[REQ] 800mm f/8 mirror lenses with Nikon D5100 help

[rolion]

Hello,

just got one of those "spam / special offer" emails from ebay.

Nikon lens 800mm,f/8 mirror lenses, priced at around €250

Watched some reviews ,found it online from Germany here and the review movie here I think for the fun of it I may go for one

What do you lads are thinking about it for using on a serious & sturdy tripod and for astrophoto planets and/or DSO ?

Thanks...

[wxsatuser]

Seems to be quite a few around these days...........slow for dso, may be moon etc.

[rolion]

Thanks for reply.

Not sure what "slow" means, can you share more, please !?

Is too late...got my offer accepted and I should have it by Friday I hope.

Just "love" the design and the look & feeling !

[rolion]

Got the lens today and I took few shots.

The best one is here but I didn't had the remote control to trigger the shot and the tripod was vibrating.

Using my hands was shaking the camera...

Very nice looking but kind of hard to get it in focus, then is a pleasure to work with...

http://DSC_0287 by Liam @rolion.me, on Flickr

[wxsatuser]

Thanks for reply.

Not sure what "slow" means, can you share more, please !?

Is too late...got my offer accepted and I should have it by Friday I hope.

Just "love" the design and the look & feeling !

I see you have got one.

By slow.......it's f/8......so would need quite long exposures on dso.

For Moon no problem, plenty of light with the Moon.

Rich down in the Photography section is messing around with a similar lens, he had focusing issues.

Thats a reasonable first Moon.

[Viewmaster]

Just bought a 900mm f8 mirror lens to experiment with DSOs.

As wxsat said f8 is very slow so maybe less subs to save imaging time. A higher ISO with noise reduction software might put me in a usable ballpark.

I am spoilt at present with my existing f2.8 200m fastie, used at f2.8 !

Have put a fine adjusting screw on my mirror lens to get fine focus at infinity but the lens barrel might move

even so when the camera is pointed up at various angles. We shall see.

[RichM63]

Cool Liam. For the lack of a remote release why not try setting the self timer for a 2s or 10s delay after you fire the shutter. Should help with the tripod vibrations and still keep the Moon in shot.

Best,

Rich...

[rolion]

Hi,

Thanks for replies...

Yes, is kind of very slow but from my end is "slow" that it takes a awhile to get the focus correct...

I have a 300mm Nikon lens, I will play with that as well and see if there is a difference.

Never thought about the shutter timer !!! Ordered a remote control, I shall have it on Saturday.

But the look and feel...oaahhh I cant say how happy I am...thinking about my neighbours when they see the tripod and the lens outside...I'm just hearing "bang" windows, "bang" blinds, bang "lights"...silly from their side I guess.

Many thanks.

[Earl]

Nice luna results, getting that fine sweet focus is tricky,

[rolion]

Well.. played longer tonight ,hard to get the focus but very handy to take a quick snapshot.

Discovered that my lovely dslr has lots of "hot" pixels...red , green and blue.

Cannot fault the lens but took longer exposure,30" and when seen the raw on the PC it looks very annoying.

I guess is time for a CCD.