Upgrade the memory of your 2018 Mac mini up to 64GB

MTF for Hartblei 120mm f/4

This is a technical page. Skip it unless you understand MTF. Or see Making Sharp Images.

Most MTF charts plot contrast (MTF) at a distance from optical center, graphing 10/20/40 line pairs per millimeter, not so here.

These charts graph MTF from zero to 200 line pairs/mm, and there is one graph for each distance from the optical center. A distance of 21.3mm is the corner of a 35mm frame; a distance of 30.4mm is the corner of a 56mm X 24mm frame, which is what you get fully shifted 10mm in the long direction.

Note that Canon and Nikon MTF charts only go to 30 line pairs/mm. Zeiss supplies 10/20/40 line pairs/mm for most of its optics. So the charts on this page should be read out to the “40” mark only, to be (somewhat) comparable to the standard Zeiss MTF graphs.

The graphs were supplied by Hartblei, and used with permission.

Red is tangential, blue is sagittal

Hartblei 120mm f/4

The Zeiss datasheet shows Zeiss’s official technical data.

At center, resolving power is very high, reaching out to 100 line pairs per millimeter. Modest astigmatism develops away from the center, and resolving power drops rapidly away from center — not the behavior we’d hope to see. At an offset of 20mm, fine detail (40 lp/mm) simply cannot be resolved; stopping down to f/8 or f/11 is key here.

Hartblei 120: MTF from 0 to 100 line pairs/mm at center
Hartblei 120: MTF from 0 to 100 line pairs/mm at 5mm offset
Hartblei 120: MTF from 0 to 100 line pairs/mm at 10mm offset
Hartblei 120: MTF from 0 to 100 line pairs/mm at 15mm offset
Hartblei 120: MTF from 0 to 100 line pairs/mm at 20mm offset

Conclusions

MTF performance examined near the edges and corners of the 35mm frame is a little disappointing. Possible explanations include field curvature, and field shots show very nice performance on “3D” images, so one can safely ignore these issues and instead be content with the superlative bokeh and color rendition.


See also Canon wishlist

B&H Deal ZoneDeals by Brand/Category/Savings
Deals expire in 12 hours unless noted. Certain deals may last longer.
$3199 SAVE $200 = 5.0% $99 FREE ITEMS Canon EOS R Mirrorless with 24-105mm in Cameras: Mirrorless
$1632 SAVE $700 = 28.0% $165 GIFT CARD LG C8PUA 55" Class HDR UHD Smart OLED TV in Electronics: Televisions
$3097 SAVE $200 = 6.0% $77 FREE ITEMS Nikon D850 DSLR in Cameras: DSLR
$1797 SAVE $200 = 10.0% Pentax K-1 Mark II DSLR in Cameras: DSLR
$998 SAVE $400 = 28.0% Sony a7 II Mirrorless in Cameras: Mirrorless
$1798 SAVE $200 = 10.0% Sony a7R II Mirrorless in Cameras: Mirrorless
$3998 SAVE $500 = 11.0% Sony a9 Mirrorless in Cameras: Mirrorless
$5987 SAVE $1839 = 23.0% ZEISS Loxia 5-Lens Bundle in Lenses: Mirrorless
$11594 SAVE $3157 = 21.0% ZEISS Otus ZF.2 3-Lens Bundle in Lenses: DSLR

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2019 diglloyd Inc, all rights reserved.