More cheap Nikon glass, for others too.

[ajohnw]

I've been curios about a certain Russian 16mm F2.8 180 degree coverage on full frame lens for some time. It covers 120 degrees on crop. I had hoped to take several shots with it but silly me most of them had the sun in the frame or just out of the crop view. Not much flare it seems but the exposures were hopeless. Another shot is more interesting but needs some work.

I did take this as a test. Minimal PP and I wish I had positioned the tree protector more to the left. Barrel and tilt correction are a little off too. New software. Not sure if the adjustment centre was off or that the tree protector has to lean a little.



And a crop showing it's not too bad a lens and that 800 iso is too high for a D7000 at this resolution.



Cheap preferred as I can't see myself using a lens like this very often but rather wider than 18mm could be useful.

Oh KR reckons it matches / betters Nikon's equivalent at some apertures. I don't see lack of AF as a problem with a lens with this DOF.

John
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[Shadowman]

Think of it as being thrifty, not cheap.

[ajohnw]

This is what comes out of the camera but it is aimed at architectural type work so if the camera is squared up most distortion should be correctable. There is also some software about that will correct verticles etc by marking them.



John
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[ajohnw]

Think of it as being thrifty, not cheap.

True and why not as I don't think lenses with this sort of angle of view are needed very often. Something to play with really.

Optically it seems ok to me but I do need to check that the focus scale is correct. Slight suspicion on that score but it's probably close enough. Nikon's AF confirm doesn't like the lens at all. The absence of flair might turn out to be very impressive. It has the hood built in for FF. An add one one might not be a bad idea for crop.

John
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[GrahamS]

And a crop showing it's not too bad a lens and that 800 iso is too high for a D7000 at this resolution.-

I think that a lot of the artifacts that you interpret as noise are in fact due to interpolation by the image distortion correction software.

[ajohnw]

I don't think so Graham but that could make it worse. The noise tends to come up during post processing. Some of this may be down to metering problems and under exposure. The shot seems to be about 1 stop under exposed. I need to read the camera manual and expect to see some sort of note about exposure when using manual lenses. It will make me wonder what has happened since all lenses were manual as there is nothing tricky about that shot.

I've looked at it again on this shot and I would guess that this one is at least 2 stops under exposed. So much noise evident in the sky that removing it globally has lost the grass detail. Centre weighted with an 8mm dia circle. Think I will look at changing that and see what the options are. Or maybe use it a little more intelligently. Need to know what it does first though. This shot is cropped from the upper right, loosing some foreground and more lost on the right. Interesting clouds that aren't clipped though one looks like it is.



John
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[ajohnw]

I should mention that according to KR this lens starts getting good at F11 and slower. I would say it's a touch soft at F11. His example seemed to be better than the Nikon 10.5mm at F16. Web sized landscapey things though - I personally don't think this matters to much at normal sizes.

http://www.kenrockwell.com/zenit/zenitar-16mm.htm

He refers to it as a fish eye but they also do one of those. This one isn't intended for that use.

Interesting read. I haven't seen any chromatic aberration either. In my mind that does matter.

John
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[GrahamS]

I agree, John, underexposure just opens the window to noise every time. I found that I got greater consistency from my D7k when I set the center weighted metering to "average" rather than any of the spot settings.

[Black Pearl]

I think that a lot of the artifacts that you interpret as noise are in fact due to interpolation by the image distortion correction software.

I'll second that. What you can see is not noise nor is it produced by noise correcting. Anyway at 800iso there shouldn't be any issue with noise from a D7000 - my K30 uses the same chip and it is very clean at those sensitivities.

The image looks like someone has just discovered a paint daub filter and gone mad with it.
The second shot just looks mad full stop. I know everyone is different but I must say John you have a very unusual processing style.

Interesting lens though. I would like to see some normally processed images, particularly ones where the distortion is used to enhance the shot so it doesn't need to be removed.

[ajohnw]

I'll second that. What you can see is not noise nor is it produced by noise correcting. Anyway at 800iso there shouldn't be any issue with noise from a D7000 - my K30 uses the same chip and it is very clean at those sensitivities.

The image looks like someone has just discovered a paint daub filter and gone mad with it.
The second shot just looks mad full stop. I know everyone is different but I must say John you have a very unusual processing style.

Interesting lens though. I would like to see some normally processed images, particularly ones where the distortion is used to enhance the shot so it doesn't need to be removed.

Bit curious that one of them is from the camera jpg and just reduced. Maybe you should get a new screen. I did make the !scenic! one a little gaudy. For good reason too.

John
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[ajohnw]

Just to illustrate a point. The noise



It can even be seen when the shot is reduced.

John
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[Black Pearl]

Pretty sure my calibrated Apple iMac screen is good enough to make a considered assessment of most images - I get that it isn't a top-end EIZE or NEC but it is pretty accurate and it does show that your images as presented do look unusual.

The last shot you posted looks like it is straight off the sensor image with no noise reduction of any sorts - that isn't the usual way to present your images or even the best way to work on your images.

You have to apply some sort of noise cancellation to most images as the iso goes up so simply throwing us a shot with nothing done doesn't mean a thing.


These are 100% crops of a 1600iso DNG file from a Pentax K30 - the same sensor as your D7000.

The bottom one has every correction turned off - in other words it is straight off the sensor...or as close as you can get.
The top one has ACR default noise reduction applied - the sort of thing you have to do to a higher ISO file.



As you can very clearly see the colour noise is obvious in the un-corrected shot - as it is in the example you presented - but with just the most basic of corrections applied it is possible to significantly improve the results.

You have posted images with no corrections then state the visible break-up is down to noise when you clearly haven't processed the shot correctly. The artefacts are nothing to do with noise and as supposed very likely due to the software used to 'correct' the distortions.
You have also posted an image with no noise correction at all which doesn't help.

[ajohnw]

I agree, John, underexposure just opens the window to noise every time. I found that I got greater consistency from my D7k when I set the center weighted metering to "average" rather than any of the spot settings.

I'm surprised that the shot came out more than 2 stops down given where it was pointed. The right side where the grass has gone really awry was in very deep shadow as a result and what little contrast brushed up went when the noise in the sky was removed. Crap exposure. I only worked on it out of curiosity. Not so good shot wise either really. Feeling mischievous due to the compositional comments kicking about so thought 2 leading lines, rather nice clouds but a slightly misty sky, an object of interest and some bits an pieces. Who could ask for more.

When I tested the focus marks on the lens I used average and it came out maybe 1/2 stop down. 800 ISO and no noise to speak of. It's curious really. I did use a Nikon film camera. Centre weighted but via an oblong shape reaching to the bottom of the frame and well short of the top. Maybe 20% of the width. Sort of one or two people reading area with some foreground and used with an 80% weighting to set exposure. It worked well and was easy to use with a bit of practice. These days I think they are all leavings from the matrix method. Might be worth trying the larger areas though. Maybe the manual gives some idea of the weighting. That would help.

John
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[Stagecoach]

John,

When I first got my D300 I experimented with the three different metering methods but have come to settle for 'Matrix' for just about everything I do. When I have time to control exposure I use the histogram of course.

As an example of 'Matrix' last weekend I shot 500 images at a car race in very varying lighting conditions, no sun, into the sun, sun behind, sky, no sky without a single shot that was poor or would have been scrapped due to exposure.

Grahame

[ajohnw]

John,

When I first got my D300 I experimented with the three different metering methods but have come to settle for 'Matrix' for just about everything I do. When I have time to control exposure I use the histogram of course.

As an example of 'Matrix' last weekend I shot 500 images at a car race in very varying lighting conditions, no sun, into the sun, sun behind, sky, no sky without a single shot that was poor or would have been scrapped due to exposure.

Grahame

If any one asks I suggest matrix on any camera. Doesn't stop me from trying other modes out of curiosity. Looking at the manual there's some qualified indication that if none cpu lenses are registered in the camera more metering modes are available. Otherwise it states 8mm dia circle only even though complete average can be selected in the menu. It's an odd area. On Canon's AF confirm adapters tell the camera that a 50mm F1.4 lens is attached in manual focus mode. All aspects seem to function reasonably even AF confirm what ever lens is on within reason. AF confirm just needs sufficient light. Can't help wandering if things in this area are really aimed at ending the very cheap end of the lens market that was around when film cameras were all manual.

John
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[ajohnw]

I just tried correcting the distortion with Hugin. More complete so more of the shot is lost. The slight error left is probably down to not setting the correct angle of view. With a crop factor of 1.5 and 92 degrees set the focal length came out as 11.5mm which I suspect is a little out. The brickwork isn't straight either which wont help.



Think I am going to try a hand held corrected panorama with it.

John
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