[pencilnink]

Hey Mike, how far does your hood protrude passed the Fa31 built in hood?

[mikeSF]

Hey Mike, how far does your hood protrude passed the Fa31 built in hood?

18mm-ish

[chickenandavocado]

i have on order a 58-49 step down ring, and then a 48-58 step up ring to fit with my 58mm hood (very shallow one that just barely passes the built in hood of the fa 31)

im pretty sure it will vignette if a filter is put in, but purchased the step up ring as a few dollar experiment just in hope, otherwise i will try it out on my cosina 55 1.2 to see if that hood still has any use

i may end up just buying a 49mm hood which looks to fit pretty flush in mike's setup

mike - does the hood take a 58mm cap?

[mikeSF]

mike - does the hood take a 58mm cap?

yes, it's a 58 cap

[wasser]

I use this Janco 58MM as my hood (you discard half and it's just a 58mm hood with threads on both ends). I then have a 58mm-49mm stepdown ring on the end. There is no vignetting. However, I attached a pretty thick 49mm empty filter ring and it appeared to vignette. I wonder if I used my slim Marumi CPL, then perhaps it wouldn't vignette.

[chickenandavocado]

i have the same hood, however unlike the setup you described i am putting 58 to 49 step down -> filter -> 49 to 58 step up -> hood

will let you know the results

[chickenandavocado]

happy to report no vignetting with 58->49 -> B+W MRC CPL -> 49-58 -> hood (in above post)

[pencilnink]

Do you have a picture of that setup?

[chickenandavocado]

sure, shall post it as soon as i can, doesnt look as nice as mike's setup but so long as it's functional and does its purpose (excellent IQ + bokeh) then im happy

[pencilnink]

Thanks! The looks don't matter to me as long as the glass is well protected and no visible vignetting. I'm curious as to what is the longest hood I can put on the 31 before vignetting becomes very pronounced. As of right now I'm just using a slim marumi filter + the janco hood

[wasser]

That's the Janco 58mm hood and a 58-49mm stepdown ring at the end. It appears to be a tad over 18mm long. No vignette. With my 49mm Marumi CPL I get a hint of vignetting at f1.8 and infinity. However, it is gone at MFD.

I also tried attaching several empty 58mm filter rings to see when it would vignette. The Janco and 2 empty 58mm filter rings, for a total length of 27mm, was the limit. Adding a third filter ring caused vignetting.

[chickenandavocado]

sorry i dont have my phone with me at the moment, plus my only camera is the k-r and fa31 alone (im travelling).

i just measured for you it is around 2CM with 58->49 step down; 49mm B+W CPL MRC ; 49 -> 58 step up; janco hood

no vignetting at all

wasser:
perhaps the reason for vignetting is because if you step down after the hood, the entrance of light might be less as opposed to step down straight away?

[wasser]

wasser:
perhaps the reason for vignetting is because if you step down after the hood, the entrance of light might be less as opposed to step down straight away?

Oh, absolutely it is. However, I do prefer this arrangement for both the protection it gives and the more compact hood. This arrangement is one inspired by SOldbear who was, I believe, inspired by the design of the Pentax hood for the DA 40mm. All mine are reduced at the end to either a 49mm or 30.5mm.

The vignetting under these circumstances is likely never to be a problem for me. My hood with the stepdown ring at the end does not vignette and I'm not likely to use any filter with my 31mm. However, if I did, the vignetting is so minor and only visible under extreme conditions, f1.8 and focused at infinity. I'm pretty sure it was gone by f2.8. So, I still wouldn't hesitate to use it.

[chickenandavocado]

interesting, thanks for sharing your thoughts and experiences

[UpNorth]

Some of us have got creative and stacked empty 58mm rings (several) partly to make the hood more restrictive and partly to allow us to mount a filter outside the inbuilt hood.

The OP's question is very relevant to my situation, I used to use a DA15/FA35/DA70 combo that had all the same filter ring sizes, now with the 31 replacing the 35, its become the odd man out.

I have to see if I have a 58 to 49 step down ring to try this out on my 31, but I have a feeling it will vignette and quite horribly at that.

Perhaps a better solution would be to use a 58mm filter and use step up rings for the other two in the trio.

So do they make a 58 to 58 "step same" ring in order to do this? I just looked on B&H, but didn't see anything. I have a bunch of 77mm filters (circ-polarizer, ND, etc) that I'd like to use on my 31 - plus it looks like if I did buy some 58mm filters for the 31 I don't know how I'd ever get them off with that darn built-in hood.
I like the idea of stacking a few 58 to 58 rings (if there is such a thing) in order to get them out to the point where I could pop on a 58 to 77 step-up ring, and then use my existing filters - assuming that's an option.

Thanks,

Tim