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DA lenses on FF

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babujr said:
It's bummer that my DA60-250/4 won't work. May be the FF will have a crop mode which will enable the use of many DA lenses, especially the zooms.
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It will still work, you just have to crop yourself.

NOTE - that if a crop mode shall be useful, then the actual crop needs to be visible in the viewfinder.
 
Concerning the FF functionality of the DA*300, the B&H website gives the following caution in the description of the lens: WARNING: Not compatible with "full-frame" (35mm size) cameras.

This seems counter to earlier posts in this thread. I'm not sure what is correct. It would be nice if the lens was compatible with FF. It's a lot lighter than the 150-450 and has enough reach for me. It's a lot less expensive too!
 
Frankinidaho said:
Concerning the FF functionality of the DA*300, the B&H website gives the following caution in the description of the lens: WARNING: Not compatible with "full-frame" (35mm size) cameras.

This seems counter to earlier posts in this thread. I'm not sure what is correct. It would be nice if the lens was compatible with FF. It's a lot lighter than the 150-450 and has enough reach for me. It's a lot less expensive too!
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The DA300 just barely covers FF on film, and is rated as "adequate" by all reports. Add in SR, and most likely you will have a marginal result. What some consider marginal, others will say "fine" as long as the corners aren't solid black. On the other hand, the DA 300 has a great reputation based on its existing use.

Then again, Pentax might not allow any of its DA lenses to be shot in full frame mode. With so many eager to use lenses that are substandard on the larger format, I will be in line with those few who defend Pentax for the decision to crop format for lenses designed for the purpose. It seems that the Pentax brand reputation is a bit better than those users who are so willing to compromise a great deal for the sake of an unearned free lunch.

Too many are quick to claim that FF is vastly superior to DA, but just as quick with the expectation that a lens designed for a smaller image circle (plus SR) will be a fine optic when repurposed. In most cases, highly unlikely. This is an unpopular view for so many optimists, but it is more realistic, IMHO.

--
JNR
www.jamesrobins.com
 
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MightyMike said:
justin23 said:
MikeSul said:
If crop mode cannot be controlled by the user that will be a big negative for the Pentax FF. This is one more reason EVFs really are preferable for many of us. The only interest I have in the Pentax FF is to be able to use all of my Pentax lenses, FF and DA, to their full potential. That won't be possible with enforced crop. Digital cameras should maximize their digital advantages and not be hobbled by mechanical restraints unless there is no alternative. By the way, I am over 70 and have been using and loving Pentax OVFs since the late 1970's but the latest EVFs are just better. I notice this every time I use my K-3. It is such a great camera but the viewfinder, clunky live-view and other mirror box constraints really do begin to disappoint.
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The term Full potential does not make sense for a DA lense. A DA lens was always designed to be used on an APS-C camera thus using to its full potential is an APS-C camera. Just because it may cover FF image circle doesn't mean you are using it to its full potential.

What you really are saying it hopefully I can use a few DA lenses in FF mode so I don't have to buy new FF lenses :-)

My personal opinion is i'd prefer an Automatic crop mode, But I'd also love to see a "Best crop" mode, where the crop is set to be what is best for the lens, so some lenses may be a 1.2 or 1.3 crop. This is unlikely to ever happen, because too many people are fixated by technical things like equivalency over artistic benefit.
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JNR said:
Frankinidaho said:
Concerning the FF functionality of the DA*300, the B&H website gives the following caution in the description of the lens: WARNING: Not compatible with "full-frame" (35mm size) cameras.

This seems counter to earlier posts in this thread. I'm not sure what is correct. It would be nice if the lens was compatible with FF. It's a lot lighter than the 150-450 and has enough reach for me. It's a lot less expensive too!
Click to expand...
The DA300 just barely covers FF on film, and is rated as "adequate" by all reports. Add in SR, and most likely you will have a marginal result. What some consider marginal, others will say "fine" as long as the corners aren't solid black. On the other hand, the DA 300 has a great reputation based on its existing use.

Then again, Pentax might not allow any of its DA lenses to be shot in full frame mode. With so many eager to use lenses that are substandard on the larger format, I will be in line with those few who defend Pentax for the decision to crop format for lenses designed for the purpose. It seems that the Pentax brand reputation is a bit better than those users who are so willing to compromise a great deal for the sake of an unearned free lunch.

Too many are quick to claim that FF is vastly superior to DA, but just as quick with the expectation that a lens designed for a smaller image circle (plus SR) will be a fine optic when repurposed. In most cases, highly unlikely. This is an unpopular view for so many optimists, but it is more realistic, IMHO.
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I surely hope I have the choice. It is probably a setting among the other 100 strange flags where you can turn the default behaviour to auto-crop off. The question is if they have a nice user interface where I can turn it off and on without digging into obscure menus.
 
Frankinidaho said:
Concerning the FF functionality of the DA*300, the B&H website gives the following caution in the description of the lens: WARNING: Not compatible with "full-frame" (35mm size) cameras.

This seems counter to earlier posts in this thread. I'm not sure what is correct. It would be nice if the lens was compatible with FF. It's a lot lighter than the 150-450 and has enough reach for me. It's a lot less expensive too!
Click to expand...
B&H never tested it on "full frame" - they're saying that based only on the DA designation.

Alex
 
Frankinidaho said:
Concerning the FF functionality of the DA*300, the B&H website gives the following caution in the description of the lens: WARNING: Not compatible with "full-frame" (35mm size) cameras.

This seems counter to earlier posts in this thread. I'm not sure what is correct. It would be nice if the lens was compatible with FF. It's a lot lighter than the 150-450 and has enough reach for me. It's a lot less expensive too!
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This is a standard disclaimer for DA lenses in order to avoid any problems with customers buying the wrong lens.
 
ozdean said:
I'm sure it will have all we hope for and more, Pentax always think things through well.
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I'm a bit more pessimistic (about both clauses).

Pentax already has shown us that the AF motor (in lens or in body) choice is not available to the user (except sometimes with a firmware hack to the lens). If the apparently marginally designed in-lens motor fails (as it often does, at least on some lenses), Pentax provided no way to switch to screw-drive AF (even if it was also available in the lens). And, it seems to me that a simple screw-or-SDM switch would have been a lot easier to provide than switchable FF-or-cropped modes (especially if the OVF has to show the crop). [I am not saying that a FF-or-crop switch couldn't be implemented -- I'm just suggesting that it would not likely be as easy to implement as an AF motor switch.] [Disclaimer -- I'm not an engineer, nor have I ever played one on TeeVee.]

As far as thinking things through well, hmmm... Well, Pentax has to judge whether the plus of allowing us to keep using DA lenses on a new FF can body is better or worse than the minus (to us, but perhaps not to Pentax) of forcing upgrades to FF lenses. [Of course, "full (or at least partial) backward compatibility" has always been both a plus and a minus for Pentax.]
 
Pentax "Peripheral Illumination Correction" ought to offset some of the DA-on-FF problem in some cases, if it's included on the FF model. -- For example, the DA 35mm Ltd. at 2.8 vignettes slightly on FF, but I think Peripheral Illumination Correction would clear it up nicely. The DA 70mm and 40mm Ltds. probably don't even need that.
 
justin23 said:
MikeSul said:
If crop mode cannot be controlled by the user that will be a big negative for the Pentax FF. This is one more reason EVFs really are preferable for many of us. The only interest I have in the Pentax FF is to be able to use all of my Pentax lenses, FF and DA, to their full potential. That won't be possible with enforced crop. Digital cameras should maximize their digital advantages and not be hobbled by mechanical restraints unless there is no alternative. By the way, I am over 70 and have been using and loving Pentax OVFs since the late 1970's but the latest EVFs are just better. I notice this every time I use my K-3. It is such a great camera but the viewfinder, clunky live-view and other mirror box constraints really do begin to disappoint.
Click to expand...
The term Full potential does not make sense for a DA lense. A DA lens was always designed to be used on an APS-C camera thus using to its full potential is an APS-C camera. Just because it may cover FF image circle doesn't mean you are using it to its full potential.
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Not sure any of MikeSul 'statements' make much sense , I can't for the life of me see what an EVF or OVF has to-do with crop mode.?

It reads as a rant for EVF with little applicability to the subject being discussed.

Mike EVF/OVF has nothing todo with "clunky live-view" nor are they "mirror box constraints" live view on DSLR's is 'clunky' because the lens are designed for Phase detect AF and do not operate efficiently when trying got work with Contrast detect mechanisms (as live view currently is)

You will see massive improvements in live view as hybrid sensors begin to filter through to dslrs, It will not matter if they have an OVF or mirror box.

But OVF only Dslrs are not on the horizon due to the poor performance of EVF under anything but ideal lighting.
justin23 said:
What you really are saying it hopefully I can use a few DA lenses in FF mode so I don't have to buy new FF lenses :-)

My personal opinion is i'd prefer an Automatic crop mode, But I'd also love to see a "Best crop" mode, where the crop is set to be what is best for the lens, so some lenses may be a 1.2 or 1.3 crop. This is unlikely to ever happen, because too many people are fixated by technical things like equivalency over artistic benefit.
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I think there is a good chance of 'optimal' crop being linked to green mode as you can already select 'MTF' program line to get 'optimal' aperture when on P modes.
 
awaldram said:
justin23 said:
MikeSul said:
If crop mode cannot be controlled by the user that will be a big negative for the Pentax FF. This is one more reason EVFs really are preferable for many of us. The only interest I have in the Pentax FF is to be able to use all of my Pentax lenses, FF and DA, to their full potential. That won't be possible with enforced crop. Digital cameras should maximize their digital advantages and not be hobbled by mechanical restraints unless there is no alternative. By the way, I am over 70 and have been using and loving Pentax OVFs since the late 1970's but the latest EVFs are just better. I notice this every time I use my K-3. It is such a great camera but the viewfinder, clunky live-view and other mirror box constraints really do begin to disappoint.
Click to expand...
The term Full potential does not make sense for a DA lense. A DA lens was always designed to be used on an APS-C camera thus using to its full potential is an APS-C camera. Just because it may cover FF image circle doesn't mean you are using it to its full potential.
Click to expand...
Not sure any of MikeSul 'statements' make much sense , I can't for the life of me see what an EVF or OVF has to-do with crop mode.?
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I have a Panasonic LX100 as my carry-around camera. It has a manual cropping mode.

It is convenient to be able to see the chosen crop in the EVF.
 
Some food for thought:

Mounted to the Pentax 1.4x converter, essentially all of the DA lenses should work well (except perhaps for some slow zooms in dim light). With the 1.4x, you'll have the use of the lenses pretty much as originally intended in terms of field of view/magnification. Of course, you'll lose one stop of light when full open, but that will be counteracted with the larger sensor, netting a DOF about the same as what is seen with lens only on APSC.

Best regards,

Daryl
 
DarylK said:
Some food for thought:

Mounted to the Pentax 1.4x converter, essentially all of the DA lenses should work well (except perhaps for some slow zooms in dim light). With the 1.4x, you'll have the use of the lenses pretty much as originally intended in terms of field of view/magnification. Of course, you'll lose one stop of light when full open, but that will be counteracted with the larger sensor, netting a DOF about the same as what is seen with lens only on APSC.
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Not only does this not really work the way you are assuming, it will never, ever, produce as good a quality image as simply using the crop mode option on the full frame (or any of the recent APSc models, for instance) - which yields a relatively similar FoV.

This is a classic example of how two wrongs make for doubly bad results. All I can say is, Pentax is probably looking at all the on-line exuberance for misusing optics and evaluating whether allowing unfettered freedom to produce bad images is a good idea.
 
JNR said:
DarylK said:
Some food for thought:

Mounted to the Pentax 1.4x converter, essentially all of the DA lenses should work well (except perhaps for some slow zooms in dim light). With the 1.4x, you'll have the use of the lenses pretty much as originally intended in terms of field of view/magnification. Of course, you'll lose one stop of light when full open, but that will be counteracted with the larger sensor, netting a DOF about the same as what is seen with lens only on APSC.
Click to expand...
Not only does this not really work the way you are assuming, it will never, ever, produce as good a quality image as simply using the crop mode option on the full frame (or any of the recent APSc models, for instance) - which yields a relatively similar FoV.

This is a classic example of how two wrongs make for doubly bad results. All I can say is, Pentax is probably looking at all the on-line exuberance for misusing optics and evaluating whether allowing unfettered freedom to produce bad images is a good idea.
Click to expand...
I posed a question to the forum almost two years ago, asking if a teleconverter was really better than a straight crop with today's equipment. I believe this was before Pentax's new 1.4x TC was available.

The answers surprised me. Not only did many feel that a good lens still out-resolved the sensor by enough margin to overcome the quality drop-off from a TC, but they pointed out the advantage of seeing the full image in the viewfinder rather than a shrunken version, making focus easier and more accurate for example.

Would this be as good as lenses purposefully designed for FF? Of course not. Would it be good enough to get you by if your budget didn't include replacing every lens you own? Possibly.

http://www.dpreview.com/forums/post/52503219
 
Mark Ransom said:
JNR said:
DarylK said:
Some food for thought:

Mounted to the Pentax 1.4x converter, essentially all of the DA lenses should work well (except perhaps for some slow zooms in dim light). With the 1.4x, you'll have the use of the lenses pretty much as originally intended in terms of field of view/magnification. Of course, you'll lose one stop of light when full open, but that will be counteracted with the larger sensor, netting a DOF about the same as what is seen with lens only on APSC.
Click to expand...
Not only does this not really work the way you are assuming, it will never, ever, produce as good a quality image as simply using the crop mode option on the full frame (or any of the recent APSc models, for instance) - which yields a relatively similar FoV.

This is a classic example of how two wrongs make for doubly bad results. All I can say is, Pentax is probably looking at all the on-line exuberance for misusing optics and evaluating whether allowing unfettered freedom to produce bad images is a good idea.
Click to expand...
I posed a question to the forum almost two years ago, asking if a teleconverter was really better than a straight crop with today's equipment. I believe this was before Pentax's new 1.4x TC was available.

The answers surprised me. Not only did many feel that a good lens still out-resolved the sensor by enough margin to overcome the quality drop-off from a TC, but they pointed out the advantage of seeing the full image in the viewfinder rather than a shrunken version, making focus easier and more accurate for example.

Would this be as good as lenses purposefully designed for FF? Of course not. Would it be good enough to get you by if your budget didn't include replacing every lens you own? Possibly.

http://www.dpreview.com/forums/post/52503219
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The drop in quality will be relative to the IQ of the lens in use.

So though an f2.8 lens will deliver F4 FF the IQ will be in line with It's original F2.8 open aperture

Hence the 16-50 will be @ peak MTF @f5.6 but will deliver higher IQ than Either cropping or an F5.6 ff Kit lens

In general High IQ lens require 1 stop closure to achieve decent MTF whereas consumer lens require 2 stop closure

So based on this (which stands the test of time)

a FF kit lens will be at the same IQ as the DA* + converter (long end) at around F11 Vs the da* f5.6

a FF FA* f.28 will be at peak @ around F4

So IMO the da + HD converter will match any FF offering at the following

da* 16-50 = 24 -70 F5.6

da* 50-135 = 75-200 F5.6

da* 200 = 300 f5.6

da* 300 = 420 f8

and for reference some FF lens and where I think their IQ MTF lies

Sigma 28-70 F2.8 = f5.6

Pentax fa* 27-70 F2.8 = f4

Sigma 400mm Telemacro = f5.6

Sigma Bigma = f9.5

So IMO the da line + converter will deliver IQ inline with midsumer FF offerings which I believe is a far cry from

"it will never, ever, produce as good a quality image as simply using the crop mode option on the full frame"

I can only assume JNR either has no decent converters or glass combinations.

HQ converter + HQ lens = HQ results

HQ converter + soso lens = poor results

soso converter + HQ lens = poor results

soso converter + sosos lens = appalling results

crop + soso lens = poor results

crop + HQ lens = marginal (good) results

what crop mode in camera give you is the ability to get your speed back at the cost of resolution, a converter gives your the resolution at the cost of speed.

Both options are good and having both is best.

--
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http://www.flickr.com/photos/awaldram/
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http://1x.com/artist/awaldram/wall
 
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Thanks for the good reply/explanation. I couldn't have said it better myself.
Daryl
--
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway

Great photography is largely a matter of perspective, both visually and mentally - Daryl Kottwitz (but probably said before :) )

My gallery: http://darylkottwitzphoto.smugmug.com
My shots on PPG: http://www.pentaxphotogallery.com/artists/darylkottwitz
 
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