Filter for FD 300/4?

I have recently acquired a canon fdn 300/4 lens. This lens has a small

compartment near the camera end where one can insert different filters

of a special mount. However, I have been known to fumble with things

in the past, so I wanted to buy a filter to the business end to

protect the glass. I measured the opening, which has threads, and

determined it must be 82mm. Then I bought a second hand 82mm filter,

and well, it's about 1-2mm too big for the lens. Researching further,

I notice that mir.com.my says the lens has a "C-84" cap. However, I am

unable to locate a 84mm filter for sale. What gives?

Well now that I have just posted this, of course I realize that I confused things, 84mm would definitely not be the right size, as even the 82mm is too big. So probably the 84 refers to the lens cover size. However, I'm pretty sure 77mm, the closest smaller standard size, would be too small. So still, does anyone have further info on this?

The front thread is a non standard 80 mm. I don't believe anyone makes filters in this size.

 

Cheers,

Well then, any other tips, besides being really careful, to protect the lens from damage?

 

Also, is there any fd lens which would take this filter I now have sitting around? It seems that canon is not making one.

The front element on the 300 f4 is a protective element. Along with the lens hood, it provides built in protection for the lens.

 

The question I have is, how would you use a polarizer with such a beast?

The Canon new-FD 300mm f/4 has a 34mm drop-in filter. The front is threaded with a 78.5mm thread. Tiffen made an adapter engraved with the words "78.5mm-to-Series 9". This will allow the use of series 9 filters but the adapter blocks the sliding hood. The Canon FD 300mm f/4.0L lens takes internal filters only and has no provision for a screw in filter. Early breech lock lenses also used a 77mm filter, but that's more trivia.

Before you surrender,maybe e mail company "Heliopan," German,makers of odd size filters,- if THEY say nein,alles ist kaput, and you can then seek a machine shop or a telescopist.Or use Saran wrap or a plexiglas ring in a telescope dewcap sleeve lined with felt to slide on tube,---failure is *not* an option"..GS,filterless most of the time, polarizer goes in the slot to save cost of humungus sizes btw.

The front element on the 300mm f/4.0 is NOT a protective element. You can verify this on the mir site. To see an example of a Canon lens that does have a protective front element, see the 500 f/4.5L on the same site. The protective elements are always rendered as non-curved surface elements in the diagrams. You will note that the 300 f/4.0 front element is an actual curved lens.<br><br>

 

That said, I owned the 300mm f/4.0 for 25 years and sold it last year with no damage to the front element at all. I also own the 500 4.5L and haven't damaged it either. Simply use special care with expensive equipment and you will be rewarded with long service life.

<br>

Back on Sept. 4 I wrote Tiffen to ask several questions about this. Read their responce to get some ideas that work for either the 300 f/4 or the 300 f/4L. to let you know what I asked here's my letter;

 

The Canon new-FD 300mm f/4 uses an exclusive 34mm drop-in filter which are very hard to find. The front of the lens is threaded with a 78.5mm thread. Tiffen made an adapter engraved with the words "78.5mm-to-Series 9". Because the lens is so old I initially thought to look for it used. As you can imagine I had no success. Is this something that Tiffen might still sell? Also, does Tiffen sell glass filters, with no thread mount or ring, in 34mm that I might be able to install in one of my drop-in filter holders? It seems that 37mm is the closest I've found in your catalog. Thank you.

 

Their e-mail to me; The 78.5 to series 9 ring has been discontinued for many years. We still make slip on to series 9 rings. Measure the O.D. of the lens barrel. We make an 80SSLR9, 83SSLR9, and 85SSLR9 (80, 83, and 85mm diameter) to slip on the end of the lens and we still make series 9 filters. We do not make anything in 34m diameter. The glass in the 37m filter is 34.9mm in diameter. We can suggest having someone edge down this glass to fit the holder.

 

Thank you, Tiffen Customer Service

 

I measured the drop in filter as accurately as I could without precision tools and came up with 34.925mm after an inch to metric conversion. Maybe these 37mm filters Tiffen sells are what we all been looking for. CAN SOMEONE WHO HAS THE PROPER INSTRUMENTS MEASURE THE FILTER OUTSIDE ITS HOLDER AND LET US KNOW (I know Mark Wahlster does, I hope he reads this). I have the five Canon filters but I sure would like to get more filters Canon never offered like warming, polarizer, 80A etc. Having a 52mm ground down costs as much as the filter too.

<p><strong>My solution to Filter Problems for the Canon FDn 300mm f/4 Lens </strong><br />Rodney M Letts. rodletts@gmail.com</p>

<p><br /> This is a great telephoto lens to use with mirrorless cameras. It weighs under 1000grams, uses rear earth glass and is sharp as a tack. The effective focal length when used with an APS-C sensor camera gives it a crop factor of 1.5 and hence an effective focal length of 450mm. The lens comes with a detachable tripod mount. It is fast enough to use handheld with care and makes a great telephoto lens to use at night if you bump the ISO up a few stops to around 800 or so, most decent digital cameras have low noise sensor performance well beyond 800 ISO.<br /> You can still get hold of this lens in mint condition for around $250 on ebay but as always, expect to pay a lot more for the L version.<br /> <strong><em>OK now for the bad news:</em></strong><br /> This lens uses 34mm diameter exclusive filters and usually comes with the X1 (clear) filter, these filters are difficult to get and are expensive, just to make matters worse Canon designed the front filter thread to be 78.5mm which is non-standard and now impossible to get any filters of this size or even step-up or step-down rings to interface with it.<br /> <strong><em>My solution to the problem:</em></strong><br /> I wanted to use all sorts of add on filters and supplementary close-up lenses and started to look into machining up a suitable adapter, after drawing up a few mechanical drawings it soon became apparent that this was going to be a fiddly job and it looked like I might get 90% through it and have a disaster with the rather delicate machining operation and perhaps finish up with a crumpled mess; so I put it on the back burner.<br /> Just by chance I needed to buy some lens hoods for a few of my other Canon lenses and concluded that the rubbery ones on ebay were the best value for money, as the original Canon FD ones were way overpriced. Finally the lens hoods arrived and looking at the 77mm diameter one I noticed that the metal ring had both a male thread that normally screws to the lens you want to use it on but it had a female thread on the other side of the ring. Between these threads was a shoulder that measured 79.7mm diameter. Hmm the light went on, if the 77mm male thread was just undersize to fit my 300mm lens, perhaps I could turn the ring down so that it was a snug fit leaving the 77mm female thread facing out from the lens so that standard 77mm diameter filters could be screwed on as required. Carefully machining the 79.7mm diameter down to 77.40mm produced a neat fit into my 300mm lens and still allowed the built in lens cap and hood to work as the adapter OD is smaller than the ID of the cap or hood. I used a few drops of Loctite 406 Superbond to permanently fix it in place on my lens. Cheaper Ethyl cyanoacrylate instant adhesives are available but I use this one because it works really well and is worth the extra $s. Don’t get it on your fingers or on the lens glass, you only need several small drops on the ring before gently pushing in place and make sure you get it on straight. Try the ring for fit prior to putting the adhesive onto the ring because once it’s in place that’s it. If everything goes to plan its ready to use straight away. Check that the lens hood slides over the adapter, it should even with a 77mm filter screwed onto the front of the lens.<br /> If you don’t have a lathe, I may be able to supply these rings already machined to size at a small cost plus postage if there is enough interest. You supply your own instant adhesive.<br /> My total cost was $28 and could have saved about $20 if I had used a lower cost adhesive.<br /> 77mm Rubber lens hood $4, Loctite 406 $23.86<br /> Setting up the lathe and measurement time etc. was about 15 minutes.</p>

<p>FYI, Canon also made a 34mm drop-in gel holder for those of you who want to use filters other than the 5~6 standard drop ins. These standard filters also include a circurlar polarizer 34mm drop in filter. But I don't think it will be easy to find either. I bought a 400mm that came with the gel holder instead of the plain glass filter. Luckily, I was able to find a drop-in plain filter. I think I bought it at KEH.</p>

<p>Thanks for the input Steven, as I have a range of 77mm filters ie CPL ND etc I can now use these easily with this lens. This should keep me going until I might be able to afford a 2.8L version and that will be quite some time away.<br>

best regards Rodney </p>

<p>Interesting approach on that adapter, good work.</p>

<p>As an aside, even if filters were available for the size of the Canon 300/4.0's, I don't believe the inside of the hood is actually threaded to "screw" anything into...I believe what appear to be "threads" at first glance are nothing more than concentric "light baffle lines" inside</p>

<p>The FDn 300/4.0L (black "bay" mount) <em>does not</em> have threads in the front. Looking at the one I purchased (back in '05) it's clear the front element is held in place with a lens "fastening ring", which has two slots for a ring removal tool. The ring does have very small, light baffle grooves. Incidentally, when I was shopping for this lens I found one in great condition with three drop-in filters - clear, red and yellow. Wish Canon made a drop-in pol filter for this lens. But apparently they didn't.</p>

<p>I have some Canon FD 300/4.0 and 400/4.5 lenses that all use the 34mm drop-in filters, and as near impossible as they are to find, when I saw a like new UV-1X drop-in on KEH, I snapped it up...if / when I ever start winding down this hobby, figured I can always re-sell it.</p>

<p>I recently acquired a FD 300mm f4 and Rodney's filter fix sounds interesting. I just purchased a "cheapy" Vivitar 77mm 3 filter set and I'm thinking another option would be to carefully wrap the filter threads with masking tape and do a friction mount. It probably wouldn't provide much front element protection (since the filter could fall out at any moment) but it would make it possible to quickly attach a filter when you need it for a shot.</p>