Lenses with bad/strong Coma?

I

ishpop

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The more I research the more I think I am slowly starting to understand all the terminology having to do with OOF rendering.

Specifically, I bellieve that Coma is somethhing that appears to create a feeling of circular bokeh if I am not mistaken.

I actually really dig images that have this feeling. Having shot digital for the last 5 years where the lenses are cropped seems to decrease if not eliminate the chances of coma happening.

This was one of many motivations for me to buy a RF, so as to get some of that nuance effect from different lenses and different film/processing.

All of that being said, I am still not that sure which lenses are known to have strong coma. Everyone generally is pursuing "creamy" bokeh which by all means is very usefull and desirable in many instances, however, I think it can also be boring at times when 50% of your image is OOF, alll depending on the subject.

So, getting to the point, does anyone have any recommendations for lenses in LTM that are known to produce some odd bokeg, specifically strong coma?

Thanks!
 
You might look and see what a wide open noctilux does for you, but that's a pretty high price to pay for what you want. I seem to recall some vivitar slr lenses give bubbly bokeh. My nikon 50/1.2 also gives bubbles wide open, but again it's an slr lens.
 
yeah, would love to have the Noctilux, but out of my range and considering I am new to RFers, would make me a poser. ;)

How much does the 35/1.4 Summilux pre-aspheric go for in user condition?
 
In M/LTM, the lenses that come immediately to mind are Noctilux, Summitar and Summarit.

Non-Leitz, most prominent in my mind: Canon 35/2 (very bad), Canon 50/1.4 LTM,
CV 40/1.4. Other CV lenses are less sensitive. The Canon 50/1.2 and 35/1.8 are
pretty good.

All Sonnar variants (Zeiss LTM and C-Sonnar, Nikkor 50/1.4, Canon 50/1.5)
are pretty robust in terms of comatic aberation, but instead loose
resolution towards the edges, wide open. Summicrons for f >= 50mm are
pretty stable too, the 35/2 ("Bokeh king") shows it a little bit.

Roland.
 
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ishpop said:
yeah, would love to have the Noctilux, but out of my range and considering I am new to RFers, would make me a poser. ;)

How much does the 35/1.4 Summilux pre-aspheric go for in user condition?
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From $600:) to $1200:mad:
 
As a matter of idle interest, when did the term 'comatic aberration' (7 syllables) begin to replace plain old 'coma' (2 syllables)? And what do the extra 5 syllables add?

Cheers,

R.
 
According to "Optics and Optical Instruments" by B.K. Johnson, 1960, coma is effected by the position of the lens' diaphrapgm. I made a "monocle" lens out of an I61 mount with the aperture well in front of the 50mm single-element optic. It is RF coupled. Did just what the book claims it should do. Lots of Coma.

Coma! You want Coma! How about "Deep Coma".

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ferider said:
Strange as it might seem, not all of us think in English.
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Fair enough. In which languages is the term 'comatic aberration' preferred to 'coma'? German is probably a strong candidate...

This is a genuine enquiry, not a wind-up.

(Translation for Americans and other whose native language is not English: a 'wind up' is a deliberate attempt to play on someone's gullibility or prejudices).

(Second note to Americans, etc: the bit about mother tongues IS a wind up)

Cheers,

R.
 
Brian - thanks for the very demonstrative image, and for the experiment that produced it. Knowing that all design is compromise, this would lead me to suppose that aperture placement in a particular lens design is a compromise. In lenses that exhibit strong coma - perhaps due to less than optimal aperture placement? - what is GAINED in the compromise?

And what's up with lenses that render coma at full aperture?

- John

BTW - the Kiev site shows some interesting images - at monitor resolution the images almost look like IR shots, but with blue sky. Very painterly.
 
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The aberration that we refer to as 'coma' is oblique spherical aberration. The term comatic aberration, strictly speaking is incorrect in English but is creeping into common use (which means it will soon become correct usage, in all likelihood), probably from German.

LTM lenses with strong coma include the Summarit 50/1.5 and Summitar. Coma occurs when rays from an off-axis point of light in the object plane create a trailing "comet-like" blur directed away from the optic axis. This creates the 'circular-swirly' look in the outer field.

The shot above with 'deep coma' actually doesn't display the effect that well - the trees aren't swirling much. There is also a good amount of field curvature and on-axis spherical aberration complicating matters.

These classic coma shots from the Nocti come from FlickR's tremendously prolific Tommy Oshima:
http://flickr.com/photos/tommyoshima/271435187/
http://flickr.com/photos/tommyoshima/281078121/in/set-72157594292218784/

I have a Noctilux but try to avoid this look.

Marty
 
Here's a side crop from a photo taken in a lit entryway. Noctilux. Guh.

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Tommy Oshima

Tommy Oshima

Actually, ironic as it may sound, I find Tommy's work inspirational. In fact, the second photo you posted is one I have posted in other forums previously as an example of the types of bokeh I find pleasing.

Obviously not the only type, but in that instance, with those colors and contrast, it really seems magical to me.

This are another couple with a Graphlex Speed Graphics:

http://www.flickr.com/photos/tommyoshima/445174821/in/set-72157594583422733/
http://www.flickr.com/photos/tommyoshima/445174813/in/set-72157594583422733/

His stuff in general is really great.

I will have to check out the Summitar. Thanks for the info everyone who has responded.
 
I have a lot of respect for Tommy too; please don't take anything I wrote above as anything except admiring - personal styles differ. I don't try to emulate him, but I like what he does and even when i don't like it, I tend to appreciate what he's trying to show.

Marty
 
Yeah I understood you. :)

And I agree, emulation is counter-productive. For me though, I definitely am interested in producing some dreamy and somewhat abstract OOF effects.

The search for the right lense continues... Simply cannot afford most of these recommended. I just want to start using my new Bessa... ;)

Freakscene said:
I have a lot of respect for Tommy too; please don't take anything I wrote above as anything except admiring - personal styles differ. I don't try to emulate him, but I like what he does and even when i don't like it, I tend to appreciate what he's trying to show.

Marty
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