[Garry Conway]

I've been using the K1 for a year now and am very pleased with it's performance. I have run into an issue with a set of 4 vivitar manual extension tubes and wonder if anyone has a solution.

I've used the tubes often on my K5 and fa*400 lens with good results , however I get heavy vinyetting with the same combination on my K1. The tubes are from the film era so they should work on the K1 in FF.

Also I've tried them with other lenses and get the same results. Which is similar to using a crop lens on full frame.

Any help would be appreciated.
Garry

[pathdoc]

I suspect you're simply going a bridge too far, film-era tubes or no film-era tubes. I had the same issue when I put a deglassed Kalimar 2X teleconverter (roughly equivalent to the longest of a set of three tubes) behind my D-FA 100mm f/2.8WR. At minimum focal distance/maximum reproduction ratio, that combo vignettes very, very badly; I had to go to crop mode.

Add enough extension tubes and sooner or later I reckon anything will vignette. Try progressively shorter focal lengths and note when the problem disappears.

[stevebrot]

Also I've tried them with other lenses and get the same results.

Your FA* 400 is internal focus, which may be the source of the problem. Does it still vignette when set to infinity when used with the tubes? Which other lenses have you tried?


Steve

[Garry Conway]

Your FA* 400 is internal focus, which may be the source of the problem. Does it still vignette when set to infinity when used with the tubes? Which other lenses have you tried?


Steve

Thanks for your reply, as a result I checked one of my much older lenses the smc M 50mm f2 and it works just fine so at least I can get the closeups.

The reason I liked the 400mm with the tubes is I could get the same closeups but with the camera 3 meteres from the subject. A real bonus when shooting insects and other wild life. I did try the 400mm at infinity and it didn't make any difference. The other lenses I tried that were vignetting seem to be ok now so I'm guessing there was a contact issue. However the FA* 400mm still has very dark corners at any setting including infinifty and at any f-stop.

The other lenses that are working (now) are smc A 70-210 f4 (Zoomed to 210) and an FA 28-105 f3.2-4.5 which is also an IF lens.

When I was shooting film I used my MZ-3 and the 400 lens often and got very good results, I also used the combination on my K5, at that time I had a set of kenko auto extension tubes, unfortunately I lost them when I was shooting in a swamp. When I got the Vivitar tubes they didn't initially work on my K5 but someone on the forum had noted this issue and said that if the mounts on the tubes are painted, which they were, it wouldn't work so I sanded the ends to get bare metal and that resolved the problem on the K5.

So I'm still looking for a solution for fa* 400mm lens tube combination but at least I can do the closeup work with the other lenses.

Thanks for your help, you could be right about the Internal Focus on thsi lens.
Garry

[Not a Number]

Try reverse mounting the 400mm on the tubes.

[pathdoc]

Try reverse mounting the 400mm on the tubes.

Reverse mounting, IIRC, loses much of its value beyond about 100mm.

[Not a Number]

Reverse mounting, IIRC, loses much of its value beyond about 100mm.

Nothing to lose by trying except the price of the adapter which can be used with other lenses.

[stevebrot]

Nothing to lose by trying except the price of the adapter which can be used with other lenses.

77mm!!


Steve