Focus Test - ZM 21/2.8 R-D1 (soft) versus Ricoh GXR (sharp)?

[rollbahn]

I'm new to rangefinders but have been shooting for about 25 years. I currently have a Ricoh GXR M Mount and just bought a RD-1 as I wanted a cheaper way to try the rangefinder system before a Leica M8.

I was taking some shots out the back window to try my new R-D1 and I noticed how soft the shots were and how the focus was off so I did a test against my GXR.

These were shot a f8 (ISO 200) and because the two cameras meter quite differently I tried to get them as close as I could but the shutter speeds are different but I got similar exposure on each.

Center

Left

For focus I turned to infinity so that the focus was exactly the same for each camera. I just pointed both cameras and took the picture. The white house is about 100 feet from me.

As you can see the GXR is much sharper and that's at 70% view to match the size. At 100% the white house is sharp as glass on the GXR but the R-D1 is softer.

So my long winded question - is there anything wrong with my R-D1? I can't see how pointing and shooting at infinity on both cameras would give a different result unless there is something wrong. Even if the rangefinder focus is off (which it seems to be at infinity - never lines up) that is only applicable when I use the rangefinder to focus, which in this case I didn;t - I just set the focus and shot.

I know the R-D1 sensor will not be up to the GXR in detail (6 versus 12MP) but the image should be sharp. The shots I have taken indoors on my ZM 35/2 are really sharp on the R-D1.

As I bought the ZM 21/2.8 second hand also I am not sure if there are focus issues there too?

Any help would be great - I really want to love this R-D1 and I am enjoying the rangefinder way of focussing - simple and fast.

Thanks

 

[segedi]

I've not used an RD-1 but might have some answers...

Wide angles can cause fits with digital but the GXR has two things going for it. Micro lenses on the sensor to bring better performance, especially to off center areas of the frame and no antialiasing filter. I'm not sure, but I'm betting there is an AA filter on the rd1 sensor which makes all images softer than the GXRs.

While softer, I don't find the rd1 images to be overly soft. And based on your saying that the 35mm images were sharp, I'm betting they weren't taken at infinity. I'd try two things, take another set of images not at infinity and also a set where you back the 21mm off just a fraction before you hit infinity.

Good luck!

 

[rollbahn]

Thanks for the quick answer.

Agreed about the AA filter although the Epson shot looks off focus to me and not just the result of the normal AA filter soft. Trying just in front of infinity is worth a go.

 

[DamenS]

Thanks for the quick answer.

Agreed about the AA filter although the Epson shot looks off focus to me and not just the result of the normal AA filter soft. Trying just in front of infinity is worth a go.

It's not just the AA filter though - as the previous poster mentioned the offset micro-lenses in front of the GXR sensor (specially designed for wide-angle M lenses and similar to those used on Leica's digital M cameras) help to reduce the softness and colour aberrations which occur at the edges/corners of the frame when a (non-telecentric) wideangle M lens is used. Try taking a crop from the centre and see if the same problem exists.

 

[rollbahn]

Thanks I was aware of both the offset micro-lenses and AA filter differences but it doesn't look like that to me eye. The lens was a 35mm ZM so I wouldn't consider that wide-angle either. The top shots are from the centre of the image also.

I definitely have experienced all the issues with wide-angle M lenses on other cameras (X-Pro1, NEX 5N etc) so that wouldn't be unexpected here but not at 35mm (50mm equiv.)

Thanks for all of your help - I'll keep testing and maybe look at getting the lenses serviced to make sure all is spot on, which I am sure they are as the GXR work great with them.