red line for 600F4 Takumar

[douglas_fisher]

when I shoot with my 600F4 wide open, I find that I get a slight red outline in high contrast ereas. My Pentax dealer said that one of the elements could be out of whack, but my camera mechanic said it was rectalinear propagation and said this was a flaw of the lens and was uncorrectable. When i stop down 2 or more stops it goes away.

Also somebody in an earlier posting said thatthey were shooting surfers with the 600 on 6x7.

Good luck!!!

I find it difficult to get sharp images even when using a big Bembo on the lens , a monopod on the body,magnifiers on the prism or waist levelor chimney, mirror lock,and 5 ton truck to block wind.

Has anyone got a really professional quality sharp trans wide open on the 600f4?

regards-Douglas Fisher-Auckland N.Z.

I hear the 400 if ed is good wide open, even if your wallet is empty.

rega

[michael_mahoney]

Your experience with the 600 F/4 is similiar to mine with my 400 F/4.

I beleive both lenses are Takumars of an older design. I don't experience your "red line" problem, but it took me a while to figure out that my 400 gave its best performance around F11 to F16, and that it needs to be well supported, and sheilded from wind. Also avoid shutter speeds around 1/8. Used carefully, this lens is quite sharp.

Steve R. may be able to offer additional help if he reads your post.

Good Luck.

[steve_rasmussen]

Douglas: I've had the color fringing also and it has not only been at f/4 but at several other stops when there is extreme contrast in the shot. At first I thought it was lateral chromatic aberration but this is quite easy to eliminate when designing a telephoto. Longitudinal chromatic is another story. After reading some info from Rodenstock and Schneider I am convinced that the problem is in fact longitudinal chromatic. So, what we have is a design flaw. What you're seeing is secondary spectrum(colors that are not foccusing at the film plane). Please be aware that all long focus lenses will have some secondary spectrum; it's just a matter of degree. To improve this lens would cost a fortune and I for one would not be able to buy it.

This lens is very soft at the edges of a fine grain transparency when shot at f/4(probably due to coma, astigmatism and spherochromatism). Try f/8 through f/45. It works for me. I feel its sharpest stop is f/22. You must use two tripods for best results. The tripod plus monopod still allows the shutter harmonic to move the system. When using two tripods, it is best to put some weight(yours)on the rear tripod. This lens is as sharp as my 105 when set up properly. SR

[gregory_rogalsky1]

I used to own a 800 f4 pentax. I feel your pain. The best solution to get sharp photos is sell your lens to some one else and get a 300 F 2.8 L . . Really , super telephoto photography in Medium format is a waste of time. As far as I can tell the problem is that damn mirror even at 1000 of a sec, and huge tripod. If you want sharp super tele shots get a 35mm

[davidgarth]

I don't agree with the blanket condemnation of long telephotos with medium format.

 

I have had really good results with the Pentax A* 600mm f5.6 for the Pentax 645. It has ED glass and is quite sharp when used with a Gitzo 1548 carbon fibre tripod.

[roy_l._jacobs]

I have the 400 EDIF and it is very sharp wide open and thereafter. I have used it on a Gitzo 320 with the NPC QR head. I use a Bogen accessory support from the camera to the tripod. The images ar sharp down to about 1/125 of a second with the moirror locked. Next I am going to try two tripods. There is a shutter shake which compromises image quality at slow shutter speeds. The lens quality is great. The 400 is often available on Ebay for less than half of new. Get it there. (Arrange with the seller that the auction is contingent on a 14 day return privlege to test the lens. I have done this a number of times with no problem. Have yet to return anything.)