[AussieG]

Great pics there. Ihave just aquired some M series lens and you might have some clues for using the zooms on a K7. The camera requires a focal length input for these lenses so what do i put in when using a zoom? I option to change the focal length only comes up when turning on the camera. I have a 35 - 70mm f2.8 t03.5 and a 80 200mm f4.5. Same question also when using extension tubes with primes.

[pschlute]

Great pics there. Ihave just aquired some M series lens and you might have some clues for using the zooms on a K7. The camera requires a focal length input for these lenses so what do i put in when using a zoom? I option to change the focal length only comes up when turning on the camera. I have a 35 - 70mm f2.8 t03.5 and a 80 200mm f4.5. Same question also when using extension tubes with primes.

Ideally you should put the focal length you are using for each shot. As that is impractical, you should err on the side of a lower focal length.... so 35 rather than 70 (unless you are shooting at 70 of course).

With extension tubes focus is ultra critical. I cannot think of a situation when you would want to use shake reduction, as the camera should be on a tripod (ie. S/R off)

[Canada_Rockies]

Ideally you should put the focal length you are using for each shot. As that is impractical, you should err on the side of a lower focal length.... so 35 rather than 70 (unless you are shooting at 70 of course).

I used shake reduction with the A 70-210/4 when I had it. I set the SR to 120mm and turned it off for lesser focal lengths. That's close to the arithmetic mean of the lens' two focal lengths (121mm), but it isn't critical. The important point made above is to never use a focal length longer than the one you will shoot at with SR active. You can train your right thumb to turn SR on and off without looking.

With extension tubes focus is ultra critical. I cannot think of a situation when you would want to use shake reduction, as the camera should be on a tripod (ie. S/R off)

I use shake reduction often with my M 100/4 macro. Extension tubes would be the same situation. Tripods don't work for me when chasing bugs around the back yard; I much prefer hand held. I leave shake reduction turned on whenever shooting hand held. I also use the focus trap (snap-in-focus, catch-in-focus) available with manual lenses and follow the bug with the centre focus point. I get more keepers that way, and framing a bit wide allows me to crop to a more satisfying composition while increasing my odds of getting an in focus shot.

[Marc Sabatella]

While the option to change the SR focal length setting only comes up on power up, you can access it at any time you like via the menu (details differ from model to model). but most people probably don't bother - just set something appropriate that doesn't *overstate* the focal length too badly too often and you should be fine.

[AussieG]

Thanks for the help all. I didn't realise the focal length input was only used for shake reduction. If that's i understand correctly I assume if doesn't matter what number goes in if shake reduction is off.

[pschlute]

Thanks for the help all. I didn't realise the focal length input was only used for shake reduction. If that's i understand correctly I assume if doesn't matter what number goes in if shake reduction is off.

Correct , the FL input is only for S/R and if you have it turned off it does not matter what you have entered.

A warning though. If you switch to another "old" lens, you need to make sure you have the correct FL set. i once switched from a 300mm to a 50mm lens and didnt check. My pictures were horribly overcompensated and shakey as hell.

On my K10 if I switch the camera on while the SR button is on, then I get prompted to enter a FL. But If I switch the camera on with SR off, and then switch SR on, it just uses the SR setting that I previously entered.

[Schmidlapper]

I just bought an M100 2.8 listed on eby as like new and excellent-plus and it arrived as advertised except it is missing the half dome plastic alignment button. I can't imagine it would cause any image impact, but could this piece be added back from a donor with glue or something? Otherwise I love this new old lens.

M100 f2.8

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Last edited by Schmidlapper; 07-07-2010 at 07:31 AM.

[Canada_Rockies]

I just bought an M100 2.8 listed on eby as like new and excellent-plus and it arrived as advertised except it is missing the half dome plastic alignment button. I can't imagine it would cause any image impact, but could this piece be added back from a donor with glue or something? Otherwise I love this new old lens.

M100 f2.8

The button is really of no use on DSLR cameras. It was introduced as a neat method of aligning the lens to the mount without looking. It was actually a very useful device. It lined up with the release button when the lens was aligned correctly to mount/dismount.

Thanks for the help all. I didn't realise the focal length input was only used for shake reduction. If that's i understand correctly I assume if doesn't matter what number goes in if shake reduction is off.

The other advantage of at least entering the focal length in the SR screen is that the camera will record that focal length in the EXIF data. When using my 400 with the 1.4X I put in 550mm and with the 1.7X I put in 700. I then know without racking my head what I was using when I took the picture.

[Schmidlapper]

The button is really of no use on DSLR cameras. It was introduced as a neat method of aligning the lens to the mount without looking. It was actually a very useful device. It lined up with the release button when the lens was aligned correctly to mount/dismount.

Thanks for your kind input, I will just live with it. Love how these older lenses image. They are such a good value for us who can use them.

[Canada_Rockies]

Thanks for your kind input, I will just live with it. Love how these older lenses image. They are such a good value for us who can use them.

I agree. My old M 400/5.6 is still doing sterling work for me. There are things to watch out for, but she still gives me some great pictures. The M 100/4 macro is as sharp as any other macro produced by Pentax or anyone else. The macro is always with me, the 400 is sometimes left at home, but then I often regret leaving her behind. She cost me $330 some 25 years ago.

[Schmidlapper]

I often wish I would have known to start buying old Pentax lenses sooner while the prices were even better. I made several false starts not knowing anything about buying old lenses and bought some stuff just because it was cheap and fit pentax, mostly low quality zooms and lesser primes. Then thanks to the Pentax community I began to learn more and I got a couple good quality moderate priced zooms. Then I started looking for certain primes. My concern at the moment is the A 50 1.7 and it's cheap aperture ring. I am almost afraid to mount it for fear I will break the plastic button. Been thinking about replacing it with an M. Does anyone know if a M 1.7 or the M 1.4 would match or exceed its sharpness and boca?

M100 2.8 @2.8

[yeatzee]

My M 28mm F/3.5 came in from repair today

I only got a chance to take a couple shots, so here's one taken at F/3.5



1/8 sec.
ISO 800
Exposure bias -0.3

Sorry for my complete absence in this thread as of late.... that K 50mm F/1.2 is addicting

[Marc Sabatella]

My concern at the moment is the A 50 1.7 and it's cheap aperture ring. I am almost afraid to mount it for fear I will break the plastic button. Been thinking about replacing it with an M. Does anyone know if a M 1.7 or the M 1.4 would match or exceed its sharpness and boca?

I know what you mean about fearing breaking the aperture ring. I just plan on using it until it breaks then worry about replacing it then. It's not like the ubiquitous M50/1.7 could possibly become horrifically expensive - and it is optically identical. Plus, I just don't use 50mm much, so I don't see any need to bother doing anything about it right now.

[Schmidlapper]

I know what you mean about fearing breaking the aperture ring. I just plan on using it until it breaks then worry about replacing it then. It's not like the ubiquitous M50/1.7 could possibly become horrifically expensive - and it is optically identical. Plus, I just don't use 50mm much, so I don't see any need to bother doing anything about it right now.

Great way to look at it.

I was taking photos of some decorative grasses with the tamron 17-50 and I wasn't happy with the results. I went back with the M100 and it was magical how different the two lenses performed with the same scene. I was able to capture what I imagined I was seeing.

M100 @2.8 1/250 ISO 400

[H-Alien]

Schmidlapper I would love the see the tamron shots aswell as a comparison, do you still have those shots?