ro_ro

I started a thread about the matrix chips some months ago here on photo.net. There you find some information. I can post a list of Nikon's US patents in the next days that are about the AF mount.

The pinout is also described in service manual for N50/N70/N90 that can be found on the web.

I stopped my own reseach, becouse my time is limited and prices for even long AF lenses are dropping. D2H is also cheap now.

 

Ro

I think there is something wrong with the sequence control. Maybe batteries got leak an the acid went into the gears.

 

It would help if you take off the bottom an take a picture of the inner part and show it here.

To Richard:

 

Yes, stop down metering should also be simple. Older cameras like FG and FA can meter during automatic stop down just before exposure: instant stop down metering. This is used in 'P' with non AI-S lenses. So even automatic exposure would work without the aperture coupler.

 

Pentax *istD can do stop down metering by pressing the DOF button. This was enabled with a simple firmware upgrade.

 

Nikon could do the same with the D70, but they don't seem to want to.

 

Ro

My D70 has also a tilted viewfinder, but the tilt is not much.

With a exactly adjusted tripod, I get even results.

 

Most of my pictures I take with the D70 are more tilted than the viewfinder is.

 

I think the problem is the small and dim viewfinder.

Hi,

 

while reading the N70 service manual, I found out, how simple the

aperture coupler seems to be. It's just a variable resitor (green in

picture), mountet around the lens mount. The couplings ring (red in

picture) is attached to it.

The aperture values a read by the main cpu by a simple a/d converter.

 

These parts cannot really be expensive and they don't need not much

space. An a/d converter is inside every mondern mcu.

 

Why has Nikon removed these parts from mid-level SLR's and all non-pro

DSLR's?

I think the only reason is, they want us to buy new AF lenses!

 

Same could happen to old AF or even AF-D lenses in near future. Since

they all use different lens protocols, Nikon could just leave out the

parts in their camera firmware an remove this little max aperture

switch from the camera to save costs.

TTL flash could be the same. No flash with non D lenses.

These old AF lenses are then almost useless and we whave to buy new

'G' ones.

 

All new lenses are AFS. This could lead to cameras without AF motor

drive in far future.

 

Nikon should improve their compatibilty with new cameras to show their

customers that old lenses don't get obsolte. The next DSLR (D100

successor) should be able to meter and flash with non AF lenses.

 

Ro

Hi Vivek,

 

nice work, but I have some comments:

 

1. Yes. I chipped a Series E 100mm wich works fine now.

 

2. What mechanical linkage?

 

3. You might get exposure errors if the camera tries to stop down further than the aperture ring is adjusted. I would prefer a non 'G' chip for lenes with aperture ring.

 

4. Focal length shouldn't be that important. The problem is that you used a 'D'istance chip ('G' is also 'D') with no mechanical distance linkage. The flash uses then a wrong power when the distance of object is different from than the chip tells. A non 'D' chip would solve the problem.

 

5. Why not? But DOF with the normal focussing screen isn't really good.

 

Another thing: I hand to adjust the aperture lever inside the lens to get correct apertures. This is easy to check: Set the camera to a known aperture an then press the DOF button an hold it. When you then rotate the aperture ring from 22 to open aperture the blades should start moving when the aperture values match.

 

Ro

Yes it's possible. The problem is to get chips. Damaged lenses are a way to get chips, but you need the right apertures. I started research on making compatible chips. See the thread I posted weeks ago.

 

Problems with metering can occur, if you use matrix metering, because not only the max F-stop is important but also vignetting data also stored in the CPU.

Another thing is a damaged (bend) aperture linkage insinde the lens, when the mod is not done properly.

 

I think Nikon should add a possibilty (special menu) to the D70 to enter lens data if a manual lens is mounted. This data should be stored in an internal database.

'D' chips are different to the old AF ones. Not only the distance information is transmitted, but also values for AF and other compensation values change.

 

This works even on old cameras that use protocol 0x22. Newer cameras that include the 'D' feature use 0x25, 0x27 and 0x28 protocols for the 'D' chip lenses. These newer protocols provide addition information.

 

My opinion is that even on older cameras a 'D' lens can provide better AF and metering.

 

But for an upgrade of old lenses the 'D' isn't important. So only a basic 0x22 protocol used with the first AI-P lenes is needed.

 

 

I got further using a fast AVR instead of a PIC. Clocked at 8MHz the AVR can handle clock speeds of 100kHz, but current consumption is too high (8mA). My old N4004 has problems with mirror and shutter if a chip takes more than 5mA.

The old NEC chips take 1mA and the new AF-D ones take 5mA. Another problem is the missing capacitor on the power pins of the micro. AVRs don't work fine without this capacitor. The chips Nikon uses do.

The old NEC 4-bit line is now obsolete and could not be used for a self-made chip. The new 'D' chip have 48pins are clock at 8MHz and have a Nikon logo, I don't know what's inside.

 

I still haven't found a suiting micro and my time is limeted. For now I stop research on make compatible chips.

If anyone wants to continue my work, please write me an email.

'D' chips could improve AF, even on old cameras. The not only transmit the'D'istance. Improved AF parameters are also transmitted during focussing.

Many thanks for your help. I got further now.

 

I made a first test with a PIC (containing my special emulation software ;) connected to a N4004. The timing diagrams shown in the patent were very helpful, but the datebyte described are different from what I discovered. There are 26byte transferred instead to the 16byte in the patent. It works, the camera tries to AF (I took databytes from an AF lens) with only my PIC attatched.

 

The bad news: Newer Nikons use a high speed clock, so the PIC cant't follow and no real data is transmitted :(

 

The serial port in the NEC chip could handle clock rates of serveral 100kHz. My software serial port could only do 20kHz.

 

ToDo: Get a faster micro or one with a hardware serial port. Case should be SO8 or smaller to be put in lenses with almost no space.

 

I won't post any software or schematics in public to get not in trouble with Nikon. I only tell what can be done to get a working chip. More in next week.

I still don't know what most databyte exacly do, but I gussed aperture and focal length.

to Walter: I disassembled a mechanically defective 35-70 and soldered wires direct to the 180R protection resistors. Extension tubes could maybe also do the job but are more expesnsive than a N4004/N50/N55 with broken shutter oder defective back. I try to get an working AF Nikon with defective shutter and solder wires direct to the inner lens connections.

 

Some on the lens data is decribed in the N90s memory map. (LENS BANK)

http://members.aol.com/khancock/pilot/nbuddy/protocol.html

I think the bytes are the same.

 

To Mike: I should contiue work on old Sigma lenses, the Nikon's databytes may be covered by US copyright. The protocol is standard I think.

Sorry, I forgot the picture

This analyzer software works great ;) I had to use the allowio driver with w2k ('allowio DIGITRACE.EXE' in the command prompt). The buffer was increased to 255000.

 

I build a simple buffer with a 74LS14 to protect the camera (Nikon N4004s)

 

lens --|>o--|>o-- lpt

 

Many byte flying on the lines but slow enough to get cought. The screenshot shows the beginning of transfer.

 

I'm busy the next days but will try to figure more out next week. The datasheet schuld tell about the bitorder.

 

Perhaps someone else who likes experiments could try the same.

The UPD7554A seems to be compatible.

 

A good datasheet can be downloaded here:

 

http://www.alldatasheet.com/datasheet-pdf/pdf/NEC/UPD7554A.html

Does anyone have detailed information about the lens protocol used in

old Nikkor AF and AI-P lenses?

 

I wonder if it should not be impossible to make custom chips by using

a 1$ PIC12C508 or similar. Open source preferred.

 

Why that? Nikon doesn't sell chips to everyone, and they are

expensive. Chips from old lenses don't often fit the apertures of the

manual lens to be upgraded. An MF lens with an AF chip makes the

Camera try to AF, not so good. Even if you find a chip with suiting

apertures, the focal length is different.

 

 

Thats what I found out myself:

 

The names of the lens contacts could be found in some old service

manuals that can be download on the internet. Search for 'n90.pdf'

with google.

 

I recently dissassembled an old Nikkor 35-70/3.3-4.5 to see whats

inside. The only important thing is a NEC uPD7554G577. The datasheet

was hard to find, but I now have one, which I could mail to anyone

who's interested.

 

The NEC CPU is an old and slow 4-bit one, so the protocol can't be

that complicated.

 

I drew a sipmle schematic to show the connections.

 

But I don't have a logic-analyzer to figure out what data is

transmitted. Could anyone help?

My 18-70DX works fine on a N65. You only get a circluar image. For slides this is not so useful, but with B/W film an self enlagement a DX lens could be used, especially with square paper.

Metacam is an opensource EXIF viewer for Linux.

http://www.cheeseplant.org/~daniel/pages/metacam.html

 

All EXIF Viewer I known don't tell about 'D'istance and Lens ID.

 

It would also be helpful to get jpg that contain the infos. Black images (leave the cap on and use 'M' with 1/100s) in lowest quality would be fine. My pictures were then smaller than 50kB.

 

Ro

Hi,

<p>

I found out, that the Tag [0x98-7] in Nikon's maker info contains

interesting information about the lens attatched.

</p><p>

The Tag could be read out by using Metacam 1.1 with '-a' option.

</p><p>

'metacam -a image.jpg' will show all info and [0x98-7] is about the

lens:<br>

<br>

50mm f1.8D<br>

-----------------------------<br>

[0x98-7]: 30 31 30 31 25 13 08 03 01 85 50 76 58 50 50 14 14 7A 14

17 42 33 43 06 00 00 00 00 00 02 02<br>

-----------------------------<br>

<br>

85 is the coded distance information code for a 'D' lens<br>

76 is the lens ID<br>

7A is the chip ID<br>

other byte contain aperture an focal length<br>

</p><p>

coding is similar to N90s data described here:

http://members.aol.com/khancock/pilot/nbuddy/protocol.html

</p><p>

I'm intereded in making a list of AF-Nikkors sorted by the Lens ID.

Could anyone here post some of the [0x98-7] tags and the lens used?

This would also help to figure out the other info in this tag.

</p>

Greets, <br>

Ro