Fixed Aperature Lenses

Numb Thumbs · 01-01-2010, 12:11 AM

G'Day guys

I just bought a Rokinon 500mm f6.3 mirror lens to go on the K200D. It was too good a bargain to pass up... I intend using it when I need more reach than the 70-300mm has, mainly for wildlife shots.

My question is, how do you use a fixed aperature lens like the Rokinon?

Do I have to use trial and error or is there a way to get the camera to get the right shutter speed for me automatically?

Cheers
Numb Thumbs

PS Happy New Year everyone!

stevebrot · 01-01-2010, 12:22 AM

Hi,
Welcome to the forum! Metering should work fine in Av mode, though you might need to dial in a little exposure compensation. You may also need to confirm that "Using Aperture Ring" is set to "enabled" despite the fact that the lens lacks a variable aperture.

Steve

Numb Thumbs · 01-01-2010, 12:28 AM

Steve

Thanks for the speedy response.

I tried that and everything was very underexposed... as in, dark! I'll play around with it a bit more.

Cheers
Numb Thumbs

Damn Brit · 01-01-2010, 12:34 AM

Moved to Lens forum.

Numb Thumbs, welcome, please be careful where you post. If you're not sure, post in Everything Else and a moderator will move it if necessary.

Raybo · 01-01-2010, 12:40 AM

Just like stevebrot said, you have to take a few shots for the team.

I have two reflex lenses a 500mm f8 and a 1000mm f10, the 500mm is a breeze to use handheld in AV mode but the 1000mm is tripod ONLY!

Just play around a bit with the exposure under different lighting conditions and you should be able to figure it out with few problems.

Numb Thumbs · 01-01-2010, 12:44 AM

Oops, sorry....

I'll keep playing with it. I had a Tamron 500mm f8 mirror lens eons ago in the "Age of Film" on Olympus OM1 and OM2 bodies but I can't remember how I did thhings way back then...

Cheers
Numb Thumbs

Raybo · 01-01-2010, 12:59 AM

Originally posted by Numb Thumbs

Oops, sorry....

I'll keep playing with it. I had a Tamron 500mm f8 mirror lens eons ago in the "Age of Film" on Olympus OM1 and OM2 bodies but I can't remember how I did thhings way back then...

Cheers
Numb Thumbs

I'm sure you remember that the higher the f stop the longer you need to keep the shutter opened OR needing higher ISO. If your images are under exposed just turn up the compensation a few ticks and go from there.

01-01-2010, 12:11 AM	#1
Numb Thumbs New Member Join Date: Dec 2009 Location: Melbourne Posts: 8	Fixed Aperature Lenses G'Day guys I just bought a Rokinon 500mm f6.3 mirror lens to go on the K200D. It was too good a bargain to pass up... I intend using it when I need more reach than the 70-300mm has, mainly for wildlife shots. My question is, how do you use a fixed aperature lens like the Rokinon? Do I have to use trial and error or is there a way to get the camera to get the right shutter speed for me automatically? Cheers Numb Thumbs PS Happy New Year everyone!

01-01-2010, 12:22 AM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Hi, Welcome to the forum! Metering should work fine in Av mode, though you might need to dial in a little exposure compensation. You may also need to confirm that "Using Aperture Ring" is set to "enabled" despite the fact that the lens lacks a variable aperture. Steve Last edited by stevebrot; 01-01-2010 at 12:27 AM.

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01-01-2010, 12:28 AM	#3
Numb Thumbs New Member Join Date: Dec 2009 Location: Melbourne Posts: 8 Original Poster	Steve Thanks for the speedy response. I tried that and everything was very underexposed... as in, dark! I'll play around with it a bit more. Cheers Numb Thumbs

01-01-2010, 12:34 AM	#4
Damn Brit Guest	Moved to Lens forum. Numb Thumbs, welcome, please be careful where you post. If you're not sure, post in Everything Else and a moderator will move it if necessary.

01-01-2010, 12:40 AM	#5
Raybo Veteran Member Join Date: Dec 2007 Posts: 872	Just like stevebrot said, you have to take a few shots for the team. I have two reflex lenses a 500mm f8 and a 1000mm f10, the 500mm is a breeze to use handheld in AV mode but the 1000mm is tripod ONLY! Just play around a bit with the exposure under different lighting conditions and you should be able to figure it out with few problems.

01-01-2010, 12:44 AM	#6
Numb Thumbs New Member Join Date: Dec 2009 Location: Melbourne Posts: 8 Original Poster	Oops, sorry.... I'll keep playing with it. I had a Tamron 500mm f8 mirror lens eons ago in the "Age of Film" on Olympus OM1 and OM2 bodies but I can't remember how I did thhings way back then... Cheers Numb Thumbs

01-01-2010, 12:59 AM	#7
Raybo Veteran Member Join Date: Dec 2007 Posts: 872	Originally posted by Numb Thumbs Oops, sorry.... I'll keep playing with it. I had a Tamron 500mm f8 mirror lens eons ago in the "Age of Film" on Olympus OM1 and OM2 bodies but I can't remember how I did thhings way back then... Cheers Numb Thumbs I'm sure you remember that the higher the f stop the longer you need to keep the shutter opened OR needing higher ISO. If your images are under exposed just turn up the compensation a few ticks and go from there.