Upgrade old Nikkors with a CPU ?

[brushmeister]

I own a Nikon 400mm EDIF MF f5.6 and a 600mm f/4. I want to make

these super sharp oldies but goodies function with my D100's

metering system. I use them now with the camera, but the metering is

manual. I guess the right combination, shoot a test shot, then

adjust the exposure accordingly. It's no problem, but I want to

improve on that, to Aperture priority. Why? Just because I can (or

think I can).

 

Say I cannibalize a CPU chip from a "for parts" Nikon lens of

similar aperture. So long as the contacts match up in the D100 body

will I fool the camera into metering aperture priority with a thusly

modified 600mm MF lens? I think yes.

 

I don't have an electronics background so maybe what I'm practicing

is electronic butchery, but that's just me. Corresponding question

on circuitry: the "for parts" CPU I have, ready to use, has a long

tail of printed ciruitry to accomodate switches for zooming, etc.

They are now redundant. If I simply snip straight across these lines

will I do no harm to the chips' basic functions? I'm thinking no

harm will be done so long as these printed circuits don't touch each

other. Is that right?

 

PS: Screw Roland Elliot. He won't answer my emails.<div></div>

[charles_miller]

My "wild guess" is that the pattern that you would be deleting by cutting at points A and B implements the "D" function on this lens. If there are a set of contact wipers somewhere that ride on these tracks, I would guess that as the focusing ring is turned, differing binary patterns are detected by the chip. So at the least, the proposed surgery seems to have the poential to adversely affect flash operation.

 

An even wilder guess is that the chip is actually specific to the 35-80 lens, and that it communicates things like the amount of light fall-off when the aperture is wide open, for instance. If this assumption is correct, then using this "35-80" chip in a different type of lens could also adversely affect non-flash exposure accuracy.

 

Over the years, Rolland has greatly limited the types of lenses he will convert, I suspect because he has learned from experience that there are only a few really good matches for his technique. I think his reticence is simply based on a desire to protect proprietary knowledge.

 

The actual operation of the chip cannot be really complex by today's standards, but reverse-engineering any typ of digital chip is an extremely tedious business. Sigma apparently does reverse-engineer the Nikon "D" chips, but I can attest that they do not always get it exactly right.

 

Bjorn Rorslett also has some experience with reusing "D" chips, and he may be able to direct you to other available information.

 

Good luck with your little adventure.

 

Charlie

[User_1172872]

I tried this and rendered a chip useless. After I snipped off the tail the camera no longer recognized the chip. I have no idea why. Before you proceed further - how are you going to install the contact block into the lens mount? The lens mount you pulled from the junk lens probably will fit, but it may have only 3 screw holes instead of 5 - and does it have clearance for the aperture stop down lever? Also - if the old lenses are AIS they will have the tab that tells the camera you have the lens set at minimum aperture. If they are AI, not AIS, you'll have to add the little tab. Finally - to function correctly, the camera ought to have information on the minimum and maximum aperture on the lens - the aperture will be controlled internally by the stop down lever. I'll speculate that as long as the range (number of stops from min to max) is the same you'll be OK. But I have no idea what happens if the range indicated by the chip doesn't match the lens!

[brian_lee9]

If this is similar to the 24-70 IX Nikkor chip, I think the part between A and B is the part that controls the variable aperature. You do not want to snip this. The D function is probably the part at the tail end of the strip that is not shown in your picture. I've heard that you can snip that part, but I just left mine as it is since it fit fine in the 75-150 E zoom that I chipped.

 

I think the hardest part for me was to put the screw holes in the lens mount so that it would be properly aligned. Also you want to make sure the mechanical aperature lever is properly aligned when putting the lens back, or you will get over/underexposure.

 

I would guess that if you put the chip contacts on your D100, the aperature will read f5.6. If you want it to read f4, you may have to soldier some of the contacts between points A and B to have it read correctly. I think it would be the two end contacts where the B arrow points to.

 

Flash will be an issue also. I don't get proper flash exposure also since I used a "D" chip. Non-flash exposure seems to be working perfectly though. I was thinking for me that I would soldier a part in the "D" portion of the chip to hard code the distance it relays back to the camera to maybe a distance that I would normally use a flash, but I have not done it yet because I rarely use my flash with that lens and I'm too lazy to take it apart again to mess with it.

[david_h._hartman]

<em>I tried this and rendered a chip useless. After I

snipped off the tail the camera no longer recognized the chip. I

have no idea why. -_canon user<br>

</em><br>

Some of the circuits would not be complete. You might be able to

solder on jumpers and make them complete but youd need to

know which trace to solder to which. Its probably not worth

the trouble. If you dont have the piece youd need

another trace.<br>

<br>

With all the people upgrading there older lenses youd think

Nikon would get off its ass and design and outsource kits for

sales to independent camera repair facilities. It wouldnt

be their headache and a lot of Nikon users would be happier. It

might cut a few sales of new AF lenses but those lenses might be

Canon lenses so I dont see how they would lose.<br>

<br>

Regards,<br>

<br>

Dave Hartman.<br>

<br>

---<br>

<br>

Myron,<br>

<br>

My advice is dont cut anything.<br>

<br>

Best,<br>

<br>

Dave Hartman.

[e._m.]

In regards to Rolland Elliot: Did you email him because you wanted answers to how you do the modification, or was it in regard to sending him your lenses so that he could do the work?

 

In Rolland's ever shrinking list, your two lenses are still listed amongst those that he will convert. Maybe it might be worth sending him the money to do it if you're in any way unsure of the kind of results you're going to get.

[mark_chappell]

If Rolland still lists the 400/5.6 EDIF, then my advice is to swallow your pride and let him do

it. He chipped this lens for me some

years back and it worked perfectly. All you have to send him is the lensmount -- or maybe it

should be called the 'cameramount' (easily detached with 4-5 screws).

 

I agree with the previous poster: if you emailed Rolland and asked him to describe his

methods, it wouldn't surprise me if he blew you off. Why should he reveal his 'trade secrets'

to a potential competitor?

[greg s]

Wish I still had my 600mm f/5.6 chipped lens mount (by Roland) so I could physically describe it. Sold it 2 months ago. Seemed kinda simple as I remember, the flex cable I mean, like a straight connect. But I can't be sure. I screwed the mount back on and never had to think about it again.

 

It metered perfectly well... flash or no flash. Good luck! -Greg-

[Prof-K]

canon user , jun 02, 2005; 12:04 p.m.<br>

I tried this and rendered a chip useless. After I snipped off the tail the camera no longer recognized the chip.

<br><br>

On the other hand, I accidentally cut it off, and it still worked. The chip I was using did not had any interesting parts on the other side.

[lex_jenkins]

Roland Elliot says repeatedly on his website that he will work only on the lenses specified in his list and that there's no need to call or write to him asking whether he'll work on a lens he's already said he'll work on, or whether he'll make an exception and work on a lens that's not on the list (he won't).

 

I don't see any reason to criticize the man for doing or not doing what he's already clearly stated he will or won't do.

 

If you want tips on doing the chipping yourself ask Bjorn Rorslett, who's done a few of his own lenses.

[Prof-K]

Roland Elliot did answer my questions, although couple of months later. But Bjorn Rorslett never did!

[brushmeister]

I agree with you, Charlie and David and Brian. Snipping the tail may be unwise, so why risk it? Was hoping someone with an electronics backround would pop up and explain with facts why going either way is best. I continue to hope for that.

 

I also agree, Brian, that drilling the screw holes in the exact right place on the lens mount is the hardest job. Think I made it easier. I first made a drilling template from a scrap piece of aluminum shaped to fit snugly in the 1/8"-wide recessed trough of the mount. The smallest drill bit off the shelf at Home Depot, 1/32", is a perfect match for those two tiny screws holding the CPU fast to the inside rim of the mount. Now I am ready to place the template, using the contacts' position relative to the rim as a guide. .....Uh-oh! Alas, I just lost one of the buggers. It's gone. Things now on hold till I am able to find another tiny screw. Bummer there.

 

By the way, as an aside, those tiny screws require a really small phillips head jewelers screwdriver. I bought a nice set for $7 at Radio Shack and promptly broke the one I needed! Brittle, or what?! The screw I tried to remove must have been super glued in there. It burns me I gotta buy a whole new set just to get that size Phillips. No tool store I have found sells these super tiniest of drivers.

 

I rarely use flash with these long telephoto lenses, so chip compatibility for flash is irrelevant to me. In any case my trusty Vivitar 283 is up to the job. Bjorn says "which chip used isn't important" but he's referring to his own modification of a Nikon M extension tube. How this applies to my project is another unanswered question. He also did not snip off any of the long tail, I see, by his pictures. Now, there's a nice clue.

 

The quest continues. Thank you all for your advice, but don't stop. Call your electronic-whiz friends. This ain't brain surgery.

[vivek iyer]

It certainly is not brain surgery and you do not have to screw anyone either.

 

See this: http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=009KFX

 

If I can do it, anyone can. There is plenty of room to accomodate this chip or even much larger ones in your lenses so don't chop anything off.

 

If you go through with one succesful "chipping", you will understand the work involved and appreciate why Rolland Elliot's charges are very reasonable (if you are in N.America).

[chris haake]

"Roland Elliot did answer my questions, although couple of months later. But Bjorn Rorslett never did!"

 

That's funny; he answered mine right away. It's possible that your email never got through, since he has his security cranked way, way up.

[bjørn rørslett]

I do get up to 200 e-mails a day and there is no way I can answer all of them. My job is being a photographer and that activity pays my bills.

[ro_ro]

I think you can cut at point 'A'.

 

The chipping of a MF lens is doable. But it needs quite a lot of time if done properly.

 

I can post images of some steps.

[bjørn rørslett]

You should <b>not</b> cut the print anywhere between "A" and "B". Try to short-circuit any pair of copper lanes in this area and you will see that the indicated aperture changes (if the pin block is put into the camera of course, so you can get the read-out). Find the position corresponding to the max. aperture on the lens you are doing a chip upgrade on, and then cut the print at that position. Then, using a small piece of wire and solder, make a permant short-circuit to connect the relevant lanes.<p>

 

The segment outside point "B" is the distance ("D") area of the print and I never had any issue with just cutting it off. On the other hand, leaving it intact won't do any harm either, if there is room inside the lens to be modified.

[ro_ro]

Here an image that shows the cut-line and the test-points that should be connected to get the apertures right. You can solder a small wire between the points.

[vivek iyer]

Bjorn is correct with his recommendation on not sniping off of the strip (see the next post).

 

Here are some different matrix chips.

 

1. An IX-Nikkor 20-60 f/3.5-4.5 zoom (now fixed at f/3.5)

 

2. A 500/4 "AI-P"chip

 

3. A chip from 50/1.4 AF

 

4 One from the 50/1.8 AF<div></div>

[vivek iyer]

While Ro Ro is technically correct about sniping the strip and connecting the points he illustrated, I find it very very difficult as these solderable spots are extremely tiny.

 

I used a thin brass shim to check the desired points to connect and soldered there.

 

Here is a close up of the soldered connection making the IX-Nikkor chip to act as a f/3.5 (well, the EXIF data of the lens will read as a 20mm focal length from the 20-60 IX-Nikkor- does not bother me one bit)for the widest aperture.<div></div>

[vivek iyer]

Now, how do you check whic is the correct aperture?

 

For this, screw the chips back on to the Nikon lens mount, attach the mount to the camera and use the shim to find the right spots.

 

Here is another IX-Nikkor chip (90-180, I think) that is connected to a T-mount before the "aperture find" operation.<div></div>

[vivek iyer]

Here is a sample from a matrix chipped 75-150mm f/3.5 E-series zoom

(as long as such gems are available used, cheap and plentiful, one need not bother with the current plasticky creations). I used the spot meter on my consumer grade D70 under overcast conditions.<div></div>

[ro_ro]

Vivek, could you please email me to share infos about metering chips.

[vivek iyer]

Did that, Robert.

[brushmeister]

Got replacement for that lost tiny screw for attaching chip to lens mount. (Thank you, Essex Camera Repair.) I installed the CPU in my Nikon 600mm. Plenty of room in that tube, for sure. One could actually connect the chip to the mount without removing mount from the lens, and tuck tail in place. But, when drilling holes you then take the big risk of filings falling down into lens interior. Don?t need that.

 

To cut or not to cut? That was my first big question.

 

Bjorn says earlier? ?The segment outside point "B" is the distance ("D") area of the print and I never had any issue with just cutting it off. On the other hand, leaving it intact won't do any harm either, if there is room inside the lens to be modified.?

 

Bjorn, you also say this tail can in fact be cut, and imply doing it right only depends on where the cut is made! That certainly lifts fog off the subject! Now if I only knew how to determine the where part.

 

Gentlemen, since there is plenty of room in there I agree, leave it intact. However, I still do not like the fact that this long tail comes all way around inside the tube and overlaps itself. What if live contacts touch each other? That was my prime reason for wanting to cut it.

 

OK, Vivek, you address the additional problems, thank you for sharing your experience/input. I see my chip/tape matches your number 1 sample, but am having trouble understanding how to take the action you propose.

 

Before going further, summing up where I am now?..with CPU installed I immediately took lens outside, mounted on D100 and shot tests.

 

First thing I found out was the D100 display blinked F - - - endlessly. At that point I thought game over until I casually stopped down lens aperture ring to min. f/22. The camera unlocked! That joy of discovery then crashed when I discovered had no control over aperture, regardless what program used, or what control wheels I turned. Something more needs to be done. Vivek, I know you have the answer.

 

Some test images grossly overexposed, others perfect. But at what settings? Looks like the same hit-miss-adjust I had before adding the CPU, but with less control. Nikon View software can?t know what was done since the chip?s ?connection? to the lens diaphragm is bogus to begin with. Although a variety of aperture/shutter speeds showed on the display, there was no way to confirm if image shot was influenced by them. If I set camera on A-Priority and changed the lens aperture I was back to F - - - and a locked up D100. Oh, yeah, baby, aren?t this fun?

 

As for the test images, shot 25 ft from tripod mounted camera, all settings same with following exception:

 

Shot 1: D100 display 1/800 sec @ f/22 Manual mode

Shot 2: D100 display 1/2000 sec @ f/4.8 Manual mode

Shot 3: D100 display 1/800 sec @ f/8 Shutter priority

 

 

Silly me. Results show camera shot all three with same aperture opening, f/22. Only changes were the shutter speeds. And, CPU not calibrated to this lens evidently caused selection of wrong shutter speed when using Shutter Priority. Nikon View thinks they were shot at 50mm. OK, fine. It?s a learning experience.

 

Well, this brings me back to square one. I?m thinking I had more options without the CPU. Obvious next key step would be to do what Bjorn and Vivek suggest??..

 

?Find the position corresponding to the max. aperture on the lens you are doing a chip upgrade on, and then cut the print at that position. Then, using a small piece of wire and solder, make a permanent short-circuit to connect the relevant lanes.?

 

Ignoring the ?cut print at that position,? (lets not go there again) part, so?.. you say I should find out where on the chip/tape it thinks F/4 is. And exactly HOW is that found again? Bjorn? Vivek? Ro Ro?

 

Guys, when I put the mount with chip attached (sans lens) onto camera and the tape is dangling out there, and used a small piece of wire to bridge contacts, I get no subsequent reactions in the camera display. By the way, have found this trick alone is a finger exercise that would challenge the dexterity of a Russian acrobat.