I've opened both pictures in Elements and matched their physical size by zooming in and out,133% and 75% if anything the No-TC version still has a slight edge over the TC version, but only very slightly.

Greg

Hi,
Talking from my perspective, I try to make the subject fill the view finder so as to get the maximum size image on the sensor, obviously by moving nearer or further away. However if I can not get any closer and using the same lens then I must use a converter to get the maximum size image on the sensor.

My interest was in trying to see if the non TC image crop is better than the TC image when viewed at the same physical size on the screen.

Bit convoluted but I hope you understand my meaning
Greg

Hi Ken,

I'm afraid I do not understand, the frosted top surface of the screen is forced up against the base of the prism by the carrier frame, if the surfaces touch or are separated by the spacer how can the thickness prevent it "sitting against the prism" even if the screen was 5mm thick the top frosted surface would still be in the same position relative to the prism as the original screens top frosted surface was. If the frosting was on the bottom of the screen then thickness would have an effect

I do appreciate that the screens position relative to the prism is not relevant to the registration measurement for focusing, the distance to the frosted surface of the screen must be exactly the same as the distance to the sensor surface.

Greg

Hi,

The with TC looks softer to me.

Could you post an example of the "without TC" blown up to the same size as the "with TC" example. That would give a better idea if there was any advantage to using the TC and not just blowing up the original.

Greg

I have never understood why the thickness of the focusing screen has any effect on the focusing accuracy.

As I understand it the focused image is formed on the frosted surface of the screen and this is on the top side of the screen which if fitted with the original spacer between it and the penta chamber will be in exactly the same position as the original screens frosted surface and registration distance.

The only difference which I can see is that a thicker screen will make a slight difference to the pressure which the cradle frame will apply to the bottom of the screen once clipped into position but that will not change the focus registration distance.

Where am I going wrong

Greg

I've been camping in Swaziland for the last four days, I may as well have stayed at home. The weather was miserable, overcast and drizzle the whole period. I had been hoping to take lots of photos of game and birds and saw virtually nothing. I don't know how you tolerate the weather over there.

Greg

I buy Rollmops here and love them, acquired the taste from my Hollander father

Greg

No 1 for me, beautiful pictures.

Greg

Hi,

I'm looking for an Ever Ready Case for my LX, anyone have a spare they want to sell.

Greg

Well someone on this list has bought this item, not me

link

Greg