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04-04-2011, 05:06 AM   #16
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QuoteOriginally posted by rparmar Quote
Most lens manufactures use the designation "APO" to indicate an apochromat; Tamron uses "LD".
That's not true. Tamron's "LD" only signals that "one or more very low dispersion elements" have been used. It is not claiming the whole optical design to be an APO design.

It doesn't make sense to include Tamron lenses with an "LD" designation in a list of APO lenses.

04-04-2011, 05:41 AM   #17
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QuoteOriginally posted by Class A Quote
It doesn't make sense to include Tamron lenses with an "LD" designation in a list of APO lenses

No, it doesn't especially considering many of them are zoom lenses with focal length ranges going well under 50mm. As I have said before there aren't any true Apochromatic 35mm lenses made with focal lengths under 100mm.

And for the record: the Schneider Apo-Digitar, Rodenstock HR Digaron-S are not 35mm lenses, they are designed for large format view cameras equipped with digital medium format backs.
04-04-2011, 05:50 AM   #18
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Thank you -- I was misinformed by an article I read. After viewing some images and test results I agree these cannot be included.
04-04-2011, 06:05 AM   #19
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you also might want to add the Pentax FA*300mm f/2.8 and pentax FA*600mm f/4 - These two lenses I have used in the past and their performance fits well within the definition of an apochromatic lens. Although the literature describing those two lenses does not explicitly designate them as such, but a close look at their lens design schematics strongly suggest this is the case*.

the funny thing I have observed is that all the major 35mm camera manufacturers E.g Canon,Nikon and Pentax do not really mention of apochromatic lens designs in their lens line ups, but Sigma,Tamron and Tamron do.

*although I have never used the pentax FA*250-600mm f/5.6 from looking at the lens design the first three elements are in a classic apochromatic arrangement, so I would tentatively put that lens on the list as well. There may be others on this forum who own this lens that could provide an account of whether my observation is correct or not.


Last edited by Digitalis; 04-04-2011 at 06:16 AM.
04-04-2011, 06:26 AM   #20
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Sigma 70-200mm f2.8 APO EX (non macro pre-DG version)

Sigma 70-300mm f4-5.6 APO Macro Super (pre-DG version, this should be improved 70-300 APO macro, hence the "Super" label)

Sigma 50-500mm f4-6.3 APO EX (Bigma)
04-04-2011, 08:12 AM   #21
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Apart from the 3 Voigtländer Apo-Lanthar and a few Sigma lenses (which are more achromatic than truly apochromatic lenses), there are no other apochromatic lenses in Pentax K mount.

There are of course the Quartz Takumar and Ultra Achromatic Takumar lenses, but these are rare as hens' teeth and they are not K mount but M42 lenses. A few APO lenses were also made in M42 mount by lensmakers from former USSR countries, like the APO-Telezenitar 135/2.8 or the APO-Telezenitar 300/4.5 from Krasnogorsky Zavod.

If you are willing to use adapters or do mount convertion, there's the amazingly good but incredibly expensive CoastalOptics UV-VIS-IR 60mm Apo Macro (Nikon mount), as well as a few Leica Apo lenses (Leica 90/2 APO Summicron-R, 180/2.8 APO-Elmarit-R, 280/4 APO-Telyt-R, or 300/4 APO) that are of very high quality indeed.

And, last but not least, don't forget that many mirror lenses are naturally apochromatic or near apochromatic...

Cheers!

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04-04-2011, 08:49 AM   #22
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Perhaps some lenses are apochromatic without having APO in their names? I can only judge by experince but from what I have seen many Pentax lenses do have less problems with fringing than Sigma lenses bearing APO label. I recall DA*50-135, DFA50, DA*300, FA135 and perhaps others.
Please enlighten me.
04-10-2011, 08:58 AM   #23
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While not exactly K-mount, there are some enlarging lenses that are true APO designs

04-10-2011, 09:13 AM   #24
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I have a nice Sigma 50-200 Apo 3.5-4.5 PK/A mount
04-10-2011, 02:08 PM   #25
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QuoteOriginally posted by Abbazz Quote
Apart from the 3 Voigtländer Apo-Lanthar and a few Sigma lenses (which are more achromatic than truly apochromatic lenses), there are no other apochromatic lenses in Pentax K mount.

Cheers!

Abbazz
I know you know a lot about this, but I definitely have a lens claiming to be apochromatic in the Rikenon XR 300mm f/4.5 prime. So... there is one other, and may even be one or two more, right?
04-10-2011, 02:30 PM   #26
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Tokina labelled a number of their zoom lenses as APO, such as the Tokina 80-200mm f2.8 AT-X 828 AF Pro SD and Tokina 80-400mm f4.5-5.6 AT-X 840 AF SD.
04-10-2011, 03:38 PM   #27
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QuoteOriginally posted by aliasant Quote
I have a nice Sigma 50-200 Apo 3.5-4.5 PK/A mount
I'd be very surprised if there were a lot of merit to this "APO" designation. Seems like it has been used liberally similarly to how the "MACRO" designation is often used for lenses which just have some close focusing ability (but are nowhere near true macros).
04-10-2011, 04:38 PM   #28
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QuoteOriginally posted by Class A Quote
I'd be very surprised if there were a lot of merit to this "APO" designation. Seems like it has been used liberally similarly to how the "MACRO" designation is often used for lenses which just have some close focusing ability (but are nowhere near true macros).
Agreed. I think most of the APO labelings of lenses should not be taken at face value. Of course, it really depends on how you define it--I mean some of these lenses might be APO at one focal lengh/aperature setting/focal distance, but not throughout most of the options. The APO-Lanthars really seem the best from what I've seens as far as actually being APO consistantly. I'm sure the APO enlarging lenses are really APO as well, although I don't know what the correction would be like outside of their standard focus range (actually, I've just won an APO-Rodagon for a song and am looking forward to giving it a try).
04-10-2011, 07:04 PM   #29
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QuoteOriginally posted by Digitalis Quote
you also might want to add the Pentax FA*300mm f/2.8 and pentax FA*600mm f/4 - These two lenses I have used in the past and their performance fits well within the definition of an apochromatic lens. Although the literature describing those two lenses does not explicitly designate them as such, but a close look at their lens design schematics strongly suggest this is the case*.

the funny thing I have observed is that all the major 35mm camera manufacturers E.g Canon,Nikon and Pentax do not really mention of apochromatic lens designs in their lens line ups, but Sigma,Tamron and Tamron do.

*although I have never used the pentax FA*250-600mm f/5.6 from looking at the lens design the first three elements are in a classic apochromatic arrangement, so I would tentatively put that lens on the list as well. There may be others on this forum who own this lens that could provide an account of whether my observation is correct or not.

Marc Langille has all of these.
04-11-2011, 01:32 AM   #30
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QuoteOriginally posted by Class A Quote
I'd be very surprised if there were a lot of merit to this "APO" designation. Seems like it has been used liberally similarly to how the "MACRO" designation is often used for lenses which just have some close focusing ability (but are nowhere near true macros).
You are probably right. I have no knowledge about this but I did test this lens against my Viv S1 70-210 Komine version at 150mm.
The Viv had some CA but the sigma had none what so ever and also slightly better contrast and colors.
Now I dont know which one to keep. Trying to cut down on the amount of lenses but I probably have to keep em both since they have different strengths.
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