anthony_bez Posted February 18, 2009 Share Posted February 18, 2009 <p>I blame Bjorn Rorslett for having to ask this question :-)<br> He has encouraged me to buy a early Nikkor O 35mm f2. From the photograph it looks like it has been AI converted.<br> Can you confirm it is safe for use on my D300.</p><div></div> Link to comment Share on other sites More sharing options...
ronald_moravec1 Posted February 18, 2009 Share Posted February 18, 2009 <p>Run your finger around the black surround to the chrome mount. If you feel a 2/3mm step, that is designed to clear the tab on the thin metal ring around the lens mount. You can find the tab around 1:00 as you look at the mount. You can move it slightly by hand and the AI step is made to move it.</p> Link to comment Share on other sites More sharing options...
james_lai Posted February 18, 2009 Share Posted February 18, 2009 <p>It doesn't appear to be AI converted. The back edge of the aperture ring is flat all the way around, a converted lens would have a step as Ronald said.</p> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 18, 2009 Author Share Posted February 18, 2009 <p>Thank you for the replies.<br> I was looking at the slot cut into the mount, thinking that was the conversion.</p> Link to comment Share on other sites More sharing options...
ShunCheung Posted February 18, 2009 Share Posted February 18, 2009 <p>If you would like to get a 35mm lens for your D300, there is a slightly newer version (by 30+ years) that is f1.8 and costs less than $200. Maybe it is just me, but the AF-S version seems to be the much simplier answer.</p> Link to comment Share on other sites More sharing options...
ronald_moravec1 Posted February 18, 2009 Share Posted February 18, 2009 <p><a href="http://www.aiconversions.com/">http://www.aiconversions.com/</a></p> <p>He has a good reputation.</p> <p>But if you can afford it, the new 35 1.8 DX AFS auto focus and all. Killer I bet.</p> Link to comment Share on other sites More sharing options...
ronald_moravec1 Posted February 18, 2009 Share Posted February 18, 2009 <p><a href="http://www.aiconversions.com/">http://www.aiconversions.com/</a></p> <p>He has a good reputation.</p> <p>But if you can afford it, the new 35 1.8 DX AFS auto focus and all. Killer I bet.</p> Link to comment Share on other sites More sharing options...
ronald_moravec1 Posted February 18, 2009 Share Posted February 18, 2009 <p>Can I add if the black does not hang over and interfer with the tab, you can manual focus and stop down meter.</p> <p>Check with a thin cardboard feelerto be sure ther is no interference. Some lenses work, others not.</p> Link to comment Share on other sites More sharing options...
peter Posted February 18, 2009 Share Posted February 18, 2009 <p>I have excatly this lens in an AI converted form which I do use on my D200 from time to time and it both works fine and produces fine shots with the obvious slight issue that the cropping factor turns this into a 50mm lens (in appearance with regard to the results that is).<br />There are a few sites on the web which give info in AI conversion - including how to do it yourself if you are so inclined. The mechanical skills involved are trivial (filing or milling a few millimeters of aluminium.) The two slightly more difficult issues are (a) correctly determining the location of the "step- down" to be cut in the ring and (b) getting the ring off and back on again - on some lenses this can be a little tricky and requires some finesse and luck. The web sites I mentioned will explain the former. The latter requires some experimentation as some lenses are easy, some more difficult until you work out the "knack".<br> PS If you search on ebay the conversion "kits" (essentially just the AI compliant aperture ring) turn up from time to time and can be bought for about twenty five bucks. I have bought one and converted the 50mm f2 of this vintage.</p> Link to comment Share on other sites More sharing options...
blumesan Posted February 18, 2009 Share Posted February 18, 2009 <p>I believe the latest 35mm is an F/1.8 AF-S DX G type and probably goes for a bit more than $200. Perhaps Shun is thinking of the F/2.0 AF D which has the benefit of an aperture ring and is an FX type.</p> <p>It is interesting that Bjorn has not bothered to review either of these lenses.</p> <p>I use a 35mm/2.0 AI on my D200 and am very pleased with the results.</p> <p>Anthony-- your lens is definitely not AI converted, but for around $30 that conversion can be done. Go to <a href="http://www.aiconversions.com">this site</a>.</p> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 18, 2009 Share Posted February 18, 2009 <p>Definitely not AI converted. Although it is a bit hard to tell with the angle and lighting, it would appear that the aperture ring skirt extends beyond the rear surface of the mount on this one. If so, it will surely jam on the AI indexing tab of your D300, and should not be mounted.</p> <blockquote> <p>I was looking at the slot cut into the mount, thinking that was the conversion.</p> </blockquote> <p>That is the slot for the bayonet lock pin. All Nikkors, from 1959 to 2009, have this slot. The photo below (from John Whites aiconversions.com site) shows what a typical non-factory AI conversion looks like. Note the step cut into the rear skirt of the aperture ring.</p><div></div> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 18, 2009 Author Share Posted February 18, 2009 <p>Thank you everyone!<br />I will most likely purchase the new f1.8 when it is available.<br />This was a £50 impulse purchase, as I mistakenly thought it was AI converted. I have a shoot which I need a 35mm for, and the new lens is not available yet. I am still happy with the purchase, as the lens has just been professionally cleaned and lubed.<br />The reason I blame Bjorn Rorslett, is because he owns an early O model and considers it the best. He also says the AFD f2 is a simpler lesser design to the manual versions. <a href="http://www.naturfotograf.com/lens_wide.html">http://www.naturfotograf.com/lens_wide.html</a><br />If I understand correctly the conversion just needs to create a slot for the camera tab. If I attempt it myself the skill is aligning the slot so the camera gives the exposure meter the correct information?</p> Link to comment Share on other sites More sharing options...
JDMvW Posted February 19, 2009 Share Posted February 19, 2009 <p>John White has been doing the AI conversion right back to the days of the change over. His prices seem very reasonable to me, and low enough that I wouldn't try myself to do this.</p> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 19, 2009 Author Share Posted February 19, 2009 <p>JDM, Yes he has very reasonable charges for the conversion, but postage costs from England to America are prohibitive.<br> Also I need the lens for a shoot next week, so I think I will try to do it myself.</p> Link to comment Share on other sites More sharing options...
steve_king5 Posted February 19, 2009 Share Posted February 19, 2009 <p>I might as well use this opportunity to shill a lens I'll probably put on eBay. It's a 35mm Nikkor-O model f2 that John White did the conversion on a few weeks ago. Lens is in terrific condition, with a tiny amount of dust and a speck smaller than a grain of salt floating around inside.</p> <p>$60 U.S. plus actual shipping? Might as well put a dent in the cost of the new AF-S 35mm DX! :)</p> <p> </p><div></div> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 19, 2009 Share Posted February 19, 2009 <blockquote> <p>If I understand correctly the conversion just needs to create a slot for the camera tab. If I attempt it myself the skill is aligning the slot so the camera gives the exposure meter the correct information?</p> </blockquote> <p>Yes, you need to create a slot for the AI tab. Getting the start point of the slot (AI indexing ridge) correct is critical to accurate metering. How long the slot is really isn't that important as long as it is long enough to clear the tab when the lens is mounted.</p> <p>I have included a photo of another f/2 lens which shows the proper location of the AI ridge. If you set the aperture ring to f/11, the start of the ridge lines up with the end of the bayonet lug. If you clear away the material from that point to the small lug on the right (EE post), you will be able to safely mount the lens on a D300.</p> <p>This page may also be useful: http://www.zi.ku.dk/personal/lhhansen/photo/mcr.htm</p> <p>Caveat emptor, and good luck should you attempt this yourself.</p> <p>Oh, and just to be clear, the aperture ring needs to be removed from the lens to cut the ridge.</p> <p>A larger version of the photo below is here:<br> http://www.photo.net/photo/8621061&size=lg</p><div></div> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 19, 2009 Author Share Posted February 19, 2009 <p>Michael, Very informative photograph... Cheers!</p> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 19, 2009 Share Posted February 19, 2009 <p>The AI indexing "offset" is 4-2/3 stops, so the ridge needs to start 2/3 stop from f/8, which pretty much aligns it right along the edge of the "11". That will get you within 1/6 stop.</p> <p>Incidentally, if you set the lens to minimum aperture (f/16 in this case) the small EE post always lines up exactly centered with the mount screw on AI/AIS lenses (at least those with three mount screws).</p> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 19, 2009 Author Share Posted February 19, 2009 <p>This lens has six mount screws, but there is no advantage to reproduce the post for my use is there?</p> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 19, 2009 Share Posted February 19, 2009 <p>No. As long as you remove enough material (90 degrees is plenty) to clear the AI tab when mounting the lens, you don't need to reproduce the EE post.</p> <p>Note that this will only allow safe mounting on D1/D2/D3/D200/D300 and D700 bodies. All others require further machining (John White's "Type B" conversion) to safely clear another switch that is present on D70/D80/D90 and D100 bodies, and consumer film bodies like the F60/F65/F75/F80.</p> Link to comment Share on other sites More sharing options...
steven_p Posted February 19, 2009 Share Posted February 19, 2009 <p>The location of where to modify the aperture ring depends on the maximum aperture of the lens. I have the luxury of an F3 with a fold up prong. I mount the lens with the prong lifted, mark the ring, remove and file.</p> <p>With the lens mounted, whether it is an F2, 3.5, F4 lens etc, the flange of the lens' aperture ring should just meet the metering prong on the camera body.</p> <p>It's not like the uniform location of the "bunny ears" at F5.6</p> <p> </p> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 19, 2009 Share Posted February 19, 2009 <p>The chart from Lars Hansen's page (link in my 11:29am post above) probably sums it up nicely:</p><div></div> Link to comment Share on other sites More sharing options...
kelly_flanigan1 Posted February 19, 2009 Share Posted February 19, 2009 <p>Here on of the 35mm F2's I have was so old Nikon never made an AI kit for it.<br /> It is one of the orphaned Nikkors; thus it was only 30 bucks used.<br /> Nikon published a list of orphaned serial number blocks in the 1970's; it is in the Black Niikkor Nikkormat handbooks revision sheets on subcribed to.<br /> Thus I AI converted it myself back in the late 1970's; back when there were no after market AI conversion folks.<br /> The comment of "good luck if you convert it yourself" is a total riot; thats what many home repair folks and individuals did to orphaned Nikkors; when the after market AI folks were not around yet.</p> <p>The two I have are both Nikkor-O's. Here is a shot at F4 with Ektar 25:</p> <p><img src="http://i4.photobucket.com/albums/y148/ektar/NZT%20dish/ntzdish640.jpg?t=1235088225" alt="" width="640" height="427" /></p> <p>Here the 1960's Nikkor-O 35mm F2 has been used for 16mm cine work too. On a D200 mine works great; it has a slight hotspot when really stopped down alot. Mine is not even a multiicoated lens either. A len hood can reduce flare. The two here are sharp between F8 to F2.8' extremely sharp between F4 to 5.6</p> <p><img src="http://i4.photobucket.com/albums/y148/ektar/NZT%20dish/ntzdishBase640.jpg?t=1235088276" alt="" width="636" height="586" /></p> <p><img src="http://i4.photobucket.com/albums/y148/ektar/NZT%20dish/ntzdishGate640.jpg?t=1235088320" alt="" width="633" height="525" /></p> Link to comment Share on other sites More sharing options...
anthony_bez Posted February 19, 2009 Author Share Posted February 19, 2009 <p>Michael, I realise you gave me the correct cut location for a f2 lens. <br> I only need to make it compatible on my D300. But do you know what extra work is involved to make it suitable for use on D90 and D80 bodies?</p> <p>Kelly, Thank you for the sample images, your experience with the lens concurs with Bjorn Rorslett's. It is a pity performance drops off at f8, but I suppose Nikon designed the lens for optimum results at wide apertures.<br> Now this is a memory tester, do you recall any difficulties dismantleing the parts for the conversion?<br> BTW I wish I had gone with your advise on the old PC lens, I was considering. It passed me by for little money, before I became confident enough to chance buying it.</p> Link to comment Share on other sites More sharing options...
Michael R Freeman Posted February 19, 2009 Share Posted February 19, 2009 <blockquote> <p>But do you know what extra work is involved to make it suitable for use on D90 and D80 bodies?</p> </blockquote> <p>Extra material needs to be removed to clear the EE post detection switch (see photo below). These bodies use the EE post to confirm that the aperture ring on AF-D lenses is correctly set to the minimum f/stop (otherwise you get the "fEE" error message). Obviously on non-CPU lenses the presence of the post doesn't do anything, but the back of the lens aperture ring does need to clear the switch when the lens is mounted and the aperture ring rotated from maximum to minimum f/stop.</p> <p>In the photo of the 50mm f/2 lens above, you would need to remove material from the EE post (at 4 o'clock in the photo) to roughly 7 or 8 o'clock. This is the "Type B" conversion that John White offers.</p><div></div> Link to comment Share on other sites More sharing options...
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