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Old Jun 9, 2005, 11:00 AM   #2
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Hope I didn't scare anybody off with that long list above. If anyone can give me any ideas on even a couple of them, it would help. Thanks.
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Old Jun 9, 2005, 4:05 PM   #3
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I was hoping some KM owners would respond.

I took a quick glance through the Ebay listing you posted, and it appears that some of the TC's you're looking at are not for AF lenses (although one appears to be). I also question the no light loss comments I saw in the text of some (typically, you lose a couple of stops with a 2x TC).

A TC can not only degrade optical quality, but make it much harder for a camera's Autofocus to work,.especially with "slower" (not as bright) lenses. A slow lens also means a darker viewfinder.

For example, that Tokina 100-400mm you're looking at (in the two lens set) is an f/4.5-6.7 lens. That's not very bright. Chances are, unless you're in very good light, you'll have trouble with the camera focusing without a TC, much less with one, at longer focal lengths.

You may get better responses by letting everyone know what your intended use for the lenses is, along with your budget. For example, if you need lenses for night sports in a stadium, or inside sports, these lenses would be a waste of money (shutter speeds would be too slow to stop the action).

Also, keep in mind that you need to multiply the actual focal length of the lens by 1.5x to get the 35mm equivalent focal length/angle of view with this camera model (because the sensor is smaller than 35mm film). So, a 400mm lens will have the same angle of view as a 600mm lens (400 x 1.5 = 600).

Once you narrow down your choices, I'd suggest visiting our Canon Lenses and Nikon Lenses forum, too. Most third party lenses are available in Nikon and Canon mounts, too.

Since there are a lot more Canon and Nikon DSLR owners (since KM just re-entered the DSLR market with the Dynax/Maxxum 7D), you'd have a much better chance of finding users familiar with the lenses you're considering.

I'd also suggest mentioning specific model lenses (versus links to Ebay postings).

Or, just let the forum members know what your intended use is (type of photography, conditions,purpose of the images produced) and budget -- asking for third party lenses that may fit within your budget.

Most lenses from Tokina, Tamron and Sigma are available in Minolta AF mount.


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Old Jun 10, 2005, 11:57 AM   #4
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What I am looking for is a couple of things, mostly just add-ons to enhance what I already have. The need for a 2x converter and/or 500mm lens is to, at least at first, take pictures of mountain goats waaaaaaay up on the mountains along the Icefields Parkway in the Canadian Rocky Mountains. I am wondering if the larger lenses I noted above will work with the 7D, and at what quality. I understand the 2x converters do have limitations, but still might work for my uses.

Any thoughts?
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Old Jun 10, 2005, 12:36 PM   #5
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Well... I don't even see the Tokina lenses you're looking at in their current lens lineup.

I do see what appear to be identical lenses being sold under other brand names like Phoenix, Vivitar and Promaster. So, I don't know who really makes 'em.

Comments on the 100-400mm f/4.5-6.7 lenses seem to indicate that they are sharp for the money except for some edge softeness, but tend to be a little softer above 300mm. Problems with Autofocus hunting at longer focal lengths have also been reported (to be expected with a slower lens).

The one TCyou've got in your list that appears to be able to work with this camera (Maxxum AF Mount), specifically mentions that Autofocus will not work unless your lenses have apertures of f/4.0 or greater. This is perfectly normal.

A camera would have enough problems trying to focus at f/6.7 without a teleconverter unless conditions were very bright.

That means you'd need a lens more than twice as bright at longer focal lengths, compared to the lens you're looking at that has a maximum aperture of f/6.7 at full zoom (f/4.0 is twice as bright as f/5.6, and 4 times as bright as f/8.0).

If you're willing to use Manual Focus, it may work. You'd really have to try it to see. But, I would expect a degradation in optical quality by using a 2X TC.

As for the Mirror Lens... I dunno. A mirror lens is a simpler design with a fixed aperture. Of course, you'd need to go manual focus with one. Other than needing to use Manual Focus, the primary downsides ofmirror lenses are their fixed apertures andpoor bokeh ability (ability to get nice background blur).

The only way to tell for sure how well one would work on the Maxxum 7D would be to try it. Sometimes, you do have compatibility problems with lenses, even if you have the correct lens mount).

Chances are, they would work.

Again, you may want to ask in the Nikon and Canon lenses forums to see if anyone else has used these lenses to get some opinions.


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Old Jun 10, 2005, 1:13 PM   #6
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Having decided thatthe Vivitar/Promaster 19-35 lens is the best way for me to go, I now want to consider expanding that thought a bit. I have a 28-80 and 70-300 lens (Quantaray) and want to consider getting a wide angle lens instead of the 19-35 that would eliminate the use of the 28-80. I see a Sigma 18-125 DC, but know that the AS can cause negative effects with that lens. I would expect the same to be true of this lens. Any thoughts on a wide angle with a wider range worth considering. Again, not looking for the expensive lenses for now. The 19-35 is about 145, the Sigma 18-25 is 289. Something along those lines.
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Old Jun 10, 2005, 1:32 PM   #7
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JimC wrote:
Quote:
I took a quick glance through the Ebay listing you posted, and it appears that some of the TC's you're looking at are not for AF lenses (although one appears to be). I also question the no light loss comments I saw in the text of some (typically, you lose a couple of stops with a 2x TC).
The first teleconverter listed is an external teleconverter that attaches to the end of a lens. These are basically small galilean refractor telescopes. It is possible for this type of teleconverter to have no light loss, but generally they also degrade image quality more than an internal teleconverter that goes between the camera and lens.
The Tokina and Phoenix teleconverters are internal teleconverters, and have a 2 stop light loss. You would also have to check that the lenses you have will work with the teleconverter.
The teleconverter from Cambridge Photo is for the MC/MD mount, and will not work on a Maxxum camera.
The mirror lenses may work, but are manual focus only, and any out of focus areas will almost certainly look weird. The price is low enough that you might want to give one a try.
On a side note, Minolta makes a 500mm f/8 mirror lens that will autofocus on the Maxxum cameras. It is relatively inexpensive for a 500mm lens (around US$600 new), and you might want to consider it.
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Old Jun 10, 2005, 1:34 PM   #8
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Jacqueaux wrote:
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Having decided thatthe Vivitar/Promaster 19-35 lens is the best way for me to go, I now want to consider expanding that thought a bit. I have a 28-80 and 70-300 lens (Quantaray) and want to consider getting a wide angle lens instead of the 19-35 that would eliminate the use of the 28-80. I see a Sigma 18-125 DC, but know that the AS can cause negative effects with that lens. I would expect the same to be true of this lens. Any thoughts on a wide angle with a wider range worth considering. Again, not looking for the expensive lenses for now. The 19-35 is about 145, the Sigma 18-25 is 289. Something along those lines.
I don't know if the Sigma 18-125 DC lens will cause a vignetting problem due to AS or not. The jury is still out. If Sigma didn't think it would be marketable, they wouldn't have offered it in KM mount, since that's the only body it would currently work on.

I know of someone that just got one, and is going to test it this weekend on a 7D and report back.

There is also a Sigma 18-200mm DC lens, as well as a new Tamron 18-200mm available.

But, when you start getting into lenses that try to incorporate a lot of range in a single lens, quality usually suffers.
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Old Jun 10, 2005, 2:07 PM   #9
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JimC wrote:
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But, when you start getting into lenses that try to incorporate a lot of range in a single lens, quality usually suffers.
With that in mind, and assuming lenses are similar, would you go with the Vivitar 19-35 and keem the Quantaray 28-80, or get the Sigma 18-125 (based solely on the range factor you noted). I also will be interested in what your contact learns about the Sigma this weekend.
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Old Jun 10, 2005, 2:50 PM   #10
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Again, I would ask in the Nikon and Canon lenses forums.

All of the lenses you're comparing are available in both Canon and Nikon mounts.

You're more likely to find forum members there that have used these lenses ona DSLR (even it it's not a Konica-Minolta DSLR, the optical charecteristics of the lenses on Nikon or Canon DSLR models would be very similar).

The only big "gray area" is the way anti-shake could influence vignetting with the Sigma DC type lenses you're looking at (lenses designed for use with Digital Cameras with a "crop factor").

I'll let you know what the 7D user trying one this weekend says about it.

But, you may still be able to get some opinions on theoptical quality of this lens from other forum members using Nikon and Canon models that may have tried it.

I'd simply tell 'em the same thing you just said... what lenses you've got, and what you're considering to replace them with to keep from swapping lenses as much by going with something starting out wider.

I don't think anyone that's familiar with these lenses would mind helping out, and you'll find members with a lot more knowledge about lenses than I have. ;-)

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