Need some advice

[Aldous Lau]

Ok, I am pretty hesisate on which lense I should be getting. I currently got the 55/2.8 as a kit len and I am thinking to get one more len soon Normally I am into landscape, decor, snap shot or portraits (sometimes), so tele lenses is not my consideration. Any advise whether I should get either 90/2.8 or 150/2.8 in my situation. I don't consider to get any wide angle right now as I will stay with the 35mm for landscape and not the zooms as well
Thanks all

 

[Pete Askew]

How about the 120 Macro? Nice length for portraits and good for the detail shots you like.

 

[Aldous Lau]

How about the 120 Macro? Nice length for portraits and good for the detail shots you like.

Thanks Pete. Never thought the Macro len which can provide the nice length for portraits as I am doing research of it now

 

[Aldous Lau]

One thing it was strange that there is no information of the 120 Macro F2.8 in Pentax roadmap.... I have only got the 100 Macro F2.8 instead....

 

[Pete Askew]

How odd, it's on the diagram. There is a 120 f/4 though.

http://www.ricoh-imaging.co.uk/en/645-mount/smc-FA-645-120mm-F-4-0-macro.html

 

[Aldous Lau]

Right Pete.... I found there is only 120 F4 only very late last night instead of 120 F2.8. I was wondering why the roadmap in this post shown 120 F2.8. The 645D is not very famous in Hong Kong so most of the store doesn't have these lenses, so internet is the only source to get information. Any clue whether 120mm with F4 provide nice DOF pls?

 

[Pete Askew]

I have no experience with this lens but I do have 120mm lenses that cover the same format. Let me have a look at them and get back to you.

 

[Pete Askew]

OK, here are two shots taken with a Zeiss 120 Makro Planar f/4 at f/4 on a Hasselblad 503CW fitted with a PhaseOne P20 back (ISO 100, 1/30s, overhead daylight). This has a 4x4cm sensor and so in terms of width is similar to the Pentax but it has a lower pixel density (16MP - but this won't impact on DoF). The camera was at about 30º to horizontal and so just off perpendicular to the face of the shell. These are files converted to 16 bit TIFF in CaptureOne and processed to JPEGs with no sharpening etc. As you can see, at maximum aperture the DoF is quite narrow and the Pentax should be very similar. No doubt the OOF elements will look a bit different though - this has a classic Zeiss look.

Focused on the face of the shell.

Focussed on the '0'-point of the scale.

The light changed a bit between the shots as it is cloudy today.

The small divisions are about about 3.3 mm.

 

[Aldous Lau]

Thanks Pete and very great sample on the 120 F4. Your Hasslblad with the Phase One back is really poison