I think this is really sharp, am I right?

iangreenhalgh1 · Expire: 2014-01-07

Hi folks

Recently I've been concerned that I might hot have a handle on what consists of 'sharp' when looking at the images from my lenses.

Just got a new lens today in good condition, shot a couple of quick test shots before the rain began and I thought they looked really sharp, am I right?

These are either f5.6 or f8, I forget:

100% crop:

This one is wide open:

100% crop:

Attila · Expire: 2025-11-18

Almost any lens even the worst ones are sharp from this distance.
Lens torture for sharpness infinity distance shoot on trees.

Sharpening in raw makes it too look real sharp, I don't see excellent sharpness on these pictures.

I did sharpen jpg.

iangreenhalgh1 · Expire: 2014-01-07

Thankyou Attila, I will take some torturous long distance shots with it tomorrow, hopefully we will have some sunshine!

Attila · Expire: 2025-11-18

iangreenhalgh1 · Expire: 2014-01-07

I never thought of sharpening the RAW files, I will have to try that.

It is very dull here, I tried a couple of quick infinity shots but they look horrible:

Both at f8:

Same two wide open:

Not as sharp as I thought it might be...

iangreenhalgh1 · Expire: 2014-01-07

It's a CZJ zebra Tessar 2.8/50 with the 1Q mark. I don't think it's as sharp at infinity as my Meyer Primagon, Lydith and Oreston...

Attila · Expire: 2025-11-18

Looks really crap wheather what you have Sad

This lens can be very, very sharp at F8-F11.

iangreenhalgh1 · Expire: 2014-01-07

peterqd · Expire: 2014-01-04

Make sure all the lens rings are nice and tight. My Pancolar had a loose ring and a slight rattle and wasn't as sharp as expected, but tightening it up made a world of difference.

Attila · Expire: 2025-11-18

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

One thing I'd like to add -- the very first batch of photos contained several images that had good strong reflections off of high-polished or chromed metallic surfaces. These are always the sorts of areas where CA will rear its ugly head, but I detected almost none. Just the slightest amount of purple fringing in a few of the images, even the wide open shot. So I would have to say that this lens is very well corrected for CA.

Also, I'm not ready to pass judgment on sharpness at infinity settings since the weather was so grim. I'd like to see retests on a clear sunny day.

iangreenhalgh1 · Expire: 2014-01-07

The focus is very stiff so needs a relube. Let's hope a good cleaning and some sunshine will bring out the best in this lens tomorrow!

martyn_bannister · Joined: 23 May 2010 Posts: 1151

Two things I must comment on Ian,

IMHO......

1) Never judge the sharpness of a lens unless you have used a tripod, or shot hand-held at a MINIMUM of 1/focal length TIMES THREE i.e, a 50mm lens should be shot faster than 1/150s. A 300mm lens should be 1/1000s.

2) Never judge the sharpness of a lens from a resized image, or one that has been saved with a lossy compression format. As soon as the image is resized (e.g. to post on a forum) the resizing algorithm can totally skew a sharp image and make it look as soft as butter. A 100% crop is better, as long as THAT hasn't been resized Smile

. However, saving a 100% crop as a JPG and then posting that means that, again, the sharpness can be compromised by the compression.

This makes it very difficult to judge how sharp an image a lens produces by means of a forum post. This is not meant as a criticism. It's an observation. I have seen plenty of posts on other forums where a lens and/or camera has been slagged off as producing less than sharp images, only to download a full sized RAW file and be totally blown away by the original.

My 2p.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

Good points, Martyn, and well worth remembering.

BRunner · Joined: 29 Jul 2009 Posts: 705 Location: Czech Republic

2.8/50 Tessar isn't sharp lens wide-open. It needs to be stopped down at least to f5.6. It's better performer on close distances, but has very low LoCAs and LaCAs stopped down.

Which monitor do you use Ian? On most images from you I see weird colors and contrast. Something like cyan cast. On my Eizo only the image of Tessar lens looks OK.
No offense here please, I'm just trying to help you.

ManualFocus-G · Expire: 2014-11-24

Those Stan D photos at the top are back focused, which is why they look unsharp. Is your adapter the correct thickness? If not, the lens might focus past infinity resulting in soft results of course. Also, as mentioned, the weather is rubbish there which could also have an effect.

woodrim · Joined: 14 Jan 2010 Posts: 4060 Location: Charleston

Ian: I would echo what has alreay been said with an emphasis on - YOU NEED to do post processing. Also, please stop photographing those row houses - jeesh!!! Wink

You need to get out and about more. Lastly, maybe if you think it's sharp, it is sharp enough for you.

nemesis101 · Expire: 2015-01-22

Hands off 'row' (terraced, for the civilized) houses!

I suspect you'd relocate Billy Elliott to some LA suburb and have him trying to come up with a 'breakout' rap mash-up?

lol

Doug

PS Where are those houses, sometimes I see Yorkshire, mainly I see the North-East and then I think South Wales!

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

martinsmith99 · Expire: 2013-11-18

iangreenhalgh1 · Expire: 2014-01-07

I'm sorry martn, I must have been in bad mood that day, shouldn't have said that. I probably meant your monitor not you personally.

I'm at my wit's end as I just can't seem to attain a really sharp image.

I'm starting to think it muight be my camera. I turned the sharpness from 0 to +2 and I see no difference at all.

If I sharpen in photoshop it gives too much noise, I find the images from my EOS 10D pretty noisy to begin with.

My monitor is a Benq G2220HD, it was cheap, about 6 months old.

Are you sure that pic with the Star D logo is backfocussed? I don't see anything in the image further away than the logo plate that looks any sharper.

I keep shooting down the front street because I can do it from my front door step and I think the rows of TV aerials and other details make it a good infinity test, not very interesting, but I like shooting the same subject over and over for testing lenses so I can compare.

Weather still gray here today, sadly.

If anyone wishes to help me try to figure this issue out, I'd be happy to send them some raw files...

Here are some similar shots (sorry woodrim!) with different lenses, see if you can see any trends here that might suggest what my problem is. None have had any PP at all.

EDIT: Can't upload pics, I get an error that the document doesn't exist.

martyn_bannister · Joined: 23 May 2010 Posts: 1151

I find that, to eliminate pilot error on the focus, it's best to shoot something (like your terraced houses) which recede into the distance. That way, unless you have gone PAST infinty, SOMETHING will be in focus.

Also make sure you have got the diopter adjusted correctly on your viewfinder.

Someone once tried to explain to me that my Canon 5D cannot be focused accurately at apertures wider that f5.6. Something to do with the viewfinder I think. I couldn't understand it at the time, so I may be telling it wrong Smile

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

@Martyn, I don't believe that situation applies to the 5D -- or if it does, I know there's a focusing screen you can get that will take care of the issue -- the ES or something like that. Not sure about the screen's name.

What that guy was trying to explain is that with some crop-body cameras, like these Canons -- from what I understand it is the cheaper small APS-C Canons like the Rebels here in the US, the 1000D, 450D, 500D, etc. in Europe. And it isn't f/5.6 -- it's about f/4. The focusing screens in these cameras are designed to make the image as bright as possible with slow lenses, but a side-effect of this is that it isn't possible to accurately focus faster lenses because the focusing screen can't handle them. Wish I could explain it better, but there are sites out there that explain the phenomenon, and I can find links to them if you want. Anyway, I've proven this numerous times to my distress with my XS (1000D). The only way to focus accurately with a fast lens on a camera like mine is to use Live View. But that should not be a problem with a 5D and a fast lens. And in this case, I mean anything faster than f/4.

@Ian, I don't see the back focus on the tripod. There are areas on that tripod that look critically sharp to me. I do think Martyn's idea is a good one. If you shoot a subject that includes items that your lens sees as infinity, then there should be something in focus -- even if your lens focuses past infinity, which I doubt. And regarding your street scene, I too was looking at the aerials and they seemed to be well rendered to me, especially considering the weather.

All that being said, though, I wouldn't make any firm decisions on the matter until the weather clears and you can take some nice infinity photos when there is no atmospheric haze.

BRunner · Joined: 29 Jul 2009 Posts: 705 Location: Czech Republic

ManualFocus-G · Expire: 2014-11-24

A couple of points:

1. The second Stan D photo is clearly back focused, I can't make my mind up about the first one!

2. DSLRs in general will only give an accurate representation of depth of field up to f2.8. Anything faster will need to be clever guesswork (it IS possible, but difficult). I changed my 5D's screen for an EE-S and it's now perfect. BUT...it's darker of course!