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02-13-2021, 11:07 AM - 2 Likes   #76
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QuoteOriginally posted by Lowell Goudge Quote
I am a fan of Murphy’s laws, and one of then states, “given enough data you can prove anything with statistics”

Edit note, actually holland’s law
I once read a survey of 10,000 people exiting bars after last call that was able to prove that the streets and buildings of the world are definitely all tilted.


Steve

02-13-2021, 11:12 AM   #77
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QuoteOriginally posted by revelstoked Quote
Conversely, when using APSC lenses on a FF body, the projection diameter can be too small for the size of the sensor, leading to circular fringes.
I'd like to see an example of that.
K-1 and DA 55-300 PLM showing vignetting,


That's not true in my experience.

You'd need to qualify by listing the lenses for which that is true or it to be useful. I use my DA*60-250, DA*55 1.4 and 35 2.4 on FF, all DAs, not DFAs, so it's not like I haven't had the opportunity.
02-13-2021, 11:27 AM - 1 Like   #78
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QuoteOriginally posted by normhead Quote
I'd like to see an example of that.
K-1 and DA 55-300 PLM showing vignetting,


That's not true in my experience.

You'd need to qualify by listing the lenses for which that is true or it to be useful. I use my DA*60-250, DA*55 1.4 and 35 2.4 on FF, all DAs, not DFAs, so it's not like I haven't had the opportunity.
Oh come on Norm.
DA 55-300 PLM on K-1 at 300mm.



At 300mm it's fine with some light cropping and the lens works wonders, but at 100mm it's kinda not as good. It's basically a 55-70 plus 150ish-300mm lens


The Tamron 17-50/2.8 (I know, not specifically a Pentax lens, but we're talking formats here) is kinda unusable:





Of course, the opposite (FF lens on APS-C body) is... I'm not commenting on any pixel projection ideas
The detail of the FA77 is the same whether I shoot the K-1 on full frame mode or on crop.

Last edited by Serkevan; 02-13-2021 at 11:35 AM.
02-13-2021, 11:39 AM   #79
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Any thoughts?

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02-13-2021, 11:43 AM   #80
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QuoteOriginally posted by Pentaxxoid Quote
Any thoughts?
That is a sensor format issue - it has *nothing* to do with the image circle of the lens.
02-13-2021, 11:53 AM   #81
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Yeah, the degree of severity does really depend on the optical formulation of the individual lense as each design will have a different internal projection diameter. That's why some of the APSC glass works fine with K1. The projection is big enough to uniformly cover the sensor. This can also change with changes in aperture which is why you can vignetting at certain apertures. Vignetting is the fall off of light at the edge of the internal projection.

QuoteQuote:
That's not true in my experience.

You'd need to qualify by listing the lenses for which that is true or it to be useful. I use my DA*60-250, DA*55 1.4 and 35 2.4 on FF, all DAs, not DFAs, so it's not like I haven't had the opportunity.
02-13-2021, 12:10 PM   #82
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QuoteOriginally posted by Serkevan Quote
Oh come on Norm.
DA 55-300 PLM on K-1 at 300mm.



At 300mm it's fine with some light cropping and the lens works wonders, but at 100mm it's kinda not as good. It's basically a 55-70 plus 150ish-300mm lens

Where we going?

I almost always take the DA 18-135 or 21 ltd and 100 macro and 1.4 TC with it, so not an issue.

Compared to any other 300mm lens if you know you're going to be gone 19 days and cary it for 45 km, along with your other gear, the DA 55-300 PLM is an absolute dream on the K-1. There's nothing that even compares, despite the limitations.

Especially since it all has to fit in the orange case and I'd really love to get my gear back into the little red one. Where are you going to find a 300 mm lens that collapses like that 300mm DA 55-300 PLM? Anyone, any company? Any time frame?



---------- Post added 02-13-21 at 02:16 PM ----------

QuoteOriginally posted by Pentaxxoid Quote
Any thoughts?
You need to take some pictures, and stop messing around with charts. I determined I'd rather take my DA 55-300 PLM instead of my DA* 60-250 or DA*200 based on experience, not on sensor charts.

As for the same information, ya, same lens and same distance etc. the K-1 is 25% more lw/ph than the K-3 (K-P, K-70) SO if you frame nice and tight with the K-3, but if you have to crop 25% with the K-1, you get the same resolution from both.

IN this case, the width with the crop is 6512. The crop from a K-3 would be 6000. You lose almost nothing using the crop sensor in many real life situations, but your subject is bigger. the K-3 is 6000 width, the K-1 is 7300. It's not as much difference as you might think. It's a 22 percent increase in pixels, despite the impression created by your chart.

The issue with the K-1 is, I'd need a 450mm lens to give me what the K-3 with the 55-300 PLM does or a possibility of more resolution, and because of the denser pixels, the K-3 may give me more resolution than the K-1 could, and that is never going to happen. As long as there are issues both ways, I'm going with the lightest smallest lens.


Last edited by normhead; 02-13-2021 at 12:35 PM.
02-13-2021, 12:58 PM   #83
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QuoteOriginally posted by normhead Quote
Where we going?

I almost always take the DA 18-135 or 21 ltd and 100 macro and 1.4 TC with it, so not an issue.

Compared to any other 300mm lens if you know you're going to be gone 19 days and cary it for 45 km, along with your other gear, the DA 55-300 PLM is an absolute dream on the K-1. There's nothing that even compares, despite the limitations.

Especially since it all has to fit in the orange case and I'd really love to get my gear back into the little red one. Where are you going to find a 300 mm lens that collapses like that 300mm DA 55-300 PLM? Anyone, any company? Any time frame?
I also like the PLM a lot*, but that doesn't make it cover the image circle completely, which was the point. Can the lens be useful despite this? Yes. Does it become basically crippled at certain focal lengths because the image circle doesn't cover the FF sensor? Also yes. Just because it's useful for you or me doesn't make it magically perfect.

I'm glad you brought up the 18-135. How's that one on the K-1? AFAIK it's solid black corners/edges throughout the entire range.


*Probably the best affordable telezoom in the market, all things considered. Maybe the newest Canon 70-300 with Nano USM motor is better, but that one's significantly bigger and heavier.
02-13-2021, 01:19 PM   #84
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QuoteOriginally posted by pschlute Quote
I struggle to understand how you are able to find the shutter button.....thoughts ?
Oh, come on, you're not suggesting these cameras and lenses are for actually taking photos, surely?

(sorry – didn't mean to call you Shirley )
02-13-2021, 01:23 PM   #85
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QuoteOriginally posted by normhead Quote
You need to take some pictures, and stop messing around with charts. I determined I'd rather take my DA 55-300 PLM instead of my DA* 60-250 or DA*200 based on experience, not on sensor charts.
Agree with Norm that this is the bottom line. You can buy a house, a car, an audio system, a computer based on numbers and stats, but the math only goes so far as an assessment tool, and nothing shows you "it is what it is" like experience with real world subjects, lighting, and then viewing the results on your media of preference.

We humans are (thankfully) always asking why? It's the left brain. Instead, IMO let the right brain start the dance and then you can let the left brain analyze the results.
02-13-2021, 01:39 PM - 1 Like   #86
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QuoteOriginally posted by StiffLegged Quote
Oh, come on, you're not suggesting these cameras and lenses are for actually taking photos, surely?

(sorry – didn't mean to call you Shirley )
Sincere apologies. I must remember the next camera I buy has the Tony northrop seal of approval and a warranty that specifies it wont be used for taking real photos
02-13-2021, 02:32 PM   #87
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QuoteOriginally posted by Serkevan Quote
I'm glad you brought up the 18-135. How's that one on the K-1? AFAIK it's solid black corners/edges throughout the entire range.
When I take the K-1 I take the DFA 28-105 instead. I haven't even tried it on the K-1.
02-13-2021, 02:33 PM   #88
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QuoteOriginally posted by normhead Quote
When I take the K-1 I take the DFA 28-105 instead. I haven't even tried it on the K-1.
Yeh, that's the point - the 18-135 forces you to crop the image quite a lot if you use it on FF. FF glass is more versatile by definition, although certain APS-C lenses are very good and can be useful despite the issues, like the PLM
02-13-2021, 02:38 PM - 1 Like   #89
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QuoteOriginally posted by Pentaxxoid Quote
Any thoughts?
Same amount of "information"?

What type of "information"? It's subjective based upon the pixel density and number of megapixels of each sensor. The lens does not really come into the equation.
You may as well remove the lens from the camera body and ask the same question. Sure, your gathered "information" won't be in focus but the relative amount of "information" will be what it will be based upon what light has reached the sensor.
02-13-2021, 02:50 PM - 1 Like   #90
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QuoteOriginally posted by MarkJerling Quote
Same amount of "information"?

What type of "information"? It's subjective based upon the pixel density and number of megapixels of each sensor. The lens does not really come into the equation.
You may as well remove the lens from the camera body and ask the same question. Sure, your gathered "information" won't be in focus but the relative amount of "information" will be what it will be based upon what light has reached the sensor.
There's no question the larger the format, the more "information" can be gathered all else being equal (lens, sensor type, etc).
The real question is if it is sufficient for our needs.
For some, APS-C suffices, others want a larger viewfinder and the flexibility to print larger or crop heavier.

The topic here is the lens and what it can do on FF vs APS-C, and it's clear that most of the APS-C designed lenses do have limitations on FF due to the image circle, especially zooms. But we already have plenty of experience as to which APS-C designed lenses can still manage to cover the FF sensor without appreciable degradation of image quality throughout the captured canvas. It was hard for me to even believe there was this concern with FA Limited lenses and whether their IQ would be maintained on FF digital, given the advances on sensor quality. It turns out their images are still hard to beat, even with the likes of the DFA 50/1.4 and DFA 85/1.4
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