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10-16-2011, 05:54 PM   #31
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@ripit,
Great deal on the Bokina! Not bad on the Rikenon 50/2 either -- mine was US$10 shipped but the 55/1.8 was only US$6. As for lens preferences: I had a pile of MF zooms but sold all but the best (or unsaleable) of the lot because I don't want to hassle with SR fudging with those. And deciding to draw a line on MF zooms saves me LOTS of time and money!

@DaveHolmes,
Nope, I've just read what I reported above. Hmmm, let's see, I kept the elements from a couple A-type TCs I've deglassed, maybe I should stick some back in and see what happens? Or maybe I'll let someone else do it. Why should I hog the glory?

10-16-2011, 06:23 PM   #32
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QuoteOriginally posted by RioRico Quote
, here's an experiment to try: Get a DA18-55/3.5-5.6 kit lens. Get a cheap used A-type 2x TC. Remove the element from the TC and re-install it REVERSED! Your TC is now a 0.5x WC, a wide-converter. The kit lens becomes a 9-28mm f/1.7-2.8 zoom! WOW! The trick is to get the TC/WC element placed exactly right. Good luck.

.
That's thinkin' outside the apeture.

I'd give you a +1 but Adam says I have to spread my love around a bit more first.

I've read something like that is effective for turning a 2000m f10 scope into a 1260mm f6.3 but would be interesting to see what would happen with a normal/wider range. Err...Vignetting?
10-16-2011, 06:30 PM   #33
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QuoteOriginally posted by ripit Quote
I went out shooting today and am starting to wonder if 2.8 would cut it anyway. I may have to learn to do it with fast 50mm primes. A lot of my shooting today was with a new 28mm 2.8 I just got. I also brought a 35-70mm 2.5-3.5 (also new and first time shooting with it), a 35-70mm 2.8 constant, and a 35-200mm. The 35-70mm 2.8 constant I have is damaged but I can still shoot with it. You have to grip the lens firmly in both hands and put a little muscle into it to make it zoom. It won't focus to infinity right now either but I can fix that.

Looking at exif, most shots were 1/20th-1/30 sec at iso 800 and that's not going to cut it hand held shooting moving targets. That includes a lot of shots with the 28mm 2.8 and I only shot wide open on all lenses all day. Iso 800 looks grainy and iso 1600 really starts to look bad on my camera. I'll probably keep casualty looking for one (lba and all) but I think I might take another run at it with some fast primes.

Thanks again for all the advice!!!
Where are you shooting that you can can only manage 1/30 sec, ISO 800 at wide open? What camera are you shooting with, I shoot with a K20D and I think I get acceptable results with minimal noise reduction at ISO 1600. You can also underexpose by 1 stop and bring it back in PP, thereby gaining one stop in shutter speed or try underexposing by even more to gain more shutter speed (time spent in PP increases conversely). Fastest zoom you will ever find is f2.8, so you can't trade in your wife.

Have you looked at a Pentax 35-70/2.8 AF (built-in motor)? This lens was built for the Pentax ME F (dead end AF camera), I think every Japanese camera manufacturer tried to make AF camera (Canon had three lenses available for the T-80), but Pentax was the only one that supplied a fast f2.8 zoom lens. I haven't tried it but I have heard/read that this is a very sharp lens but little bit awkward to manually focus because of the hump where the motor is located. I think this lens can be found for around 50-60.00.
10-16-2011, 07:22 PM   #34
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QuoteOriginally posted by steve1307 Quote
I'd give you a +1 but Adam says I have to spread my love around a bit more first.
I can wait a few minutes more.

QuoteQuote:
I've read something like that is effective for turning a 2000m f10 scope into a 1260mm f6.3 but would be interesting to see what would happen with a normal/wider range. Err...Vignetting?
Good question. I eagerly await some obsessed experimenter trying this. It will be a few days at least before I'll be able to lab-rat myself. Dang that outside world...

10-16-2011, 11:00 PM   #35
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QuoteOriginally posted by RioRico Quote
Good question. I eagerly await some obsessed experimenter trying this. It will be a few days at least before I'll be able to lab-rat myself. Dang that outside world...
CHICKEN!! You know you have the time and especially the spare gear to test it on! Heck, you probably have enough glass from your 50mm's to make a few new custom lenses!
Hmm I'm looking at my elements from my TC I disassembled months ago.. I thought I taped them together in the proper stacking order.. now they are here loose and spread out! Love having a 4 year old kid who can help me "fix" things! UGHH! Time to do some google searching for some standard 2x TC element design, Then reverse it!
10-16-2011, 11:21 PM   #36
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QuoteOriginally posted by Chex Quote
CHICKEN!!
What the cluck?!?!? I'm just winging it. I don't know eggzactly what to do. I'm not cackling nor brooding over this. Just don't ruffle my tailfeathers or I'll flip the bird. Hmmm, I wonder if the elements should be nested?

QuoteQuote:
Time to do some google searching for some standard 2x TC element design, Then reverse it!
That's the spirit! Gargling is good for you!
10-16-2011, 11:49 PM   #37
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Send me a 50 1.7 and I'll send you my modified TC when I'm done!
10-16-2011, 11:57 PM   #38
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QuoteOriginally posted by excanonfd Quote
Where are you shooting that you can can only manage 1/30 sec, ISO 800 at wide open? What camera are you shooting with, I shoot with a K20D and I think I get acceptable results with minimal noise reduction at ISO 1600.
Strong national museum of play in Rochester NY. It's maybe 30% behind glass exhibits, 30 percent nostalgic exhibits the kids can play with and 40% just stuff the kids can play with. They are always having new the history of type exhibits. It's great for family photos but many areas have low lighting, high ceilings, angular walls and or celings and I swear they paint some areas with light absorbant paint. A high power flash just gets absorbed when you try to bounce. It's also good practice to learn to shoot low light situations. It was a complete madhouse this last weekend though (super hero weekend, meet batman etc). People were parking on the grass etc. I kind have wished I had not been in lens testing mode and was more in get some good shots mode. Its an hour and a half drive so we don't go there too often.

here is one I wish I hadn't botched so bad (feeling stupid for not using flash, I didn't even think of it but it probably would have worked here).
museum Photo Gallery by Richard Homeyer at pbase.com


Camera is an old ist-ds which explains the poorer high iso performance. A newer body with beter high iso performance is on my save up for list.

QuoteOriginally posted by excanonfd Quote
Have you looked at a Pentax 35-70/2.8 AF (built-in motor)?
I have seen it once or twice but not enough I started searching for it. I have recently taken an interest in such lenses though (won a canon fd vivitar 28-70mm cheap with internal autofocus) and lost a similar chinon one. I can start looking for the pentax one and do some research on it. thanks.

10-17-2011, 07:11 AM   #39
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QuoteOriginally posted by riorico Quote
originally posted by chex chicken!! What the cluck?!?!? I'm just winging it. I don't know eggzactly what to do. I'm not cackling nor brooding over this. Just don't ruffle my tailfeathers or i'll flip the bird. Hmmm, i wonder if the elements should be nested?
lol rofl!!!
10-18-2011, 05:25 AM   #40
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Post removed. Can't be bothered arguing about the uselessness of the silly 'reversed TC' suggestion.

Last edited by thoughton; 10-18-2011 at 05:35 AM.
10-18-2011, 11:03 AM   #41
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10 TC on way...
10-18-2011, 01:48 PM   #42
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QuoteOriginally posted by thoughton Quote
Post removed. Can't be bothered arguing about the uselessness of the silly 'reversed TC' suggestion.
I agree, some people like weird projects to kill time.
10-18-2011, 04:26 PM   #43
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Back in the mid-eighties, I did a lot of party photographing with a Tokina AT-X 2.8/35-70 in PK/A mount. I bought it new, and I still own it, but I never made test shoots to compare with other lenses. But I remember it was a bit soft at 2.8. At that time, the price was less than DM 200 (less than € 100 today, but how to compare? With the same logic, a SMC-A 2.0/50 = €50, a SMC-A 1.4/50 = €140).
At that time, Tokina had record sales in Germany, far better than Tamron, Sigma, or Vivitar, so one should think the AT-X 2.8/35-70 has sold well. But I am checking all Pentax related stuff on german eBay since 2 years, and in all that time only 1 (!) of these lenses was offered. It seems people don't like to part from this lens.
By the way, the lens is quite big (for a 35-70). And quite heavy, too (big front lens)!
10-18-2011, 04:58 PM   #44
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QuoteOriginally posted by Chex Quote
I agree, some people like weird projects to kill time.
Don't knock it if you haven't tried it, eh?

Really, it's not a wild-ass fantasy. A TC group really IS a reversed retrofocus group. Such addenda really ARE used in astrophotography. As I said before, I've read that element placement really is critical. This might not be suitable for anything BUT long teles. If it was easy, everyone would be doing it. But if we don't experiment, we don't learn anything new. I seem to recall when build-your-own microcomputer kits and projects were just weird time-killers. "Oh, those TV typewriters, they'll never amount to anything." Fine.
10-18-2011, 08:17 PM   #45
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Even if it is a weird project to kill time, why not? I bet the first guy to reverse a lens got some pretty funny looks (and probably tried other things that were not as sucessfull). Did he know it was going to make a macro lens or was he just experimenting? Its not like a teleconverter is an expensive or rare item to risk. If I can find out some more information I will probably try it myself. I might have another project that will come first though. Its a vivitar 28-70mm that I am going to convert from canon to pentax. Interesting thing is, its the kind with built in auto focus.

How many elements does the average teleconverter have anyway? Best I can tell many have 4 or 7? I have a vivitar 2x-22 or a quantaray 2x (both MF) that are canadates to be victums. I'm guessing the more elements, that harder to figure it out and the less chance of sucess?
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