[normhead]

Thank goodness we have a resident genius to point us all in the right direction

One? OK which one of us did you nominate for the position? I see at least 5 here.

For many of us, there is little in this world more painful than having to correct some one that just watched a Tony Northrup video. It would have been much easier to address the question without having to deal with the mis-information he puts out there.

There are guys on the site, Digitalis and Falconeye , Photoptimist a few others capable of coming out with the mathematics and putting together some excellent illustrations of the various theories. Tony isn't one of those guys and neither am I. Calling anyone geniuses might be little overstating everyone's qualifications. Perhaps even showing a bit of contempt.

You don't have to be a genius to understand the flaws in Northrup's logic.

You do need a bit of experience dealing with his particular brand of subterfuge. But once you're on to it, you realize he's a one trick pony. Once you know the trick, it's all the same old same old.

"There's more light if you don't take depth of field into account."

Now discredited as any kind of rational argument, he's recycled the same ol argument into "don't use a full frame lens on an APS-c camera" using the same flawed logic. Apparently, it's all he has.

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Last edited by normhead; 11-05-2017 at 12:19 PM.

[stevebrot]

One? OK which one of us did you nominate for the position? I see at least 5 here.

Me too! Me too!


Steve

[jddwoods]

I have been using F 28mm, FA 50mm, DFA100 WR on my K-3 and K-5 bodies and they take great pictures and are very compact. So, I do not know what is the issue against using FF lenses on crop bodies. I did not see any convincing reason not to use FF lenses on crop bodies on the video either.

[BigMackCam]

I came to this one pretty late, and everything has already been said...

I quite like Tony Northrup, but this really is one of his more misleading and less helpful videos. @stevebrot is probably right - Tony would likely avoid the subject or (hopefully) change his tune nowadays.

Full frame glass works just fine on any size sensor, whether it's (so called) full frame, APS-C, micro 4/3 or even smaller. A 24-70mm f/2.8 lens will let in the same amount of light and - when shot at the same distance - will produce the same depth of field on any sensor. The field of view will, of course, differ depending on the size of that sensor (if the sensor is cropped, the field of view will be cropped accordingly) and that will determine the appropriate use-cases for the lens and camera combination. Furthermore, the greater the pixel density of the sensor (a combination of sensor size and resolution), the more demanding it will be of a lens' resolving capabilities. Fit a poorly-performing lens to a high-res 24 megapickle APS-C camera, and you'll notice the deficiencies more than you would on a slightly-lower-resolution 16 megapickle APS-C camera. On a (by today's standards) relatively-low-res 12 megapickle full-frame camera, you'll notice those deficiencies less still. But, if you shoot full-frame and APS-C cameras with same pixel density sensors side by side, with the same lens, you're going to get exactly the same performance from the lens.

The glass I have most fun with is old Soviet stuff intended for use on 35mm film cameras. Some of those lenses are sharp, some less so; some produce weird bokeh (occasionally nice, often distracting), others have contrast or flare issues. I use them on my Sony full-frame and Pentax / Samsung APS-C cameras with no obvious difference in results, save for the different field of view based on sensor size. My full-frame cameras use 24Mp sensors, and I have APS-C cameras with everything from 6 to 24Mp sensors.

One of my favourite - and most used - lens / camera combinations is the full-frame Tamron 28-75 f/2.8 on the 10Mp Samsung GX-10 (Pentax K10D). The focal length / field of view range on APS-C is perfect for much of what I do. I have the same lens in Sony A-mount for my full frame gear, and it gets used much less - purely because of the field of view.

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Last edited by BigMackCam; 11-05-2017 at 01:47 PM.

[ScooterMaxi Jim]

i did indeed, thanks for pointing out my error, I have corrected it. In my defence i had a cocker spaniel trying to stand on me as I was typing

---------- Post added 11-05-17 at 06:12 PM ----------

For those who have not viewed this, i highly recommend it for a dose of reality.

Come On People, It's Time to Stop Arguing About Crop Factors Already

Nothing finer than an English cocker for a good excuse; wonderful dogs. It was pretty clear you knew the right stuff, but didn't want others confused.

[ScooterMaxi Jim]

I came to this one pretty late, and everything has already been said...

One of my favourite - and most used - lens / camera combinations is the full-frame Tamron 28-75 f/2.8 on the 10Mp Samsung GX-10 (Pentax K10D). The focal length / field of view range on APS-C is perfect for much of what I do. I have the same lens in Sony A-mount for my full frame gear, and it gets used much less - purely because of the field of view.

Interesting... I have the Tamron 28-75 lens in Canon mount where it was used both for crop and FF needs. Photozone indicates that the lens performs especially well on crop, but the edges and corners have too many issues for FF. I found that it was really fine at FF when stopped down to f/4, but not adequate wide open (no lens I've owned has dramatically improved so much in a single stop). I'm just the opposite in terms of my shooting needs. I really enjoy lenses that go from wide to mild telephoto - with "normal" roughly in the middle. Starting at normal feels very limiting to me.

[BigMackCam]

Interesting... I have the Tamron 28-75 lens in Canon mount where it was used both for crop and FF needs. Photozone indicates that the lens performs especially well on crop, but the edges and corners have too many issues for FF. I found that it was really fine at FF when stopped down to f/4, but not adequate wide open (no lens I've owned has dramatically improved so much in a single stop).

I do see the limitations in the borders and corners on full-frame, but not to a degree that bothers me. For center and mid-frame performance (frame-wide on crop), I'm quite happy with it wide-open after AF fine adjustment, for certain types of shot - though I agree it benefits hugely from being stopped down to f/4, where I think it really shines

I'm just the opposite in terms of my shooting needs. I really enjoy lenses that go from wide to mild telephoto - with "normal" roughly in the middle. Starting at normal feels very limiting to me.

I can understand that, for sure. I've just found that, for most of my own shooting, 28mm on APS-C is usually as wide as I want to go - in fact, I'd say 28 to 50mm is my preferred range, though it's nice to have a little more headroom for certain situations. I guess I'm a little uncommon in that respect... I certainly wouldn't recommend 28-75 on APS-C as a walk-around combo for most, but it works really well for me I do have wider-angle lenses I enjoy using too (the DA21 on crop is a favourite), but I rarely find myself wanting to go wider. My DA15 is, sadly, my least-used lens, though I love the IQ

[Sandy Hancock]

Oh great, another equivalence thread. Just what we all needed.

My two favourite lenses on crop are my FA31 and FA77, closely followed by my DFA100WR. And I have owned all the DA limiteds and DA* lenses at one time or another. Nothing Tony Northrup says is going to change that.

[johnyates]

I'm so old, I can remember back when photographers would make a living by creating and selling photographs.

These days it seems the name of the game is driving web traffic by creating click bait on YouTube etc.

AFAIK, the only disadvantage to using FF lenses on crop cameras is that the FF lenses admit more non image forming light into the camera which can cause flare. However, by using a sufficiently long lens hood, this problem is mitigated.

And of course the big advantage is the crop sensor gets the best image quality from the centre of the lens.

I'm quite satisfied with what I get from my FF lenses--I only own one DA lens. Of course I only create photographs--I'm not trying to be an 'expert'.

[timb64]

Of course I only create photographs--I'm not trying to be an 'expert'.

There are more than enough who fancy they are

[Digitalis]

The instant he plugged his publication and mentioned DxOmark he lost all credibility. Also his comments about "perceptual" resolution between full frame and APS-C are way off the mark. I'd love to meet his friend the "genius" and tell him he has been listening to a willfully ignorant sellout.

As long as you are getting the results you are happy with, use whatever lenses you want!

[fwcetus]

About half of my lenses are full frame and I have never had a problem with them using them on an APS c body.

About the same here, except that it's ~most~ of my lenses that are full frame lenses. Absolutely ~no~ problems at all from such use...

[normhead]

There are more than enough who fancy they are

Ya, really, that's not a productive road to go down. You can get lost down there.

[ScooterMaxi Jim]

On a more serious note, I do tend to notice some difference in general between crop lenses designed for digital and FF lenses designed for film. You tend to get a snap and saturation with the newer lenses, but a busier look in the near-OOF areas. Especially for landscapes and portraits, I tend to prefer the older, softer look that strikes me as more realistic. This became especially apparent with the DA 50 compared to the older 50s.

Not sure why that would work that way, other than differences in the coatings. One thing I really appreciate with the FF lenses is that they tend to render sharpness similarly on crop across the frame (even though they are likely to have heavier CA on the edges) whereas modern lenses often show considerable sharpness degradation toward the edges compared to the ultra-sharp center. This center-corner sharpness difference is especially apparent in comparing the FA 35 to the DA 35 on crop.

[jpzk]

I happily use the D FA28-105mm on the K7, and I think anyone would be hard pressed to find any disadvantages to it. Indeed, one big advantage to it is that I won't need to buy another wide to mid-tele zoom if I eventually get a FF Pentax camera, something that figured in my reasoning when I bought the lens.

Exactly my thoughts too !