Rolleiflex, Close Focusing, What to over expose by

I have a Rolleiflex 2.8F Carl Zeiss Planar TLR. To date i normally focus at infinity or close to infinity.

I just shot a role where I was trying to focus as close as the camera would let me which meant that the front of the camera was fully extended increasing the lens to film distance

I just developed my negs and the shots that were exposed with focusing close to infinity are correctly exposed. The shots that where taken focused as close as possible are under exposed by about 1 to 2 stops I am guessing.

I metered with an incident meter so I am sure the meter reading was correct. No filters on the lens

My question is, I am presuming I do need to over expose the negs when close focusing. Does anyone know the exact amount of exposure I am supposed to over expose by for this camera?

Any help would be great...

M

What is the close focus limit of the thing?

At 0,9 m/3 ft, the compensation required is not even 0.3 stops.
So i would believe that the cause for the underexposure (by 1 to 2 stops) is not the extension.

No way can a Rollei TLR underexpose because of close focus. It just plain doesn't have that much extension. Are you by any chance shooting a dark toned subject, which looks underexposed on your neg just because it is a dark subject?

Do you use the diffuser yock on your Rolei meter? Regarding the exposure, the focusing distance is not a measurable factor here...

Thanks for the feed back all,

Q.G.: Don't know the exacts but it focuses down to around 3 ft
eddym: yea only seems to come out by around 12mm or so, so you could be right
milosz: No didn't use the cameras meter, used a hand held Sekonic meter and took an incident reading

I exposed two more roles this afternoon at an outdoor vintage car show focusing as close as I could. I over exposed the negs by a stop to compensate. Will see how they look after i develop them tonight

Thanks again
M

The bellows factor for a typical Rolleiflex with 80mm (3.15") lens at 3 feet (about .25" extension) is less then 1/4 of a stop.

Very strange. Open the camera back and fire the shutter at 1/4 with the camera focused at infinity, and again at 3 ft, and see if the shutter speeds are the same. I don't think the shutter speeds can differ depending on how you focus, but the test above would rule it out.

You could also try with film. Camera on tripod, maybe with a sign or tree in the foreground at 3ft, and a landscape in the background. Focus at infinity and take a shot, and then one at 3ft. Use the same aperture and speed. Develop the film and check the results.

Even incident light reading can be done wrong especially when you are close to the subject. Chances are that you cast a shadow onto the subject while taking the picture which was not there while reading the lightmeter.

Ulrich