new 75mm f2.8

Has anyone tried the new 75mm f2.8? If so, what is your opinion of it?

I have not tried it yet but have to wonder why they wanted to make

another 75mm. There are already three other lenses that will shoot

this focal length(75 f/4.5, 75 shift and 55-100 zoom). Their time and

money would have be better spent on a 40mm rectilinear. The main

reason the new 75mm uses aspheric surfaces is for distortion, with

spherical aberration correction being a minor consideration. But, the

75 f/4.5 has so little pin cushion distortion that it's nothing to

worry about. I'm sure the new 2.8 is performer but did we need it?

I think we probably did need it, Steve. At least, I'm tempted by it

and I already own a 75/4.5.

 

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I shoot mainly horticultural subjects and my main lenses are the

75mm, for modestly wide-angle views and particularly for whole tree

shots, and the 135mm macro for closer work. I use diopters rather

than extension tubes when I want the 135mm to focus even closer.

 

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The new 75/2.8 focuses to 45cm (I think}, which is far better than

the 70cm of the old 75. Combined with the f2.8 aperture that fact has

me wondering what it would perform like with a 2x converter. You'd

effectively have a 150/5.6 that focuses to 45cm. Compare that with

the 135 macro that focuses to 70cm. It wouldn't be flat field, I'll

admit, but the prospect interests me.

Hi Steve,

 

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If you want to increase the speed of the lens, the trade off is

usually more distortion, to keep this on the same level as the 4.5

version you need to do the trick with aspheric surfaces.

The report I have read in the dutch Camera Magazine stated even less

distortion and 5,6 and 8 as best performinging apertures.

 

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I would love to have a brighter view finder, but I already own the

4.5 and think the upgrate is too expensive.

 

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And yes Steve I would like to have a 40 mm with AL lenses.

I gave up on the 45mm I have owned 3 of them and they all are not

sharp in the corners! maybe a re design would do.

 

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Kind regards Gert Jan

Sounds like there is a market for this lens. Gert, when the speed is

increased in a lens, consideration must be made by the designer to

compensate for rays that are entering the optic that are farther off

axis from that of slower designs. Of particular importance is the

improved correction of the off axis aberrations(coma, lateral color

etc.). Usually, more elements are needed to compensate for these

aberrations. The 75mm shift is a good example of how further

correction is necessary beyond that of a standard 75mm to compensate

for using the lens in the off axis mode(shift). Distortion is caused

by many things, including element surface shape, the placement of the

stop, symmetry or lack of it, etc. Please explain how increasing the

speed of the 75mm to 2.8 will make distortion harder to correct?

Geoff, the 75 2.8 with a 2x should be pretty close to having a flat

field unless the converter was not designed with this new lens in

mind.

Steve - There certainly is a need for this lens as far as I am

concerned. I use the old 75 mm as a standard lens, almost always from

a tripod, because it performs optimally at f11. This new lens is said

to be very good at f5.6 and usable at f2.8.

 

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This means handheld use is possible more often for those situations

where it is not practical or possible at the moment.

 

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Tony

Aaron Reynolds on the Pentax Discuss Mailing List http://www.pdml.net

has been using the 75/2.8 for a few weeks and his preliminary reports

suggest that it is very sharp with excellent bokeh. He provided some

examples of handheld shots at both wide and small apertures. The

results appeared to be excellent, insofar as that can be determined in

lo-res web scans.

Paul Stenquist

An image from Aaron to demonstrate bokeh. It's wide open at 1/30 second

off a monopod.

 

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http://homepage.mac.com/aaronreynolds/.Pictures/bokeh2.jpg

Paul gave me a heads up about this discussion. :)

 

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I'm very happy so far with the 75mm f2.8. I had not considered

the 75mm f4.5 because I thought it was a little too slow for the

kind of shooting I like to do.

 

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Not only am I very pleased with its sharpness, but also its small

size and weight -- it is nearly identical to the 105mm in terms of

size, shape and handling. Also, it has an excellent minimum

focus distance (under 1.5 feet). So far I've mostly shot with it

between f2.8 and f5.6, but I have taken a few pictures at f11 and

f16. I have no complaints at all.

 

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If anyone has any specific questions that they'd like to hear

answers to or anything that I can look for in the images I've shot

(or shoot a test of, within reason), please let me know.

I´m owner of the old 4,5/75 and the new one is on top of my list.

I shoot landscapes and fashion with my 67. For landscapes the old

version is ok, because I use a tripod anyway. But with fashion the

faster lens is great, also the same filter size as the 2.8/165. Both

uses 67mm filters. The old lens uses 82mm and that is really big.

 

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Reinhard

Tony, the 75mm f2.8 is very useable at 2.8 and fabulous at f4.

I'm very much enjoying it.

 

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Here's an image, 1/30 at f4, MLU, handheld, Ilford Delta 3200:

 

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http://homepage.mac.com/aaronreynolds/.Pictures/

sgt%20%26%20mrs%20pepper%20at%20home.jpg (you may

have to paste that together)

 

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Here's a closer view:

 

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http://homepage.mac.com/aaronreynolds/.Pictures/

sgt%20%26%20mrs%20pepper%20close.jpg

I bought this lens several years ago to replace my older 75mm f4.5. I have not been sorry. My older 75mm I could never get really good pictures with. They were always on the soft side. This new version is absolutely a gem!!!