Hmmm. I meant the unfiltered view. Then again, I don't usually check both on the same night.
The brightness of IC434 is similar to that of the Veil.
I beg to differ. It must be considerably fainter. The Veil (eastern half) is easy as pie in any of my telescopes, even unfiltered, but I've never seen a hint of IC 434, despite looking for it on some very good nights in the past.
Hmmm... Finally last night I had a chancve to test my above statement. Under SQM 21.04 (steady!) skies I had The Veil and IC 434 at approximately similar altitude - neither very high. Case is settled: Under similar conditions, in my 18", the Veil (all main segments) were considerably brighter than IC434. My previous statement was gloriously toppled! I guess the fact that by late October I rarely check the Veil and I don't normally bother for the HH until mid December created somehow in my mind the illusion that the unfiltered view of the Veil was similar to that of IC434. No chance. Without filter the Veil was readily visible with direct vision and with structure visible, and in the 31mm Nagler with UHC it became a superbly detailed object. On the other hand, IC 434 was barely visible with averted vision in unfiltered views (provided Zeta Orionis was not in the filed). With the 31mm Nagler and UHC, IC434 was visible with direct vision (including an ill-defined horsehead!) provided Zeta Orionis was kept out of the field. The UHC-filtered view of IC434 was considerably fainter than the unfiltered view of either Veil segment. Adding a H-Beta filter made IC434 more obvious, but still not as bright as unfiltered Veil views.
In another important aspect, I did check the HH visibility with two different eyepieces that gave me a similar true field of view: The TV Ethos 13mm (158x) and the TV Panoptic 19mm (108x), both providing a 0.63-degree TFOV. Using the H-Beta filter, the Horsehead was clearly visible in both eyepieces, but the Panoptic gave a much better, more 3-D view and dare I say, it provided a more detailed image of the HH (the "snout" was more pointy and overall more visible). The Ethos 13 is giving me a 2.9mm exit pupil, while the Panoptic 19 is giving me a 4.2mm exit pupil. The image difference was confirmed by the two astrobuddies who were there with me. So, at least under the good conditions we have had last night, the eyepiece that gave the greatyer exit pupil gave the best image!