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Old Aug 4, 2010, 3:42 AM   #11
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Originally Posted by lesmore49 View Post
I've thought of the Bigma...stretches out to 500 mm....and then whatever the 35 mm equivalent is.

I thought about the DA 300...but it gives no more reach then my 55-300 and I find my 55-300...even at 300mm is very sharp.

What Pentax needs to do is bring out something like the Canon L 400 mm, F 5.6.
Hi Les,

That kind of thinking will get you 100mm extra reach for $1500-2000 (not enough return on the money, IMO). Assuming that an SDM/HSM 1.4x TC is somewhere in the works for the relatively near future, the DA*300 will give you an outstanding medium fast prime, and with the 1.4x, a 420mm f5.6 to boot for the same price as the 400/5.6 or less (and it would be smaller and lighter). Add the AFA, and you'd have a 510mm f6.8, and you'd still be considerably under $2000 which seems to be the going price for a nice FA*400/5.6 nowadays.

Most of the past 300/4s have been exceptionally good optically, while the 400/5.6s have been considered very good, but not exceptional. Even if you consider image degradation from the TC, IQ would not probably not be much different.

An F* or FA*300/4.5 would give you the AF 420/6.3 right away, with either a Tamron or Sigma AF 1.4x TC, and with a 1.7x AFA you'd get a very useful 510/7.7 (sounds slow, but it will AF nicely down to under Ev 12--I do it all the time). Remember that f8 is the magic number for AF reliability with Pentax bodies. Even my DS and K100DS AF reliably with this combo.

I'd not consider buying a DA* 400/5.6 (no matter how good it is), but I would have to give a DA* 400/5.0 some thought. The former would have a 72mm front element, and the later would need an 80mm, so it wouldn't be that much bigger. The fractional stop faster would allow some room for a 1.4x TC which would then give you 560mm at f7, which would be fast enough for reliable AF in most outdoor situations. A 560/8 (400/5.6 +1.4x TC) would be iffy in everything but bright sunlight, even with the K-7's added AF sensitivity. Remember 1 stop is twice the light -- a fractional stop is quite a bit when you're approaching the limits of the AF system.

I'd only pay premium money for an ultra tele lens I know I could use a TC with -- possible exceptions would be the FA* 250-600/5.6 or an A*600/5.6, either of which give you enough reach that I wouldn't need a TC. . . my experience with the Tokina 80-400 tells me that 400mm isn't really enough. . .

When your next step up is a lens that costs well over $1000, you need to get some versatility out of it, IMO. A 400/5.6 would be a $1800 dead end to my way of thinking.

Scott
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Old Aug 4, 2010, 3:59 AM   #12
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Actually, Scott, that was quite interesting and helpful. It would be one thing if you offered all that information to a person you just met a a party. But we're all members of a photography forum, right? And I asked for input. And I thank you for it. Outside-of-the-box thinking is good.
Hi Biro,

IMO, The 1/7x AFA changes your way of thinking about ultra tele lenses, and opens up a lot of possibilities that long shooters of other platforms don't have.

I tried to give a pretty well rounded view of the AFA -- some people don't like using it, but I only see it as a major plus for Pentax, especially if you rely on AF as much as I do. Thinking outside of the box is unfortunately something of a necessity for a Pentax birder. . .

Scott
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Old Aug 4, 2010, 11:14 AM   #13
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Default Lil'Bigma

I have a Lil'Bigma -- Sigma APO DGL 150-500/5-6.3 in Pentax mount -- that I bought in a flash of insanity and just don't use. It is about one pound / 0.5kg lighter than the Bigma and has the same 500mm reach. IQ is superb. It is in almost-mint condition, complete with box and case and everything. I paid too much for it and I'll take a terrible loss to sell it -- but sell it, I must. If you are interested, make an offer. Thanks.

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Old Aug 4, 2010, 3:50 PM   #14
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I'd love to get the AFA TC, but just can't quite talk myself into it at the moment. I hope that Pentax will address the TC issue and come out with an SDM one - that might convince me to finally sell the A*300 (or maybe not). Now if they were to sell a TC that's just like the AFA AND is SDM compatible, I could really go for that! And the A*300 would probably get used a lot more than it does now, I'm getting used to having AF now since more of my lenses have it than not. Oh well, perhaps I'll luck into an AFA TC for about half of what they are going for and justify it that way.

That's how I'd like to do something longer than 300. I've thought about the Sigma lenses, but I just can't deal with something that heavy on a regular basis, and I wouldn't use it enough to put out so much money.
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Old Aug 4, 2010, 7:20 PM   #15
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Scott,

Thanks for the detailed information and advice re; telephoto lenses. Much appreciated as I do like to make informed decisions.

As mentioned before I'm torn. My Pentax 55-300 lens is as we know a consumer level lens.

When I'm out and about photographing wildlife....I have to say that the clarity and sharpness of this relatively inexpensive lens is really quite exceptional IMO.


But given that I have 300 mm capability and very good capability with the 55-300...I have wondered about the Sigma zooms that peak out at 500 mm...more with 35 mm equivalent.

That additional 200 mm of telephoto is very appealing.

But, I just don't know how sharp and good they are and tack sharp is very important to me.

Les
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Old Aug 4, 2010, 9:43 PM   #16
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well with cropped sensor size, a 300mm built for FF becomes a 450 right off bat.

Something like the pentax 100-300 would suit u well. Just saw the FA 100-300 pentax go for 47.00 on ebay. A great price if u ask me.

Though Ive never owned the Bigma, my experiences are the shorter the focal length range on a lens usually the better it fairs throughout its range. IE. the 80-200 shots much sharper than the 28-200.

My favorite wildlife lens are my primes.

When I go hiking I bring usually just two lenses around. My 300mm 2.8 CZ and my 24-60 2.8 sigma ex.

Theres rare moments where something in the middle is needed. When I feel like doin macros Ill also bring along my vivitar macro but I dont mind switching lenses to keep IQ up and more keeper shots.

Id rather take one great shot, than a ton of good ones, so having sharp glass and fast aperture is important to me when im doin wild life. Id say , trying to get perching birds or small critters in often dark and badly lit forests means youre gonna want something very sharp and fast on the long end

just my .02

Edit: I am mentioning these because you can easily get away with sticking a TC on a prime to push its focal length, where as a TC on your 50-300 might not yield tack sharp results like you are wanting.

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Old Aug 5, 2010, 1:00 AM   #17
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well with cropped sensor size, a 300mm built for FF becomes a 450 right off bat.
No, it doesn't. A 300mm lens remains a 300mm lens, no matter what size frame it illuminates. Does a 12" (300mm) lens from an 8x10" view camera become longer if it's put on a 5x7" or 4x5" or 9x12cm or 645 body? No, it doesn't. The only difference is that a smaller frame receives less of the projected image.

Cut out a picture from a magazine. Draw a 1.5 x 1 inch rectangle on it. That's the size of a FF negative or frame. Now draw a 1 x 3/4 inch rectangle inside that. That's the size of an APS-C frame, like all Pentax dSLRs except the 645D. Notice that the picture hasn't changed. Perspective and object relationships remain the same. The smaller frame just sees less of the picture.

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Something like the pentax 100-300 would suit u well. Just saw the FA 100-300 pentax go for 47.00 on ebay. A great price if u ask me.
That is indeed a great price for an under-rated lens. I paid US$120 for mine a couple years ago. I don't care for birds, but my best bird shots came from the FA100-300/4.7-5.8 (avoid the 4.5-5.6 version -- see the reviews here). I really like that 100-300, it's lightweight, much lighter than my very sharp Lil'Bigma -- which is partly why I want to sell the Lil'Bigma (see my previous post above).
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Old Aug 5, 2010, 11:03 AM   #18
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I get what you are saying about the crop, but what we perceive is what is on the frame, so IMO that is where it counts, while im 100% aware the lens isnt making me shoot twenty feet closer to subject, It sure looks that way to the sensor, which is why the shots exif read it differently than whats used and why the shots arent going to look the same on 35 mm film and digital. My explanation was nonexistent but the way u are wording yours are as if theres no difference, and while there is no magic bending the glass when its mounted on a DSLR, it does appear to be a longer focal length when a FF lens is used on cropped sensor.


This works against us when trying to use 35mm ultra wide lenses but works for us when we want a longer focal length
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Old Aug 5, 2010, 5:48 PM   #19
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Originally Posted by lesmore49 View Post
Scott,

Thanks for the detailed information and advice re; telephoto lenses. Much appreciated as I do like to make informed decisions.

As mentioned before I'm torn. My Pentax 55-300 lens is as we know a consumer level lens.

When I'm out and about photographing wildlife....I have to say that the clarity and sharpness of this relatively inexpensive lens is really quite exceptional IMO.


But given that I have 300 mm capability and very good capability with the 55-300...I have wondered about the Sigma zooms that peak out at 500 mm...more with 35 mm equivalent.

That additional 200 mm of telephoto is very appealing.

But, I just don't know how sharp and good they are and tack sharp is very important to me.
Hi Les,

I don't own the DA55-300, but I still am considering getting one. . . As a light, compact walkaround. Since I rarely shoot wide, it would probably be even better for me than the DA 18-250. I don't dispute the quality and utility of the lens, and will get one if I find the right deal -- but I already have 8 lenses that cover 300mm, so I can wait for the freakish deal. I would be willing to bet that in a direct comparison, the DA 55-300 with an F*, FA*, or DA*300s the * primes would be noticeably better -- maybe not enough to justify the price for many, but dedicated long shooters will pay the price for the IQ difference and TC versatility.

I think the big Sigma zooms are excellent lenses. My impression from others is that the Bigma is slightly better at 500mm than the 170-500. My thinking is that the users that complain about softness at the longer FLs are probably seeing the effects of camera shake more than softness. The shots suffer from either too slow a shutter speed, inadequate technique for the FL, a tripod/head that's not up to the task for such a long and heavy lens, or some combination of these factors. When judging a lens' performance from user images, I generally tend go by the best I've seen, rather than the average opinion, as user error is much too prevalent as a cause of problems. The best I've seen from the big Sigma zooms is very good indeed.

There are the reasons I've never bought one of the Sigma zooms. My FA*300/4.5 + 1.7x AFA is, IMO, better and a lot lighter as a handheld alternative -- it is slower, but not by even a full stop, and the much lighter weight offsets this easily in an advantage in handling. A 300/2.8 + AFA is only slightly heavier, but considerably faster at 510mm (f4.8 compared to f6.3-6.7 -- about a stop) and at a comparable speed (f6.7), I get 714mm with a 1.4x +1.7x stacked, and still have AF. I don't feel the IQ suffers, even from the stacked TCs -- see the links further down for examples. Remember that with the AFA, the AF is considerably faster, and the most frustrating aspects of AF are almost entirely eliminated -- the lock-to-lock hunt, and failure to lock focus.

Sure, the zoom range is an advantage for the Sigmas, but my ultimate priorities are reach and reliable AF. I'm sure it's neat to be able to have everything between either 50 or 170mm to 500 in one lens, but if I want to shoot wide to tele, I'd rather just bring a shorter lens (say the Sigma 17-70, FA 50/1.4, or Tamron 28-75/2.8) than shoot a 4lb+ 50mm f4. Also, the Sigma zooms extend physically pretty far to get to 500 mm (most of the pictures you see of the lens are at 50mm). This is not ideal for gimbal use, as the gimbal's handling advantage is based on balance, and this advantage is negated when you use the zoom on the Sigmas. All of my fast 300s are internal focusing and the balance point doesn't change. It's important to prioritize the compromises you're willing to make. If I wanted an xxx-500 zoom, I'd probably prefer a Sigma EX 100-300 f4 APO (IF) since it's also an internal zoom, and use it with the AFA -- actually, I've already bought a broken Sigma 100-300, but haven't gotten around to having it repaired. . .

An example of the user-error thing is my own experience with my 300/2.8s+TCs. At first, I handheld everything, because that was my preference. I liked the freedom it gave me -- I could just go out and shoot, carrying only the camera/lens. I could usually lean up against a tree or my car and I got some spectacular results, so I was pretty happy.

Note that this is with a DS, so no SR. . .
http://forums.steves-digicams.com/pe...shot-date.html

The Oriole shot in this post was with a K100DS, FA*300/4.5 _ 1.7x AFA:
http://forums.steves-digicams.com/pe...ne-jelpee.html

Then I started using a tripod with the big lenses. . . and my "keeper" percentage went up significantly -- and the IQ bar for "keepers" went up as well, enough so that I eventually ended up buying the Sigma EX 300/2.8 as an upgrade from the Tamron 300/2.8 Adaptall 2, and ultimately found a nice user-grade FA*300/2.8. I also ended up investing in a Wimberley Sidekick to give me an edge in handling with the big lenses on the tripod.

http://forums.steves-digicams.com/pe...portraits.html

http://forums.steves-digicams.com/pe...ps-6-imgs.html

http://forums.steves-digicams.com/pe...-kingfish.html

An interesting note to all this is that so far, this year, I've gone back to shooting mostly handheld, so the 300/4.5 +AFA is getting more use, as well as my new Sigma 180/3.5 Macro +AFA (305mm f6 1.9:1 ratio) Although the weather has been limiting, and I haven't really been shooting a lot, I carry less gear, and get a lower percentage of keepers, but I've been having more fun at it. . . That will probably change when things cool down a bit, but it's nice to have the options of different styles for different moods.

Scott
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Old Aug 5, 2010, 11:56 PM   #20
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great pictures scott, I enjoyed seeing a few of those again and caught a few for first time.
That FA*300 is one sharp lens and you hand hold it well
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