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Old May 14, 2008, 11:05 AM   #11
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And another one. Both of these I used a tripod and Auto focus. This one from around 50 feet distance. Similar settings.

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Old May 16, 2008, 3:42 AM   #12
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Hey Dawg, really nice bird photos. I have a sears 2X tele conveter PK. It shows a K1 on inside front face. There is plenty of room for any of my Pentax/Sears'Rikoh lenses bases. It seems to produce good images using my long lenses (Sears 60-300mm f/4-5.6, Tamrom Adaptall II SP 60-300mm f/3.8-5.4, Pentax 70-210mm.) I am going to run some tests to see which of those lenses give me the sharpest pix at various focal lengths and f stops, at three distances from camera, probably at 12 feet, 24 feet and 50 feet, all of the same photographed object. I have done this on other lenses, but never with the TC. The testa will be made with seven color cards attached to a printed page having half-inch high letters graduated downward to teeny-weeny. It is surprising to me how much difference there can be in the color rendition from one lens to another. I use a K10D, and have experimented with color tests to see whether the camera settings seem to correspond properly between the camera setting (i.e. sun, cloudy shade, etc.) and the actual conditions at the time of shooting. I have gotten some erratic results doing this, and have concluded that if the result looks good, to just leave the picture without fussing around with trying to get accurate tonal images. So far, I think that has worked pretty well. The place I think that method falls down is when shooting well-known human subjects. For example, I have some beautiful teen-age granddaughters. My pictures of them sometimes end up with too much red in their hair, even though the face is correctly colored. Or, I may get good hair but wrong skin.

I would liketo receive your comments, if you will, please,on the whole colorization subject.

I would also like to know how the 2XTC affexts the lens F stop setting,and what difference the TC makes in the F stop results. In other words, with a camera setting of f/8, and a 2X TC, what is the real-time F stop? And will the camera's EXIF reading actually show the modified F stop?

It seems that a 1.5X or 1.7X TC is preferred by most users. Why is that? Using a zoom lens, adjusting the zoom factor should allow you to have exactly the same result with either TC power. Can you throw any light on that subject.

Sorry to lean on you forso much information, but you appear to have been around these situations quite a bit, so I suspect you have most of the answers to these sorts of questions.

Please help me if you can.

To me, having the questions, then finding the answers (and reasons), is almost as interesting as the actual photographic results. I know that if you know the reason why something happens, you can make adjustments in the mix ofcomponent patsto reach the result you want. The trick is to get the right mix, and most of this can be intuitive or from experience. You seem to excell at both.

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Old May 16, 2008, 4:14 AM   #13
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Old Engineer wrote:
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I would also like to know how the 2X¬*TC affexts the lens F stop setting,¬*and what difference the TC makes in the F stop results.¬* In other words, with a camera setting of f/8, and a 2X TC, what is the real-time F stop?¬* And will the camera's EXIF reading actually show the modified F stop?

It seems that a 1.5X or 1.7X¬* TC is preferred by most users.¬* Why is that?¬* Using a zoom lens, adjusting the zoom factor should allow you to have exactly the same result with either TC power.¬* Can you throw any light on that subject.
Old Engineer¬*
Hello OE,
I'm sure Dawg will be along later to answer your queries, in the meantime I'll give you my comments ...
a 2X TC will drop you 2 f stops of light, the 1.4 or 1.7 drop less in direct proportion, and that is why they're preferred to the 2X, also adding a TC to any lens adds more glass to the optical path which can have adverse effects. It is generally well known that some lens + TC combinations work better than others, so you need to experiment with your own lenses and TCs to see which works for you. It is a fact that a TC works better with a prime lens than it does with a zoom. Hope this helps ... Jack.
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Old May 19, 2008, 12:16 AM   #14
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Wow. the Pentax TC are very very expencive.

Think i have settled on the Kenko 1.5x from BnH. Anyone delt with them. Only place i can find one. None in Australia.

Nice birds bigdawg.

I use bigma for surf shots. But at times i need that little extra, why i will get a 1.4x Sigma TC. Would love along prime. Out of my reach at the moment. Plus i will use it with the Sigma 70-200mmf2.8,{105-300mmf2.8 on the K10D} Take it to about 147-420mmf4. If it ever gets released.:P
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Old May 20, 2008, 6:40 PM   #15
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Craig66 wrote:
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Wow. the Pentax TC are very very expencive.

Think i have settled on the Kenko 1.5x from BnH. Anyone delt with them. Only place i can find one. None in Australia.

Nice birds bigdawg.

I use bigma for surf shots. But at times i need that little extra, why i will get a 1.4x Sigma TC. Would love along prime. Out of my reach at the moment. Plus i will use it with the Sigma 70-200mmf2.8,{105-300mmf2.8 on the K10D} Take it to about 147-420mmf4. If it ever gets released.:P
Craig...B&H is the very best place to order in my book with Adorama almost in a tie. B&H even though a little higher than some places will give you good service time after time.
The higher TC's 2X and 3X will give your photo a softer look than the 1.4's and 1.7's. That is a given fact. Most Lens and camera Manufacturers do not offer larger than 1.7X for digital cameras. The distortion and soft focus will be the result time after time with a Digi-cam and a TC that is above 1.7X. There are certain lens and TC combos that are the exception. You'd need to be lucky to figure that out and not spend a fortune on lenses and TC'c to get the right combo. Scott, "Snostorm" has gotten great results with a 300mm prime lens and stacked TC's. You could ask him what combination he prefers. Anyway the IQ of a photo taken with a 2X as oposed to a 1.4 or 1.7 will be lower. You might not readily see this in a web posted photo but when pixel peeping you would start to see edge softnes slightly higher with the 2X. If you are getting results you like with a 2X then by all means keep using it for your photos. I didn't so I sacrificed mine to make a Macro tube. I'll stay with the 1.4 for now!
Color shift can come from the angle of the light being reflected from the subject or a change in the F/stop or EV setting. Or a change in the place the ambient light is striking the subject. or your Auto White Balance is fooled by the colors recieved by the sensor. That happens sometimes. I don't worry about it that much and use RAW and adjust it later. A test photo is one good way to go if you must get it in the Camera so-to-speak. And adjust the white balance temp till you get the results you want then shoot away. If the Grand child is older it is easier to do this...With my youngest ones it isn't, so I use Auto White Balance and do the adjustments afterward! Another good bit of software to have for thos portraits is DCE Tools Portrait skin cleaner. It tidies up the face in portraits and is a free program that I use a lot. It can be found with the Auto Enhance Bundle from Media Chance .com. It is an evaluation version that never runs out and has no annoying pop-ups.


dctools1.exe from Mediachance.com (1.2 MB)

If that works and you want the full version go here and buy it.
http://mediachance.com/plugins/dceessentials.html

Hope any of this made sense and helps!

Dawg
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