Is this just a crappy lens or is it me?
Jan 25, 2015 08:02:46 #
RedAdmiral wrote:
F stop of the lens is fixed at f8. The shutter speed is 1/80th sec.
Your shutter speed in the exif reads 1/16 second, ISO 400, doesn't give a reading for f/stop, except to say it's manual.
Set your exposure to maybe 1/125, your ISO to 100, and f/stop to maybe 8 or 11. See if that doesn't improve things.
Look at exactly what improved, and make further adjustments from there.
Jan 25, 2015 09:31:19 #
For the moon you can't use the meter for your exposure, it will almost always over expose the moon. Start with f8 and 1/250 and bracket.
Jan 25, 2015 09:50:43 #
Morning Star wrote:
Your shutter speed in the exif reads 1/16 second, ISO 400, doesn't give a reading for f/stop, except to say it's manual.
Set your exposure to maybe 1/125, your ISO to 100, and f/stop to maybe 8 or 11. See if that doesn't improve things.
Look at exactly what improved, and make further adjustments from there.
Set your exposure to maybe 1/125, your ISO to 100, and f/stop to maybe 8 or 11. See if that doesn't improve things.
Look at exactly what improved, and make further adjustments from there.
I'm really curious, MorningStar - how do YOU change the lens opening from f8 to f11 on an f8 mirror lens?
Jan 25, 2015 09:50:48 #
oldgeezer3
Loc: SoCal
One thing has been overlooked in all this discussion. All astronomers will mention 'atmospheric disturbance.' I think that is what makes the brighest part of the moon so soft. Red Admiral, you mentioned what looked like heat waves in one of your posts, that is exactly right. That is the atmospheric disturbance I mentioned. So you lens is OK, and you are OK, too. Astronomers have been fighting that problem ever since they started photographing celestial objects.
Jan 25, 2015 09:54:59 #
oldgeezer3
Loc: SoCal
twowindsbear wrote:
I'm really curious, MorningStar - how do YOU change the lens opening from f8 to f11 on an f8 mirror lens?
You can't! The f-stop is determined by the diameter of the mirror and its focal length. As far as I know, no telescope is fitted with a diaphram to adjust an f-stop.
Jan 25, 2015 10:21:25 #
[quote=RedAdmiral]Camera data with and old lens does not show much detail. However at 1/15 sec exposure you will get blur from moon movement and if no tripod camera movement too. David
No f-stop and no mm lens shown
Jan 25, 2015 11:07:05 #
twowindsbear wrote:
I'm really curious, MorningStar - how do YOU change the lens opening from f8 to f11 on an f8 mirror lens?
I don't!
First, in the initial message, OP did not mention that it was a lens with fixed f/stop. In many instances, I will look up something on the 'net before I type a response, in this case I didn't.
Secondly, I don't have any lenses with fixed f/stop, mirror or otherwise.
Third, from the exif data, I could not deduce that this was a mirror lens with fixed f/stop.
So, that's my answer: I don't!
PS - I notice that, besides being critical of my response, you have not given any suggestion or help to OP at all.
Jan 25, 2015 11:16:20 #
RedAdmiral wrote:
Taken through a Rokinon 500 mm lens on my Canon 70... (show quote)
I don't think this is a "Crappy Lens."
I played with it a little in LR and brought up some detail.
The edge of the moon is blown out, but that's due to exposure.
Jan 25, 2015 11:47:11 #
Morning Star wrote:
First, in the initial message, OP did not mention that it was a lens with fixed f/stop.
The OP specified that it was a Rokinon 500mm, which nails it as a mirror lens with a fixed f/8 aperture.
Not knowing that is not a big deal. I took the question about changing aperture to f/11 as a joke. (Taken any other way wouldn't reflect kindly on the author. But it is true that folks should be careful making such jokes because some people might think they are serious...)
Jan 25, 2015 11:55:51 #
oldgeezer3
Loc: SoCal
RedAdmiral wrote:
Taken through a Rokinon 500 mm lens on my Canon 70... (show quote)
Red, if this a mirror lens, then you will always get soft images of the moon or other celestial objects, because of so much atmosphere the light has to pass through. Try on objects a few hundred yards away and see if the photos turn out more crisp.
Jan 25, 2015 12:05:29 #
oldgeezer3 wrote:
Red, if this a mirror lens,
Same thing happens if it's not a mirror lens. :-)
Jan 25, 2015 14:11:46 #
RedAdmiral wrote:
F stop of the lens is fixed at f8. The shutter speed is 1/80th sec.
Mirror lenses are just plain hard to focus. IF you "nail it', your picture will really look crisp. Unfortunately that is a very big if. The other problem contributing to the softness is the long exposure ... ANY vibration during the exposure will soften the image. Mirror lenses are prone to vibration because they are small and light. The moon is not a good subject for a mirror lens. Believe it or not, if you can shoot A 1/1000 or faster you can skip the tripod.
Jan 25, 2015 15:50:18 #
Apaflo wrote:
The OP specified that it was a Rokinon 500mm, which nails it as a mirror lens with a fixed f/8 aperture.
Not knowing that is not a big deal. I took the question about changing aperture to f/11 as a joke. (Taken any other way wouldn't reflect kindly on the author. But it is true that folks should be careful making such jokes because some people might think they are serious...)
Not knowing that is not a big deal. I took the question about changing aperture to f/11 as a joke. (Taken any other way wouldn't reflect kindly on the author. But it is true that folks should be careful making such jokes because some people might think they are serious...)
I was NOT joking, I am not familiar with a Rokinon 500mm lens, I hope I am not expected to know every lens that is mentioned here on the hog or elsewhere.... That I also mentioned f/8 was co-incidental, it had struck me that the exif gave f/0 for lens opening, which of course can't be.
I also mentioned that I often, but not always look up things on the 'net, but had not done so in this case.
So let's leave it at that, shall we? No need to start WW3 about this.
Jan 25, 2015 16:58:32 #
Great Job I Really Like This! However Every Time I Try It ,This Is What I Get. How Can i Keep This Girl From Photo Bombing This Shot?
Jan 25, 2015 17:00:44 #
Jim Peters wrote:
Great Job I Really Like This! However Every Time I Try It ,This Is What I Get. How Can i Keep This Girl From Photo Bombing This Shot?
:thumbup: :thumbup: :thumbup:
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