Skylight Filters and Focus (1 Viewer)

Al,

Good for you. I dont really care about the cost as I have sorted the problem without wasting any more money - which may have happened if I bought another "non" brand filter. Normally I am very sceptical of such things but in this case it worked. Maybe a Hoya or a Sigma et al would have worked, maybe not. I was not prepared to take that chance. Leica assured me that the uV77 would work to my satisfaction and it did. I personally will be getting the Leica 62 UV filter if they make it.

I suggest everyone reads the other thread, esp. about the guy with the Zeiss 65 - he seemed pretty convinced as am I.

I get the feeling that there are a few doubters out there - fair enough I suppose. I am not interested in the Laws of Physics - I would rather trust my eyes. I would post some pix of the comparisons between the Leica and the Jessops but it would be a waste of time since someone will just say I deliberately didn't focus as well with the Jessops one ;-}

Linz

Photographic filters have a different focal length to some manufacturers spotting scopes.

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You spoke to an 'Optical Expert' and he said THAT??? And you believed him when he said your 'polishing might be the wrong wavelength'???

Fantastic! I'm going to use that as an excuse from now on. My polishing is the wrong wavelength. Brilliant.

Al

mak said:

Snip
If you are an optical expert then my apologies.

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But if we just use our eyes to do our testing?

We HAVE to believe some/all of the BS that sales people try to feed us?

Andy

(Edited for carp spelling)

I personally will be getting the Leica 62 UV filter if they make it.

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Just before you do...

After reading your other posts, and given your concerns about the vulnerability of Leica's coatings, it seems a bit illogical to pay top-dollar for the best filter available, made by Leica with presumably the same coatings. Yes, it's a fraction of the cost of the scope to replace, but at £90 or whatever I'd still be really pissed off if I had to replace it frequently. In fact I'd probably be just as worried about scratching the filter as the scope.

I completely understand the physics - putting even the most optically correct piece of flat glass in front of a convex lens is going to affect convergence AND the amount of light transmitted; they wouldn't be called 'filters' otherwise. But if you're actually able to notice an effect on the focussing through your original filter then it must be made of melted toffee wrappers or something.

Before you commit to all that extra money for a Leica filter, why not take your scope to a good camera shop and try a couple of more mainstream models?

Al

My eyes dont lie. Believe me I would rather spend £20 than £80 on a leica filter - but IT works.

Cheers for your comments Mak. One small point Lindsay is a "He" not a "She" ! Happens all the time mate ! Apparently my spelling is the masculine form.

I hope the gender issue is not why one poster implied I could not focus a telescope ! - I think I can just about manage that....now if only I could do it on a 4500 screen whilst tracking a small passerine !

Best to ya all

Al Downie said:

Filters don't have focal lengths. They don't focus anything.
Al

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Correct, and I should not have put it, but I was doing other things at work, yes for an optical company and it went in, some time after I had spoken to a colleague about some other points. Which did include camers, filters and focal lengths (but thats another story). I will edit that part out of my original post. What should have been entered was that if the filter is incorrectly fitted it will create a wedge effect and that in turn will affect the image plane.

Lindsay, sorry but it was a typo.

I STAND CORRECTED

Al,

I find your last post both insult to my intelligence as well as patronising - I suggest you go out and watch some birds or something.

It was a Jessops Filter, possibly made under licence by a Japanese company, NOT a toffee wrapper - I think I could tell the difference and to suggest that I cant is beyond me. Fair point about scratching the filter - I have weighed this up and would rather replace the filter than send another scope away to be reparied.

I am not saying that there are no other useable filters out there other than the leica, that was the point of my initail query. Clearly there are. It is a shame that you did not reply at the time and perhaps I could have saved £60. With all due respect I solved the problem on my own before I received a reply from anyone, and it now sounds like certain people want to question either my judgement and/ or gloat that they spent less money. Sad.

I just came back from viewing a Desert Wheatear this morning and ended up getting some informal digiscoping advice from a prolific, experienced, respected birder and photographer. He agreed that the Leica Filter on my Apo 77 produced a brighter, crisper, blue image than the £40 one on his Apo77, and indeed was surprised. This said it did not strike me that he was going to rush home and order one. His pictures were also a LOT better than mine - but mine are getting there !

I am out of this thread. Many thanks for the advice that everyone has submitted. This thread may be useful for informing other people with the same problem in the future - I know I have found old thread useful for research.

It is a sad fact that these things can turn into handbags at ten paces and unfortunately this thread is starting to display that trait. I for one cannot be arsed with that attitude.

I have now been insulted twice on this thread and enough is enough.

Al, get your Apo 62 and BN bins that you have been singing on about and actually go watch some birds. Much more fun.

Off to see this Wheatear again - may be gone for some time.................