Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Non-AI to AIS
Post new topic   Reply to topic
Home   Manual Focus Lenses
View previous topic :: View next topic  


PostPosted: Fri Aug 08, 2008 8:07 pm    Post subject: Non-AI to AIS Reply with quote
Today I asked friend of mine who is an excellent professional photographic repair man. Is he able to convert my Nikkor 20mm f3.5 UD to AI ? Yes he able to do even to AIS ! So I am happy now I will have a great lens for my Nikon FA.


PostPosted: Fri Aug 08, 2008 8:30 pm    Post subject: Reply with quote
Is it an expensive operation?


PostPosted: Fri Aug 08, 2008 9:15 pm    Post subject: Reply with quote
He doing from 35 USD.

http://www.aiconversions.com/PricesAndShipping.htm

In USA better deal to order from them, due high international shipping cost.


PostPosted: Sat Aug 09, 2008 2:29 am    Post subject: Reply with quote
wow, that's a deal. i've done all of my own AI conversions, but at that price i'd probably just send them to him and save myself the trouble.


PostPosted: Sat Aug 09, 2008 9:19 am    Post subject: Re: Non-AI to AIS Reply with quote
Attila wrote:
Today I asked friend of mine who is an excellent professional photographic repair man. Is he able to convert my Nikkor 20mm f3.5 UD to AI ? Yes


Great! The only two people advertising that service that I found were in the US, which makes the operation unattractive due to shipping costs. I'd be interested to have contact details for this guy (once you report back that a lens is well converted). On my D40 I can use pre-Ai but if I ever move up to a D300 I would loose the use of my pre-Ai lenses unless they were Ai converted.

Attila wrote:
he able to do even to AIS ! So I am happy now I will have a great lens for my Nikon FA.


That surprises me and I suggest you check on this. Its easy enough to mill a slot into the back of the mount, of course, which is the visible difference between Ai and AiS. The invisible difference (which this slot allows cameras like the FA to detect) is that the movement of the aperture is linear with the movement of the aperture control lever. This is what allows shutter priority mode to be used, with the aperture ring set to smallest aperture and the actual aperture controlled by the camera.

Taking a lens which does not have a linear movement and making it linear sounds like a more complex operation, mechanically. What I don't know is how many lenses had a linear movement anyway - in that case it would just need the AiS slot to be machined into the mount, and be easy for a workshop to do.


PostPosted: Sat Aug 09, 2008 11:26 am    Post subject: Reply with quote
Thank you for warning, I will take a try with him. AI surely will works, I just hope AIS. He is learned in school how to repair photographic accessories and did it in the last 25 yrs, so I believe he has deep knowledge. I will inform you how this process going.


PostPosted: Sat Aug 09, 2008 11:42 am    Post subject: Reply with quote
this is probably similar to Pentax K and KA lenses...

the only external difference of K and KA is presence of some pins which "tell" the camera the maximum f-number of the lens.

but there is a difference in the diaphragm actuation of the K lenses and KA; the K lenses have the DIAMETER of the diaphragm linearly proportional to the lever actuation distance; while the KA have the AREA of the diaphragm proportional to the lever actuation.

so while it might be possible to mill a hole into a K-mount lens and put an insulator there so that the camera will think a KA lens is mounted, i don't think that shutter-priority or program mode would work (and metering would only work with wide-open aperture).


PostPosted: Sat Aug 09, 2008 6:13 pm    Post subject: Reply with quote
Thank you Chris! I would like to use on Nikon FA


PostPosted: Sat Aug 09, 2008 7:37 pm    Post subject: Reply with quote
Seymore wrote:
Ron White has converted (pre-AI to AI) 2 lenses for me and I have no complaints about the work done. Consider him if you need anything like this done.


I hear many recommendations for his work. I would like to know of someone similarly skilled on this side of the Atlantic, though.


PostPosted: Sun Aug 10, 2008 9:31 am    Post subject: Reply with quote
I don't know I am asking too. Is there any benefits ?


PostPosted: Sun Aug 10, 2008 6:57 pm    Post subject: Reply with quote
AIS lenses only benefited the FG/FG20, FA and I think the F301 and F501 (2000 and 2020 I think for the American models). It allowed a Hi speed option in program (and possibly shutter priority) mode for longer lenses (135mm or greater), that's about all. It had no benefit for manual or aperture priority modes. Later cameras didn't need it.


PostPosted: Sun Aug 10, 2008 7:02 pm    Post subject: Reply with quote
Thank you Richard! I use all time aperture priority, so don't need for me.


PostPosted: Sun Aug 10, 2008 7:04 pm    Post subject: Reply with quote
Attila wrote:
Thank you Richard! I use all time aperture priority, so don't need for me.


No problem - forgot the F4!

http://www.mir.com.my/rb/photography/hardwares/nikonfmount/ais_lars.htm


PostPosted: Mon Aug 11, 2008 12:58 am    Post subject: Reply with quote
Seymore wrote:
Attila wrote:
Thank you Chris! I would like to use on Nikon FA


OK Attila. Can you please share what benefit the AIS lenses have over the AI lenses on the FA?

There's also something about the FA and the SB-15 flash using the focal-length and/or distance that the lens is set at, to make a "perfect" TTL exposure. I don't have a manual for my FA, but I think I read that someplace...


PostPosted: Mon Aug 11, 2008 11:38 am    Post subject: Reply with quote
Thank you Dan!
Post new topic   Reply to topic
Home   Manual Focus Lenses
Page 1 of 1