Where do I find MTF graphs?

micmac · 07-18-2012, 02:28 AM

Hi, can someone let me know where to find MTF graphs for all Pentax Lens, I think it would be nice to have them incoporated with the lens review section. Thank you.

Adam · 07-18-2012, 02:31 AM

Wrong forum-moved to the lens section.

adpo · 07-18-2012, 02:35 AM

not available for all lenses, but Photozone has a pretty comprehensive set of them

micmac · 07-18-2012, 06:12 AM

Thank you, and sorry for posting in the wrong thread.

lytrytyr · 07-18-2012, 06:56 AM

Originally posted by adpo

Photozone has a pretty comprehensive set of them

Unfortunately those are only the MTF 50 curves,
with a particular sensor, AA filter, and raw processor.
They are easy to read,
but less informative than the classic curves of the kind
that I included in my M100/2.8 review on the following page:

SMC Pentax-M 100mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database

I'd certainly be interested to know if curves of this type
are available for other Pentax lenses (M50/1.4 excepted),
especially for the newer lenses.

Other manufacturers, such as Sigma and Zeiss,
make these curves available for all their lenses.

macTak · 07-18-2012, 07:45 AM

Dxo's lens tests of Pentax lenses (not that there are that many of them) come in MTF chart form.

lytrytyr · 07-18-2012, 07:59 AM

Originally posted by macTak

Dxo's lens tests of Pentax lenses come in MTF chart form.

Good point.

Those charts are presented in a form that I find very clunky to read:
You have to open so many different windows.

Also, in some ways they have too much information,
like separating the red/green/blue channels,
and at the same time they have too little information,
like only giving charts for the middle distance range.

I've found the Schneider-Kreuznach charts to be the best.
Traditional charts, but for close, middle, and "infinite" distances.

My overall beef with many of the formal lens tests
is that they only test at middle distance,
while a lot of my own photography is at "infinity."

macTak · 07-19-2012, 07:44 AM

Originally posted by lytrytyr

Those charts are presented in a form that I find very clunky to read:

I couldn't agree more, but alas there are few places left that give MTF charts, and DxO might be the only independent site testing lenses that still gives any MTF charts. It's a pity as I find them quite helpful, but they do require one to learn how to read them, so I suppose it is not entirely unsurprising that they have largely been supplanted by easier to read presentations of IQ.

07-18-2012, 02:28 AM	#1
micmac Junior Member Join Date: Jun 2011 Location: N/A Photos: Gallery Posts: 42	Where do I find MTF graphs? Hi, can someone let me know where to find MTF graphs for all Pentax Lens, I think it would be nice to have them incoporated with the lens review section. Thank you.

07-18-2012, 02:31 AM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	Wrong forum-moved to the lens section. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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07-18-2012, 02:35 AM	#3
adpo Veteran Member Join Date: Apr 2011 Location: Arizona Photos: Gallery Posts: 888	not available for all lenses, but Photozone has a pretty comprehensive set of them

07-18-2012, 06:12 AM	#4
micmac Junior Member Join Date: Jun 2011 Location: N/A Photos: Gallery Posts: 42 Original Poster	Thank you, and sorry for posting in the wrong thread.

07-18-2012, 06:56 AM	#5
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by adpo Photozone has a pretty comprehensive set of them Unfortunately those are only the MTF 50 curves, with a particular sensor, AA filter, and raw processor. They are easy to read, but less informative than the classic curves of the kind that I included in my M100/2.8 review on the following page: SMC Pentax-M 100mm F2.8 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database I'd certainly be interested to know if curves of this type are available for other Pentax lenses (M50/1.4 excepted), especially for the newer lenses. Other manufacturers, such as Sigma and Zeiss, make these curves available for all their lenses.

07-18-2012, 07:45 AM	#6
macTak Veteran Member Join Date: Apr 2010 Photos: Gallery Posts: 759	Dxo's lens tests of Pentax lenses (not that there are that many of them) come in MTF chart form.

07-18-2012, 07:59 AM	#7
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by macTak Dxo's lens tests of Pentax lenses come in MTF chart form. Good point. Those charts are presented in a form that I find very clunky to read: You have to open so many different windows. Also, in some ways they have too much information, like separating the red/green/blue channels, and at the same time they have too little information, like only giving charts for the middle distance range. I've found the Schneider-Kreuznach charts to be the best. Traditional charts, but for close, middle, and "infinite" distances. My overall beef with many of the formal lens tests is that they only test at middle distance, while a lot of my own photography is at "infinity."

07-19-2012, 07:44 AM	#8
macTak Veteran Member Join Date: Apr 2010 Photos: Gallery Posts: 759	Originally posted by lytrytyr Those charts are presented in a form that I find very clunky to read: I couldn't agree more, but alas there are few places left that give MTF charts, and DxO might be the only independent site testing lenses that still gives any MTF charts. It's a pity as I find them quite helpful, but they do require one to learn how to read them, so I suppose it is not entirely unsurprising that they have largely been supplanted by easier to read presentations of IQ.