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04-21-2021, 12:13 PM - 3 Likes   #31
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QuoteOriginally posted by biz-engineer Quote
Out of topic, English not being my mother tongue, is a "dog" lens better or worse than "lemon" type lens?
A dog implies that every sample is going to be bad.
Think Yugo cars.
A lemon implies that some samples will be good, others not so much.
Think anything from General Motors.

Regarding sharpness, I had a number of lenses that were at best mediocre on film that were suddenly pretty good on digital when digital was 6mp and only using the center of the lens. As pixel counts went up, the lenses got progressively worse until I got the K1 and they became dogs again.

Also, F8 is the great equalizer. Even a lowly FA50/1.4 is nearly as sharp as a D FA*50/1.4 at f8

---------- Post added Apr 21st, 2021 at 01:20 PM ----------

QuoteOriginally posted by RICHARD L. Quote
Proof of the imaging quality of this particular new HD DA 55-300 mm lens is that it remains sharp even on a K3 @ 24 Mpx. Sometimes a lens performs well on a lower resolution sensor (14,7 Mpx for a K20 and 16 Mpx for a K5, for example) but doesn't fare too well on a higher resolution recording medium. This HD lens performs brilliantly on any APSc sensor.
You do realize that you don't have to shout to be heard?

04-21-2021, 01:29 PM   #32
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My most un-sharp lens is a Hoya 135mm f2.8 HMC. I think it might be mean for portraits as it fails at landscape, giving them that dreamy look.
04-21-2021, 02:48 PM - 1 Like   #33
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When a photographer knows what he's doing and is striving to get the best picture possible, even "rather mediocre" lenses can deliver. Most lenses have a "sweet spot", a focal length (for a zoom) or an aperture where it performs decently. Below a sharp image realised with a "so-so" lens (older FA 28-105 mm f/4-5.6) at 65 mm FL and f/9.5, its optimal settings.


Last edited by RICHARD L.; 04-21-2021 at 03:25 PM.
04-21-2021, 04:17 PM   #34
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QuoteOriginally posted by koolimy Quote
Hi, this may be the stupidest question ever posted on the forums, but my most recent LBA acquisitions have me confused about everything regarding camera lenses so I wanted to pose this question here.


Background: For a long time my only lens was a Samyang 35mm F1.4. I bought it when I bought the Pentax K-30, and it was my one and only lens. As you may know, it is a very highly regarded lens known for it's sharpness in all apertures and at least to my eyes, yes, it was very sharp at all apertures and the pictures it took were beautiful, only limited by my ability.


Unfortunately, my K-30 broke shortly after I bought it and I didn't take photos for quite a while. I never sold the Samyang however, and recently I bought a Pentax K20D from a forum member to use the Samyang again. In a fit of LBA I also bought a Pentax 80-200mm F4.5, and a Pentax M 50mm F1.7 to go along with my Samyang.


Much to my astonishment (and dismay, LOL) I found that both lenses were as sharp as my Samyang, even wide open!
Hi Koolimy, I think sample pictures can be very misleading, which is why the industry uses MTF charts to judge these things. Here's your Samyang 35mm f1.4, with its sharpness at different parts of the picture frame:

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04-21-2021, 04:19 PM   #35
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And here's a current Canon. The Samyang's cheaper but the Canon's a much sharper lens.
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04-21-2021, 04:50 PM - 2 Likes   #36
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“Sharpness is a bourgeois concept” ~ Henri Cartier-Bresson
04-21-2021, 10:55 PM   #37
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QuoteOriginally posted by Wheatfield Quote
A dog implies that every sample is going to be bad.Think Yugo cars.A lemon implies that some samples will be good, others not so much.Think anything from General Motors.
I was asking because all I found in the dictionary was that lemon is a fruit and dog is an animal , although I knew Apples are computers, I needed to expand (or expend?) my English vocabulary. So thanks a lot for the clarification

04-22-2021, 07:19 AM - 1 Like   #38
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A funny answer in reference to the thread question, I would ask: Are all knives sharp? xD
04-22-2021, 08:52 AM - 1 Like   #39
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QuoteOriginally posted by biz-engineer Quote
I was asking because all I found in the dictionary was that lemon is a fruit and dog is an animal , although I knew Apples are computers, I needed to expand (or expend?) my English vocabulary. So thanks a lot for the clarification

I think if you talk to a lot of people, the terms are fairly interchangeable.
04-22-2021, 10:14 AM   #40
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Lest we forget Donkeys (ponderous) and turkeys (see Dogs (but not in biz engineers dictionary)). My descriptive terms are generally more florid, less ambiguous and certainly banned from PF
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