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Dandelion Focus Confirm/CPU modification?

David L. , May 21, 2010; 05:43 p.m.

Hello all - Does anyone have any experience with the ~$35 Dandelion focusing confirmation chip as installed on a Nikon lens with a Nikon (D)SLR?

I have read of many 4/3rds, Canon EOS, and Pentax users who have purchased lens adapters with these already installed for their repsective mounts, but no Nikon users with Nikkor glass. I intend on installing the Nikon-type ones onto my library of Nikon MF lenses with the intent if having my D300 recognize the lens in the same way it reads the old Rolland Elliot CPU modifications. In fact, I think this may be superior to the R.E. mods, as the Dandelion chip can be programed with the correct aperture and focal length for each lens as opposed to the R.E. hacks which only transmitted the correct aperture.

So my query is to see if anyone has tried to install the Dandelion onto their AIS lens and how it is working out? Also, where would one learn and find details on where and how each lens mount needs to be cut out? Or does anyone provide the installation as a service? It would have to be an independent shop as no Nikon authorized service center is allowed to do it (I've asked around).

I assume there are limitations for some lenses. I consulted this Bjørn Rørslett chart detailing lens upgrade options for a service he does not seem to actually offer.
I would love to upgrade as many of my older Nikkors as possible and maybe even replace the R.E. installed chip in my 300/2.8 that has the CPU from a 45mm/2.8 which gets mixed up with the real 45mm/2.8 that I own when sorting in Lightroom... So any pointers?


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Walter Schroeder , May 21, 2010; 07:18 p.m.

David this looks very promising.
Is there a link to a distributor?

Ian Rose , May 21, 2010; 07:58 p.m.

Borjn has done this on some of these conversions so lets hope he sees this thread and gives us some insight as I have a 28mm 2.5 that I would like to convert.

Ian R

Peter Hamm , May 21, 2010; 08:18 p.m.

I would probably pay some money for a chip for my 55mm f3.5. It would be even more useful with this.

Carl Becker , May 21, 2010; 09:01 p.m.

This is very interesting. I have a chip from Bjorn for my 28mm f2. I have yet to install it though. If the picture is everything included it should be much easier then OEM Nikon chips. If this works out to be easy I have several AIS lenses to convert.

Richard - , May 21, 2010; 10:19 p.m.

There's this note on the programming page about even older lenses than AIS:

Note: In pre-AIS series lenses manufactured before 1981 the aperture control mechanism has a non-linear construction. When making pictures with such lens a slight expo correction may be needed.

Sebastian Moran , May 23, 2010; 09:25 a.m.

How does the Dandelion ring attach to the lens mount? I have a couple of lenses with chips added by Rolland Elliot, and it takes some relatively precise handwork to drill two screw holes to attach the chip. Same with Dandelion? They work great, matrix metering and TTL flash exposures with various Nikon Bodies.

Dandelion says theirs won't work with F90x (=N90S?)... But my R.E. modified lenses work fine with my N90S.

David L. , May 23, 2010; 12:53 p.m.

Well, so far, this post seems to have generated more questions than answers...

@Walter - These chips are manufactured in Russia and are being sold through some sellers on eBay as well as Leitax as an option for their lens mount conversions. Leitax will install the chip onto an adapter for a small fee (€10).

@Carl & Ian - I contacted Bjorn a few times in regards to the chips he mentions on his site and he said he was out. How long ago did you get yours and were they actual Nikon chips, clones, or something else like these Dandelions?

@Richard - Most people don't put the terms "precise handiwork" and "Rolland Elliot" in the same sentence ;) Depending on the lens, sometimes it is much more than the insertion of a pair of threads to install a chip. Many require large sections of the lens mount (chrome area) or the rear element housing (matte black area) to be removed in order to facilitate the chip. Generally, the longer the lens, the less work is required.

John Schroeder , Aug 13, 2010; 02:00 a.m.

I just chipped my 20mm f3.5 Nikkor. It is critical to install the chip properly. It is rather fragile due to it's small size. There really isn't any way to make it bigger and have it work properly. My first attempt ended miserably because I didn't position it properly and bent the pins. On the second attempt I used a depth gauge to properly position the chip. Measure twice glue once. Programming the chip is rather straight forward. You MUST read the directions. There is a reset function if you screw up the programming. If you use a super glue type adhesive cover the pins with a bit of gaffer's tape. Cyanoacrylate based based glues out gas and cote the pins. A light touch with some emery paper will clean it off but the chip won't work until you do. Let the glue harden for 24 hours before reinstalling the lens mount back onto the lens so the out gas doesn't coat the rear lens element.

Nathan Wong , Aug 19, 2010; 06:26 p.m.

So after all that work, did the chip work on your lens? Where or who did you buy it from? I'd like to get a couple.

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