DESCRIPTION
ROKINON 500mm f/8 MIRROR LENS
Purchased from overstock.com for $119
Came with T-mount for Pentax mount, x2 multiplier and 3 filters.
More details: http://www.overstock.com/Electronics/Rokinon-500mm-1000mm-Mirror-Lens-for-Nikon/3863117/product.html
USE
So far I have only used it for night sky photography and some telescopic silhouette patterns
PROS
Very compact and light 12.7 ounces and 3.4 in. L x 3 in.Diameter.
CONS
Terrible image quality (see images below)
Terrible light transmission at f/8 and f/16
Rough manual focus.
EXPERIMENT
Here I compare pictures of a full moon taken with the same pentax k-x body (at 12 MP) but with various lenses:
1. 70-300 mm zoom lens by Sigma at 300mm and f/5.8
2. 500 mm ROKINON mirror lens at f/8
3. 500 mm ROKINON mirror lens x 2 multiplier at f/8 theoretically
Click images to view in full resolution. Caveat, the images are cropped around the moon so expect the files to be bigger for the 500mm ones but is this extra tele worth the image quality?
OBSERVATION
I took more than 50 images to adjust to the right focal length but it seems that the image quality is independent. It is either T mount lenses in general, mirror lenses in general, ROKINON mirror lenses in particular or my ROKINON mirror lens specifically, but I doubt the latter. I wonder if any mirror lens owner can share his two cents worth conclusion to this confusion.
That is terrible, what did overstock say? Are you returning it?
ReplyDeleteDo not assume that all mirror lenses must be poor performers based on your purchase of a $120 Rokinon lens. Minolta's mirror lenses were of very high quality, especially the 500mm length, which was built originally for manual focus cameras and then redesigned for autofocus cameras. The autofocus version was also rebadged with the Sony name until it was discontinued a couple of years ago. Lesson to be learned: Stay away from cheap third party mirror lenses, and look instead at the considerably more expensive alternatives from the major manufacturers.
ReplyDeleteI got one for my canon 40D, I need to adjust the exposure to -1 2/3 to get better picture...I have some photos to share with you https://app.box.com/s/y2nexvhanyn7rnerm38d
ReplyDeleteI have a samyang/rokinon 500mm f/8. True that its image quality isn't very sharp but I don't remember it being THIS bad. Focusing is tricky. I am assuming you nailed the focusing on the image? May we know the settings you used?
ReplyDelete