[kenspo]

Tamron maybe be close in sharpness in ideal conditions..but thats about it. I have used a lot of Sigma and Tamron..Some of the lenses are sharp as hell..But when it comes to speed, build quality etc..They are not even close. But its no biggy..You guys can buy the the Tamron, i will use the new Pentax, and we are all happy

[Rondec]

I wasn't talking about the kit lens, more like inexpensive but good primes and zooms, but in some cases even a kit lens will resolve more on more MP or larger format (or both) than a super-good lens on lesser MP or smaller format.



What is a myth is that you need 'the best glass', or you won't see any benefit to more MP, or FF, or both. This gets repeated all the time because it sounds 'truthy' and it has it's genesis in the film days, where it was a bit more true.

In the example given here, the Tamron 70-200 2.8 vs, the upcoming Pentax 70-200 2.8 (or existing Nikon/Canon 70-200 2.8 VR II,) the inference people make is that you should dump the Tamron and get the Pentax/Nikon 70-200 in order to 'take advantage' of the new camera - that it's a waste if you don't spend $2K on a zoom - and that's the myth. The Tamron will perform better on the new camera than it did on the old, that's almost guaranteed, unless you have an out-of-spec Tamron.

You can get the 3x as expensive Pentax/Nion 70-200 2.8 if you want, and you may see a slight improvement over the Tamron - but those $$ lenses are not required to see an improvement over the previous camera. If you're interested in 'maximizing' the difference, sure, get the $2K zoom, but that absolute maximization of MTFwill probably bring more diminishing returns than you'd be comfortable with, for that price. If the Pentax focused faster, more accurately, or had a better MFD, something like that, that might be a better reason to get it vs. any resolution difference. (It's not likeley to have better bokeh - that Tamron is a bokeh monster.)

More and more I think spending uber-$$$ on glass is the waste of money, not the other way around. Get good glass (not the 'best',) get the best sensor you're comfortable buying, then you'll see the best IQ returns at any given time.

I think the two big things you would see buying a Pentax over the Tamron 70-200 are going to be that the Pentax will focus faster and more precisely with camera bodies and the colors will be better with the Pentax lens. Those things may be unimportant to many people and the Tamron may be adequate (certainly it is quite sharp), but there will be some who want the things the Pentax offers.

It does seem odd to me, Jay, that on one side you beat the drum that full frame is better for the small improvement you get in your image quality from it and then you say that you should mount cheap lenses, some of which are known to have weak borders and borderline performance on that expensive camera. I will tell you that when I got my K5 I got rid of several older lenses that I had been satisfied with to that point because they didn't perform as well as I wanted on the K5. They weren't worse on it than on the k7, but I wasn't seeing the improvement in resolution that I did with my other lenses.

If I am going to spend close to 3 grand on a body, I want to get maximum out of it.

[normhead]

I think the two big things you would see buying a Pentax over the Tamron 70-200 are going to be that the Pentax will focus faster and more precisely with camera bodies and the colors will be better with the Pentax lens. Those things may be unimportant to many people and the Tamron may be adequate (certainly it is quite sharp), but there will be some who want the things the Pentax offers.

It does seem odd to me, Jay, that on one side you beat the drum that full frame is better for the small improvement you get in your image quality from it and then you say that you should mount cheap lenses, some of which are known to have weak borders and borderline performance on that expensive camera. I will tell you that when I got my K5 I got rid of several older lenses that I had been satisfied with to that point because they didn't perform as well as I wanted on the K5. They weren't worse on it than on the k7, but I wasn't seeing the improvement in resolution that I did with my other lenses.

If I am going to spend close to 3 grand on a body, I want to get maximum out of it.

That's the big problem with FF. If you're the kind of person that eventually pushed everything to the max. you're going to spend a pile of money. If you're the kind of person who can by an FF and use glass that doesn't make maximum use of it's abilities then you get off pretty cheap. IF I buy an FF, I'm going to want a 14-24, and 24-70 that are top of the charts. I would expect a $7k investment. With the 70-200 it would be 10. I've already looked at Nikon stuff and decided I'm not doing that. I expect Pentax will be no different. Especially since they don't even have the lenses I'd want at present. I have my Sigma 8-16 and Pentax 10-17 fisheye for ultra wide angle on APS-c. And ultra wide angle is the one area where and FF might give ma a bit of an edge. With my widest Pentax FF glass at 35mm... I currently can't do what I do, just by buying an FF body. There has to be at least one more lens, a lens that doesn't exist.

[mikeodial]

That's the big problem with FF. If you're the kind of person that eventually pushed everything to the max. you're going to spend a pile of money. If you're the kind of person who can by an FF and use glass that doesn't make maximum use of it's abilities then you get off pretty cheap. IF I buy an FF, I'm going to want a 14-24, and 24-70 that are top of the charts. I would expect a $7k investment. With the 70-200 it would be 10. I've already looked at Nikon stuff and decided I'm not doing that. I expect Pentax will be no different. Especially since they don't even have the lenses I'd want at present. I have my Sigma 8-16 and Pentax 10-17 fisheye for ultra wide angle on APS-c. And ultra wide angle is the one area where and FF might give ma a bit of an edge. With my widest Pentax FF glass at 35mm... I currently can't do what I do, just by buying an FF body. There has to be at least one more lens, a lens that doesn't exist.

Another alternative is not to buy expensive zoom lenses, but buy the three amigos FA31, FA43 and FA77. I can carry these three babies with me all the time in a small shoulder bag with my K3, I hope to be able to do the same with the FF, unless it's much bigger than the K3. My point is those three lenses, purchased used, can get you into full frame mode for around $2k used. (I did it for less with some creative buying and selling on ebay, and got the Pentax new deal before Christmas last year.


Those three lenses plus the FF (if around $2k) will get you some fine glass (way above my ability to ever our perform it), for around $4k and you won't need a Sherpa for your gear. My 2cs.

[normhead]

Another alternative is not to buy expensive zoom lenses, but buy the three amigos FA31, FA43 and FA77. I can carry these three babies with me all the time in a small shoulder bag with my K3, I hope to be able to do the same with the FF, unless it's much bigger than the K3. My point is those three lenses, purchased used, can get you into full frame mode for around $2k used. (I did it for less with some creative buying and selling on ebay, and got the Pentax new deal before Christmas last year.


Those three lenses plus the FF (if around $2k) will get you some fine glass (way above my ability to ever our perform it), for around $4k and you won't need a Sherpa for your gear. My 2cs.

The 31 gives me nowhere near what my Sigma 8-16 gives me on APS-c for landscape. That's just crazy talk. If I buy a system for landscape, it has to do landscape at least as good as what I have now. Otherwise, I'm not buying it.

[mikeodial]

The 31 gives me nowhere near what my Sigma 8-16 gives me on APS-c for landscape. That's just crazy talk. If I buy a system for landscape, it has to do landscape at least as good as what I have now. Otherwise, I'm not buying it.

Yes, you are right. A much wider angle is required. I sold my full frame 14mm Rokinon, but a good prime replacement could be had for around $500, versus the big bucks required for a wide angle zoom. I have a 16-50mm DA, which I am sure will not cover the entire base on the FF.

[jsherman999]

Tamron maybe be close in sharpness in ideal conditions..but thats about it. I have used a lot of Sigma and Tamron..Some of the lenses are sharp as hell..But when it comes to speed, build quality etc..They are not even close. But its no biggy..You guys can buy the the Tamron, i will use the new Pentax, and we are all happy

I'll go with that! The Tamron isn't going to match Pentax/canon/Nikon in build quality, and as long as it's not SDM the Pentax may focus a bit faster on a Pentax body than the Tamron.

[kenspo]

I'll go with that! The Tamron isn't going to match Pentax/canon/Nikon in build quality, and as long as it's not SDM the Pentax may focus a bit faster on a Pentax body than the Tamron.

Then i think we're almost on the same page

[jsherman999]

It does seem odd to me, Jay, that on one side you beat the drum that full frame is better for the small improvement you get in your image quality from it and then you say that you should mount cheap lenses, some of which are known to have weak borders and borderline performance on that expensive camera.

Which lenses have I advocated that have 'borderline performance'?

And you should know I'm not advocating 'cheap lenses', I'm advocating 'good lenses' - good lenses just don't have to be expensive.

The lessons you or anyone should take here is that:

1) These days IQ can usually be improved more by using good lenses on a great sensor than great lenses on a worse sensor, and
2) The delta in quality between 'good' and 'great' lenses is often very small, smaller than the difference between, say, sensors of different sizes and same gen
3) It generally costs more to chase great glass than it does to chase great sensors, and the returns diminish faster with 'great glass'

I should point out that everyone's idea of what's 'good' vs. 'great' is different, though. If I were to qualify what I mean,

Good: FA 50 f/1.7 Great: Zeiss Planar f/1.4
Good: Tamron 28-75 f/2.8 Great: Nikon 24-70 2.8
Good: Tamron 70-200 2.8 Great: Nikon 70-200 2.8 VR II

If I am going to spend close to 3 grand on a body, I want to get maximum out of it.

The problem there is to get the 'maximum' out of it you could easily spend another $6 or $8K in one shopping trip. I'm here to warn you that $6K-$8K just might not be worth it to you, when all is said and done. 'maximizing' things just means travelling all the way down the existential, shrinking funnel of diminishing returns to the very end, and realizing you ended up only three feet from your comfortable stopping point

[ACG]

No, no, no.



Yes, yes, yes.

Now - everyone knows that the K28 f/3.5, K35 f/3.5, K55 f/1.8 and K85 f/1.8 are not 'the best possible glass' - so how could they be good on 36MP? (this is where 'the best possible glass' myth does damage - unless pointed out, few might realize the lenses you mentioned could fall into that category and be very nice on 36MP FF. And they would, I've owned them all.)

---------- Post added 04-11-15 at 04:22 PM ----------



I think you missed mine.

It will likely perform close to the Pentax 70-200. You'll probably be hard-pressed to see any difference in output. Here's a snippet from dpreview's review:



I guess the Pentax 70-200 could blow the Canon/Nikon 70-200's out of thewater... but I wouldn't count on it. It's likely to perform on-par with them.

I didn't realise that "everyone" had used the Pentax legacy glass with a 36 mp sensor to make the broad brush assessment that they were not the "best possible glass". My understanding is that assessment of the legacy glass dates back to reviews that are 30 years old and based on their behaviour with film only. I can only give anecdotal evidence based on real world images taken using the legacy glass and can only relay to forum members the pleasure that I have in using and owning them.
Hopefully when the Pentax ff camera comes to fruition there will an abundance of threads regarding their quality when used with 36mp sensors or higher.
Until then, the legacy glass stays mounted to the camera at the expense of the costly underperforming modern Sony glass.

[osv]

My understanding is that assessment of the legacy glass dates back to reviews that are 30 years old and based on their behaviour with film only.

wrt resolution measurements, eric has done some imatesting with pentax glass on ff sony mirrorless cameras: By Lens : ERPhotoReview

there are others as well.

real-world testing at infinity can actually be more beneficial, and there are a metric ton of pentax lens photos on ff sony cameras out there already... no need to wait for a pentax ff camera to see what pentax lenses will look like on it.

most of that applies to primes tho, because that's what pentax built it's rep on... did they make any world-class legacy zooms? i never paid much attention to it.

[ACG]

Many thanks for the info.
I still can't find any useful reviews of the a7r and the k series lenses that I listed. But then, do i really care about mtf charts?? Plenty of pictures as you suggest.
My testing merely involves photographing landscapes at f8 and scrutiny of the results digitally at 100% mag and the resultant a2 prints. On these two counts, the lenses performed remarkably well!!

[Ian Stuart Forsyth]

Which lenses have I advocated that have 'borderline performance'?

And you should know I'm not advocating 'cheap lenses', I'm advocating 'good lenses' - good lenses just don't have to be expensive.

The lessons you or anyone should take here is that:

1) These days IQ can usually be improved more by using good lenses on a great sensor than great lenses on a worse sensor, and
2) The delta in quality between 'good' and 'great' lenses is often very small, smaller than the difference between, say, sensors of different sizes and same gen
3) It generally costs more to chase great glass than it does to chase great sensors, and the returns diminish faster with 'great glass'

This is how I look at the augment of selecting FF or Apsc
My needs in a Apsc
16-50 F2.8 $1070
50-135 F2.8 $1170
200 F2 $6800
300 F2.8 $7500
Total =$16540
FF
24-70 F4 $1370
70-200 F4 $1300
300 F2.8 $7500
400 F4 $7500
Total=$17670
With apsc I would save 7% on buying my dream system lenses
Why would I not spend the little extra on the FF body and gain all of the benefits of FF for just $1500 dollars

The price difference we see between FF and APSc lenses really is not from that of the format but rather what lenses are not available with same aperture diameter. The benefit with Apsc is that sometimes we are forced into buying a lens with a larger aperture diameter in FF than what would need and this is what drives up the cost of FF

[ACG]

Similarly, if you are not intending to print bigger than a3 and if low light photography is not a major part of your repertoire then you could get similar IQ and a cheaper and more portable solution with the omd, mft lenses and zuiko 4\3 lenses!!

[osv]

Many thanks for the info.
I still can't find any useful reviews of the a7r and the k series lenses that I listed. But then, do i really care about mtf charts?? Plenty of pictures as you suggest.
My testing merely involves photographing landscapes at f8 and scrutiny of the results digitally at 100% mag and the resultant a2 prints. On these two counts, the lenses performed remarkably well!!

that's close to how i do it as well, but at f/10... isn't that K28 f/3.5 that you own supposed to be one of the pentax magical wonder lenses? here it is vs. the 31mm limited on the a7r, i think that it takes a back seat to the 31ltd, but not by much, and not everyone agrees with that:
Sony a7R 28mm Lens Shootout - FM Forums

one of the best 28mm primes that i've tested for landscape shooting on 36mp is actually the m28/3.5: pentax-m 28mm f/3.5 comparison

nobody gives that lens any credit... i never used it on my old k10d, it wasn't until i put it on 36mp that i realized how clean it was across the frame, when stopped down.

your k35/3.5... if it's the same optical formula as the takumar 35/3.5, the sides are slightly weak on 36mp, the fa35/2 is a much better choice, but of course for more money.

i guess that the moral of the story is to not sell what you have, until you evaluate it on 36mp... even if it's the magical k28/3.5, it won't be worth much if it's decentered.