A link to a wide range of official and user generated profiles

http://tinyurl.com/5utgavf

Regards -Steve

Ok , we have to be quite sure that we are not confusing lens profiles with camera profiles. Camera profiles are all about matching what you see on the camera screen, with what you see on the computer screen.

Lens profiles are something entirely different and their purpose is to correct recurring problems of under/over exposure, vignetting, CA and distortion, that occur with a specific camera/lens combination.

Lens profiles tend to be camera specific , hence you will see the camera model and lens in the name. If I leave the program in auto detect it will quite often pick a K20D lens profile, as they seem to more available than K10D lens profiles and are possibly the closest match.

Lens profiles are generally created for adjustment of RAW images and that is why there will not be many available, if you are processing a JPG. That said some people have created JPG specific profiles. I am not sure if it is possible to create combo profiles (RAW/JPG), but on my system if I open a JPG with the auto detect option enabled a DA 17-70 is selected.

There are quite a lot of profiles that can now be downloaded from the Adobe website and they have created a free of charge download program for that purpose. There are also lots of user created profiles around , which can easily be found with a google search. Be aware though that not all profiles are created equal and the profiles in the last update were provided by Pentax and as such are my preferred choice.

Regards - Steve

I may be wrong here, but this is my understanding of how CS5 and Lightroom handle camera profiles.

Firstly I too have a long list of profiles here: CrogramDataAdobeCameraRawCameraProfilesCamera

For Pentax cameras the selectable options available on my machine are
Adobe Standard
Camera Standard
Pentax 1.00
Embedded
ACR 3.7
ACR 4.4

Adobe standard is the default profile, and the one that I use most of the time. As I understand it, when I open a RAW image with CameraRaw or Lightroom, the program reads the exif data and loads the camera specific version of Adobe Standard.
So for example if I open a RAW image captured with a K10 CS5 would use this file CrogramDataAdobeCameraRawCameraProfilesCameraPentax K10DPentax K10D Camera Standard.dcp which it would call Adobe Standard

If I were to open a RAW image captured with a K7 then this is the file that CS5 would use CrogramDataAdobeCameraRawCameraProfilesCameraPentax K-7

Take a look when you open a file you should see something like Pentax K10D - IMG6421.PEF at the bottom of the CameraRaw window.

Camera Standard is I believe an interpretation of the customised in camera setting used to display (on camera) and output JPEGs

Pentax 1.00 is a generic profile that was probably created by Pentax, but which I believe not been updated since its relase several years ago.

The ACR profiles are throw backs to earlier versions of CameraRaw and may not be available if you did a clean install.

The Embedded profile I know little about, but assume that when selected it preserves any ICC profile that may have been embedded within the image.

Finally for information purposes only, if you browse the directory of your hard drive you might find several files relating to one particular model. That is because Canon and also Nikon developed multiple profiles for some camera models.

I am sure others will come along to correct any errors, but I hope this explanation provides a general idea of how camra profiles are applied.

Regards - Steve

Focussing screens have tended to get brighter over the years as technology, particularly treatments such as Optibrite have improved.

For example: I believe there is 1 stop difference in metered EV between a Z1 and Z1P screen, when placed in the same camera.

Regards Steve

Hi Bret, this is a relatively easy fix. The replacement part(s) should not be too expensive. I replaced the SR switch on my K10 for less than £10 including postage.

I contacted Johnsons Technical, who sent me a parts list and a schematic. I think I still have it somewhere, if you send me a pm with your email address I will forward it on to you.

A couple of points:

There are essentially 2 types of screw, depending upon whether they tap into metal or plastic.

The rubber thumb grip is secured by double sided tape. There is an access point, that is not stuck down, which allows the grip to be pulled away, revealing another screw.

Once the screws have been removed the parts of the case come apart and you will have access to the switches.

You may find that you need only part of the assembly. I confirmed the part I needed with Lee in Johnsons Technical department and he ordered the part for me over the phone. It is unlikely that they will have the part in stock, but in my case the the SR switch arrived inside 2 weeks.


Regards - Steve

Try this site for lots of Pentax information http://www.bdimitrov.de/kmp/lenses/index.html

The sticking aperture and F stop click are relatively easy fixes. I wonder if Pentax offer a restoration service for the ' big glass' lenses.
Looking forward to seeing some shots.

Regards Steve

Not a budget lens, but I believe that a DA*135-400 F4 would be a good addition.

Regards Steve

Exactly, minimise risk and exposure

That is why good market research is essential, listen to the users, do not design lenses as technical exercises.

Not sure about the AFA 1.7 , but certainly the original FA 43 contained more lead in the glass.

That is fine up to a point. Certainly when there were no new lenses around, the availability of 'old glass' was a major selling point, however we have been told that the capabilities of the latest cameras exceed the capabilities of many older lenses, in fact I recall reading a comment by Ned Bunnell stating that the FA limiteds were borderline in this respect.

We should also remember that from a manufacturers point of view the availability of so many old lenses is actually a curse and does not help them sell new lenses. The biggest winner on this score is eBay, as lenses are bought and sold on a regular basis.

Don't get me wrong I love the old lenses and use them regularly, but I repeat from where Pentax are now I don't think that they are helping.

I advocated a while ago an exchange/upgrade program, if anyone at Pentax is reading this I repeat it now. I would start by offering the DA 35 F2.4 for £100 plus any old K M or A 28mm, 35mm or 50mm lens.

Regards - Steve

Going back to the original post, I thought I read something somewhere that stated the FA 31 was closer to 32mm.

Was it also not the case that the M and A seriues 28's were closer to 30mm than 28mm

Regards - Steve