gartmore wrote:

.

This makes sens and answers my question. Thanks

Regards, Horst

Sigma has this very fast wide angle lenses. For example a 20mm f1.8 and a 28mm f1.8.

I can understand a portrait lens like a 77 f1.8 or a 50mm with a similar speed.
but a lens used mainly for landscapes?

What advantage has the very small depth of field in a landscape?

Even if it is for available light, then it still has a very shallow dept of field.

Or is it only a status symbol?

Regards, Horst

Well, what about an answer to this reasonable question?

The same of course goes images taken with a Pentax camera and non Pentax lenses.

Or what about images taken with a Rico camera ( I own one) before they bought Pentax?

I suppose the management should answer this.

I agree, normally images taken with a complete opposition Camera -lens kit, should be avoided, but sometimes it would be handy to see either the negative or the positive of a foreigner.
Don't just see everything in black and white (no pun intended), but see the grey shades too.

Regards, Horst

The forum often is used to show differences between equipment or images .
Also to show technical topics. Or to show the results of a specific lens etc.

The Galley is to show your picture which you think is worth showing.

Regards, Horst

This is pretty pathetic. The way I see it, the lenses Jet owes are not crappy 3 dollar lenses. They are quite expensive and should be made to such a close tolerance that no adjustment is needed.
The same goes for the camera. It is not a box camera, but an expensive piece of equipment.

This day and age manufacturers should be able , with all the super high tech equipment to produce a quality piece of merchandise to a great accuracy.

Even the idea that one has to set up a lens to focus correctly is ludicrous.
If Pentax (Rico now) is not able to make equipment accurately enough, thy should build paper planes or make sausages.

regards, Horst

Is it showing its backside to you?

Regards, Horst

You made a good case here.

Maybe from now on we'll have streamlined lens hoods.

Regards, Horst

Hi, I like to experiment with very early lenses. Modified to fit my K5.
Of course they aren't Pentax lenses, because Pentax in most cases did not exist then.
The lenses I can use, have a minimum focal length of 90mm, because they where not made for SLR's.

The lens i want to demonstrate is a Federal Anastigmat "Fedar" f6.3 3.5"
(90mm) non coated enlarging lens. I believe made about 1950 in the USA.

It cost me $AU15.- on Ebay.

The pictures show , how it is assembled to fit on to my Camera.

From the front to the back:

1. The lens head, mounted on to a 42mm lens cap.
2. A small M42 extension tube.
3. A variable extension ring. Also M42
4. a M42 to K mount adapter. Not the Pentax type, but the one with a flange. This mounts with the locking pin.

No 3 and 4 I use for all my other old lenses. These have the appropriate Extension tubes for their respective focal length.

4 pictures of the lens and its mechanics:













The next picture was taken when I walked along the road where I live going to the local park. (No, I didn't wear a trench-coat)




I found some red fallen flowers on the way




Now in the park, this bird in the tree was taken with the sun about 2 o'clock from the focal point.
Not to bad for an un-coated 64 year old lens.




Some tree bark.




I inserted a 40mm extension tube and took the following two flower close ups:







I would say this is not to bad for an un-coated aging lens.
of course the contrast is less than the modern multy-coated lenses.
So is the flair, but if you don't shoot in or to a close angle to the sun, with a lens hood it is quite good.
The co;lours are very good and so is the sharpness.
All pictures where taken at f11.

Rregards, Horst

Thanks Gwyn,
maybe I should have known, but I get a bit lost with all the Abbreviations.

Regards, Horst

Whats a CPL?

Regards, Horst