a camera properly to get proper exposures too, that too was used in your "tests" to bias your crap results to what you wanted them to be. Wow what a foul mouth you have. That does not help your case. Both cameras were operated at the same ISO, thus no bias. lens I have tested. So opening up the super zoom lens would have reduced diffraction up to 40%, but other aberrations would have reduced the image quality more. Wrong, you ****ing MORON. Because the smaller glass for superzoom cameras allows the makers the ability to figure them to diffraction limited quality at an affordable price, whereby opening up the aperture DOES increase resolution. Unlike your piece of **** DSLR glass that ALWAYS degrades the images at larger apertures, because *NO* DSLR glass can ever be figured to diffraction-limited quality without putting their cost outside the reach of everyone. Again, your foul language does not help your case. The fact is that the FZ35/FZ38 (same camera different label depending on where sold) as well as every other lens test of a superzoom cameras I have seen, none are diffraction limited wide open at full zoom. Here is an example: http://www.imaging-resource.com/PRODS/FZ35/FZ35A4.HTM The center shows a quite soft image, definitely not diffraction limited and as you move off center, the lens is really bad. They were the highest resolution jpeg each camera produces. And since the web image is one image with both the DSLR and P&S image embedded in it, the jpeg compression of the web image is identical. So because they were the highest resolution available from each camera, you thought nobody would notice that if you didn't crop 1:1, pixel for pixel, representations from each camera, that NOBODY would see you trying to bias your test results with this blatantly obvious and simple TROLL'S BULL**** of yours again. As for JPG compression, I'm talking about SOURCE images you ****ing MORON. Again your foul mouth does not help your case. I was talking about source images. Care to trip over your side-stepping bull**** some more? So far your dance in your field of bull**** isn't going very well, is it. The rest of your BULL**** is just more of the same BULL****. No sense even replying to more than this. A waste of everyone's time. BTW: Someone already proved that they can get images of the moon with more detail and clarity using a handheld superzoom camera compared to $5000 worth of your DSLR crap gear. Even when your waste of money is mounted on sturdy tripods with mirror lock-up engaged too. Don't you remember that test? About 2 years ago. The last time you were laughed out of these newsgroups. Of course you do. That's why you've now spent two years of your useless life in fudging tests of images of the moon while trying to climb out of that pit you dug for yourself, and still you fail. Have some more omelet on your face. You're nothing but a ****ing joke. Again wrong on all counts. I was not laughed out of this newsgroup. I chose to leave, like many of the other excellent photographers, because of the degradation of any discussion, like you are dragging this one into the mud with your foul language and lies. It has not ever been shown that an image from a superzoom camera with its lens at full zoom could match a DSLR and fixed focal length telephoto. Not even close. If you can't actually prove a point with facts, foul language and name calling does not help your case. Roger |
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Telephoto Reach and Digital Cameras - lens comparison
On 12/14/10 PDT 8:37 AM, Roger N. Clark (change username to rnclark)
wrote: Again wrong on all counts. I was not laughed out of this newsgroup. I chose to leave, like many of the other excellent photographers, because of the degradation of any discussion, like you are dragging this one into the mud with your foul language and lies. It has not ever been shown that an image from a superzoom camera with its lens at full zoom could match a DSLR and fixed focal length telephoto. Not even close. If you can't actually prove a point with facts, foul language and name calling does not help your case. Hi, Roger, nice to see you back. We don't allow mission posters, haters or those spewing 6th grade obscenities to deter us. Many have found that simply ignoring this pest is the best we can do. I've even prayed for his tormented soul—didn't work! You don't need to defend anything, and thanks for your contributions over the years. -- John McWilliams Oh, he'll be sure to "refute" any and everything, but see if you can let it slide, please... |
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Telephoto Reach and Digital Cameras - lens comparison
Hi, Roger, nice to see you back. We don't allow mission posters, haters
or those spewing 6th grade obscenities to deter us. Many have found that simply ignoring this pest is the best we can do. I've even prayed for his tormented soul—didn't work! You don't need to defend anything, and thanks for your contributions over the years. -- John McWilliams Yes, welcome back. Most of us have simply kill-filed the pest, and I hope it's obvious to any newcomers that something which needs to resort to such foul language in that manner has little of value to contribute. What is perhaps confusing is the effect of diffraction in object space and sensor space. As I understand it, in object space - what the camera sees - the effect of diffraction can best be visualised in angular terms, so that a larger diameter lens has a smaller diffraction "cone" (if you like), and hence can resolve more detail on a given surface. In sensor space - where the image is produced - the effect of diffraction can be visualised making each image spot a finite diameter for a particular f/number. When the pixel size is larger than the diffraction spot, the pixel size tends to be the limiting factor in resolution, and this can happen in large-pixel DSLRs with the best lenses. Where the pixel size is smaller than the diffraction spot, the effect of diffraction would be the dominant factor in determining resolution. So while the small-sensor camera /may/ be closer to diffraction-limited, given good enough optics (which is questionable at the price), that diffraction limit is a much lower resolution in object space, due to the smaller actual diameter of the optics. The ratio of the sensor sizes might be 30/6.5 (for an APS-C camera to a "1/2.7-inch" sensor camera) - so about 4.5 times, and hence the scale of the optics, and that ratio might set the upper limit for the resolution ratio if both cameras had diffraction-limited systems working at the same f/number. Your comparison shows the benefit of the larger diameter optics.... http://www.clarkvision.com/articles/...are.moon.a.jpg Thanks, David |
#9
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Telephoto Reach and Digital Cameras - lens comparison
On 2010-12-14 12:57:22 -0800, "David J Taylor"
said: Hi, Roger, nice to see you back. We don't allow mission posters, haters or those spewing 6th grade obscenities to deter us. Many have found that simply ignoring this pest is the best we can do. I've even prayed for his tormented soul—didn't work! You don't need to defend anything, and thanks for your contributions over the years. -- John McWilliams Yes, welcome back. Most of us have simply kill-filed the pest, and I hope it's obvious to any newcomers that something which needs to resort to such foul language in that manner has little of value to contribute. Agreed. Welcome back. I had not seen much evidence of "He who remains unnamed" for some time until this exchange. All I can recommend is to filter/kill-file, or just ignore. -- Regards, Savageduck |
#10
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Telephoto Reach and Digital Cameras - lens comparison
On Tue, 14 Dec 2010 09:37:58 -0700, "Roger N. Clark (change username to
rnclark)" wrote: It has not ever been shown that an image from a superzoom camera with its lens at full zoom could match a DSLR and fixed focal length telephoto. Not even close. The test two years ago, pitted against your OWN photos, shows that the superzoom not only matched your PIECE OF **** DSLR gear, but it BEAT IT. THAT'S WHY YOU'VE NOW SPENT 2 YEARS OF YOUR USELESS LIFE TAKING IMAGES OF THE MOON TO TRY TO PROVE THAT IT COULDN'T BE TRUE. What a ****ing MORON! LOL!!!!!!!! |
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