Extension tube querie


waynef6117

Link Posted 04/07/2015 - 20:55
Hi again,
I have a question regarding my macro setup I hope someone on here can help with.
The gear I am using is a Pentax k50 + Vivitar automatic extension tubes + 50mm smc da f1.8.
I have changed the settings in camera to accept the extension tube but when I take an image using the view finder the screen shows a blank image but when I use live view the image is taken correctly.
Have I over looked another setting or am I stuck using live view with this setup?
Thanks in advance.
Wayne

pentax

Link Posted 05/07/2015 - 10:15
Hi Wayne I am surprised that you can't see the image through the viewfinder. I have used extension tubes on Pentax k511 without a problem. I don't know the solution.
Derek

Chrism8

Link Posted 05/07/2015 - 10:23
If I've understood your Q as above, when looking throu Live View your seeing the image your about to shoot, if the image you've then shot is blank, or possibly an under-exposed image ( Black ) its easy to think the screen is blank.

Just to test, set an exposure of 15 seconds or more, if you then get anything from a correctly exposed image to something drastically over-exposed, just refine you shutter speed / aperture combination.

Hope this helps
Chris

www.chrismillsphotography.co.uk

" A Hangover is something that occupies the Head you neglected to use the night before".

-------------------------------------------------------------
K1 - Sigma 85mm F1.4, Pentax 150 -450 F4.5 / 5.6, Pentax FA 24 - 70 F2.8

Sigma 100-300 F4, Samyang 14mm F2.8, Sigma 70-200 F2.8,

K5iis - Sigma 17 - 70 F2.8, Sigma 70 - 300 F3.5/F5.6, Sigma 18 - 200 F3.6 / F4.5.
Last Edited by Chrism8 on 05/07/2015 - 10:23

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waynef6117

Link Posted 05/07/2015 - 11:24
Hi Chris thanks for input maybe I never explained myself clearly enough.
If I compose the image using the view finder and take a shot the image is blank and if I press the live view button and compose the shot via the screen take the same shot is taken as it should be. I'm sure it's something I'm doing but I've taken a look in the settings and can't see any other changes that I need to make.

JohnX

Link Posted 05/07/2015 - 15:23
I believe you need to a set up your camera as if you are using a manual lens.

Can't remember the setting off hand as I never shoot with a manual lens, but think it's something to do with 'Using the aperture ring' in one of the C menu's (see camera operation manual).

Also, with some extension rings you need to scrap away some of the paint on the extension ring mount(s) to enable electrical contact between the ring and the camera mount.

Hopefully someone will see this thread and know what I'm going on about.
Last Edited by JohnX on 05/07/2015 - 15:25

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screwdriver222

Link Posted 05/07/2015 - 21:05
i am not sure if there are settings that need to be changed for an extension tube. I know with a manual lens/extn tube you just switch to manual focus and flash or manual on the dial, with aperature set by the lens aperture ring.

Does the extn tube have electrical contacts.

Still dont know why its ok in live view but not through the viewfinder unless maybe your lens is stopping down to its maximum which would make the viewfinder very dim but not effect live view.

Anyway hope you solve this issue

Jeff
Flickr link

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waynef6117

Link Posted 05/07/2015 - 21:20
Thanks very much to everyone who's had input.
I set the dial to manual instead of aperture priority and the image was under exposed as a couple of members pointed out so thanks again for all your help this is an excellent forum with very helpful members.
Cheers

screwdriver222

Link Posted 05/07/2015 - 22:00
I think i am right in saying that if your extn tube does NOT have electrical contacts then its only really suitable for lenses that have an aperature ring. As thats the only method to change the f stop and so would be of very limited use with DA lens

Jeff
Flickr link

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waynef6117

Link Posted 05/07/2015 - 22:05
screwdriver222 wrote:
I think i am right in saying that if your extn tube does NOT have electrical contacts then its only really suitable for lenses that have an aperature ring. As thats the only method to change the f stop and so would be of very limited use with DA lens

Jeff

Hi Jeff,
I think your right this set up is not ideal I think my bet option would be to sell the automatic extension tubes and purchase manual ones.
Thanks very much.

screwdriver222

Link Posted 05/07/2015 - 22:19
Or you could get a vheap manual lens off ebay. I have used an smc m50 f1.7 with manual tubes. just posted some pics on Fickr actiually as I went down Cornwall for a week and forgot to take a macro lens.

Anyway all the best

Jeff
Flickr link
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