Mirror lenses!

woodrim wrote: Snegren wrote: I tried hand held shooting with the Mino AF 500 at 1/320 shutter speed and the movement the IBIS causes on the sensor is such that the image goes extremely wonky. This is in silent mode, perhaps that matters. Any opinions on this? Tripod works much better, naturally. No complaints on sharpness on these images that were taken over great distance, even as they were taken on my 'travel 3-pod. Amazing lens, focusing a bit nervous on the LA-EA5, another thing the tripod solves..... Paul: I do the vast amount of my mirror shooting handheld. I do use a monopod with bigger and heavier lenses. I have noticed some wonkiness when in portrait orientation but not landscape. I stopped using silent more or front shutter-whatever after finding that I was getting dark bands when using high shutter speeds. The birds have gotten used to me and are now not frightened by the shutter clank. I did briefly use my AF Reflex this past Sunday with the LA-EA4 and suspect I must again check the micro-adjust. I'm not perfectly happy with the focus accuracy. I have not yet checked but wonder if the camera lost the setting I had in it. The last I saw, the LA-EA5 did not support the Reflex on my A7II. I may have to do the MonsterAdapter modification.

So the wonkyness is because of silent shutter. It makes sense.

The LA-EA5 requires latest generation cameras like A7RM4. Even on A7M3 it doesn't work. It's either a new camera or a Monster Mike!

For me too it will be just for that lens.

Paul: I did not say the wonkiness was from silent shutter. The silent shutter results in dark banding at the top of the image when shooting fast shutter speeds. The wonkiness as I understand it is a wiggling, nervous image in the viewfinder when in portrait orientation and it happens to me in loud shutter mode too.

"Foggy winter morning"

a7RIVa + Minolta MD 250/5.6 RF Rokkor

Snegren wrote: I mean wonki as in distorted lines in the image, not in the viewfinder. Perhaps I have to produce a sample to illustrate. Hardly ever had a problem with black bands but that is probably because here we generally have a shortage of light while you have an abundance.

Paul, in the silent mode you're limited by the readout speed of the succesive lines of sensor, which is quite long vs. the actual shutter speed. So if you move your camera slightly during the exposure the subject moves slightly and straight edges become wavy or wonky. The total readout readout time of the A7Riv sensor in silent mode is 1/10th of a second uncompressed and 1/20th of a second compressed. The Riii series models are slightly faster but the Rii series even slower. So especially with a long lens you will see the effect of a slight camera movement during this 1/10th or 1/20th of a second. The A9 and A1 are the only ones with a much faster readout speed (< 1/100th sec)

And the black lines people talk about with the silent shutter you only get with electric lamp light when you see the effect of the 50 cycles alternating current. Sunlight is continuous enough not to see this effect

Edited by pegelli - 11 January 2022 at 21:25

Thanks for the earlier remarks about dealing with the baffle on the Vectis 400. I had asked because I had looked at the rear of my lens and inspected the baffle, (look away now) put my finger in and the baffle came out with the smallest of tugs. I put it back in but now the manual focus appears not to work, with the lens apparently fixed on infinity.

I'll study the link Woodrim posted, but I'm not confident about making the contacts connect again.

Good while it lasted, but I was planning using it with my S1 at one point.

Ho hum; back to the AF 500.

Well, I did say 'look away now'!

Snegren wrote: It appears the Rubinar MC 4.5/300 contains a 1.3x teleconverter in its optical scheme that can be removed (don't know how) to obtain a 3.5/230 Mirror lens with some vignetting on FF. Neat, right. Not that I'm going to try it, the MC Rubinar's go for like 600 Euro.

Interesting. I have a f5.6 300mm Paragon mirror lens which is quite sharp.