[LensBeginner]

If your lense can resolve 24MP on APSC, it can resolve 54MP on FF. It may fail to do so on borders but for an heavy crop that not that important.

From experience with K3 I get very sharp center performance from most lenses. I agree I have mostly prime but I can say an FA50 would do it, a DA50-135 or FA77 too. I think all macro lenses would have no issues and theses one are not that expensive typically.

That's the point, I knoe for certain my lenses are good enough at 16MP APS-C, but 24? Never tried so can't be sure.
Also, I had to adjust shutter speeds considerably for moving subjects coming from a lower-MP camera (because pixels are much smaller. You want to crop, right?), and I wouldn't want to go even lower.

[Nicolas06]

That's the point, I knoe for certain my lenses are good enough at 16MP APS-C, but 24? Never tried so can't be sure.
Also, I had to adjust shutter speeds considerably for moving subjects coming from a lower-MP camera (because pixels are much smaller. You want to crop, right?), and I wouldn't want to go even lower.

Yeah but so what? 16MP APSC is already 36MP on FF. You know it works then. For 24MP APSC, you can just look at the crops available on the net, look at the photos, ask the one that now have a K3. If you need to try to know then try. If you think you need to try but doesn't try and then raise concerns, there a bit of inconsistency in your argumentation to me.

The shutter speed is a false argument. You should have the shutter speed that match the intended framing. If you hope for a 300mm shoot using a 300mm lense on APSC you need a 1/500 or faster without shake reduction. That you get your 300mm framing from a 300mm lense, or from a shorter focal length like a 135mm or 200mm, the speed should be at least 1/500. Shake reduction can drastically reduce it as can a tripod/monopod. But from a practical point of view it doesn't change anything to use a shorter focal length and crop or use the proper focal length and not crop for the shutter speed.

Here just as one example a DA50-135, a 80mm shoot and a 100% crop of K3. The reframing is equivalent to 400mm, so 5 time the focal length:

It was 1/250s at f/5.6, for a 400mm on APSC, this mean the speed should have been 1/600s. You see that SR indeed really works.



Most primes and most quality zoom would do it without issue in the f/4-f/8 range.

Anyway I think the discussion is not for your or my lenses. We speak of a 5MP being enough or not and why Canon now has decided to offer a 50MP FF (and 24MP APSC). Our lenses would not be ideal for such body anyway.

This would not prevent for one to buy it, use some Canon primes on it and benefit of the resolution it provide.

[Digitalis]

That's the point, I knoe...

[cringes]

[stevebrot]

If your lense can resolve 24MP on APSC, it can resolve 54MP on FF

Except that lenses do not resolve megapixels. The lens resolution is fully independent of the capture medium.


Steve

(...sorry, pet peeve...)

[stevebrot]

That's the point, I knoe for certain my lenses are good enough at 16MP APS-C, but 24?

Your lenses will perform at least as well with a 24 Mpx sensor as with a 16 Mpx sensor. After all, the lens has no idea what is being used for capture. There is so much angst about a particular sensor making one's lenses obsolete or less good. That fear is unfounded.


Steve

(...went from 10 Mpx K10D to 24 Mpx K-3 using same mix of lenses...)

[LensBeginner]

Yeah but so what? 16MP APSC is already 36MP on FF. You know it works then. For 24MP APSC, you can just look at the crops available on the net, look at the photos, ask the one that now have a K3.

I'm fine with 36MP on FF, in fact. I'd rather not have 50...

The shutter speed is a false argument. You should have the shutter speed that match the intended framing.

*snip*

I was replying to Clavius which was talking about heavy cropping. Shutter speeds for a heavy crop need to be faster.

[cringes]

I take it that you never, ever replied from a smartphone while walking in a hurry...
I noe how to write that, a "k" somehow got in the way...

[Nicolas06]

I was replying to Clavius which was talking about heavy cropping. Shutter speeds for a heavy crop need to be faster.

Sure but no more than if no cropping and a longer focal length was used. And tripods/monopod/SR are all mechanism to keep the shutter speed under reasonable limit.

[Nicolas06]

Except that lenses do not resolve megapixels. The lens resolution is fully independent of the capture medium.


Steve

(...sorry, pet peeve...)

The lense doesn't resolve anything. It is fully dependant of a complete system that need light to operate. That's why we have lenses optimized for digital that's why Sony is thinking of curved sensor and the associated lenses. A scanner can record very high resolution image and doesn't need a lense. A mirror can reflect an image with many details and there no lense again.

A lense without any camera compatible with it is just an expensive paperweight.

[mrNewt]

It was 1/250s at f/5.6, for a 400mm on APSC, this mean the speed should have been 1/600s. You see that SR indeed really works.

IMGP2661 by Nicolas Bousquet

Is that a Famas!? With bayonet? Nice...

[Nicolas06]

Is that a Famas!? With bayonet? Nice...

I'd say it look like it is one !

[6BQ5]

Can I borrow it for dust spotting my 10,000 DPI 8X10 format drum scans? - doing that at 100% view on a small 30" monitor is a pain.

You have all the cool toys, don't you?

[LensBeginner]

Sure but no more than if no cropping and a longer focal length was used. And tripods/monopod/SR are all mechanism to keep the shutter speed under reasonable limit.

Of course but

1. it's a sneakier thing than checking a 400mm-picture directly, because you'd have to zoom on the poor-quality camera display and "guess" if it's ok for a crop in addition to being ok as it is (which is what you're accustomed to check in a normal situation).
Try and judge that from a fuzzy jpeg preview, maybe when you've shot RAW and are looking at the embedded jpeg.

2. the fact that the lens has to be able to withstand heavy (heavier-than-usual) pixel-peeping still stands.

If you want to crop heavily, everything (lens, technique, conditions) must be more than up to scratch, and if just one thing is missing (e.g. low light, hence can't stop down as required) it's a no-go.

[biz-engineer]

The lense doesn't resolve anything

Yes it does. The optical bandwidth is measured in lines per mm for a given contrast value, there is also an attenuation of the spacial bandwidth due to diffraction, so even a lens built with perfect glass material has a limited resolving power, that's why is you close down the aperture the optical imperfection diminishes but the diffraction increases, independent from the sensor. Unfortunately, there are limits to everything.

---------- Post added 03-25-15 at 08:30 PM ----------

Your lenses will perform at least as well with a 24 Mpx sensor as with a 16 Mpx sensor.

Yes, indeed, the lens is the same, but when you had the K100D, you zoomed your image at 100% on you LCD and "waooow, this lens is sharp", a number of years later, you buy the K-3, you capture a photo with the same lens, you load it on your computer and zoom it at 100% on you LCD, and realize, beurk, it's blurred, this lens is not as good as it used to be ;-)

No , 5 Mpixels is not enough. According to the resolution of your own eyes and the viewing distance at least the diameter of the print, the right number seems to be 7 mega pixels (http://www.pointsinfocus.com/tools/minimum-resolution-calculator/).

[Rondec]

I guess the thing is that the only downside to having more megapixels is the fact that the files are bigger. Hopefully there is more resolution (usually there will be), with more option to crop or print bigger. Certainly you aren't going to have worse resolution going from a 6 megapixel sensor to a 24 megapixel sensor, but you could have a lot better resolution depending on the situation.

[LensBeginner]

Yes it does. The optical bandwidth is measured in lines per mm for a given contrast value, there is also an attenuation of the spacial bandwidth due to diffraction, so even a lens built with perfect glass material has a limited resolving power, that's why is you close down the aperture the optical imperfection diminishes but the diffraction increases, independent from the sensor. Unfortunately, there are limits to everything.

---------- Post added 03-25-15 at 08:30 PM ----------


Yes, indeed, the lens is the same, but when you had the K100D, you zoomed your image at 100% on you LCD and "waooow, this lens is sharp", a number of years later, you buy the K-3, you capture a photo with the same lens, you load it on your computer and zoom it at 100% on you LCD, and realize, beurk, it's blurred, this lens is not as good as it used to be ;-)

No , 5 Mpixels is not enough. According to the resolution of your own eyes and the viewing distance at least the diameter of the print, the right number seems to be 7 mega pixels (Print Resolution Calculator - Points in Focus Photography).

This, and this.