Teleconverter--getting it sharp
Feb 19, 2012 22:33:51 #
The rule of thumb here, about teleconverters, seems that the better the quality the original lens, the better the results when used with a "good" quality TC. If I use my 1.4 TC on my 100-400 zoom, the quality is unacceptable. When used on my 500mm prime, it's exceptional. Is there some degradation? Yes, but the difference is insignificant.
Take two photos of the same object, with the same lens and from the same distance, one with and one without the TC. Enlarge/crop them both so that the resulting photo has the object at exactly the same size. If at that point, you can honestly say that the image taken with the TC is inferior, then don't use it. In my own testing with my 500mm I loose less sharpness by using the TC than I do from having to enlarge/crop an image that much more. I know this because I have tested my lenses. Don't ask me to post comparison photos because I didn't keep those tests. (I could always do them again!)
As to the sharpness of the photos that are posted on HOG there are so many variables that it can be difficult to be certain weather the original was sharp or not. Much of it has to do with the Post Processing and the export compression algorithms that are in use. For example a JPEG that had been edited and saved several times will not look as sharp as the original, unaltered file. If you then do a further compression to export to the web the image will have been degraded even further. The sharpness of the lens becomes less of a factor. Are there out of focus photos posted on HOG? Absolutlely! Is every photo that looks a little soft due to a poor lens or poor technique? No.
As to ISO: I find that I can consistently shoot at ISO 800 and get incredibly sharp results...assuming I have good light and only need to crop moderately.
My point is this: digital photography is a complex system with few hard and fast rules. Every camera body, lens, Post Processing combination will have somewhat different results. The only way to know what your equipment can be expected to do is to test and compare results. Read and learn what all the variables are. Ask questions, especially here on UHH, then go out and practice, practice, practice. In sports they say that it takes 10,000 hours of practice to get really good at anything. I doubt photography is any different.
Take two photos of the same object, with the same lens and from the same distance, one with and one without the TC. Enlarge/crop them both so that the resulting photo has the object at exactly the same size. If at that point, you can honestly say that the image taken with the TC is inferior, then don't use it. In my own testing with my 500mm I loose less sharpness by using the TC than I do from having to enlarge/crop an image that much more. I know this because I have tested my lenses. Don't ask me to post comparison photos because I didn't keep those tests. (I could always do them again!)
As to the sharpness of the photos that are posted on HOG there are so many variables that it can be difficult to be certain weather the original was sharp or not. Much of it has to do with the Post Processing and the export compression algorithms that are in use. For example a JPEG that had been edited and saved several times will not look as sharp as the original, unaltered file. If you then do a further compression to export to the web the image will have been degraded even further. The sharpness of the lens becomes less of a factor. Are there out of focus photos posted on HOG? Absolutlely! Is every photo that looks a little soft due to a poor lens or poor technique? No.
As to ISO: I find that I can consistently shoot at ISO 800 and get incredibly sharp results...assuming I have good light and only need to crop moderately.
My point is this: digital photography is a complex system with few hard and fast rules. Every camera body, lens, Post Processing combination will have somewhat different results. The only way to know what your equipment can be expected to do is to test and compare results. Read and learn what all the variables are. Ask questions, especially here on UHH, then go out and practice, practice, practice. In sports they say that it takes 10,000 hours of practice to get really good at anything. I doubt photography is any different.
Feb 23, 2012 14:30:38 #
That's a good point about compression. Especially here, since the site automatically resizes photos that are wider than 600 pixels. And not very well, IME. You'd probably be better off resizing the photos yourself before posting, but a lot of people can't be bothered.
As for teleconverters...I think for some kinds of photography, you pretty much have to use them. I wish I could afford a 500mm f/4, but I can't, so I use a 1.4 teleconverter with my 300 mm f/2.8. I suspect I would still be using the teleconverter no matter what lens I got. When I go out shooting bald eagles, I see people with 800mm lenses who are using teleconverters to extend their reach.
I use both 1.4 and 2X extenders. Not together, but depending on the situation. Sometimes speed is more important, sometimes reach is.
As for teleconverters...I think for some kinds of photography, you pretty much have to use them. I wish I could afford a 500mm f/4, but I can't, so I use a 1.4 teleconverter with my 300 mm f/2.8. I suspect I would still be using the teleconverter no matter what lens I got. When I go out shooting bald eagles, I see people with 800mm lenses who are using teleconverters to extend their reach.
I use both 1.4 and 2X extenders. Not together, but depending on the situation. Sometimes speed is more important, sometimes reach is.
Feb 23, 2012 15:30:28 #
I uaed a 2x canon convereter on 70-200 to get close enough to the Eagles Know i have 100-400 canon is lens worked very good with a 1x converter
Feb 24, 2012 06:28:05 #
William Bennett wrote:
I uaed a 2x canon convereter on 70-200 to get close enough to the Eagles Know i have 100-400 canon is lens worked very good with a 1x converter
I hope you meant a 1.4X converter, otherwise I got some extension, errr, 1x converters i'll make you a deal on!
Feb 24, 2012 17:57:25 #
Feb 28, 2012 12:09:14 #
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