Originally posted by rawr That's awesome, esp given the 5.67 crop factor of the Q.
Now I can turn my 50mm FA f1.4 into a 283mm f1.4.
Or turn something modest like a M 200 f4 into a 1130mm lens.
Potentially a lot of fun to be had with this.
Or in APS-C terms, is the crop factor even greater - at 8.5? Wow.
Hi rawr,
I believe that the Q's crop factor is 5.53x, and since this gives you 35mm EQ as does the Pentax DSLR's crop factor, in APS-C terms, you'd need to divide by the DSLR's factor to get an equivalent for them. The crop factor which gives you the equivalent actual FL on an APS-C camera for a lens on the K mount lens on a Q is 3.61x. Thus a 100mm lens would be the FOV equivalent of 553mm on a 35mm camera and a 361mm lens on a 1.53x crop sensor camera like the Pentax DSLRs.
To make things more confusing, if you shoot macro, with the same lens on a Q compared to, say the K-5, at Minimum Focusing Distance, The magnification ratio stays at 1:1, but the magnification factor grows as the sensor gets smaller. The same lens on a 36x24 sensored camera would reproduce a 36mm long subject at lifesize on the sensor. On a K-5, it would be a 23.4mm subject, and on a Q, it would be a 6.17mm subject. So effectively, the Q has about a 3.8x magnification advantage over an APS-C DSLR when shooting macro. Of course, DOF would be the same for all three at MFD since it's the same lens, but with the magnification difference, you could shoot a Q at a greater working distance to get the same frame fill as you'd get with APS-C, so you'd get greater DOF with the additional distance at a given Av.
Scott