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06-29-2015, 01:27 PM   #151
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QuoteOriginally posted by Simen1 Quote
Actually you don't get better DOF...because it doesn't have as large apertures available as FF will get.
You have obviously never shot medium format. Subject isolation by shallow DOF is the hallmark of the format and easily attained at even f/5.6.


Steve

06-29-2015, 01:34 PM   #152
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QuoteOriginally posted by Simen1 Quote
Where is all the f/1,4 primes and f/2,8 zooms for 645?

What 645 offers over FF is primarily higher real resolution (line pairs per picture height).
QuoteOriginally posted by stevebrot Quote
You have obviously never shot medium format. Subject isolation by shallow DOF is the hallmark of the format and easily attained at even f/5.6.


Steve
It would be great if the sensor inside the 645Z was just a little bigger to give even a bigger difference between medium format and full frame. Well we don't see to many medium format images so people in general don't know the difference.

There might be some image in that would be considered NSFW in the USA!

User review of the 645D.



The review is in Dutch and I made it in 2012, but the images should show enough of the work and exif is inside the images.

Last edited by RonHendriks1966; 06-29-2015 at 01:41 PM.
06-29-2015, 03:20 PM   #153
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Since I found out the 1.4 HD AW teleconverter WILL work with the Sigma 150-500 (takes a few tries to lock AF, but will work) I think I really want to see the Tamron 150-600 in Pentax mount so I can give it a shot.

The EXIF info is wrong, showing the lens was at 500mm and aperture was f/6.3, but it did work and I got what I expected with it.
06-29-2015, 03:46 PM   #154
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I think for most APS-C users mounting their favorite FF lenses on the new Pentax FF for the first time, the biggest lens 'shock' will not be potential resolution issues at the edge of the frame.

The degree of vignetting that some of even the best old and new FF lenses produce, particularly wide-open, will be the biggest surprise.

06-29-2015, 04:30 PM   #155
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QuoteOriginally posted by rawr Quote
I think for most APS-C users mounting their favorite FF lenses on the new Pentax FF for the first time, the biggest lens 'shock' will not be potential resolution issues at the edge of the frame.

The degree of vignetting that some of even the best old and new FF lenses produce, particularly wide-open, will be the biggest surprise.
How are you defining "old" lens? My Pentax-M and Pentax-A lenses were used with 35mm film, which, by definition, is exactly the same size as a FF sensor image.
06-29-2015, 05:10 PM   #156
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I recognize that digital works differently than film. Just not sure how that means that older lenses will be compromised on the new FF body. Older coatings would show up on even the newer APS-C bodies. Image circle of FF lenses should, I would think, apply to digital as well as film. Sharpness might be an issue, if the claim is that the resolving power of digital FF is better than that of film. Would an FA* 28-70 or an FA*85 look all that different on a FF digital than on a K-5iis or K-3 series?
06-29-2015, 05:59 PM   #157
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I've written this before and I still believe it. The resolution of my K lenses will not be challenged by a FF sensor. All I want is that the sensor register the entire image circle cast by my K-series lenses. Everything else is gravy.

Otherwise, I have an MZ-S for my FA's, and many manual focus FF film cameras.
06-29-2015, 06:15 PM   #158
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QuoteOriginally posted by reh321 Quote
How are you defining "old" lens? My Pentax-M and Pentax-A lenses were used with 35mm film, which, by definition, is exactly the same size as a FF sensor image.
Of course. The observation I wanted to pass on is that FF lenses can often vignette more mounted on FF than on APS-C. Whether they are old K,M or A's, or new Sigma 35 f1.4's. The visible extent of this may surprise people when they move from APS-C to digital FF.

Pic related - the brand new FF Sigma 35 f1.4 A on APS-C (top) and FF (bottom), from the lenstip review.



This change in vignetting might also have an impact on apparent lens resolution, as well as issues like camera metering behaviour when using the FF.


Last edited by rawr; 06-29-2015 at 06:29 PM.
06-29-2015, 09:35 PM   #159
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QuoteOriginally posted by rawr Quote
Of course. The observation I wanted to pass on is that FF lenses can often vignette more mounted on FF than on APS-C. Whether they are old K,M or A's, or new Sigma 35 f1.4's. The visible extent of this may surprise people when they move from APS-C to digital FF.

Pic related - the brand new FF Sigma 35 f1.4 A on APS-C (top) and FF (bottom), from the lenstip review.



This change in vignetting might also have an impact on apparent lens resolution, as well as issues like camera metering behaviour when using the FF.
Interesting behaviour. I wonder if it's due to attenuation in the lens, or a characteristic of the oblique incidence angle on the edge micro-lenses on the sensor.
06-29-2015, 11:29 PM   #160
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QuoteOriginally posted by RobA_Oz Quote
....or a characteristic of the oblique incidence angle on the edge micro-lenses on the sensor.
I wonder if a BSI sensor will reduce the ammount of apparent vignetting versus ealier FF sensors....
06-30-2015, 12:24 AM - 5 Likes   #161
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I wonder if I cut my lawn in horizontal patterns will it allow the light diffracting off the shed to hit the underside of my socks to dry them quicker?
06-30-2015, 12:30 AM - 1 Like   #162
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QuoteOriginally posted by noelpolar Quote
I wonder if a BSI sensor will reduce the ammount of apparent vignetting versus ealier FF sensors....
Sony's own diagrams of the new sensor seem to indicate this, because they show light hitting the sensor from more oblique angles. I think it's a bigger issue with short flange mirrorless cameras than DSLRs these days. It was a problem for people mounting M-mount lenses on mirrorless cameras. I think it's also the reason they can't just throw any old sensor into a camera like the GR, which must have its rear element very close to the sensor.
06-30-2015, 01:43 AM   #163
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QuoteOriginally posted by tromboads Quote
I wonder if I cut my lawn in horizontal patterns will it allow the light diffracting off the shed to hit the underside of my socks to dry them quicker?
Good idea. I must try it next time I cut the lawn.

Of course vignetting can usually be easily corrected in software, but like any adjustment for lens aberrations (eg CA, or optical distortion), any software adjustments may have an impact on resolution.

It's also interesting to see that some lenses I know from the old days on film (eg the M 50 f1.7) seem to vignette more on digital full-frame (I've seen some when shot on Sony A7). I never noticed much vignetting with that lens on film, but in those days I guess we never looked at our images on bright, high-res 23 inch computer monitors.
06-30-2015, 02:08 AM - 1 Like   #164
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QuoteOriginally posted by JPT Quote
Sony's own diagrams of the new sensor seem to indicate this, .
nah nah tromboards......pays not to show your ignorance to soon.......

Last edited by noelpolar; 06-30-2015 at 03:20 AM.
06-30-2015, 02:53 AM   #165
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QuoteOriginally posted by rawr Quote
Good idea. I must try it next time I cut the lawn.

Of course vignetting can usually be easily corrected in software, but like any adjustment for lens aberrations (eg CA, or optical distortion), any software adjustments may have an impact on resolution.

It's also interesting to see that some lenses I know from the old days on film (eg the M 50 f1.7) seem to vignette more on digital full-frame (I've seen some when shot on Sony A7). I never noticed much vignetting with that lens on film, but in those days I guess we never looked at our images on bright, high-res 23 inch computer monitors.
It does seem interesting that Sony has decided for their FE mount lenses to do a lot of software correction of defects rather than optically taking care of them. Like their Zeiss 35mm f2.8 has 2.6 stops of vignetting wide open and even corrected, it still has 1.4 stops of vignetting (per Photozone review). I guess it keeps the lens smaller, but it does seem like doing less work on the optics and then using software to correct things after the fact is the current trend..

I'm not sure I like it. If you are shooting at iso 100, of course it is pretty easy to fix a stop of vignetting, but if you are shooting high iso, you don't really have the ability to pull that shadow detail out of the corners.
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