Ahh, yea, that's right ! Of course, the whole filmstrip is 35mm, but the actual image area is 24x18mm.

Just out of curiosity, ( I don't mean too hijack this thread ) but is there anyway to calculate what my 50mm lens would turn into, if I use the 24x18 area on my groundglass?

In terms of depth-of-field, nothing changes, 50mm is 50mm, is and always will be, but perspectively, field-of-view becomes narrower so for a similar field-of-view, the 35mm now becomes the "normal" (ballpark only) lens. A 28mm is also near enough.

You don't get the incremental sizes in stills lenses like you can with motion picture lenses. On these wider lenses, f1.4 is ideal, f1.8 adequate but any narrower and you may be more likely to run into a corner falloff (hotspot) problem.

Hi Lau Ho Ming,

I live in HK as well and I am eager to start building my first DIY 35mm adapter. Seems like you are pretty experienced in this area. It would be greatful if you can give me some advice? Even pointing the direction to where I can find the parts in HK would be helpful~ Please contact me via msn: firebird0415@hotmail.com if you have the time to give me a helping hand. Thank you very much!

I can't believe it XD I thought I'm the only Hong Kong dude. I added your MSN.