Sony E-Mount to M42 adapter? (or...)

[Amaranthus]

I have a couple of E-mount lenses for my Sony NEX-3, and was thinking to use them for wide-angle shots using my new QHY22, which has M42 threads. Does anyone know of an adapter to screw an E-mount lens onto an M42 body?

(I obviously have the M42 to E-mount adapter - this is what I use to attach my NEX-3 to the scope, but I can't seem to find the reverse!)

Failing that, does anyone recommend M42-threaded lenses in the 16 to 150mm range that you've used successfully with a mono CCD?

[Occulta]

Barry

ZWO cameras come with an M42 to 1.25" nosepiece for the front of their cameras. You may be ble to get one direct from them.

Chris

[Amaranthus]

Thanks Chris, I have plenty of those nosepieces!! No, I'm looking for a M42 to E-mount adapter. The E-mount is standard for various Sony Alpha DSLRs.

[axle01]

http://www.amazon.com/Fotodiox-Adapter-E-Mount-Camera-NEX-5N/dp/B0054EORJC

[Amaranthus]

Thanks Alan, but that's what I've got - an M42 Lens to Sony NEX E-Mount Camera.

What I need is the inverse, i.e. a Sony NEX E-Mount lens to M42 thread adapter :) I wish to use my E-Mount lenses on my CCD camera.

[Ross G]

Hi Barry.

It might be difficult to attach your E mount lenses to the QHY ccd because of the very short back focus of the E mount lenses.

A good quality alternative is to use old Olympus OM lenses. I have an Olympus 35mm F2.8 lens, that I got for about $50, on my QHY9 and it works very well with sharp stars right to the corners when you stop it down 1 stop.

To attach it, I got a Canon to T thread adapter from Theo at Gamma Electronics. I then got an OLYMPUS to CANON adapter from ebay for about $20. With this arrangement I have used Olympus 35, 50, 135 and 200mm lenses with very good results.
Alternatively you can get a NIKON to CANON adapter from ebay for the same price and use old Nikon lenses.

PM me if you need any more info.

Good luck.

Ross.

[Eden]

G'day Barry,

PreciseParts.com may be able to help. They have a build configuration for an adaptor which goes from Sony Alpha lens to M42 female (a la QHY). They're not cheap though ($250 USD). Hope this helps!

[Amaranthus]

Thanks Ross & Eden. You may be right that the short backfocus distance is the reason that this is not produced for E-mount lenses. If I have to pay $250 for an adaptor, I'd be better going down the suggested path of getting a 'native' M42 lens, such as a Pentax, or maybe the Canon/Olympus route.

A thought that occurred to me - for something like a QHY CCD, how would one mount it when not attached to prime focus? I guess tube rings around the lens? :shrug:

[gregbradley]

You should be able to mount an E mount lens on a one shot colour CCD as Sony flange distance is something like 20+ mm. But mono with a filter wheel would be way too wide for an E mount adapter.

I agree you would be better off with other lenses. Pentax 67 lenses are cheap. You may need a Precise Parts adapter for it though.

Lenses I am aware of that are good for astrophotography are:

1. Nikon 50mm F1.8D Nikon 50mm F1.8G. Nikon 14-24mm. I hear the 16-85 is good but no personal knowledge.
2. Nikon 105mm F2.5 AIS.
3. Nikon 85mm F1.8 G (needs to be stopped down to F2.8).
4. Nikon 180mm F2.8 ED (a bit of chromatic aberration, again stopped down helps but Lightroom gets rid of the blue halos easily enough).
5. Pentax 67 75 F3.5, 165 F2.8 300mm F4.
6. Pentax SMC 100mm, 150mm.
7. Not too sure about Canon EF lenses but there would be plenty. The 50mm F1.8 is almost identical to the Nikon so I assume it would be good.
8. Samyang 12, 14, 24mm. Samyang 8mm fisheye (APSc sized).

Not too sure about Canon FD lenses. Possibly the L series may be fine.

Greg.

[Amaranthus]

Thanks Greg, great to get feedback from an experienced DLSRer like you.

[Amaranthus]

Time to update with my solution. Given that I was using a mono CCD, I really needed to find a satisfactory way to change my filters (LRGB and NB). I ended with with the following imaging train:

-- QHY22 (15.5 mm back focus)
-- 0.5 mm brass spacer ring (http://www.edmundoptics.com/optomechanics/lens-mounting-tubes/t-mount-components/t-mount-brass-spacer-rings/2761/)
-- TS Filter slider (http://www.teleskop-express.de/shop/product_info.php/language/en/info/p2165_Filter-Quick-Changer-incl--1x-1-25--filter-drawer---low-profile.html) (15 mm optical length)
-- 2 + 1 mm brass spacer rings
-- TS EOS-EF to T2 adapter (http://www.teleskop-express.de/shop/product_info.php/language/en/info/p6991_TS-CCD-Adapter-for-Canon-EOS-lenses-to-T2---only-10mm-length.html) (10 mm optical length)
-- Total optical length = 44 mm

The optical length matches exactly with the FFD of the Canon EF mount lenses, and this setup allows me to change filters on the fly without unscrewing anything.

Attached is an image of the setup (connected to a 135 mm f/2.8 EF prime lens).

I'll be mounting it on the top dovetail of my SW120 refractor (which will be used as the guidescope), with two DVR125 delrin-tipped guidescope rings used to secure the camera body and the lens.

Unfortunately, it's been raining/cloudy here in Tasmania for the past fortnight, so I've not yet had a chance to image with it. But when I do, I'll post back with the results.