Any difference between 35mm 1.4 AI and AIS?

[vietnam photo]

I have an opportunity to buy 35mm f1.4 AI at a very good price. Just

curious if there is any difference in performance between AI and the

newer version AIS? Thanks.

[rjm photo]

The AIS has two extra blades in the aperture....which should result in smoother out-of-focus areas. A very fine lens IMO.

[michael_briggs2]

The AIS has 9 blades, the AI 7. Robert, do you really think that will make a noticably difference?

 

Though this wasn't the question, there is definitely an optical difference between the pre-AI versions and the AIS version -- apparently undisclosed by Nikon. The pre-AI versions (which frequently appear with factory AI rings -- probably these lenses were mostly owned by pros) have some thorium glass which turns tea colored with time. The color can be cleared with UV light. See "yellowish cast looking through 35mmf1.4" at http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=0054IM. The first post says that the lens being discussed is AI, but later the poster says that he has a "N.C." lens, so I think that he probably has a pre-AI lens with a factory AI conversion ring. I haven't measured an AI lens, so I can't say for sure whether it has the radioactive glass, but from when it was made, it seems unlikely.

[fisheye]

It could be an answer for your question.

 

http://www.cameraquest.com/aidaiais.htm#AI'D

[alan_wilder1]

Michael, that's great information. I use to have a pre-AI 35/1.4 Nikkor with the rubber ribbed focusing ring and I too noticed it had a pinkish brown coloration against white paper. I used to think it was a result of the coating transmission or tinge to optical glass. Now I know the truth.

[ShunCheung]

The reason to get the f1.4 version of the 35mm is to use it wide open at or near f1.4. In such case the number of aperture blades should not make any difference. :-)

[james_c._turner]

I thought when a lens is wide open, that IS when you get the effect of whatever aperture blades you have, in the bokeh.

[rjm photo]

James...remember that when the lens is "wide open" the aperture blades are completely folded and out of the way and in no way effect the image. At stopped down settings the blades start to become involved with the image your camera records.

[roland_vink]

The Ai and AiS 35/1.4 have the same optical design - 9 elements in 7 groups with CRC focusing down to 0.3m/1 foot.

 

The coatings are the same except for very recent AiS lenses which have an improved coating - but the original coating was already very good and the lens is known for resistance to ghosting.

 

The AiS version has 9 aperture blades, the Ai has 7 blades. This has no affect on the image or optical performance except for the shape of out of focus highlights when the lens is stopped down.

 

The Ai version has a longer focus movement - DOF marks are further apart, focusing is slower and more precise. The AiS lens has a shorter focus movement so you can focus more quickly for action photography. I've found little practical difference between the two.

 

If the Ai lens is in good condition and the price is right, get it.

[vietnam photo]

Thanks all for your help. Just paid for it :-)

[james_c._turner]

Robert... When you have shallow DOF, ie f1.4, is when you get the bokeh in the background, which comes from the aperture blades, they are not "out of the way", light passes through/over them. If a lens is at f16, you have much greater DOF, and no bokeh. The more aperture blades you have the smoother the bokeh, when wide open.

[ShunCheung]

James, I have my 35mm/f1.4 AI-S right in front of me. When that lens is wide open at f1.4, the aperture blades are completely out of the way of the light path. That is why we say it is "wide open." Therefore, the number of blades is completely irrelevant.