The following still camera Ektars were documented in a booklet, Kodak Lenses and Shutters, published by Eastman Kodak in 1939; this appears to be a precedessor to the later Kodak Data Books describing Kodak optics. Much of the text was replicated in the original edition of the Kodak Reference Handbook - Lenses, Rangefinders and Shutters section, © 1940. The earlier booklet also contained significantly more information about optical theory and Kodak's design and production processes. Since I became aware of this source in 2010 and because of its completeness, I have departed slightly from the design of these "data book" pages, by including all of the Kodak lenses--not just the Ektars--for which there were detailed profiles.

Though there were undoubtedly other differences as Kodak designed new Ektars and converted Anastigmats to Ektars, the difference most oftened mentioned is improved color correction. Rudolf Kingslake notes in a later book that Kodak was experimenting with soft coatings at this point, but these were not discussed in the original Reference Handbook, nor as far as I can tell, until promotional materials for the Kodak Ektra in 1941. Collectors have noted hardcoated lenses, often in models produced for the U. S. military services, with production dates as early as 1941, but without any special marking to denote special coating.

31.5mm slipon adapter ring, Ser VI.
This lens existed at the time of publication of the Reference Handbook, but was not documented there.
Earliest versions had no coating; starting ~1939 calcium fluoride may have been applied to on inner surfaces; later may have had magnesium fluoride.

27mm No. 17 slipon adapter ring, 21.7mm No. 21 screwin Ser V.
This document lists this simply as "Ektar", but other sources report versions as "Anastigmat Ektar". Some Ektars were Kodak U. S. production; others were rebadged Schneider Xenars. Examples through 1939 are unlikely to have been coated. Only some Retina models were imported by Kodak to the U. S. Beginning with the lens specifications in the Kodak Reference Handbook in 1940 through Kodak Data Book: Kodak Lenses, Shutters and Portr Lenses, 4th Edition, 1953, no Kodak A.G. production was listed. Those looking for specific lens versions should consult Retina sites or titles.

38mm slipon adapter ring, Ser VI.
Earliest versions may had calcium fluoride coating (undocumented) ‚; later had magnesium fluoride.

Comparisons to the later 105mm f /3.7 Ektar.

75mm slipon adapter ring, 4 inch square.

From the list of Anastigmats below, it is obvious why this was the first of the Eastman Ektars introduced.

f /4.5, 5 in
f /4.5, 5 1/2 in
f /4.5, 6 3/8 in
f /4.5, 7 1/2 in
f /4.5, 8 1/2 in
f /4.5, 10 in
f /4.5, 12 in

No. 771
No. 31
No. 32
No. 33
No. 34
No. 35
No. 36

No coating.

This was not an Ektar at this point, had no inner coating and later versions that were Ektars may have been slightly redesigned with different glass.

33mm slipon adapter ring, Ser VII.
Angle of view at Inf 35° x 47°

1 1/4 31.5mm No. 5A slipon adapter ring, Ser V.

15/16 23.5mm No. 3 slipon adapter ring, Ser V.

1 1/4 31.5mm No. 3A slipon adapter ring, Ser V. - Special Six-20
1 5/16 33mm No. 7A slipon adapter ring, Ser Vi. - Special Six-16

1 1/4 31.5mm No. 5A slipon adapter ring, Ser V.

1 1/4 31.5mm No. 5A slipon adapter ring, Ser V.

1 1/16 31.5mm No. 17 slipon adapter ring, Ser V.

1 1/4 31.5mm No. 5A slipon adapter ring, Ser V. - Recomar 18
1 21/32 42mm No. 16 slipon adapter ring, Ser Vi. - Recomar 33
.

1 1/4 31.5mm No. 6A slipon adapter ring, Ser VI. - Junior & Senior Six-20
1 5/16 33mm No. 7A slipon adapter ring, Ser VI. - Junior Six-16
1 1/2 38mm No. 23 slipon adapter ring, Ser VI. - Senior Six-16

1 1/8 28.5mm No. 3A slipon adapter ring, Ser VI. - Junior Six-20
1 1/4 31.5mm No. 3A slipon adapter ring, Ser VI. - Junior Six-16 & Senior Six-20
1 5/16 33mm No. 7A slipon adapter ring, Ser VI. - Senior Six-16

†
Occassionally Kodak lens designers reversed the elements in the rear group of the Tessar design so that the positive element was next to the stop. This arrangement was used in the 50mm f /3.5 Anastigmat Special on the Kodak 35 and again for the 78mm f /3.5 Ektar on the Chevron.