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01-01-2010, 05:24 PM   #16
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QuoteOriginally posted by bdery Quote

About lenses being made in Vietnam... Comments like these always annoy me. I work for a company assembling optical test & measurement devices, and even though our R&D is in North America, a significant part of our manufacturing is now made in China. Our knowledge tranfer processes and our quality control processes ensure that there is no difference between the two manufacturing plants that we have. And a single device usually costs about the same price as the entire Pentax lineup. And we're a much smaller company than what Pentax must be. So there is no reason to imagine that THEIR quality control is more lacking that anyone else's.

one thing that you must consider that they don't share the same personnel in those plants. the question is how QC is being implemented. products that seem to pass the standard of one manufacturing plant may not be the same as that of the others. and this is not an assumption.

for the record, I'm not an optical designer engineer nor anything that is associated to camera lens optics, but had worked as an intrumentation tech in various manufacturing plants. getting familiar with their system with regards to QC and processing and in every plant, they vary on what they look as an approved material eventhough they show similar standards. a friend of mine who works in a different company is assigned in R&D dept and my dad was a former operations manager (mechanics department). so those are other sources of my info aside from my own.

this quality difference is mainly due to different personnel. following the logic of same owner but different workforce.

eventhough I own some Pentax lenses that are made in Vietnam, I do find them not quite up to the standards of the ones that are made in japan. though some defects are inevitable, they do seem to do something about it especially if it's something made in their own turf. and such cases are not of significant number to cause any alarm if there is a problem concerning QC. Japan wouldn't had gotten it's great QC reputation if it didn't really deserve it. it's too bad that they needed to do some cost-cutting and had to transfer their plants which in a way affected the quality of their homegrown products.

I just hope that the ones that are being manufactured in Vietnam now, especially the DA* zooms, are given enough attention especially that there is a real QC concern going on. my thoughts on this matter is continued development and better QC.


Last edited by Pentaxor; 01-01-2010 at 05:45 PM.
01-02-2010, 07:21 AM   #17
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QuoteOriginally posted by emr Quote
Thanks for the input, bdery! Since you're in the optical business, may I ask how did you end up getting the lenses you have in your signature (Sigma 17-70 | DA 18-55 WR | FA 100-300 | FA 50 macro | F 50 mm f1,7 | M 150 mm)? I mean did you get them based on reviews or non-formal testing or did you perform some more rigorous optical testing?
Many of these lenses were bought used, on auctions sites, here, or in classified ads.

When I first got into the Pentax system, I decided right away that I didn't want the kit lens, but bought the Sigma instead, as a good all-around package (if the DA 17-70 had been weather sealed, I would have bought it instead). I already had a few manual primes. I wanted a fast night photography lens in my kit, a macro, a tele, and I just recently bought a WR kit for snowshoeing and difficult situations (bought it here from the marketplace).

Regarding the Sigma, I chose it because of reviews and user reports, and based on its features.

I bought the F 50 f1,7 knowing that every fast 50 is good. I found the 50 as part of a kit sold online and bought it. I don't regret it, it's perfect for what I need. Any f1,4 or f1,7 50 will be great though (I have owned the A 50 f1,4 before, and sold it because I wanted AF).

I found an amazing deal for the 50 macro, and I knew it was one of the sharpest lens out there, which is what I wanted. Any macro lens is probably good.

The M 150 was an almost-freebie I bought and even though I don't use it much, it's useful in some specific situations.

The only lens I'm not 100% satistied with is the FA 100-300. It's a good lens, but it lacks the special something of most of the others. It doesn't have real flaws, but results are always good, not great. Maybe I'm part of the problem I got it to replace a 70-210 f3,5 lens which was bette optically, but was also much, much larger and heavier, and MF (meaning the wife would not use it). this is the lens I will at some point replace.

I do not do extensive testing on my lenses, I do check their general performances when I get them, to know what to expect at different apertures and focal lengths. But my "tests" are based on real life photos. For instance on my (5 minutes) test the 100-300 proved sharp and mostly aberrations-free, but it still lacks something ...

Even though I understand lens design, it would be impossible for me to evaluate lenses based on their designs, there are way too many choices and possibilities and design parameters implicated. The best test is just to mount a lens and start shooting. Being an "optics expert" so to speak lets me understand a bunch of things but there is more than that to photography.

I hope it answers your question. Feel free to ask for clarifications.

QuoteQuote:
one thing that you must consider that they don't share the same personnel in those plants. the question is how QC is being implemented. products that seem to pass the standard of one manufacturing plant may not be the same as that of the others. and this is not an assumption.
Pentaxor, of course you are right. The way QC is implemented is the critical point. For instance, in our company, the manufacturing process is put in place at our main plant, with the participation of the R&D team. Then, when all the tests are agreed upon, the tolerances defined, we can transfer to China, where the products have to pass the same tests. It's the job of the R&D to make sure the right things are tested.
01-02-2010, 09:58 AM   #18
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Great thread!

Like someone already said old glass (mostly primes) are often compared to morden kit lenses and that is not a fair comparison. Primes should be compared to primes, not price to price, if you get what I'm trying to say.

Having tried or used lenses from the original takumars to modern DAs I can come to the conclusion that build quality started dropping with the M-series, FA-limiteds still doing well against the earlier though. Optical quality I don't know about, I haven't had the chance to test equal lenses.

Modern optical design is surely more precise than in the 70's but cost cutting may well eliminate that advantage in all but the best of glass (again talking primes). IMHO probably the best glass you can buy for money are the modern Carl Zeiss primes. But then again you can get a whole bunch of nice old Pentax glass for the same price as just one CZ lens. And I truly think some of the old Pentax lenses can rival everything before and since (thinking K28/3.5 and K35/3.5).
01-02-2010, 04:30 PM   #19
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QuoteOriginally posted by Jimfear Quote
Great thread!

Like someone already said old glass (mostly primes) are often compared to morden kit lenses and that is not a fair comparison. Primes should be compared to primes, not price to price, if you get what I'm trying to say.

Having tried or used lenses from the original takumars to modern DAs I can come to the conclusion that build quality started dropping with the M-series, FA-limiteds still doing well against the earlier though. Optical quality I don't know about, I haven't had the chance to test equal lenses.

Modern optical design is surely more precise than in the 70's but cost cutting may well eliminate that advantage in all but the best of glass (again talking primes). IMHO probably the best glass you can buy for money are the modern Carl Zeiss primes. But then again you can get a whole bunch of nice old Pentax glass for the same price as just one CZ lens. And I truly think some of the old Pentax lenses can rival everything before and since (thinking K28/3.5 and K35/3.5).
the advantage that I did notice with the new lenses is with regards to flare resistance. as for overall resolution, IMO the older lenses are better in general. of course there are a few lens exceptions and those are mostly identified in the lens review.

01-03-2010, 03:56 AM   #20
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Thanks for all the interesting info. Over the holiday I have found two lenses that I am interested in -
Pentax M 135mm f3.5 or the M 100mm f2.8. From the comments I have read image quality re sharpness and bokeh is pretty good for each so I am leaning towards the 135 because it is $50 cheaper.
01-03-2010, 11:00 AM   #21
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Both are indeed very good lenses. If the 135mm focal length works well for you, then I'd certainly recommend the M135/3.5 with no hesitation. Only half a stop slower (which doesn't mean much with today's high ISO capabilities), but the built-in hood alone makes it a nice choice.
01-03-2010, 11:36 AM   #22
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QuoteOriginally posted by Jimfear Quote
And I truly think some of the old Pentax lenses can rival everything before and since (thinking K28/3.5 and K35/3.5).
+1 Indeed!
01-05-2010, 09:16 PM   #23
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Thanks again for all the info. I went ahead and bought an M 135mm f3.5 and after taking some test shots it seems as sharp wide open as my DA 70 Ltd. I now have to get used to focusing manually. This will be good practice because my 70 in Auto focus is far from perfect. Now all I have to do is make sure the diopter is set up correctly?

Thanks again

01-06-2010, 12:05 AM   #24
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QuoteOriginally posted by kiwao Quote
...I went ahead and bought an M 135mm f3.5 and after taking some test shots it seems as sharp wide open as my DA 70 Ltd...
Shhhhh...not so loud! The prices on the vintage glass is high enough!

Steve
01-06-2010, 02:03 AM   #25
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QuoteOriginally posted by kiwao Quote
I have read comments that state old pentax lenses are of superior quality to the new made for digital lenses.
The biggest problem I noticed with old pentax lenses is purple fringing. Mechanically, they can be very solid and desirable, particularly for the smooth manual focusing that has been lost in this AF era. For the money, they're great value.
01-06-2010, 03:40 AM   #26
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There is no rule here.

some of the FA limiteds are better than the new DA limiteds some of the DAs better than the FAs, Depending on what you want exactly. The DA's are slower, lighter and smaller and are generally sharper over the frame.

You also get distortion and CA correction in the body on the DA limiteds with Kx or K7 bodies.

I think you'd be mad to choose the FA 77mm over the DA 70mm (despite the 77 being awesome the 70 is more awesome).

I also think the FA31mm is better than the DA35mm.

I think the DA40 is too slow and Id have the FA50mm or 43 over it.

Anyway read reviews and decide what you want in your lens.
01-06-2010, 07:52 AM   #27
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There is no quick answer to this one. The older SMC 135/2.5 is one of my favorite lenses of all time. It is always snappier than anything I get from a modern zoom. However, it weighs as much and is MF. The MF may also be why it seems sharper. My biggest frustration of the recent age in SLR technology is autofocus, and modern lenses make downshifting to MF increasingly difficult.
01-06-2010, 09:05 AM   #28
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QuoteOriginally posted by GeneV Quote
... modern lenses make downshifting to MF increasingly difficult.
You got that one right! I was all set to get a Tamron 70-200/2.8 until I saw the focus throw. If it is 45 degrees, I would be surprised.

Steve
01-06-2010, 09:10 AM   #29
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As some have pointed out, pentax lenses have always been respected as some of the finest available.

Others have correctly pointed out that some of the lenses produced in the past do not have current production equivelents, therefore, in this case it is not an issue of old better than new, simply old better than nothing.

In reality, I believe that there are two issues with the pentax lens line up today.

the first issue is that they truely do not have as full a range of lenses as they have had in the past.

the second issue is that they have (it appears) to have modified their lens line up and ranges to be equivelent to a small portion of the film range in the past, with the emphesis on reduced size and weight. As a result, a 70-200 F2.8 no longer exists, but we have the ASP-C corresponding 50-135 F2.8.

While this may be fine for some shooters, it is not for every one, and they have not done their entire range form the past, only portions of it. There are a lot of people who want to take advantage of both the really fast lenses of the past and the new sensor format for sports, nature , etc but the big telephotos are gone. They don't even have equivelents to them based upon format. Ther is no equal today for example of the 400 F2.8 or 600 F4 lenses.
01-06-2010, 09:20 AM   #30
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QuoteOriginally posted by nulla Quote
I agree 100%
I used to be Nikon film ...when coming back to my hobby and new to DSLR it was the quality of Pentax glass that made me make the right decision. I am one of these Pentax people that find it strange that people use a Pentax camera and buy lenses other than Pentax.
Cheers
Neil
I'm with you, Neil. I've strayed from the right path on occasion, always to my financial detriment. There is a look to Pentax lenses that is unmatched by anyone else.

Lowell, at last count, the 600/4 is still available on special order.
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