abc1234 Loc: Elk Grove Village, Illinois

A lot of opinions here but not much science. I evaluate my lenses with Reiken's FoCal. The first relevant conclusion is that the old saw about being sharpest two stops down is true. Once you go down another two stops or so, the sharpness falls off dramatically. The second relevant conclusion is that you get what you pay for. The more expensive professional lenses are noticeably sharper than the cheaper kit lenses.

wdross Loc: Castle Rock, Colorado

Maybe in general for full frame lenses, but not true for other formats both bigger or smaller. Most 4/3rds lenses are sharpest at wide open or one stop down. With f1.2 lenses, the sharpest point may be two stops down. The reason for this is 4/3rds already has twice the depth of field of full frame for the same aperture and diffraction starts raising it ugly head by f8 and f11 in 4/3rds. This is why the 4/3rds lenses are very sharp wide open and we 4/3rds photographers avoid f8 and higher if possible. With even smaller formats, sharpness is at the beginning and diffraction is even earlier. The opposite format direction is also true: sharpness occurs more towards mid aperture range and diffraction occurs even later.

So your sharpness statement really only applies to full frame and to a majority of full frame lenses in general.

mwsilvers Loc: Central New Jersey

True, but I'll bet many of us have wasted a lot of money purchasing multiple unsatisfactory lenses we could afford rather than invest that money in a lens we "couldn't" afford. Probably for most of us, the equipment journey has been much more expensive than it otherwise might have been if we had the foresight to make the right decisions from the outset.

Bill_de Loc: US

Depending on science would be a good way to go.

However, this is UHH where differences of opinion are what pays the rent.

The more we click on a link, the more admin puts in his pocket.

On the plus side, we all get to play for free.


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burkphoto Loc: High Point, NC

I would agree that the majority of lenses are USABLE at f/8, provided they are made for, and used on, a full frame digital camera. Notable exceptions would be super telephoto lenses that have smaller maximum apertures.

However, I have a Micro 4/3 camera. Diffraction starts to become visible around f/8, which is similar to f/16 on full frame lenses. By f/16 on MOST Micro 4/3 lenses, the image is marginal, at best.

All my f/2.8 lenses are sharpest at f/4 or f/5.6. They are just fine when used wide open! In fact, they are sharper at f/2.8 than they are at f/8, but with much shallower depth of field (similar to f/5.6 on a full frame lens with the same field of view, which has twice the focal length).

Many professionals use lenses that are sharpest when nearly wide open. Some of them are still sharp at f/8, but not as sharp as at f/5.6 or f/4.

My point is, when you buy a lens, research it on various review sites and check the MTF (modulation transfer function curves) performance at various apertures. Or make your own tests to see how it performs on the same subjects at each full aperture on the lens. I think you'll be surprised at what you see! Be sure to photograph a flat plane subject and a set of 3D objects, as two separate tests. You may refer to them often in the future, once you see the results.

OldCADuser Loc: Irvine, CA

I have what you'd call a 'cheap lens', a 400mm 1:6.3 Tele-Astranar that I bought in 1970 for $39.95 (I guess if you consider inflation, perhaps it wasn't that cheap after all). Anyway, I've had good results with it but then I do try to shoot at either f8 or f11, never wide open.

As for your comment about the Minolta MC 50mm f1.4, I've got one of those myself. Came with the Minolta XG-M I bought in 1982. I used that camera for 20 years, eventually having to replace it with a used Minolta X-700 body when it froze-up (I had been using it with a motor-drive only to learn that despite the 'M' designation, it wasn't originally designed for that, so it finally just wore out).

OldCADuser Loc: Irvine, CA

A comment about the difference between 'cheap' and 'expensive' lens.

When I got my first SLR, a Minolta SR-1, back in 1968, someone with a lot more experience than I had told me that if optical quality was all that I was looking for, then a 'cheap' lens would probably work just fine. But he told me, if you buy an 'expensive' lens and you drop it, you've still got something that you can use. Case in point: the first auxiliary lens I bought, in 1969, was a Minolta 135mm f2.8 lens. That was a tough one as I was still in school and it cost me a month's pay, when I was working. However, I used it for 37-years, taking nearly 2,000 pictures with it, the last one in 2006 (see below). And in those years, it got abused, and it still carries scars on the barrel of the lens where it was dropped, while still attached to a heavy camera body, more than once, but it never failed me and I've never been able to detect any loss of definition or focus.

The 'Lone Cypress Tree' on the '17-Mile Drive' along the Monterey Peninsula near Pebble Beach, California - August 2006 - Minolta X-700, 135mm

abc1234 Loc: Elk Grove Village, Illinois

I like you response.

dustie Loc: Nose to the grindstone

Is it time to start a thread or five on how to attract scientists to join and participate on UHH?
.........or would that send the UHH sacred traditions, cliques, fan clubs, clown cars, dinosaurs, cutting edge techies...........the whole kit and caboodle........completely off the rails in the middle of the trestle?
🥶

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Science is fun BUT...Even if a photograher knows all the optical theories about lens performance- every possibe abberation, idiosyncrasy, super-finite fact about any of his or her lense, how many of them are going to take their lenses apart and alter them- not many! Do the research, make the tests and buyer beware.

All we can do is be aware of the characteristics of each of our lenses and select the ones that suit our needs and work around some of the faults.

MJPerini

Ahhh, another UHH ‘straw man post’…..

If putting your kit lens on f/8 & auto gets you the kind of pictures you seek, I think it’s great and I’m happy for you.
Especially if you are getting good and interesting pictures.
Photography can be enjoyed at many different levels—- that is its blessing and curse.
But don’t conflate what you choose to do as more “correct “ than any of the thousand other (equally correct) ways that others choose to do it. Debating it for twenty pages changes nothing and steals time you could be out making beautiful f/8 pictures.

dustie Loc: Nose to the grindstone

I understand.......agreed.

Can you chime in on my earlier questions ( https://www.uglyhedgehog.com/t-794664-2.html#14340079 ) if it is accurate to place all considerations on image sharpness on lens aperture, apart from the system within which that lens is connected? If you don't want to bother with that, it's okay.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

No bother at all. Sadly, this is not going to be a very scientific answer or response. I am not a scientist. It's like I am a good tradesman but not an engineer. It's nice to know the cause and effect of varios photographic phenomena from a science/physics/optics point of view but again, I am not going to take any of my lenses apart and attempt to alter them. I am stuck with waht the engineers, designers, and sellers who sold me and have to learn to work around various issues. I try to buy well and get the ones that suit my purposes.

I guess that digital sensors are more vulnerable or subject to showing the effects of diffraction than film ever was. I learned all the abberation, especialy in my millitary photography training as these imact many kinds of aerial cartography, survalance photography and the like. Regardless of that fact, the cameras, and lenses, supplied to accommodate those specifications and requirements did not suffer from most of these defects or shortcomings. The methodologies we were taught addressed worked around any existing issues, like don't shoot at f/32, etc!

In my job as a portrait and commercial photgraher, I never had a client complain of difraction or the ill effect thereof. No client would accept an out-of-focus or muddy image- a tiny bit of color fringing? nobody ever complained. Am I in denial or crazy but it does not bother me, especaillif since it is virtually undetectable without a microscope? My own opinion is that many photographers are preoccupied with difraction and a myriad of other aberrations to the extent that they go looking for them.

If I were engaed in scientific, clinical, or precise aerail survayig, I would be more concerned that any flaw or failure could cause serious issues in diagnosis, documentation, or military strategies. I general pictorial work, commercial work or portraiture is a matter of art and a decent clean image. My favorite part les has a terrible case of zonal spherical abberation- it's HOLLYWOOD MAGIC!

larryepage Loc: North Texas area

Ed...I think your acknowledgement about not being a scientist nor an engineer is very honorable. And I know you to be a very skilled tradesman, and will extend that to include being an artist. I also do not believe it necessary to understand as much science and engineering as is sometimes implied here necessary to be.

I just finished a two-day LightRoom class to try to get my understanding brought in synch with all of the changes which have been implemented over the last five years or so. It was a good class with a recognized instructor. The LightRoom part was very good, and I'm glad I took the class. But it broke down when discussion extended into a couple of areas where popular lore and personal belief prevails over facts and logic. Even the instructor fell into the "my way or the highway" trap a couple of times.

I think this will probably never change. I cannot abide it in the classroom at school, but I've resolved to try just to let it go in places like UHB and classes like the one this weekend. Hopefully the next generation can get thongs straightened out.

JD750 Loc: SoCal

On UHH you get:
(1) Expert advice
(2) Strong conflicting opinions
(3) completely wrong answers

and it's up to the reader to sort them out.