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**boriscleto** · 08-21-2013, 07:12 PM

Originally posted by thornburg

If it's too dark to see your CAMERA, how are you going to take pictures? Was there an SMC-A 50/0.05 that I missed? (Imagine that... the front element would be something on the order of a meter across!)

You've never used a LX have you? Done any astrophotography or light painting?

thornburg · 08-21-2013, 07:40 PM

Originally posted by boriscleto

You've never used a LX have you? Done any astrophotography or light painting?

Nope, I have never used an LX.

I do some astrophotography, but I pretty much always have a flashlight with me. I also don't need to change lenses while doing astrophotography. I used to keep my cheap 500/8 or my 400/6.3 with a 3x teleconverter on for astrophotography. Now I use my newly acquired Celestron C90 1000mm reflex. I haven't tried a TC on it yet, but I'll probably drop a 2x on it and see what it's like.

stevebrot · 08-21-2013, 07:48 PM

Yellow? White? How about green cloisonne enamel? (FA 77/1.8 Limited)

Steve

**boriscleto** · 08-21-2013, 07:55 PM

Originally posted by thornburg

Nope, I have never used an LX.

Well the LX could meter from -6.5EV to 20 EV with a maximum shutter speed of 125s in auto mode. So yes, you could take pictures when it was too dark to see the camera.

John Poirier · 08-21-2013, 09:41 PM

Originally posted by npridgeon

On a lot of manual lenses there is a yellow round button on the aperture ring, no...above the aperture ring. It doesn't seem to do anything when pressed. What exactly is it's purpose, and if it's missing, what affect will it have on the lens? I saw a lens on ebay claiming to be mint, yet the thing was missing.

As others have said, the bump is just an index to help with alignment when changing lenses.

I happened to have a KX with a 50/1.7 as well as a K 85-210 sitting on my desk while looking at this thread, so I played with them a bit. I've been using the lenses with bumps since the late seventies, and it was interesting to note that my hands instinctively made use of the bump in the lens changing process. It's something I learned when doing newspaper photography with prime lenses in fast-changing situations. With practice the bumps can be very useful for fast accurate lens changes.

Or maybe the bumps are pixie dust reservoirs.

08-21-2013, 09:41 PM	#20
John Poirier Veteran Member Join Date: Dec 2006 Location: Gabriola Island Posts: 619	Originally posted by npridgeon On a lot of manual lenses there is a yellow round button on the aperture ring, no...above the aperture ring. It doesn't seem to do anything when pressed. What exactly is it's purpose, and if it's missing, what affect will it have on the lens? I saw a lens on ebay claiming to be mint, yet the thing was missing. As others have said, the bump is just an index to help with alignment when changing lenses. I happened to have a KX with a 50/1.7 as well as a K 85-210 sitting on my desk while looking at this thread, so I played with them a bit. I've been using the lenses with bumps since the late seventies, and it was interesting to note that my hands instinctively made use of the bump in the lens changing process. It's something I learned when doing newspaper photography with prime lenses in fast-changing situations. With practice the bumps can be very useful for fast accurate lens changes. Or maybe the bumps are pixie dust reservoirs. Last edited by John Poirier; 08-21-2013 at 09:44 PM. Reason: speellinggandgrammer

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08-21-2013, 07:12 PM	#16
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by thornburg If it's too dark to see your CAMERA, how are you going to take pictures? Was there an SMC-A 50/0.05 that I missed? (Imagine that... the front element would be something on the order of a meter across!) You've never used a LX have you? Done any astrophotography or light painting?

08-21-2013, 07:40 PM	#17
thornburg Senior Member Join Date: Aug 2012 Location: Doylestown, PA Posts: 200	Originally posted by boriscleto You've never used a LX have you? Done any astrophotography or light painting? Nope, I have never used an LX. I do some astrophotography, but I pretty much always have a flashlight with me. I also don't need to change lenses while doing astrophotography. I used to keep my cheap 500/8 or my 400/6.3 with a 3x teleconverter on for astrophotography. Now I use my newly acquired Celestron C90 1000mm reflex. I haven't tried a TC on it yet, but I'll probably drop a 2x on it and see what it's like.

08-21-2013, 07:48 PM	#18
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Yellow? White? How about green cloisonne enamel? (FA 77/1.8 Limited) Steve

08-21-2013, 07:55 PM	#19
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,477	Originally posted by thornburg Nope, I have never used an LX. Well the LX could meter from -6.5EV to 20 EV with a maximum shutter speed of 125s in auto mode. So yes, you could take pictures when it was too dark to see the camera.

Manual lens yellow button

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