DaveL59 Posted October 27, 2022 Share Posted October 27, 2022 (edited) 2 hours ago, John Wick said: Sorry to jump on the thread, but have been considering something like this myself in 500mm, looking on ebay I see such a variety of prices. For instance why is this so cheap? Would it work for say lunar photos or andromeda or similar. https://www.ebay.co.uk/itm/165500634226?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=sNyqHN0JT6O&sssrc=2349624&ssuid=xekd7DxnSz6&var=&widget_ver=artemis&media=COPY Generally the 500mm mirror lenses fall into 2 categories, junk and ok-good as I understand it. The junk are the non-camera manufacturer branded ones like Centon, tho there is a good Sigma/Tamron one I believe, can't recall which. Also the russian made ones tend to be good tho pretty hefty, there's a 1000mm version in those. Not sure I've seen Canon/Nikon branded mirrors but Minolta's (& rebadged to Sony) 500mmAF is supposed to be very decent too and the only AF mirror around if you have a Minolta/Sony DSLR to pop it onto that is. For daytime photography they do have the benefit of size/weight for the FL but can be a bit dim at a fixed F8/F10 and lack contrast, the bokeh tends to be little doughnuts rather than discs which isn't to everyone's taste. For the moon, so long as you can achieve good focus it'd work but results across the range of options could be pretty variable. That's likely why there's many cheap mirror lenses out there, folks try them out on their DSLR, get disappointing results and decide to get a regular lens instead. Someone here does have a russian 1000mm mirror lens IIRC, hopefully he'll chime in. Edited October 27, 2022 by DaveL59 1 1 Link to comment Share on other sites More sharing options...
powerlord Posted October 30, 2022 Share Posted October 30, 2022 On 27/10/2022 at 17:15, John Wick said: Sorry to jump on the thread, but have been considering something like this myself in 500mm, looking on ebay I see such a variety of prices. For instance why is this so cheap? Would it work for say lunar photos or andromeda or similar. https://www.ebay.co.uk/itm/165500634226?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=sNyqHN0JT6O&sssrc=2349624&ssuid=xekd7DxnSz6&var=&widget_ver=artemis&media=COPY I have one that looks like same lens. It's trash. Link to comment Share on other sites More sharing options...
John Wick Posted October 30, 2022 Share Posted October 30, 2022 Any opinions on this? Only caught my eye as it does have more than 1 exposure setting, unlike most I have seen. https://www.ebay.co.uk/itm/304660860095?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=pYaXG5c7SOa&sssrc=2349624&ssuid=xekd7DxnSz6&var=&widget_ver=artemis&media=COPY Link to comment Share on other sites More sharing options...
Ratlet Posted November 4, 2022 Share Posted November 4, 2022 Hmmm. The Tair 3 didn't work so well. Good focus on the dimmer stars but the brighter ones... Oh boy, Little bit of flare around them. Hopefully I've just put the front element in the wrong way around. 1 1 Link to comment Share on other sites More sharing options...
powerlord Posted November 4, 2022 Share Posted November 4, 2022 (edited) I got this in post: https://www.ebay.co.uk/itm/403885638783 seemed worth a punt: 55 quid for a 500mm APO. the 'front element does have some light spiderweb style fungus around the outside edges' is more 'every lens is covered in fungus;.. however, amazingly it does actually funciton pretty ok on an eos M100 (with FD to EOS-M adapter. With the eos M you can reach infinity with the adapter. Shooting at some trees about 1km away from my bedroom, the result is not far off what I get with my 300mm L F4 and 2x canon tele extender. I really just bought it to play with daylight photography, but might try it at night once with the m100 (aps-c). I can't even get the front lens off to clean it though - there are no notches in the retaining ring.. so god knows how you are suppose to remove it. If I could get that out, I reckon maybe the next few lenses might come out too and I could get a fair bit of the fungus off. ISO 2000: ISO 400: Edited November 4, 2022 by powerlord 1 Link to comment Share on other sites More sharing options...
LaurenceT Posted November 4, 2022 Share Posted November 4, 2022 I used to have lots of fun with elderly Canon FD lenses adapted to my Sony FF body. I bought them all from Ebay over the years but sold most of them when I realised how much people value them these days. I did keep this one for some reason and it gets good reviews and when stopped down to F4-5.6 is said to be very sharp. I'd like to have a go with this and my ASI224mc planetary camera probably for some EAA to start with but I'm hitting a brick wall with regards to mounting the setup onto a dovetail bar. I've managed to secure an FD to T2 adapter. Link to comment Share on other sites More sharing options...
powerlord Posted November 4, 2022 Share Posted November 4, 2022 just measure the diameter and have a look on ebay. There's plenty of lens supports on there. Just something a bit bigger, and some slices of rubber, etc and yer good to go. Elsewise, get a 3d printer - I've made my own supports (and EAF mounts) for all my lenses. once you do one, it's easy to modify it to do more. stu 1 1 Link to comment Share on other sites More sharing options...
Elp Posted November 4, 2022 Share Posted November 4, 2022 24 minutes ago, powerlord said: seemed worth a punt Hope you get a result. My sigma 70-300 apo can't reach infinity focus on stars. Yet in daytime it's excellent and the manual focus is great to use. Link to comment Share on other sites More sharing options...
powerlord Posted November 4, 2022 Share Posted November 4, 2022 56 minutes ago, Elp said: Hope you get a result. My sigma 70-300 apo can't reach infinity focus on stars. Yet in daytime it's excellent and the manual focus is great to use. yeh you won't reach focus on an EF camera. Only with an eos M. Link to comment Share on other sites More sharing options...
LaurenceT Posted November 4, 2022 Share Posted November 4, 2022 (edited) 1 hour ago, powerlord said: just measure the diameter and have a look on ebay. There's plenty of lens supports on there. Just something a bit bigger, and some slices of rubber, etc and yer good to go. Elsewise, get a 3d printer - I've made my own supports (and EAF mounts) for all my lenses. once you do one, it's easy to modify it to do more. stu Thanks for that. I've had a look on Ebay and decided the best solution would be a tripod lens collar. The diameter of the lens at the best place is about 61mm and the internal diameter of the collar is 65mm so I'm sure I can find an adhesive something or other to stick to the inside of the collar to absorb the excess in size, just not sure what. In fact I've bought 2 because the asi224 camera is the same diameter so I can mount the collars on a dovetail and support both of them. Sorry to waffle on but I'm pleased I may have found a solution. Edit: I've just put the Vivitar on my Sony body and I'm quite pleased with the quality of the lens. 1/400th, f5.6, ISO4000. Edited November 4, 2022 by LaurenceT 1 Link to comment Share on other sites More sharing options...
Ratlet Posted November 4, 2022 Share Posted November 4, 2022 3 hours ago, LaurenceT said: Thanks for that. I've had a look on Ebay and decided the best solution would be a tripod lens collar. The diameter of the lens at the best place is about 61mm and the internal diameter of the collar is 65mm so I'm sure I can find an adhesive something or other to stick to the inside of the collar to absorb the excess in size, just not sure what. In fact I've bought 2 because the asi224 camera is the same diameter so I can mount the collars on a dovetail and support both of them. Sorry to waffle on but I'm pleased I may have found a solution. Edit: I've just put the Vivitar on my Sony body and I'm quite pleased with the quality of the lens. 1/400th, f5.6, ISO4000. I wouldnt worry about waffling. Figuring out how to mount a lens to a dovetail is an issue for using vintage glass so it no doubt will help someone in the future. I had a look at the lens and there was a distinct bullseye pattern on the inside of the glass. I did indeed have the front element in the wrong way round lol. Round 2 with it on Sunday. 1 Link to comment Share on other sites More sharing options...
alacant Posted November 4, 2022 Share Posted November 4, 2022 1 hour ago, Ratlet said: mount a lens to a dovetail Here's an idea which works well, seen here with one of our Tair 3s lenses. HTH Link to comment Share on other sites More sharing options...
Elp Posted November 4, 2022 Share Posted November 4, 2022 (edited) Here's mine: I find the filter drawers are excellent mounting points if you're using astro cameras. I also repurposed an old Z61 telescope tube ring for another camera by making up the difference on an EOS adaptor with some oring washers to get the correct diameter, now clamps tight. Edited November 4, 2022 by Elp 1 Link to comment Share on other sites More sharing options...
powerlord Posted November 4, 2022 Share Posted November 4, 2022 2 minutes ago, Elp said: Here's mine: I find the filter drawers are excellent mounting points if you're using astro cameras. I also repurposed an old Z61 telescope tube ring for another camera by making up the difference on an EOS adaptor with some oring washers to get the correct diameter, now clamps tight. nice. 1st prize for 'how many cameras can I fit on an az gti' ! 🤣 Link to comment Share on other sites More sharing options...
Elp Posted November 4, 2022 Share Posted November 4, 2022 10 minutes ago, powerlord said: nice. 1st prize for 'how many cameras can I fit on an az gti' ! 🤣 Thanks. One is for autoguiding. I was actually considering fitting a third so in future if I had all mono cams I could image all filters in one session... Link to comment Share on other sites More sharing options...
Ratlet Posted November 6, 2022 Share Posted November 6, 2022 Success! No more bullseyes. Unfortunately the Hypercam is off for repair so I could only test with the canon which I struggle to focus and it doesn't play well with NINA. Decided to test for chromatic aberation using a bright target. Finally an astrophotographical use for the moon. 1 Link to comment Share on other sites More sharing options...
Ratlet Posted November 29, 2022 Share Posted November 29, 2022 (edited) Managed to nfinally get the Tair 3 out for a quick go last night. Got some good data and I was mostly happy with the chromatic aberation. Quick stretch and process in photoshop (my Pixinsight trial ran out and I have no idea how to photoshop). All in all I am quite happy. For £60 for the lens I am very happy and the fungs does not seem to have had a significant impact (compared to my shady processing). I suspect to get better I would need to spend significantly more than I have done so far. 40 minutes of data with the lens stopped down to F5.6 or so using a step down ring. Edited November 29, 2022 by Ratlet Uploaded jpg was blurry for some reason. fixed 3 Link to comment Share on other sites More sharing options...
LaurenceT Posted November 29, 2022 Share Posted November 29, 2022 57 minutes ago, Ratlet said: Managed to nfinally get the Tair 3 out for a quick go last night. Got some good data and I was mostly happy with the chromatic aberation. Quick stretch and process in photoshop (my Pixinsight trial ran out and I have no idea how to photoshop). All in all I am quite happy. For £60 for the lens I am very happy and the fungs does not seem to have had a significant impact (compared to my shady processing). I suspect to get better I would need to spend significantly more than I have done so far. 40 minutes of data with the lens stopped down to F5.6 or so using a step down ring. Very impressive results. 1 1 Link to comment Share on other sites More sharing options...
John Wick Posted November 29, 2022 Share Posted November 29, 2022 2 hours ago, Ratlet said: Managed to nfinally get the Tair 3 out for a quick go last night. Got some good data and I was mostly happy with the chromatic aberation. Quick stretch and process in photoshop (my Pixinsight trial ran out and I have no idea how to photoshop). All in all I am quite happy. For £60 for the lens I am very happy and the fungs does not seem to have had a significant impact (compared to my shady processing). I suspect to get better I would need to spend significantly more than I have done so far. 40 minutes of data with the lens stopped down to F5.6 or so using a step down ring. Very nice, what lens was that? Might see if any lurking on ebay Link to comment Share on other sites More sharing options...
Ratlet Posted November 29, 2022 Share Posted November 29, 2022 38 minutes ago, John Wick said: Very nice, what lens was that? Might see if any lurking on ebay Tair 3 photosniper. Its a weird lens on eBay as usually they go up for £100+ but they very rarely sell for that. Just bide your time and pick one up cheap. There is another version the Tair3A which is very similar but a more conventional design and the one I picked up had some slight astigmatism. It also does not have coatings which may or may not affect performance. The photosniper does have coatings. Link to comment Share on other sites More sharing options...
Ratlet Posted January 4, 2023 Share Posted January 4, 2023 (edited) Got out again with the Takumar 200mm SMC. Constantly impressed with how it performs. 45 minutes of data with a AA Hypercam 533c. Moon would have been about 90% illuminated and about 30-40 degrees from the targets. Edit: I just did a crop on my android phone and decided to hit the enhance option. Shows up the noise and shows some artifacts around the stars more but also improves the nebulosity. I really need to work on my processing lol Edited January 4, 2023 by Ratlet My dumb phone can process it better than I can 3 Link to comment Share on other sites More sharing options...
Ratlet Posted January 4, 2023 Share Posted January 4, 2023 And Orion from the same night. 90s subs, 45 minutes. Link to comment Share on other sites More sharing options...
Ratlet Posted September 19, 2023 Share Posted September 19, 2023 (edited) Managed to get out and do some imaging with the 135mm Takumar SMC stopped down with a ring to F5.6 ish, Altair 533c, and SVBONY 220 dual band filter. Fluffed my focus for the first round on the veil, but got it pretty much as good as possible for the crescent. 27 minutes of data where processing was stacked and stretched with tiny tweak to the saturation and some green noise removal (all done in Siril), @vlaiv would be proud I think. If I were good at processing I could probably get more out of it. I think though it shows the potential of a cheap bit of vintage glass (and not missing your focus). This lens cost £15 on ebay... Edited September 19, 2023 by Ratlet 5 Link to comment Share on other sites More sharing options...
alacant Posted September 19, 2023 Share Posted September 19, 2023 2 hours ago, Ratlet said: Fluffed my focus Even so, excellent images. Don't forget that the four element Takumars focus only the green and blue to the same point, leaving red as an unfocused halo. The best method for focusing is by zooming in on a mid brightness white star. Focus to infinitty or where you see the sharpest image, then move away from a tiny amount until the red halo just disappears; a compromise, but one which will give pinpoint true-colour stars. The crescent: Close. Maybe even a little too much: The veil: perhaps needs a little more 'compromise'. Cheers and HTH. 1 Link to comment Share on other sites More sharing options...
Ratlet Posted September 19, 2023 Share Posted September 19, 2023 42 minutes ago, alacant said: Even so, excellent images. Don't forget that the four element Takumars focus only the green and blue to the same point, leaving red as an unfocused halo. The best method for focusing is by zooming in on a mid brightness white star. Focus to infinitty or where you see the sharpest image, then move away from a tiny amount until the red halo just disappears; a compromise, but one which will give pinpoint true-colour stars. The crescent: Close. Maybe even a little too much: The veil: perhaps needs a little more 'compromise'. Cheers and HTH. Aye, usually that's the method I aim for, unfortunately I must have knocked it off focus for the Veil (first imaged). Spotted the issue when I slewed onto the Crescent but I think I took it just a nip too far. I usually find processing responds better to a hint of blue/green than a small red halo. The photometric calibration usually gets rid of it completely. Link to comment Share on other sites More sharing options...
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