Sorry, this isn't correct. You don't multiply your aperture at all. A 50mm f1.7 is still f1.7, and behaves like it.

Because of the focal length multiplier you may consider that the DoF changes, but don't forget that you have to take into account the sma;;er circle of confusion (which is key to the DoF calculation), and is smaller for the APS sensor. The net result is that the DoF is actually very slightly shallower on the APS sensor (not the other way around!).

Check out my replies here: https://www.pentaxuser.com/forum/viewtopic.php?t=1440&start=30
And this online DoF calc: http://www.dofmaster.com/digital_coc.html#coccalculator and http://www.dofmaster.com/dofjs.html

Matt

Haha! Well, technically the focal length cannot change. A 50mm focal length is 50mm. End of story.

But, the angle-of-view is another thing A 50mm will give you the same angle of view as a 75mm would on a 35mm body. This topic has been discussed many times on this forum, but quite simply if you want really wide angle you'll need something like the SMC-DA 16-45mm or the forthcoming SMC-DA 12-24mm.

Conversely, if you want telephoto, then an SMC-FA 80-320mm behaves very well, giving a very telephoto view of around 480mm

Matt

Helen - the Date Back imprints the date and/or time on the image.
Whether that's a useful feature depends on your needs

Hi Thea,
Yes, it's a very friendly forum here with lots of useful bits of information. Welcome aboard!
You certainly can Be aware, though, that since the *ist-DS sensor is smaller than a ful 35mm frame the lenses have a narrower field of view. In practical terms, a 50mm lens will appear to behave like a 75mm on the *ist-DS.
That is useful for sports photography since any telephoto lens behaves "longer". Although I don't take sports photos, I have recently acquired a secondhand Pentax SMC-FA 80-320mm, and used with a monopod (Manfrotto carbon fibre) is surprisingly sharp. You can get the lenses at around £100 in the UK.
Here's a link to the lens specs: http://www.bdimitrov.de/kmp/lenses/zooms/long/FA80-320f4.5-5.6.html

Hope that helps!
Matt

I too have the SMC-FA 24-90. It is not as sharp as the SMC-DA 16-45, but it has a certain quality that I haven't found in any other lens. It's very light, and the 67mm filter is useful, especially as the 16-45 has a 67mm too.

IMHO, it's worth every penny BTW, Ffordes.co.uk have a second hand one available, and Park Cameras have it at a reasonable £299.99.

Matt

There's also the "ZigView" that's worth at least investigating!
http://www.ephotozineshop.com/photo/zigview/zigview.html
That fits the *ist-D with the optional adapter
Matt

According to this link: http://www.bdimitrov.de/kmp/bodies/M/MG.html

The MG takes:
LR44s are very easily obtained, so you shouldn't have any problems at all

Matt

Although getting off topic a bit here... it's worth saying that vinyl masters are not the same as CD masters. Vinyl has to be prepared with a RIAA preamp in mind, and so has to be "tweaked" at the master stage.
The only way to do that test is to compare against the master tape (which is usually digital these days) in the studio
Matt

Looks like some fine results

BTW, I find that Capture One LE does a really, really impressive job of handling the highlights in sunset and sun-in-view images If you can afford the Pro version then that will upsample to 4x as well for some seriously impressive results.

Matt

Buy an ND4 filter or...
one circular polariser and one linear - stack them up and you have variable ND control
Matt